You may be coming to this book from any one of a variety of different situations. Perhaps you are interested in learning more about breast cancer in general (after all, it is the most common solid tumor to affect women in the United States). Maybe you consider yourself to be at risk for the disease and are trying to arm yourself with the best information for the future, or you have a family member or friend whom you are hoping to support in her diagnosis. For the majority of readers, however, the most likely scenario is that you yourself have been diagnosed with breast cancer or have found something that has a high likelihood of turning out to be breast cancer. If that’s the case, then you may think that you should just skip over this chapter. Why read about risk for breast cancer or how to detect it when you’ve already been found to have it? In fact, the information in this chapter is still relevant to you. Understanding the risk factors that may or may not have contributed to your diagnosis could be important. You’ll also learn about mammograms and other different types of imaging that can still come into play even after you have received a diagnosis of breast cancer and in the years ahead.
Mammograms
For many women, the diagnosis of breast cancer starts with a mammogram. These women in particular usually do not need much convincing of the value of mammograms in the early detection of breast cancer. Over the past few years, however, there has been a huge amount of conflicting information out there regarding mammograms, leaving many other women feeling uncertain and confused. As a breast cancer surgeon and specialist, I’m often asked to speak to the general public about issues surrounding breast cancer screening, treatment, and care. Some of the most common questions I get during the Q&A portion go something like this:
“My sister was diagnosed with breast cancer when she felt a lump one month after a normal mammogram. Why should I get one if it didn’t work for her?”
“I have a friend who was diagnosed with breast cancer at age thirty-eight, before she had even started mammograms. Shouldn’t we all be starting earlier?”
“I heard that sonograms and MRIs are better than mammograms at picking up cancers in women with dense breasts. Why aren’t they recommended for all women?”
It doesn’t surprise me that so many women have so many questions about mammograms and screening: they are looking for answers on some very controversial issues.
Mammograms aren’t flawless—no test is. Mammograms have been associated with both underdiagnosis (missing cancer) and overdiagnosis (when we find things on a mammogram that, if left alone, would not have caused a problem). Hence the frequent controversy about when and whether to use them. But even when all these variables are taken into account, mammograms are still the best tool currently available for identifying breast cancer in the vast majority of women.
It’s important to get the facts straight, beginning with this one: the mammogram is the only test that has been shown to decrease the actual risk of dying from breast cancer by detecting cancer earlier—effectively reducing mortality by 15 percent or more in women from ages forty to seventy.
And here’s a lesser-known fact: 80 to 90 percent of women diagnosed with breast cancer have no preexisting risk factors—no family history, no genetic issue, nothing. So we are all at risk, and that’s why appropriate screening is relevant to all women.
When we look at the breast cancer cure rate, the good news is that it has increased substantially in the past few decades. To a large degree, this is because of early detection—a direct result of better screening, primarily with mammograms. Currently over 60 percent of newly diagnosed breast cancers are early stage. These cancers are localized, and are usually detected by mammography before a woman or her doctor could feel anything on examination. So with all the conflicting information out there, it can be easy to lose sight of the bottom line here: mammograms help to detect breast cancer earlier and save lives.
Mammograms: what to expect
A mammogram is an X-ray of the breasts. Most often—including during a routine, annual mammogram—both breasts are X-rayed. This is called a bilateral mammogram, and two pictures are taken of each breast, resulting in a total of four pictures. A unilateral mammogram (just one side, right or left) consists of two pictures. There are a variety of different reasons why a woman may need a mammogram on only one side: occasionally a follow-up at a shorter interval, usually six months, for one side only will be needed to make sure something we saw previously is indeed normal or has not changed. In addition, for women who have had a prior breast cancer and had one breast removed, we only perform mammograms on the one remaining breast. Finally, if a recent bilateral mammogram was normal but a few months later a woman feels a lump on self-examination, repeating the mammogram just on that one side might be needed. In any case, when a mammogram is done, the breast is pressed between two paddles to flatten out the breast tissue, and the entire process of positioning and shooting the picture takes about a minute for each picture, or a couple of minutes for each side. I don’t think anyone would argue that having your breast pressed between two paddles is exactly pleasant. Women do sometimes complain that mammograms are painful or at least uncomfortable, and there are many jokes circulating about how men could never tolerate the same procedure on certain parts of their anatomy. But the discomfort should be short and tolerable, especially at a mammography facility with experienced, well-trained technicians. If you are someone with especially sensitive breasts, discomfort may be minimized by making sure your mammogram is not scheduled right before or during your menstrual period, when breasts are usually most sensitive.
On a mammogram, cancers typically show up as white, irregular spots against the darker background of regular, mostly fatty breast tissue. Denser normal breast tissue also shows up as whiter, so in dense breasts it can be harder to see the white cancer against a white background (imagine trying to spot a polar bear in a snowstorm). If you do have dense breasts (very common in younger women), you may get a recommendation for additional tests, such as a sonogram, and you also may want to make sure that you are getting a digital mammogram. Digital mammograms have been shown to be better at picking up cancers in younger women with denser breast tissue. Other findings that we look for on a mammogram that could indicate cancer are areas of calcifications, which are tiny clusters of white spots, almost like grains of salt grouped together. And lastly, an area of asymmetry, where the tissue looks distorted or pulled, especially if different from what is seen in the other breast, could raise suspicion for a cancer as well.
