Prostate cancer 101

Prostate cancer is the second most deadly cancer for men in North America next to lung cancer, yet it’s seldom diagnosed in other countries where men eat much less animal fat and more soy. A heart-healthy diet and life-style appear to prevent and slow prostate cancer. Cruciferous vegetables, such as broccoli, and lycopene found in cooked tomatoes may also be protective.

Studies are investigating the promising role of antioxidants such as selenium and vitamin E in preventing prostate cancer. Some supplements such as zinc and calcium can increase risk of prostate cancer if taken to excess yet may be useful in combating diseases such as osteoporosis and macular degeneration.

Get it checked
If early prostate cancer does not trigger symptoms, it may only be found during a checkup. More than 90 per cent of prostate cancers can be successfully treated if still confined to the gland, so finding the cancer before it spreads beyond the prostate to surrounding tissue, lymph nodes or bones of the hips and spine is critical. It’s especially important if the cancer is a dangerously aggressive type. Typically prostate cancer tends to be slow growing; the patientay succumb to another disease before the prostate cancer causes serious trouble.

The Canadian Cancer Society says men 50 and older should discuss the pros and cons of early detection methods with their doctors. Men of African descent and those with a strong family history of prostate cancer should do this at a younger age. The American Cancer Society recommends an annual prostate specific antigen (PSA) test and a digital rectal exam (DRE).

PSA is a protein secreted by prostate cells. It turns up in the blood in tiny amounts. Several prostate disorders can elevate blood PSA levels. PSA testing remains controversial: it can miss cancers or find cancers that don’t really need treatment, worrying patients needlessly. Some governments don’t pay for PSA screening tests, yet advocates say the test helps find prostate cancers at a potentially curable stage.

PSA velocity (an increase in PSA over a period of time), is more suggestive of prostate cancer than is a single PSA test.

Prostate cancers tend to form in the “peripheral zone” just inside the gland. During a DRE, the doctor’s gloved and lubricated finger feels the prostate through the rectum to estimate the gland’s size and consistency and to check for hard, discrete lumps that may indicate cancer. By doing this annually, the doctor can track changes that may be significant. Cancers in the prostate’s transition zone in its interior are harder to detect during a DRE, and tumours on the front of the prostate, where the doctor can’t reach, may be missed.

After an abnormal DRE or PSA, the doctor may order an ultrasound test to look at the prostate. Often, a biopsy harvesting several tiny samples of tissue is done at the same time to look for the presence of cancer cells.

Deciding what to do
Older men whose health indicates a life expectancy of less than 10 years and whose cancer appears slow-growing may simply be monitored using PSA tests and DREs, a process called “watchful waiting,” since surgical and radiation treatment risk urinary, bowel or sexual complications.

Younger men expected to live more than another 15 years and whose cancer hasn’t spread beyond the prostate have more options to discuss with their doctors. They include removing the entire prostate and surrounding tissues (radical prostatectomy), and radiation, which can be done from outside the body or with brachytherapy. The latter involves inserting tiny, radioactive seeds close to the tumour inside the prostate.

Reports in both the New England Journal of Medicine and the Journal of the American Medical Association indicate surgery may be the better option for men with a long life expectancy as it appears to be more effective in reducing the spread of prostate cancer later on. The JAMA study also followed men with low-grade tumours and found aggressive cancer appearing after 15 years.

Treatment for men whose cancer has spread to tissue outside the prostate includes drugs that counter testosterone, which stimulates the cancer. Side effects include risk of osteoporosis, anemia, diminished libido or hot flashes.

ConnectPLUS
Canadian Cancer Society: 416-488-5400 or 1-800-268-8874; www.cancer.ca

The Prostate Centre (Toronto’s Princess Margaret Hospital): 416-946-2100; www.prostatecentre.ca