Posted: Aug 04, 2016
Dr. Michael Zelefsky, a radiation oncologist, is Professor of Radiation Oncology, Chief of the Brachytherapy Service, and co-leader of the Genitourinary Disease Management Team at Memorial Sloan Kettering Cancer Center in New York City.
Prostatepedia spoke with him about the pros and cons of radiation therapy versus surgery in terms of cancer control and side effects. (Download Prostatepedia’s August issue to read the interview.)
Radiation therapy and surgery represent excellent treatment options and treatment interventions for prostate cancer. In general, when you look at the disease stage or aggressiveness level, it seems to provide equal outcomes for the treatment groups. I think there has been a significant change in thinking over the last five years in terms of the management of prostate cancer. Recommendations are based upon the initial risk group of the patient. A risk group is defined as the initial PSA level, the biopsy Gleason score, and the stage of the cancer based on rectal examinations.
More recently, we are provided with much more detailed information about the extent of the disease from MRIs and some of the new types of MRIs. This new technology has given us a much more detailed view of what is going on in the prostate.
Based on these risk groups, physicians now are better able to categorize and characterize the disease to make appropriate recommendations. Over the last number of years, I think especially at our institution, those patients who are known to have low-risk disease— that is those with PSA levels less than 10 and Gleason scores of 6 and below, without any significant volume of disease based on the biopsy— are recommended to undergo active surveillance. We encourage patients to go on active surveillance because their quality of life may be better in the long run than if they chose intervention for a disease considered biologically indolent and non-aggressive.
When it comes to men with intermediate-risk disease, or cancers with somewhat more aggressive features, then radiation and surgery are two really excellent options. Getting back to your particular question, those are the situations where patients have to make really complex and difficult decisions about treatment selection. I feel these decisions should be based more on their own preferences about quality of life. You can achieve similar results and cure rates with appropriate radiation dose levels, with hormonal therapy or without depending on the individual case, and these results are comparable to surgical outcomes.
Ultimately, a patient has to make a decision about what is better for him. There are clear advantages to radiation and advantages to surgery. For instance, there are lower risks in general for urinary incontinence with radiation-based approaches. There is really no major invasiveness associated with radiation-based procedures. It’s not a major operation. That may be very suitable for a patient who has underlying heart-related issues or other medical-related issues that could pose a challenge for the body to undergo a major procedure. Leaving those considerations aside, there are some people who prefer to avoid an operation and would rather go with less invasive approaches.
The disadvantages of radiation are that there is a higher chance for urinary bother or irritation symptoms, which translate into frequent urination or urgency. Some of those symptoms persist for a number of months, but they could persist even well beyond that and even require certain medications. Although the urinary control is excellent, there may be more frequent urination issues at night or during the day. There is also sometimes rectal bleeding or the like. Fortunately, with newer technologies and carefully-delivered radiation treatments, the likelihood of rectal, bladder, or bowel injury is nowadays less than 1%. Then, of course, there is sexual dysfunction. It appears that the risk or odds of sexual dysfunction after surgery or radiation is the same. Overall, there is about a 25% or 30% risk of loss of erection, which very often can be helped with medications like Viagra or Cialis. But this risk depends on many other factors, such as the baseline sexual function of the patient, age, and whether there are other medical issues present like heart disease or diabetes.
Dr. Zelefsky: While immediately after surgery, there could be erectile dysfunction, which could improve, there is certainly a percentage of patients in whom improvements are not seen. They are left with erectile dysfunction. In my experience, the odds of having erectile dysfunction after surgery or radiation are pretty similar. I counsel patients that in both cases, either surgery or radiation, an individual needs to expect that there is a possibility of permanent loss of erections.
We’ve done some important studies in this area: in a randomized trial of 200 patients getting radiation, we gave some Viagra as a prophylactic to improve blood flow and others a placebo drug. The group who received the prophylactic Viagra (sildenafil) had better sexual function after two years compared to the group who did not have Viagra. This concept, known as penile rehabilitation, is well known among patients who undergo surgery. Many patients at Memorial Sloan Kettering who undergo surgery are advised to take medications like Viagra or Cialis (tadalafil) on a regular basis after the procedure.
Dr. Zelefsky: Given the way our study was conducted with radiation patients, we recommend that they initiate these medications before radiation begins, continue during radiation, and for at least six months to a year after radiation has completed. As far as the pros and cons of radiation versus surgery, I think overall in terms of cancer control, if the appropriate forms of radiation are given with great attention to the quality and accuracy of the therapy, the success rates will be similar.
There are different side effect profiles: more urinary incontinence with surgery compared to radiation, while on the other hand, radiation has more urinary bother symptoms. Sexual dysfunction is still an issue for both of these treatments. Fortunately, rectal side effects such as rectal bleeding have been significantly reduced in recent years, which we could attribute to more accurate delivery of the radiation beam.