One of the most exciting new developments currently available is 3-D mammography. Although it is associated with a slightly higher dose of radiation exposure with each mammogram, the 3-D images that we capture extend through the breast, section by section, in great detail. Looking at the results is a little like looking through the pages of a book, and we can pick up more cancers that are hidden among overlapping dense breast tissue as a result. In addition, 3-D mammograms have been shown to significantly reduce callbacks for additional tests, which means fewer scary phone calls and less nail-biting time for you. This new mammography technique has been widely integrated into many practices, but not everywhere.
NEED TO KNOW
What is the most appropriate screening regimen for the average woman?
My recommendation, the recommendation of countless breast cancer physicians across the country, and the recommendation of the American Cancer Society, the American College of Radiology, and the National Comprehensive Cancer Network (NCCN) is that your first mammogram should be at age forty, with yearly mammograms after that. The average woman’s risk of getting breast cancer over her lifetime is approximately 10–12 percent if she lives to be about eighty years old. For the average woman there is less risk toward the earlier part of her life and more risk toward the later part of her life—the average age of women who get breast cancer is approximately sixty years old.
MYTH: “If you don’t have a family history of breast cancer, then you are not really at risk and there’s no reason to start mammograms at forty.”
The normal screening guidelines are for women at average risk for breast cancer. The reality is that 80 to 90 percent of women diagnosed with breast cancer have no special risk factors. So we are all at risk, and that’s why appropriate screening is relevant to all women.
Why not start screening earlier?
There are some women in a higher risk group who do need to start screening for breast cancer earlier than forty (see below for more on this). But for women at average risk, screening beginning at forty is standard. Some doctors do order baseline mammograms for their average-risk patients prior to age forty, usually after seeing a few upsetting cases of breast cancer diagnosed in very young women. These exceptional cases stand out in the minds of physicians, and, not wanting to miss a cancer, ever, they sometimes order mammograms earlier than recommended for their other patients. But seeing one thirty-five-year-old with breast cancer does not necessarily mean that all thirty-five-year-olds should get a mammogram earlier. Overall, for women turning thirty, less than 1 percent would be expected to develop breast cancer over the ensuing ten years. So again, beginning testing at forty for most women is the norm, and your risk of missing a cancer by not doing mammograms before forty is extremely low. If you are going to get a mammogram prior to age forty and don’t have a family history, consider the facts I’ll lay out below about the pros and cons of earlier mammography, and make sure you discuss the pros and cons with the doctor who is ordering it.
Why not start screening later?
There are many people who sincerely believe that it’s okay to start mammograms later, at age fifty. And it’s important to know that in some countries, such as in the UK, the current recommended age to start mammograms is age fifty, despite data showing a benefit for starting earlier. Part of the recent controversy over mammograms can be traced back to a recommendation made in November 2009 by the United States Preventive Services Task Force (USPSTF) to begin screening later, starting at age fifty—a change from their previous recommendation to start at forty. The USPSTF is a committee charged with reviewing data and making recommendations for health care organizations regarding the relative benefits of various services, and many women and their doctors are strongly influenced by this group’s recommendations.
Here’s why screening beginning at age forty remains my recommendation and the recommendation of many other physicians and breast cancer organizations around the country. Simply put, we don’t accept the rationale behind the USPSTF’s 2009 recommendation. The USPSTF seems to have made its new recommendation largely based on data indicating that women in their forties have a higher number of callbacks for additional pictures and biopsies after mammograms, many of which prove to be insignificant (also known as false positives). A false positive result means that a concerning finding was identified but then did not prove to be cancer—the radiology equivalent of a false alarm. The USPSTF reasoned that if we stopped doing mammograms in this group, we would be sparing a lot of women a lot of unnecessary tests and everything bad that goes with them (unnecessary biopsy in some cases, and anxiety and worry while waiting for the results). While additional tests, especially biopsies, can be stressful and even unpleasant for women, as far as I’m concerned, this isn’t enough of a reason to forgo mammograms in the forty-to-fifty age group. The main reason: the proven reduction in mortality of 15 percent or more for women ages forty to fifty who have regular mammograms. That is a significant percentage, translating into tens of thousands of lives saved each year. And I’m not alone in this reasoning. The USPSTF findings from November 2009 have been dismissed and decried by almost every major medical professional society, national cancer organization, and breast cancer advocacy group in the United States.
A WORD TO THE WISE
While lives saved is the most important measure of a screening test’s success, there are other potential benefits of screening with mammography that are less frequently publicized but extremely important as well. What about the fact that a cancer found by mammogram, before it is picked up by self-exam, is less likely to require extensive surgery? And less extensive surgery, such as lumpectomy, is associated with quicker recovery and minimal overall change in appearance. Plus women with smaller, earlier cancers, such as those detected by mammogram, may be less likely to require subsequent aggressive treatment, such as chemotherapy. The point is that picking up cancer earlier is better for so many reasons, and that’s what mammograms do. Mammograms are worth it, even if they do sometimes lead to additional and unnecessary testing.
MYTH: “Mammograms don’t reduce cancer mortality.”
Occasionally I hear women say, “Mammograms prevent breast cancer.” It’s important to clarify: mammograms don’t actually prevent breast cancer from developing, but they do reduce the risk of dying from breast cancer by detecting it early in the vast majority of cases. Many women have seen or heard of studies that suggest mammograms don’t reduce cancer mortality. You may feel that this is enough of a reason to delay getting a yearly mammogram, or not getting one at all. After all, if it won’t increase survival, why bother with the test?
