9
Prostate Cancer
IN THIS CHAPTER YOU’LL DISCOVER
→ Prostate Cancer Staging, Grading, and the Gleason Score
→ Treatments for Prostate Cancer
HALL OF FAME SPORTS writer Jack McCallum learned he had cancer just in the same way as many other men — undergoing an annual prostate screening test, known as a PSA. “Your PSA is 3.8. That’s not overly high, but the concern is how it has steadily risen,” he recalls his doctor saying.
McCallum wasn’t alarmed, but he was concerned. Cancer was on his radar. He had brushed aside any suggestions from his doctor that he submit to an annual cardiac stress test because he was convinced that, due to his family’s medical history, when it was his time to go, “the Big C” would get him, not heart disease.
Still, he was unprepared to learn he had early stage prostate cancer. His story ended well, and he is now cancer-free after surgery, but the experience sent him on an emotional rollercoaster ride fraught with difficult decisions, fear, and uncertainty — so much so that this life-altering journey inspired him to write a book about it. The Prostate Monologues focuses on how much is still unknown about this disease, and the ramifications it poses for the men who face it.
What Is Prostate Cancer?
The prostate gland, exclusive to men, is an exocrine gland of the reproductive system. It secretes the majority of what constitutes semen and aids in the ejaculatory process. In order for the gland to function properly, it requires testosterone.
A soft gland a bit larger than the size of a walnut, it is located behind the penis, below the bladder, and in front of the rectum (thus, it can be felt during a rectal exam). The prostate surrounds the urethra at the neck of the bladder.
Made up of various types of cells, it is primarily the glandular cells of the prostate that become cancerous. (These are the cells responsible for the secretion that becomes part of seminal fluid.) Glandular prostate cancer is known as adenocarcinoma. While most adenocarcinomas grow slowly and remain confined to the prostate, some can grow and spread quite rapidly. Though other cancers, like sarcomas and small cell carcinomas do occur, they are extremely rare.
Statistics
About 240,000 men are diagnosed with prostate cancer each year, making it the most common cancer that occurs in men. The median age at diagnosis is 67, and about 30,000 deaths will occur annually due to the disease.
The greatest risk factor for prostate cancer is age. Risk begins to climb after the age of 50, and more than 80 percent of prostate cancers are diagnosed in men who are 65 or older. African-American men are at higher risk than Caucasian men, and Hispanic men are at lower risk, but men of all ethnicities can develop the disease.
About 75 percent of all prostate cancers are sporadic, which means they occur for no known reason. Although only five percent of cases are directly inherited, prostate cancer that runs in families (familial prostate cancer) accounts for about 20 percent of cases.
A mutation in a gene located on chromosome 17 increases the risk of prostate cancer by 44 percent. Other genes that may cause an increased risk of heritable prostate cancer include HPC1, HPC2, HPCX, and CAPB.
A disorder similar to hereditary breast and ovarian cancer in women, hereditary breast and ovarian cancer (HBOC) syndrome also occurs in men, though posing breast and prostate cancer risk instead. A predisposition to this syndrome in both sexes is primarily due to mutations in the BRCA1 and BRCA2 genes.
Working with toxic materials — like cadmium, zinc, rubber, and oil refining processes — also has been linked to prostate cancer. Obesity and a high-fat diet may contribute to its development as well. Trichomoniasis, a common sexually transmitted disease (STD) increases prostate cancer risk as well as cancer-related mortality rate.
Outcome and Survival Rates
Almost 2.8 million men in the United States today are prostate cancer survivors. As with most cancers, the survival rate is dependent on how early the cancer is treated. More than 90 percent of all prostate cancers are discovered in the local or regional stage, for which the five-year survival rate is nearly 100 percent (Stages I–III). However, if the cancer spreads to distant organs (Stage IV), the five-year survival rate drops to 28 percent.
“Prostate cancer is not a death sentence. When prostate cancer is caught early, the outcome is superb, but you have to find a doctor who will fight for you,” says Dr. David Samadi, who is chief of robotic surgery at Lenox Hill Hospital in New York City.
The PSA Test
One of the biggest controversies in prostate cancer is the use of the PSA blood test for screening. The PSA test measures the blood level of prostate specific antigen, a protein produced by the prostate gland. The higher a man’s PSA level, or score, the more likely it is that he has prostate cancer.
Adult men usually have PSA levels below four nanograms per milliliter (ng/mL). A PSA level between four and 10 is borderline-high and suggests a 25 percent cancer risk. A PSA above 10 is high, and suggests a risk above 67 percent.
