Dr. Robert Nam is head of genitourinary cancer care at Sunnybrook Research Institute in Toronto. As Dan Hill’s doctor, he worked with him to decide what would be an appropriate treatment for his prostate cancer. (In the April 16 issue of Maclean’s, singer-songwriter Dan Hill penned a candid and moving account of what it’s really like to be diagnosed with prostate cancer.) Here, Dr. Nam provides a summary of prostate cancer—what it is, how it is diagnosed and various treatment options. Dr. Nam also outlines how Hill came to decide what approach would be best for him.
What is prostate cancer?
Prostate cancer is the most common male cancer and is the third leading cause of cancer death for males. It is estimated that the lifetime risk for developing prostate cancer for men in North America is one in six. Researchers have made significant progress in understanding how to better diagnose and treat prostate cancer. The majority of men (85 per cent) who are diagnosed with prostate cancer have it contained within the gland. Patients with this early stage prostate cancer have the highest chance of being cured with treatment, compared to patients with cancer that has spread to other parts of the body or metastasized. Early detection is due to the widespread use of a blood test that measures the concentration of a protein called prostate specific antigen (PSA).
What is PSA or prostate specific antigen?
PSA is exclusively produced by the prostate gland and it plays an important role in male reproductive functions. The cells that produce PSA within the prostate gland are also the most common cell type that can turn into cancer cells, which correspondingly will increase PSA production. Thus, patients who develop prostate cancer will have a rise in blood levels of PSA. This observation has led to the use of the PSA test to screen healthy men for the presence of early stage prostate cancer. Recently, there has been a large amount of controversy as to whether it is worth performing the PSA screening test.
Although PSA can identify patients with early stage prostate cancer, it cannot distinguish which types of prostate cancer are the most aggressive and lethal. There is a wide spectrum of aggressiveness of prostate cancer cells—some forms are indolent and do not shorten a man’s natural lifespan, while others are very aggressive, spread quickly and can significantly shorten survival. The indolent forms do not require any treatment and men will often die with the disease, rather than from the disease. The aggressive forms require radical treatment as soon as possible. Radical treatment includes surgical removal or the delivery of radiation to the prostate gland. These treatments are not without their side effects, which can include problems with urinary control and sexual function. Thus, many experts argue that if the PSA test cannot distinguish between men with indolent and lethal forms of prostate cancer, a large proportion of men with indolent disease would undergo unnecessary treatment. On the other hand, proponents for PSA screening argue that a large, well-conducted clinical trial from Europe did show a benefit in improving survival in men who underwent a PSA screening test compared to men who did not. Also, the side effects of contemporary surgical or radiation treatments have been greatly reduced and a large proportion of men have excellent quality of life following treatment. Although the PSA test may detect indolent forms that could lead to overtreatment in some men, it would not be appropriate to miss the patients with aggressive forms of prostate cancer that could be cured.
Prostate cancer risk factors
Recently, researchers have taken a more selective and individualized approach. Rather than solely relying on the PSA test, prostate cancer risk calculators have been developed that incorporate other risk factors and markers for prostate cancer to estimate an individual’s risk for not only having prostate cancer, but also the aggressive forms. Factors such as age, ethnic background and having a blood-related family member affected with prostate cancer can influence the risk for developing prostate cancer. The older a man gets, the higher the risk for developing prostate cancer. Men of African ancestry have the highest risk, while Asian men have the lowest. Men with one or more close family members such as a father, brother or uncle who have been diagnosed with prostate cancer also have an increased risk.
Prostate cancer risk calculator
We have developed a comprehensive prostate cancer risk calculator (www.prostaterisk.ca) that incorporates these factors and others in addition to PSA. These factors can better estimate a given individual’s real risk for having prostate cancer that cannot be appreciated by using the PSA test alone. The goal is to try to reduce finding the indolent, non-aggressive forms of prostate cancer, while increasing the detection rate of patients with the aggressive and lethal forms. Experts continue to debate this issue and the risks and benefits of cancer screening should be carefully discussed between the patient and physician.
For Dan Hill, his PSA level was 4.8 ng/mL. To some experts, this level may not be considered abnormal and some would not recommend a prostate biopsy. However, our prostate cancer risk calculator estimated his risk for having any cancer was 27 per cent to 43 per cent and, more importantly, his risk for aggressive cancer was 12 per cent to 23 per cent. Dan’s risk had to be calculated within a range of probabilities because his father was of African ancestry and his mother was of Caucasian descent. The lower risk was based on being Caucasian and the higher risk was based on an African ancestry—a clear example of how ethnic background can alter the risk for prostate cancer. Each person will react differently to these risk factors. For Dan, even a risk of 12 per cent was worrisome and his risk tolerance was very low. As such, he wanted to proceed to undergo a prostate biopsy.