Yes, it’s true that there have been various studies claiming to prove that mammograms do not reduce cancer mortality in significant enough numbers to warrant mammogram recommendations as they currently stand. The most recent of these, in 2014, highlighted the findings from a study done on screening mammography conducted over thirty years ago in Canada. This one study did not show a survival benefit associated with regular mammograms. What much of the recent coverage of the thirty-year-old data did not mention, however, was that this trial had largely been discredited due to, among other factors, the poor quality of the mammography equipment used and problems with the randomization of the selection process (where more women with obvious cancer may have been pushed toward the mammography group). Despite these criticisms and the fact that it is the only study that did not show a survival benefit, the trial continues to make headlines, calling into question the benefit of mammograms. And again the response from those of us on the front lines of cancer treatment and cure was that one flawed trial from over thirty years ago should not change recommendations for women today.
At what age is it okay to stop getting mammograms?
Of all of the trials that showed that mammography reduces the risk of breast cancer mortality, very few included women over the age of seventy. Remember, most of these studies were performed in the 1970s, when the average woman was only expected to live to her early seventies! So while there is little actual data to suggest screening mammograms benefit women over seventy, this is probably because the benefits in this age group have not been adequately studied.
Today, the life span of the average woman is well into her eighties; more impressively, a woman who lives to be eighty-five will most likely live well into her nineties. When making decisions regarding continuing screening with mammography, it’s important to take into consideration not only chronologic age but physiologic age as well. In other words, we ask ourselves: if we find something on the mammogram, is the person healthy enough to tolerate further tests and possibly surgery? If the answer is no and our patient’s other significant health issues will most likely limit long-term survival, then screening with a mammogram to identify an early breast cancer is probably of very limited added benefit. Conversely, if the expectation at any age is for long-term health and good quality of life, there is no reason not to get a mammogram with the same goal of early detection of breast cancer. I have many patients who are very healthy and spry well into their eighties, and for these women I do recommend mammograms, knowing that there is a high likelihood of them living well into their nineties. So the decision to have a mammogram (or to stop getting them) in the older age group needs to be determined on a case-by-case basis by a woman and her doctor.
When earlier screening is necessary, and the factors that increase risk
It bears repeating: women at average risk for breast cancer should get their first mammogram at age forty. However, even the word “average” denotes a range. And you might have risk factors that elevate you to slightly higher than average risk. What then?
Assessing individual risk is complicated and sometimes involves mathematical modeling in order to zero in on an individual’s true level of risk. The Gail model is one commonly used tool for assessing risk that you may hear about, and there are others as well, such as the Tyrer-Cuzick model and BRCA-PRO. Many are available online (see the links to online resources at the back of the book), but it would be hard to go online and figure out how to input appropriate data and use these models yourself. More important, the results and their significance may be difficult for a layperson to interpret. Most breast specialists and even many primary care doctors and gynecologists know how to use these models and discuss the results, so in general my advice is to work with a doctor when trying to figure out your personal level of risk for developing breast cancer. Many specialized breast centers have high-risk programs to evaluate women who think they may be at increased risk for breast cancer, thereby enabling physicians to make more personalized recommendations for screening and prevention.
It’s worth keeping in mind that most women tend to overestimate their risk of developing breast cancer because the disease is so common and everyone knows someone who has been affected. So getting a true understanding of one’s risk—average, moderately increased, high, extremely high—is critical. A trusted physician can ask you important detailed questions about your family and medical history, assess your personal risk factors, perform risk modeling, and give you a realistic sense of your personal risk for breast cancer and whether or not early or additional screening is appropriate.
NEED TO KNOW
For women with a family history of breast cancer, the general recommendation is to start getting mammograms ten years younger than when your youngest relative was diagnosed. So if your mother was diagnosed at age forty-seven, you might consider starting to get mammograms at age thirty-seven.
Here are the main risk factors to know about in terms of early screening:
1. Family history. In the majority of cases, additional risk is due to breast cancer in the family. While it’s true that a family history of breast cancer does increase your risk of getting the disease, it’s important to remember that the degree of increased risk varies. Sometimes a woman’s family history gives her a minimally increased risk, and so there’s no need to screen earlier. Sometimes she may have a significantly higher risk, in which case early screening is important. The factors that your doctor will take into account when recommending early screening include the number of relatives with breast cancer, the closeness of those relatives (sister or mother versus second cousin once removed), and the age at which those relatives were diagnosed. As an example, if your grandmother was diagnosed with breast cancer at age seventy-seven, the increase in your risk of breast cancer would probably be minimal. If your two sisters both developed breast cancer before age forty-five, then this would put you at substantially increased risk. Many women have a family history of breast cancer where the degree of increased risk for other family members is not so clear-cut. For example, if you have an aunt with breast cancer at age fifty, you might understandably be totally unsure as to where this puts you in the big picture of breast cancer risk. In these types of situations, the effect on risk can be quite variable, and you simply have to review your family history as well as other risk factors with a specialist to get an accurate assessment of what your particular family history means for you.