Other factors are taken into consideration as well. PSA levels rise naturally with age, which is known as PSA velocity. A higher-than-normal rise in this number increases the likelihood of prostate cancer. There is also an indicator known as free PSA that is taken into consideration. One form of PSA attaches to blood proteins and another circulates freely in the blood. Men with prostate cancer have lesser amounts of free PSA than men without prostate cancer.
For the past several years, the PSA test has been used as a screening tool to diagnose prostate cancer in healthy men, which has led to about one million men undergoing biopsies each year, but only one-fifth of them have resulted in a finding of cancer. This is because many other factors can lead to high a high PSA score, including a past infection of the prostate gland, interrupted blood flow to the gland, or benign enlargement (hyperplasia) of the prostate (BPH), which is common in men as they age.
Because of the great possibility of false findings, which can result in anxiety and unnecessary treatment, PSA screening is one of the hottest controversies in medicine. The US Preventive Services Task Force no longer recommends that healthy men be screened, and the American Urological Association (AUA) has scaled back its recommendation to endorse the test only for men aged 55 to 69, following a discussion of risks versus benefits with their doctor.
Dr. Robert C. Flanigan, professor of urology and chair of the department at Loyola University Medical Center, disagrees with the recommendation of the US Preventive Services Task Force. He contends that PSA screening does save lives: “No doubt there is a problem in that we have overtreated some prostate cancer cases, and there have been some side effects from treatment in cases where the disease is not life-threatening. But before screening became widespread, 25 to 30 percent of men undergoing surgery had cancer that had spread and was incurable. Now that rate has dropped to approximately two percent when PSA is routinely done,” he says.
Types of Prostate Cancer
Nearly all prostate cancer tumors — 95 percent — are adenocarcinomas, which is a malignant tumor that begins in the tissues of a gland. The remainder is comprised of different types of rare cancers.
Stages of Prostate Cancer
As with other forms of cancer, the stage at which prostate cancer is diagnosed predicates its prognosis and treatment. The staging of prostate cancer, however, is particularly complex because it is often very difficult to determine how risky a tumor could become. Therefore, there may be differences in prognosis based on other factors, including the volume or size of the tumor, the part of the prostate in which it is located, the PSA score, the number of cores (samples from a hollow needle biopsy) in which the prostate cancer is found, and the tumor grade.
Today, most physicians stage prostate cancers using the TNM system: T (tumor), N (node), and M (metastasis). For patients with presumed localized prostate cancer, stages T1 through T4 indicate whether or not the cancer can be felt by the physician, and if so, the size and location of the tumor. The node categories NX, N0, and N1 indicate whether or not the cancer has spread to the lymph nodes. And finally, metastasis stages M0 or M1 are determined based on whether or not the cancer has spread past the lymph nodes, and if so, to which parts of the body/organs it has spread.
Grading Prostate Cancer: The Gleason Score
The Gleason score is a formula used to determine the aggressiveness of the prostate cancer. In the Gleason scoring system, two numbers are assigned to each biopsy containing a cancer. The first number is the grade (ranging from 1 through 5) of the tumor pattern making up the majority of the tumor, and the second number refers to any other tumor pattern that may be present. If the tumor appears to be uniform (containing only one pattern), the same number is simply repeated. For example, if there is only one tumor pattern in the sample and that tumor pattern is graded at 3, the Gleason score is 6: 3+3=6. The highest score (10) is reserved for the most varied cancer samples. The greater the variety of patterns found in a sample, the more aggressive the case.
Stage Grouping
When the cancer is staged using the TNM system, a Gleason score is applied, and a PSA level has been determined, this data is taken together to form more detailed sub-stages of the broader ones listed here:
STAGE I
Cancer is found in the prostate only, usually during another medical procedure. It cannot be felt during a digital rectal exam or seen on imaging tests. It also has a lower Gleason score, meaning the cells resemble healthy cells and the cancer is more likely to grow slowly.
STAGE II
The cancer is more advanced but has not spread beyond the prostate. This stage is divided into Stage IIA and Stage II B. There are several different classifications, depending on the PSA levels, Gleason scores, and the amount of tumors found on one lobe (of which there are four) of the prostate.
STAGE III
The cancer has spread beyond the prostate’s outer layer and also may have spread to the seminal vesicles, the pair of tube-like glands located behind the bladder that secrete fluid into the ejaculatory tract. The PSA can be any level and the Gleason score can range from 2 to 10.
STAGE IV
Again, the PSA can be any level and the Gleason score can range from 2 to 10. In addition, the cancer may have spread beyond the seminal vesicles to nearby organs, such as the rectum, bladder, or pelvic wall, to nearby lymph nodes, or to distant parts of the body, which may include bones or additional lymph nodes.
