Last Modified: January 13, 2008
Dear OncoLink "Ask The Experts,"
I am 59 years old, and just diagnosed with prostate cancer (T1c, Gleason 6). The surgeon recommended a prostatectomy, partly because he says that with radiation treatment, a second cancer may occur in 15-25 years, perhaps due to exposure to the exposure to radiation. He stated that the success rate between surgery and radiation are about the same over 5-10 years, but the risk [of recurrence] after 15 years is more for radiation. Could you comment on this, please?
Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:
There are no good, randomized clinical trials comparing surgery and radiation therapy for prostate cancer. This makes any comparison of these two treatments speculative, at best. We also do not have data using PSA as a measure at 15 to 25 years after treatment with modern techniques. For example, Dr. Patrick Walsh only described the nerve-sparing prostatectomy in 60 patients about 20 years go, and even then, this technique was not generally adopted until about 12-14 years ago. Similarly, 3-D conformal radiation has only been around for 15 years, and IMRT (intensity-modulated radiation therapy) for only 8 years. We know that radiation dose is an issue in prostate cancer, and the "adequate" dose of 78 Gy has only been used for 5 years in major centers, and still is not generally available in the community. There is also the problem that most men are biopsied by an urologist who likely operates on the men he/she wants to operate on, sending the rest of the patients to radiation. Which means comparisons of treatments are not likely to involve truly comparable patients. In the best hands, the results that can be achieved are probably very similar, if not equal. There is no data to suggest that radiation is better than surgery, while many surgeons assert that surgery is better than radiation, with no data to back it up.
It really comes down to two things: the skill of the practitioner and the patient's peace of mind. The surgical risk of incontinence varies from 1% to 50%, and the risk of impotence is anywhere from 35% to 100%. Some of this is surgical skill, and some is definition of the terms “incontinence” and “impotence”. For instance, one study reports 50% of the men were wearing pads for incontinence all of the time. Of the other 50%, some may need pads occasionally, but were not considered by the study authors to be incontinent in the reported results. Similarly, some people say a man wearing 1 pad a day but not soaking it is still continent, while others say if you are wearing a pad at all, you are not continent by definition. Similarly, some surgeons say that men are not potent unless they can have an erection and complete intercourse with no mechanical or pharmacological aids, while others say that if you respond to medications, you are potent. You need to ask your doctor what the risks of incontinence and impotence are, and also what their definitions are for these specific complications. Another factor is that a doctor who does more than 200 radical prostatectomies a year is much less likely to experience complications than one who does 50 or fewer in a year.
As far as peace of mind is an issue:
As for the risk of secondary colon and rectal cancers years down the road, there is no good data to support this. We do not have long enough follow up with current techniques, such as 3D and IMRT. Some reviews have shown a higher risk of colorectal cancer, but the risk is equally high for tumors in the radiation field as it is for those out of the field, so this may just reflect an increased risk of colorectal cancer in men with prostate cancer, and not a radiation effect. Also, the older a person is, the more likely they are to get colorectal tumors, so age may also have a part in it.
As a 55-year-old man, I check my PSA regularly, and I have picked out a surgeon if it ever goes up. In his hands, the risk of incontinence is 1% and the risk of impotence is 35%, using the strictest of definitions. When I turn 60, the risk of incontinence rises to 4% and impotence is 50%, and at that point I would choose radiation. My surgeon says that when he is 70 and the risk of incontinence is 12% and impotence is 90% with surgery, he too would choose radiation. We both believe in what we do, and we think we do it well. I don't think there is a wrong answer from a medical standpoint, and would recommend you pick what you feel comfortable with. Talking to a radiation oncologist may be helpful, but if they start telling you the other guy doesn't know what he is doing, you need to find two new doctors.