2. Atypia and LCIS. Many women who have suspicious findings on their imaging studies or feel a lump will undergo breast biopsies. Most of these biopsies will show normal findings. Sometimes a biopsy will show some cell changes that, while not cancer itself, indicate an increased risk for developing a future breast cancer. Two types of cell changes are called atypia and LCIS. For women who are found to have atypia, their risk of getting breast cancer over their lifetimes is mildly elevated to approximately 15 percent. LCIS stands for lobular carcinoma in situ. Despite having a name that includes the word “carcinoma,” LCIS is not breast cancer and does not turn into breast cancer. But it does moderately increase one’s risk of getting a future breast cancer, to approximately 20 percent.
3. Hormonal exposure and reproductive factors. These can include getting your period early in life, not having children or having children later in life, late onset of menopause, not breastfeeding, and taking certain types of hormone replacement therapy. Most of these factors in and of themselves do not increase breast cancer risk substantially, but put some of them together and the risk can add up. For example, a forty-five-year-old woman who first got her period at age ten and had her first child after age thirty has an estimated lifetime risk of developing breast cancer of approximately 15 percent, which is slightly higher than the average woman’s (approximately 10 to 12 percent).
4. When family history is hard to assess. What if you were adopted and have no idea of your biological family’s medical history? What if there haven’t been many female ancestors in your family for generations (your mother died at a young age of other causes and had three brothers, and your father was an only child)? It can be hard to tell with family backgrounds such as these whether or not someone has a family history of breast cancer. Your doctor can help you determine whether the lack of information regarding family history is enough to warrant further assessment.
5. Women genetically predisposed to breast cancer as a result of harboring a BRCA-1 or BRCA-2 mutation. There are two factors that put women at the highest risk for developing breast cancer, and one of these is having a BRCA-1 or BRCA-2 mutation. Women in this category have an 80 percent risk or higher of developing breast cancer in their lifetimes, and a 20 to 40 percent chance of developing ovarian cancer. And while the most common age to be diagnosed with breast cancer for the average woman is in her sixties or seventies, for women with BRCA mutations, the average age of diagnosis is in their forties (roughly twenty years earlier). For these women, screening should begin at approximately age twenty-five. It’s important to realize that women with BRCA mutations represent only a very small group of women who get breast cancer, and even among women with a family history, most do not have these mutations. So not all women diagnosed, even those with a family history, require testing for this gene. However, if you have been diagnosed with a BRCA mutation, I definitely recommend early screening. (For additional information on BRCA mutations, see chapter 15.)
6. Women who have received chest wall radiation in the past, especially if that radiation was received at a young age. This is the second group at highest risk. With many cancer treatments, there is a component of robbing Peter to pay Paul. In other words, we often give treatments to cure a life-threatening cancer today knowing that there may be side effects that will increase the risk of developing another cancer down the line. Hodgkin’s disease is a type of lymphoma, and its treatment can involve chemotherapy, radiation, or both. When chest wall radiation is necessary to treat Hodgkin’s disease in girls and young women, especially during the critical phase of breast development in the teenage years, there is an increased risk of developing breast cancer—as much as forty times that of the average woman. A young woman treated for Hodgkin’s disease in her teens should start screening for breast cancer as early as her twenties, as the development of the breast cancer can be seen as early as eight years after treatment.
When you are at increased risk: options for prevention
Many women at increased risk for developing breast cancer are interested to know what, if anything, they can do to reduce their risk. While there are many options for treatment of breast cancer, unfortunately the effective options for prevention are surprisingly limited.
1. Obesity and heavy alcohol consumption are two lifestyle factors that increase risk for breast cancer for all women (see chapter 13 for more on the topic of lifestyle factors), so avoiding these is definitely advisable for women already at increased risk.
2. Prophylactic or risk-reducing mastectomy (surgically removing the breasts) is typically reserved for those at highest risk for breast cancer, such as BRCA mutation carriers (see chapter 15).
3. Tamoxifen is a medication that is most commonly given to women with breast cancer as a treatment to reduce the risk of their cancer coming back (see chapter 9 for more on tamoxifen treatment). But tamoxifen is also approved as a preventive agent and prescribed for selected women who don’t have breast cancer but who are at increased risk for developing it. In this group, tamoxifen reduces risk by approximately 50 percent. So, for example, women with LCIS who have a 20 percent lifetime risk of developing breast cancer can take tamoxifen, thereby reducing their overall risk to approximately 10 percent. Many assume that most women at increased risk for breast cancer, the majority of whom are understandably anxious about developing the disease, would enthusiastically take a medication that could reduce their risk so dramatically. Surprisingly, only a small percentage of those eligible for tamoxifen as a preventive agent actually do take it. In part this is due to physicians’ lack of awareness: many general doctors are not familiar with the criteria that place a woman at increased risk, and therefore don’t offer the drug to their patients who are eligible. But research also shows that even among eligible women who are offered tamoxifen, only a minority take it. The majority of women who are at increased risk for breast cancer but otherwise generally healthy cite the fear of side effects as their main reason for being unwilling to take it. I do offer tamoxifen to my patients who are eligible and encourage them to take it. But for many the side effects are real and a source of concern, and I completely understand why some choose not to take it. Raloxifene (Evista) is another drug similar to tamoxifen that is an option for breast cancer prevention, but it is effective only in postmenopausal women. Evista was actually initially approved as an osteoporosis medication and is primarily prescribed for that indication. However, in a large breast cancer prevention trial comparing raloxifene to tamoxifen, raloxifene was found to have a preventive effect on breast cancer, although not as robustly as tamoxifen, but also was found to have a milder side effect profile as well. For postmenopausal women who have osteoporosis and are at increased risk for breast cancer, raloxifene can be a good option, killing two birds with one stone.