Signs and Symptoms
In its early stages, prostate cancer usually does not cause symptoms. Later on, when symptoms do occur, they may include the following:
- • Frequent urination, especially at night
- • Trouble initiating or holding back urine flow
- • Weak or interrupted urine flow
- • Pain or burning during urination
- • Blood in the urine
- • Blood in the seminal fluid
- • Pain the lower back, pelvis, or upper thighs
Specific Diagnostic Tests
DIGITAL RECTAL EXAM
The doctor inserts a lubricated, gloved finger into the rectum to check the prostate, feeling for bumps and other abnormalities.
IMAGING TESTS
Once a diagnosis of prostate cancer is confirmed, imaging tests, including CT (computed tomography) scan, MRI (magnetic resonance imaging), and bone scans are used to see if it has spread. (When prostate cancer spreads, it often targets the bones, hence the necessity for a bone scan.) A transrectal ultrasound may be performed — a procedure in which the doctor inserts a probe into the rectum that uses sound waves to provide an image of the prostate. In some cases, biopsies may be done with ultrasound direction after an MRI of the prostate is added into the ultrasound image.
BIOPSY
Tissue samples are required to confirm a diagnosis of prostate cancer. The core needle biopsy is the type generally used in prostate cancer. The doctor quickly inserts a thin, hollow needle through the wall of the rectum into the prostate gland. When the needle is pulled out it removes a small cylinder (core) of prostate tissue. This is repeated from eight to 18 times, but most urologists will take about 12 samples. This procedure is used to confirm a diagnosis of prostate cancer as well as stage it, as the number of core samples that turn up positive for cancer is an indication of the disease’s progression.
Treatments
EARLY STAGE PROSTATE CANCER
The controversy over PSA screening is not the only debate when it comes to dealing with this disease. For most types of cancers, the treatment protocol is well-defined. But, when it comes to prostate cancer, even top experts can disagree on which type of treatment is the best for early stage, localized prostate cancer.
The following are the alternatives that will be offered to you based on the philosophy of your healthcare practitioner:
- • Active surveillance (known also as “watchful waiting”)
- • Surgical, radical prostatectomy (open, robotic, or laparoscopic)
- • Radiation (brachytherapy or external beam)
IS SURVEILLANCE OR TREATMENT BEST IN EARLY STAGE?
What makes dealing with early stage prostate cancer so difficult is that currently there is no foolproof way to determine whether it is an indolent (slow-growing) disease, or if/when it may suddenly turn aggressive and life-threatening.
“Most urologists classify prostate cancer as low-, intermediate-, and high-risk, but even among low-risk patients there are different factors, such as age, etc., that can be very important. Often there is no right or wrong decision as to the type of treatment, so a physician has to outline the positive and negatives with each approach, and every case requires a personal decision,” notes Dr. Flanigan.
“When patients are newly diagnosed with prostate cancer, there is a lot of information coming at them fast and furiously. I discuss the options with my patients according to their individual case, and I also provide them with a written explanation of their options so that they have an opportunity to consider it and also talk it over their loved ones,” he adds.
ACTIVE SURVEILLANCE
Although this option is often termed watchful waiting, or monitoring, the term “active surveillance” is more accurate, because it does not mean just sitting back to see if the cancer becomes aggressive. Instead, if you opt for this choice, you would undergo a schedule of periodic PSA tests and digital rectal exams. You would also have undergone a biopsy to obtain as much information as possible about the tumor and how it may be changing over time.
Although active surveillance is a popular option, care must be taken in making certain that the appropriate patients are selected, and that the specifics of the particular patient are taken into account, including age, the size of the tumor and Gleason score, and also any co-existing medical conditions. Such a course might be preferable for a man who is of an advanced age, with another serious medical condition that may end up claiming his life instead, as opposed to a younger man with no co-existing conditions, who could possibly die of prostate cancer should his tumor become aggressive.
PROSTATECTOMY
The surgical removal of the prostate gland is generally the treatment of choice for prostate cancer patients who are younger, or also for those who are older but are in very good physical condition, with a normal remaining lifespan that would exceed at least 10 years.
This surgery, which is done with the goal of curing the cancer, is called a radical prostatectomy. It can be done in two ways: either open, which means using a traditional surgical procedure that involves a large incision, or performed laparoscopically, which utilizes a series of small incisions instead.
Robotic-Assisted Prostatectomy
Laparoscopic surgery to remove the prostate can be done by hand, like traditional surgery, but increasingly the doctors who perform it use a robotic system. Done this way, the doctor guides the robotic arms that wield the surgical tools.