Prostate cancer biopsy
Once the decision has been made to undergo prostate cancer screening and a high risk for having prostate cancer is determined, patients will need to undergo a prostate biopsy to confirm the presence (or absence) of prostate cancer. The only current method is by examining prostate tissue under the microscope to look for the presence of cancer cells. The procedure involves inserting an ultrasound probe into the rectum, and needles are inserted through the rectal wall and into the prostate gland, which is positioned right in front of the rectum. Only local anaesthesia is required and the procedure takes 10 minutes to perform. Patients require antibiotics and a bowel cleanser to minimize the development of infection. It is important to emphasize the actual rates of serious infections are low (less than one per cent to four per cent) and should not deter patients from undergoing a prostate biopsy.
In Dan’s case, he has a history of diabetes, but he is also a very fit 57-year-old who runs 10 miles almost every day. Despite his increased risk for infection, we did not need to take any special precautions or use different antibiotic regimens for his prostate biopsy due to his general good health and well-managed diabetes. His prostate biopsy was performed without significant discomfort and no complications occurred. Within 72 hours at our Rapid Prostate Biopsy Clinic, we had our answer—prostate cancer.
Diagnosis of prostate cancer
When faced with a diagnosis of prostate cancer, it is important to understand that the natural course of prostate cancer progression—from being confined to the prostate gland to growing outside and spreading—can take an average of 10 years. Compared to other cancers, it is generally a slow-growing tumour, although there are some types that can grow very quickly. One of the best measures of aggressiveness is a scale called the Gleason Score. It is a measure of how aggressive the cancer cells appear under the microscope and is determined by a pathologist. The scale ranges from five to 10. The higher the number, the more aggressive the prostate cancer—five is the least aggressive and 10 is the most. That is not to say that patients with a Gleason Score of six or less do not have aggressive forms of prostate cancer. Patients need to have an in-depth discussion with their prostate cancer specialist. In Dan’s case, his Gleason Score was seven out of 10, an aggressive form of cancer, as predicted by our Prostate Cancer Risk Calculator.
Treatment options for prostate cancer Active surveillance
The treatment options for patients with prostate cancer confined to the prostate gland primarily consist of surgery, radiation or watchful waiting. Recently, the term watchful waiting has been changed to active surveillance. Watchful waiting refers to not providing any treatment and only providing treatment when symptoms arise or if prostate cancer spreads to other areas in the body. (It is hoped that it will never spread and patients will die from other causes.) Active surveillance differs to watchful waiting in that patients will be closely and regularly monitored to look for signs of prostate cancer growth—by using the PSA test and by performing prostate biopsies. If and when progression of the cancer is determined, patients would then undergo surgery or radiation treatment. The obvious advantage is that a significant proportion of men would be saved many years of reduced quality of life from the side effects of treatment or even never undergoing any treatment. The disadvantage is that by the time it is determined that the cancer has progressed, it may have reduced the chances for cure or have already spread beyond the prostate gland. Current monitoring with PSA and prostate biopsies may not be sufficient to accurately assess how fast prostate cancer may grow, and a proportion of patients may have missed their window of opportunity for cure.
Radical prostatectomy vs. radiation treatment
If treatment is decided to be undertaken, the patient has an opportunity to decide between surgery, called radical prostatectomy, or radiation treatment. Both treatment approaches are equally effective in cancer control. Thus, it becomes a personal decision as to which treatment would be the most appropriate. At the very least, patients need to seek out both a surgical opinion from a urologist who specializes in cancer surgery and a radiation opinion from a radiation oncology specialist, in order to make a well-informed decision. Other factors will also need to be considered, such as age and health conditions. The advantage of undergoing surgery is that we have the benefit of analyzing the cancer (because it has been removed), and we will be able to precisely determine if the cancer has spread beyond the prostate gland. If the cancer is more aggressive or it returns at a later time, we can then provide radiation treatment to maximize the chances for cure. Whereas for patients who choose radiation treatment, if the cancer returns, surgery often cannot be performed due to the collateral damage that is caused by the effects of radiation. The advantage of the radiation treatment, however, is that it is not as invasive as surgery, and the complications related to urinary control function and sexual function occurs less frequently compared to patients who undergo surgery. In most cases, the ultimate decision for treatment will be left with the patient, and it is important to have a detailed discussion with each specialist to weigh the pros and cons of each treatment.
For Dan, based on his Gleason Score of seven out of 10 and other parameters, I recommended that watchful waiting or active surveillance would not be suitable for him. After a detailed discussion with me and with a radiation oncologist, he ultimately chose to undergo surgery. Dan was still very young for patients with prostate cancer. Younger patients have leaned toward undergoing surgery because historically the effectiveness of radiation may not be as durable beyond 20 years after treatment, although newer techniques may prove to be more effective.
In general, patients only need to stay overnight after surgery, which takes two hours. For Dan, we planned to keep him for two days in the hospital to ensure that his diabetes and his blood sugars would be stable before he went home. The surgery went very smoothly with very little blood loss. He had had a tube inside his bladder called a catheter that was removed about 10 days later and then he was on his way to recovery.
Dan’s pathology report showed that the cancer was a Gleason Score seven out of 10 and was confined within the prostate gland with no evidence of spread. All the edges (called margins) were also clear of cancer. As such, he did not need to undergo radiation treatment after surgery. He now has the best chance for a cure.