MYTH: “Having breast implants increases your risk of cancer and makes it harder to detect cancer on a mammogram.”
Let me just say this plainly: breast implants do not increase one’s risk of getting breast cancer, nor do they make it more difficult to detect breast cancer on mammograms. In most well-equipped and experienced radiology practices, the technicians are trained to get good views of the actual breast tissue by displacing the implants back toward the chest wall. It’s worth keeping in mind that extra images are almost always routinely needed for women with breast implants, as extra views allow us to more fully visualize the breast tissue surrounding the implants on all sides. What is true is that breast implants may make it more difficult to do a needle biopsy of an abnormality if one is found on a mammogram. If the abnormality is deep in the breast, many radiologists are appropriately nervous about the puncture risk associated with sticking a long, sharp needle anywhere near the implant. In these cases, you may need surgery, which can remove the concerning area under direct visualization, with less risk of damaging the implant. An experienced breast radiologist will usually be able to guide you toward the appropriate procedure if you have implants and need a biopsy.
Mammograms and radiation exposure
Mammograms use radiation to create a picture of your breast tissue. Many women are understandably concerned about the amount of radiation an annual mammogram exposes them to (as well as the radiation from any associated tests required if the mammogram shows an abnormality). My answer to this is that concerns about radiation exposure from mammograms causing cancer are unwarranted and not a good excuse for opting out.
For one thing, it’s important to know that we are exposed to radiation in day-to-day life, no matter what we do. For example, people who live at higher altitudes have increased radiation exposure over their lifetimes because there is less atmosphere to absorb sources of radiation from above. The same goes for people who take regular airplane flights. These small increases in radiation exposure are not significant enough to increase the risk of developing cancer for the vast majority of women—which is why people continue to live at high altitudes and fly in airplanes! The mammogram is associated with one of the lowest amounts of radiation exposure of any medical test, roughly the equivalent of ten long plane flights. By contrast, a CT scan of the lungs, such as might be recommended for lung cancer screening, is associated with more than twenty times the radiation exposure of a mammogram (or two hundred long plane flights).
Mammography and overdiagnosis
There is no question that as mammograms and other screening tools get better and better and identify more and more findings, in some cases cancer is being overdiagnosed and therefore overtreated. For example, there are many cancers that are small and slow-growing, and if not detected, they could percolate along for years before causing any harm whatsoever. A woman with one of these types of cancers may end up dying of some other, unrelated illness, and the only way we would find out that incidentally she had breast cancer is from an autopsy. It stands to reason that there’s no point in treating these types of less threatening cancers.
However, at this point in time, we in the medical profession are not very good at distinguishing the life-threatening cancers from the ones that may just cruise along. Let me be clear: most cancers don’t just cruise along. And so when we see a cancer, no matter how small or apparently insignificant, we typically treat it, knowing that the risk of no treatment would be losing the opportunity to cure a life-threatening cancer. One day we will have the tools to reliably tell the difference between a cancer we need to treat and a cancer that we don’t, but we are not there yet. Much research is being done in this area, and I’m confident that in the future our tools for diagnosis will improve substantially. Until then, the mammogram remains our most reliable tool.
Screening Versus Diagnostic Tests
There are other tests that we can use to screen for breast cancer, specifically ultrasounds and MRIs, but the context in which we are administering the test is important. When talking about testing in general, it’s necessary to distinguish between two types of test: screening and diagnostic.
1. Screening tests
A screening test is a fishing expedition of sorts. When a person has no identifiable or specific abnormalities that we are investigating, the test she undergoes is a screening test. So when a woman comes to my office for her annual checkup and has a mammogram, this is a screening test. If a woman has a normal mammogram and a normal physical exam and we want to do an ultrasound just to see if anything else can be found, it’s a screening ultrasound.
2. Diagnostic tests
A diagnostic test is thought of as a targeted exam: it means something of concern has already been identified, and we want to get tests to figure out or diagnose exactly what is going on with the finding. So if a woman comes into my office after noticing a mass in her breast, then we would do a diagnostic mammogram and/or ultrasound.
Ultrasound: when to screen
For the vast majority of women, ultrasounds alone are not appropriate for early breast cancer detection, as they are not nearly as effective as mammograms. In fact, when the physical examination and mammogram are normal, screening ultrasound picks up only a very small percentage of additional cancers—1 to 2 percent in most women. Furthermore, even the most thorough ultrasound examination cannot give us a comprehensive and total picture of the whole breast the way a mammogram does, since the ultrasound probe allows us to visualize only one segment of the breast at a time, and spots can be missed.
In general, ultrasounds should be performed in selected patients in addition to mammograms as a screening test, or as a diagnostic test to get a better look at something already identified either by mammogram or because the patient or doctor feels something that seems new or abnormal. The risks and benefits of screening ultrasounds are variable based on the patient, and so, just like everything related to breast cancer, there is no one-size-fits-all recommendation. What we know for certain is that not all women need a screening ultrasound, and screening ultrasound is associated with an increased number of false positives, since the more you look, the more you find. Some of the factors that may influence your and your doctor’s decision about whether to add an ultrasound to your screening include
• Having a higher risk for breast cancer related to some of the risk factors described above.