Radical Open Prostatectomy
In open surgery, the surgeon makes a vertical eight-inch to 10-inch incision to reach the prostate gland. The incision may be made either in the lower belly between the navel and pelvic bone (retropubic approach), or in the perineum, which is the area between the anus and the scrotum (perineal approach). The lymph nodes are often also removed from this area so they can be tested for cancer; however, if the lymph nodes are believed to be free of cancer based on the grade of the cancer and results of the PSA test, the surgeon may opt not to remove lymph nodes.
Laparoscopic Prostatectomy
Similar to radical open prostatectomy, this type of surgery is performed to remove the prostate gland, along with all of the cancer. The surgeon makes a series of small incisions, and then uses special instruments to reach in and remove the prostate.
Robotic-Assisted Laparoscopic Radical Prostatectomy
This technique, which is becoming increasingly popular, is performed through small incisions in the belly. The surgeon sits at a computer and, using hand and wrist movements, remotely operates robotic arms that translate his motions into finer and more precise action in order to remove the prostate and other cancerous tissue.
COMPLICATIONS OF RADICAL PROSTATECTOMY
Complications that occur during or early after prostatectomy most often include bleeding, infection, and pain. The major long-term complications associated with prostatectomy are loss of the ability to have erections and loss of bladder control (incontinence).
In general, a robotic prostatectomy causes less bleeding and less pain, but the control of the cancer, sexual, and urinary side effects can be similar to a radical (open) prostatectomy. The robotic procedure has not been available for as long as radical (open) prostatectomy, so there is less information on long-term results.
“Robotic surgery has been marketed extremely well. There aren’t any large, randomized studies that compare robotic and open surgery, so when you look at the data, you can come to different conclusions,” says Dr. Flanigan.
In selecting the type of procedure to opt for, it’s very important to make sure that the surgeon is extremely experienced with the specific treatment technique.
“Unfortunately, there is also no central clearinghouse that offers data regarding a surgeon’s experience level. So you should choose your prospective surgeon carefully. Ask the surgeon such questions as, ‘What types of cases make up your practice?’ and, ‘How many of these procedures have you done or do you do each year?’ It is generally important to choose a surgeon who performs these procedures on a regular basis. In many cases, if a surgeon does only a relatively small number of the procedure you need, his or her skills may not be at the highest level,” Dr. Flanigan says.
Radiation
Radiation therapy is the use of high-energy rays to kill cancer cells. Radiation can be used to treat early-stage prostate cancer as part of the first-line therapy (along with hormone therapy) for cancers not completely removed by surgery, and for recurrent prostate cancer.
BRACHYTHERAPY
Brachytherapy is the insertion of radioactive sources, called seeds, directly into the prostate gland, supplying a high dose of radiation to the cancer itself without disturbing nearby, unaffected tissues.
EXTERNAL-BEAM RADIATION THERAPY
This is the most common type of radiation performed to treat prostate cancer. External-beam radiation therapy focuses a beam of radiation on the area with the cancer.
Intensity-Modulated Radiation Therapy (IMRT)
This type of external-beam radiation therapy involves CT scans to form a three-dimensional picture of the prostate cancer before treatment, which is used to determine how much radiation is needed to destroy it. This way, high doses of radiation can be directed at the prostate without increasing the risk of damaging nearby organs.
Proton Therapy
Also called proton-beam radiation therapy, this type of external-beam radiation therapy destroys cancer cells with the use of protons (positively charged particles) rather than X-ray radiation, which can be more harmful to nearby organs.
HORMONE THERAPY
This mode of therapy relies on the removal or suppression of the male hormone, testosterone, which fuels the growth of prostate cancer. This can be accomplished either by removing the testicles (orchiectomy), or by injecting Lupron, a substance that suppresses testosterone. This treatment is generally used either prior to surgical removal of the prostate or to treat symptoms when the cancer is advanced.
CRYOTHERAPY
This type of treatment involves the use of freezing techniques to destroy the prostate. This is not a treatment for primary prostate cancer, but it is an option for treating recurrent prostate cancer, especially if radiation does not kill enough cancer cells.
CHEMOTHERAPY
Sometimes chemotherapy is used for prostate cancer, but not as much as it is used to treat other types of cancer.
IMMUNOTHERAPY
Researchers have long hoped to discover a cancer “vaccine” that would stimulate the immune system and, finally in 2010, the FDA approved the first one: sipuleucel (Provenge). This treatment is for men with prostate cancer that has spread but has not responded to hormone therapy and is causing few symptoms. Other types of immunological treatments for prostate cancer are currently in the testing stages.