It is a simple case of cause and effect. As more American men live longer, more cases of prostate cancer will be diagnosed. For older men diagnosed with the disease in its early stages, the question becomes whether to treat the cancer aggressively or whether to wait and see if it progresses, a process known as watchful waiting. Conventional wisdom has held that treatment is not required because early stage prostate cancer grows so slowly that these men will most likely die from other causes. A new study challenges this accepted belief -- its results suggesting that older men who receive treatment for their prostate cancer live longer than those who do not.
Prostate Cancer 101
The widespread use of prostate-specific antigen (PSA) screening has been accompanied by an increase in the number of men diagnosed with early stage prostate cancer (defined as organ-confined, or well or moderately differentiated disease). The American Cancer Society estimates that there were approximately 234,000 new cases of prostate cancer diagnosed last year in the US, with approximately 27,400 men dying from the disease. However, not all prostate cancers are equally aggressive. When a man is diagnosed, his disease is categorized into one of several clinical stages. Treatment is designed to either cure the disease or slow its progression depending on the staging of the individual's disease. Based on the characteristics of the cancer, physicians may alternatively recommend that they watch the cancer closely and defer treatment for the time being. If during this watchful waiting the disease becomes more active, physicians may recommend treatment.
The Study and its Results
The study, published in the December 2006 issue of the Journal of the American Medical Association, analyzed data from 44,630 men aged 65 to 80 who were diagnosed from 1991 to 1999 with early stage prostate cancer. Of these men, about 32,000 received either surgery or radiation therapy for their prostate cancer, while about 12,600 opted for watchful waiting. (Those receiving only hormonal therapy were excluded from the study.)
The results from the observational, non-randomized trial indicated that at the end of the 12-year study 37 percent of men in the watchful waiting category had died compared with 23.8 percent of those in the treatment category -- a 31 percent lower death rate for those receiving treatment. The reduction in the death rate for men who received treatment for their prostate cancer also applied to the sub-group of men in the study aged 75 to 80, who saw a 27 percent reduction. (These death-rate percentages include all causes of death.)
Experts Counsel Caution
However, doctors caution that the study, which only assessed patient records and not the patients themselves, may have missed other explanations for the reduction in the death rate. Randomized, controlled trials are still needed to definitively prove whether or not the potential gains of treatment outweigh its complications -- which can include erectile dysfunction, urinary incontinence, and bowel problems. Two large clinical trials that seek to directly compare treatment with watchful waiting are now being conducted, and their results are expected within the next three years. In the interim, the specific condition and overall health of each patient, especially those 75 and older, should be carefully assessed before making treatment decisions.