• Having dense breasts. Breast density becomes a factor when the normal tissue appears thicker, making it more difficult to pick up cancers against the normal background on mammograms. If you have dense breasts (based on results from your mammogram), screening ultrasound is often useful and recommended. Recently legislation has been passed in many states—starting in Connecticut and including California, Texas, New York, and others—requiring radiologists to inform patients of their breast density after a mammogram so that screening ultrasound can be discussed and added to the testing lineup. So you can certainly expect that ultrasounds will be offered to more women and discussed more frequently, because many states now mandate it. The degree of breast density is determined by the radiologist reading your mammogram, and classified based on a four-level scale:
1. Fatty: breast tissue is composed of primarily fatty tissue, not dense at all
2. Scattered areas of density: minimal amounts of dense tissue
3. Heterogeneously dense: significant amount of dense tissue seen in different parts of the breast
4. Extremely dense: dense tissue uniformly throughout the breast
As the extent of breast density goes up the scale, the more difficult it can be to see a cancer against the background of dense tissue, and therefore the more potential benefit of detecting a cancer that mammograms might miss by adding ultrasound to the screening regimen. If you live in a state where notification regarding breast density is mandated, and you do receive notification that your breasts are dense along with the results of your mammogram, ask the doctor who ordered the mammogram, “Should I also be getting an ultrasound? Might it be beneficial in my particular case?”
Ultrasound: what to expect
Unlike mammograms, ultrasounds do not involve radiation exposure, and are appealing for that reason. An ultrasound exam (also called sonogram) involves lying on your back on an exam table. Usually the ultrasound technician or the doctor puts some clear gel on the breast skin surface to allow the ultrasound probe to glide over the skin surface more easily and smoothly. The ultrasound probe is about six inches long and is usually the shape of an electric razor but with a smooth surface on its working end. The end of the probe is placed on the skin surface and moved methodically over the breast in circles until as much of the skin surface as possible has been covered. The ultrasound probe is actually transmitting harmless, painless sound waves through the skin, allowing us to see structures in the breast tissue. This permits us to differentiate between fluid (a cyst, for example) and solid (perhaps a tumor), and often shows us lumps that stand out from the surrounding normal breast tissue.
A WORD TO THE WISE
It’s true, mammograms are not perfect and do miss cancer in approximately 10 to 15 percent of cases. But that doesn’t mean ultrasounds for everyone are necessarily the solution to this problem, and it’s important to know that the benefits of ultrasound are often overestimated. The perception exists that ultrasounds close that 10 to 15 percent detection gap, picking up most if not all the cancers that mammograms miss. But that’s not really the case either. For example, my patient Mary came into the office after she felt a mass in her left breast. A mammogram was done, but it did not pick up the mass. An ultrasound was then done of the specific area where Mary felt the lump; we call this a targeted ultrasound. The targeted ultrasound identified the mass. We then performed a biopsy and the mass proved to be cancer. In this scenario, Mary could have easily gotten the impression that the ultrasound “detected” the cancer. In fact, it did not. Her self-examination detected the cancer! The ultrasound confirmed it and facilitated the biopsy, which made the diagnosis. (More on self-examination below.)
MRI: when to screen
Screening for breast cancer with MRI is also controversial, and currently it is recommended only for groups at significantly higher risk. Though MRI does not involve radiation, it is—like ultrasound—associated with a high rate of false positive findings, more than seen with mammograms, and is generally not recommended for screening in the general population at all. Even among those at elevated risk, current recommendations involve screening only those at highest risk. As a reminder, the highest-risk groups are those who are known or suspected BRCA mutation carriers, those who were treated with chest wall radiation at a young age, and those with a combination of risk factors that put them at a risk of 20 to 25 percent of getting breast cancer over their lifetimes.
For other risk groups, such as those with atypia or those at 15 to 20 percent risk (the mild to moderately elevated risk group), less is known about the benefits of MRI screening. And even for women who have already had breast cancer, the benefits of yearly MRI screening in detecting future recurrence or a new cancer in the other breast have not been clearly established.
As breast MRI is not a standard testing procedure for breast cancer, the decision to get one should not be made lightly. Instead, it needs to be based on your personal risk factors and the results from other imaging tests. Unless you are in a particularly high risk group, it’s likely that an MRI could lead to an unnecessary biopsy, multiple follow-up MRIs, and other tests. This likelihood far outweighs the likelihood that MRI will find a cancer.
MRI: what to expect
MRI is an imaging test that can be performed on almost any part of the body. However, to get the best picture of the breast, special machinery and software are needed, and not all facilities have these critical additions. Certainly most specialized breast centers and major or academic medical centers will. If you are at a smaller facility, you may want to ask if they have an MRI machine dedicated to breast imaging. With MRI, you usually lie facedown in a big tube as you go through the MRI machine, and an injection of dye called gadolinium is given through an IV during the test to better differentiate cancer from normal tissue. The test takes approximately thirty to forty-five minutes. With MRI there is no radiation involved, only magnetic waves, which have no known side effect. There are very few known side effects of the gadolinium injection (occasionally there can be an allergic reaction to the gadolinium), but we don’t know if it’s safe during pregnancy, so it’s not recommended for pregnant women. In addition, women who have certain kinds of metal implants in their bodies, such as pacemakers, usually cannot have MRIs because the magnetic force of the scan runs the risk of displacing any metal device secured in the body.
