I’ve written before about the controversies in screening for and treating prostate cancer.
Prostate cancer presents a unique challenge because it is extremely common, affects men who on average are older than patients with other cancers, and usually takes many years between diagnosis and disability or death. In 2007, approximately 1 in 6 men in the United States were diagnosed with prostate cancer, and 1 in 34 died of it. The median age at diagnosis was 68 years, older than that for any other cancer. Because prostate cancer strikes men whose life expectancy is usually limited by age or by other diseases, it has been difficult to prove that screening for prostate cancer saves lives, or that any treatment for it is better in terms of survival than any other.
Last week’s New England Journal of Medicine had a very useful review of treatment options for localized prostate cancer (that is cancer that has not spread beyond the capsule of the prostate). Treatment decisions are based on the following factors: the patient’s age, life-expectancy, Gleason score (microscopic appearance of the cancer), the PSA (prostate-specific antigen, a blood test used to screen for prostate cancer), and the clinical stage (roughly related to the estimated volume of the tumor).
Expectant management, also called active surveillance, involves frequent re-evaluation of the PSA, the digital rectal exam, and prostate biopsies with the hope of detecting progression of the cancer when it is still curable. This strategy is thought to be appropriate either for men who have a life expectancy of less than 10 years, or for healthy men 65 or older with low-volume low-grade prostate cancer. Some small studies suggest that this strategy is no worse for survival than the other two, and it is much less invasive.
Radiation therapy offers the promise of a potential cure of the cancer with treatment that is somewhat less invasive than surgery. New technological improvements have made it possible to better spare normal surrounding tissues while targeting the radiation to the prostate. Nevertheless 40 to 60% of patients suffer impotence and 18% have rectal bleeding requiring transfusion or invasive intervention. (Expectant management sounds better now. Right?)
Surgery is thought by some to be the most likely to be curative (again, without much evidence). The complications, however, include urinary incontinence (3% of patients) and impotence (30% of patients in the hands of the most experienced surgeons).
What is truly startling, however, is that there are no studies to help patients definitively choose the right treatment option. Treatment options of millions of men are made largely with well-intentioned hunches. Three large randomized trials are in progress to answer if screening and treatment for prostate cancer saves any lives. We may have some answers when two of the trials reach completion five years from now.
In the meantime, patients who opt for radiation should use centers with extensive experience and with beam shaping technology that minimizes injury to surrounding tissues. Similarly, patients choosing surgery should be referred to surgeons with extensive experience in radical prostatectomy.
And, in my opinion, patients should receive guidance from an oncologist experienced in prostate cancer treatment, an experienced urologist, and a radiation oncologist, before making any decision.