Lying down in a tube doesn’t sound uncomfortable (unless you are having the MRI for a back issue or other orthopedic concern in which lying down itself is uncomfortable), but many people feel very claustrophobic. There are open MRI machines, but most of these open machines do not do a great job of looking at breast tissue. So getting an MRI if you feel anxious in closed or tight spaces could be a problem. But getting screened with MRI is a critical part of the screening regimen for those at the highest risk, and important to do if you fall into one of these groups. If an MRI is recommended for you but you are worried about the experience, speak to your doctor about strategies for relaxation, meditation, or even medication to get through it.
Cutting-edge screening and diagnostic tools
Not yet ready for prime time, but possibly coming soon
Many biotechnology companies are championing and promoting new, exciting techniques for breast cancer screening and detection. Some of these are interesting, but more work needs to be done to ascertain the ultimate benefit for most women. Here are some of the newer tests that are being used selectively at reputable breast centers across the country:
• For many years scientists have suggested that cancer cells generate more heat than normal cells. If this is the case, it may be possible that we can use thermography to detect subtle temperature differences in cells and therefore identify cancers. Thermography is offered as an experimental test in some centers. Interesting, but certainly not ready for prime time.
• There are newer tests that combine PET scanning with mammograms or MRIs. PET scanning examines how a suspicious area takes up glucose, because we know that tumors take up more glucose than normal tissue. This type of testing may help refine results, helping determine whether something seen on a mammogram or MRI is more or less likely to be cancer.
• BSGI, a test that looks at uptake of certain radioactive dyes by tumors, is being used in combination with standard imaging in many centers throughout the country. Much research is being done to try to define how it might help differentiate cancer from normal tissue and reduce false positive results on mammograms and MRIs.
Experimental breast imaging: a cautionary tale
A few years back, a test called ductal lavage attracted a lot of interest, and was actually being performed by a number of doctors in their offices. The idea behind the test is that you could draw fluid and cells from the breast through a needle inserted into the nipple, and these cells could give you information regarding a woman’s risk for developing breast cancer in the future. It was believed that the same test could even tell you whether or not she had already developed the disease, even if the cancer could not be seen on other imaging tests. The problem with ductal lavage was that before it was put into practice, it was never fully evaluated in a way that reliably and scientifically determined the validity of the test’s results. As a result, if a doctor performed the test and retrieved cells that looked like cancer, it was very hard to know what to do with this information. Was it possible that the woman did not actually have cancer? Yes. What was the likelihood of this? Not known. If the doctor performed the test and got cancer cells out, was it possible that the woman did have cancer? Yes. However, if the mammogram and other tests were normal, how would we find it? We can’t. And if the doctor found nothing on these standard tests, then what? Not sure. Rarely did the physician actually performing the test (usually a primary care physician or gynecologist) know what to do with the test results or how to act on them if they were abnormal. So as quickly as ductal lavage came into practice, it fell out of favor, and it is generally not promoted or performed anymore by practitioners of any kind.
So if your doctor wants to perform a nonstandard or experimental test (in other words, any test other than mammogram, ultrasound, or MRI), you should find out exactly how he or she intends to deal with the results. When your physician proposes a new diagnostic test, you can simply ask the following questions: “What are the possible outcomes of this test? What will you do in each eventuality?” If the answer to the second question is “I’m not really sure, but I can send you to a breast specialist to figure it out,” you probably should think twice and see the breast specialist for advice before you have the test. The reality is that experimental tests can open up a whole can of worms, leading to extensive amounts of additional unnecessary tests, biopsies, and anxiety—and even with all the additional testing, you may not receive a definitive, satisfying resolution. So be careful when starting down this path of additional tests of unknown significance. And never assume that there is no downside. Remember, more is not necessarily better.
Testing frequency: why screening more regularly doesn’t necessarily lead to better results
If screening improves the chances of cancer being detected earlier, then many people make the leap to assuming that more frequent testing would be even better. Many patients ask me why I don’t order mammograms for them two or three times a year. They would be willing to do it if it would reduce the chance of a cancer being missed. But in most cases, when a mammogram does miss a cancer, it’s because the cancer just isn’t seen on a mammogram at all, even when we know that it is actually there. This is the case with 10 to 15 percent of all breast cancers. Doing mammograms more frequently won’t detect a cancer that can’t be seen on a mammogram in the first place. Sad to say, no matter which screening regimen is appropriate for you, it must be understood that there is no test or combination of tests at any interval or frequency that can effectively guarantee early detection.
Interval cancers
Every now and again, a patient whose mammogram was normal the month before comes in because she feels a new lump. And then the lump turns out to be cancer. In these cases, patients are understandably upset. “I have been totally on top of my screening,” they say. “How did the mammogram miss my cancer? What happened?” This can happen because, no matter how frequently exams (physical or radiologic) are performed, there are cancers that cannot be seen on imaging studies, some of which are biologically aggressive, that can develop. These are known as interval cancers. They are demoralizing to both doctor and patient, and shake the foundations of our belief that surveillance and close follow-up are our safeguards. Fortunately, these cases are rare. The good news is that appropriate screening does increase the likelihood of early detection, which leads to a higher likelihood of cure. And certainly these interval cancers are still as potentially treatable and curable as their mammographically detected counterparts.
A WORD TO THE WISE
When getting any breast imaging test—mammogram, sonogram, MRI—there are two things that factor into the quality of the exam: the caliber of the equipment and the expertise of the radiologist actually looking at and interpreting the results. While it’s difficult for a layperson to evaluate the actual equipment, there are ways to make sure you are at a facility that delivers quality care. Here are some things to look for:
1. In 1992 Congress passed the Mammography Quality Standards Act (MQSA), aimed at improving and unifying the standards for facilities, personnel, and the practice of performing mammography across the country. Today, a facility requires actual U.S. Food and Drug Administration (FDA) approval to perform mammograms, and you should always make sure the facility where you are having your mammogram is FDA approved. The FDA website does have a list of almost nine thousand facilities across the country that are approved (see the list of online resources at the back of the book).
2. You increase the likelihood of getting state-of-the-art technology by going to a facility that does a large volume of breast imaging, such as a dedicated breast imaging center, and that has the capability to perform breast biopsies if necessary. Your breast radiology facility should definitely offer digital mammograms. If it doesn’t, you can be sure it is behind the times.
3. When it comes to the physician, if at all possible make sure that it’s a specialized breast radiologist who is reading your mammogram, sonogram, MRI, or other breast imaging test. Reading and interpreting these tests accurately (not missing a cancer if there is one and, conversely, not overcalling normal findings) is best done by specialists who are looking at high volumes of breast imaging tests every day and who have received specialty training in this field. Breast imaging and the technology involved are also constantly evolving and improving, and simply put, it’s hard for a general radiologist to keep up. Clearly a general radiologist who is looking at a brain MRI one minute and a chest CAT scan the next cannot possibly have the same level of expertise as a specialist when looking at your mammogram. And if an abnormality is identified on your images, a specialized breast radiologist would usually be the best person to perform and interpret the follow-up studies and biopsy if necessary, which involves a very specific skill set and training. Most specialized breast radiologists have done advanced training in breast imaging, and most read a minimum of approximately two thousand mammograms a year to maintain their skills.
4. If it is the first time you are going to a new breast radiology facility and have had previous exams elsewhere, the new facility should insist that you bring prior images if at all possible. Every woman’s “normal” mammogram pictures differ in subtle ways, and comparing your previous pictures to the new ones is a critical part of interpreting your imaging study results, whether it’s a mammogram, sonogram, or MRI.
It’s easy to find out if your facility is FDA approved, whether or not it offers digital mammograms, and who will be reading your mammogram. Just ask at the facility.
Self-examination
As with mammograms, there’s been plenty of controversy and conflicting information surrounding the value of self-examination. Should women check themselves for lumps? How could there possibly be a downside to self-examination? The main downside, again, is the anxiety and fear generated by uncertainty. How do you know if you’ve found something irregular? If your breasts feel lumpy anyway, how can you tell if you’ve found something you should be worried about?
When it comes to self-examination, my recommendation is that it is always advisable for you to be familiar with your body and therefore aware of what is normal for you. In the same way that we consider it important for a woman to take notice when a new mole or dark spot has developed on her skin, it is critically important for you to have a basic idea of what’s normal for your breasts so that if something new develops, you have a higher likelihood of noticing it.
That said, self-examination can be difficult, intimidating, and anxiety-provoking, especially if you are very lumpy and bumpy. But here’s the deal: every woman’s breasts can feel like a cobblestone street. Lumpy can be normal. And a woman’s own exam can change over the course of the month related to her hormonal cycle as well. What you are looking for is a “dominant” finding or a change from what was previously there. And the only way to notice if there is a change in your breasts is to be somewhat familiar with what they feel like in the first place. Here are some signs to look for when you are looking for a new development:
• A mass in the breast that is new or larger than before. These features are more worrisome if the mass is firm and irregular.
• A new thickening in the breast. A thickening is less obvious than a mass, but it can feel as if there is a ridge of tissue in the breast. A thickening in the breast may be especially concerning if it is asymmetric when compared to the other breast.
• A subtle dimpling or indentation of the skin. These kinds of irregularities are often noticed when looking down at the skin, or seen on the undersurface of the breast when looking in the mirror. A dimpling can look as though the skin is being pulled inward by something beneath the skin’s surface.
• Any change in the nipple, such as an inversion, hardening, scabbing, or flaking, especially if it’s new or asymmetric to what you feel or see in the other breast.
• Nipple discharge, especially if it’s bloody, and especially if it’s only from one breast. Nipple discharge is also more concerning if it’s spontaneous, meaning it comes out by itself rather than when the breast is squeezed. Spontaneous nipple discharge is commonly first noticed as a small stain in the bra or on pajamas. While there are also many noncancerous reasons for nipple discharge, new nipple discharge can be related to cancer and should be investigated.
• Changes to the breast skin color or thickness. New redness or thickening of the breast skin (so that it looks and feels leathery or like the skin of an orange), especially if not related to breastfeeding or a known breast infection, is something that should be checked out.
• An enlarged or hard lump or lymph node in the armpit.
My advice is to examine your breasts once a month or so, but not obsessively. For women who menstruate, the best time each month is usually a week to ten days after you get your period. After a few cycles of self-exams, you’ll likely become more comfortable and familiar with your baseline “normal” and less anxious overall.
THE TAKEAWAY
• For women without any identifiable risk factors, mammograms need to start at age forty.
• Mammograms may need to start earlier for those with a family history of breast cancer diagnosis at a young age.
• Ultrasounds can be done as an adjunct to mammograms for women at increased risk or with dense breasts.
• MRIs are for women at the highest risk for breast cancer.
• Regular self-exams are a good idea.
• Early detection is a goal, not a guarantee for anyone, no matter how diligent you are.