Dr. Michael Zelefsky of Memorial Sloan Kettering Cancer Center talks with Prostatepedia about using radiation therapy if a man’s prostate cancer comes back after treatment. (Download Prostatepedia’s August issue to read the interview.)
After surgery, patients are generally followed. There is always a concern if we see
high-risk features after surgery that would put a patient at risk for the disease coming back. High-risk features could be positive margins or if the cancer breached the capsule or invaded the seminal vesicles.
We also ask if preventative radiation therapy, which is known as adjuvant radiation therapy, could be of benefit? Or would it be just as reasonable and logical to watch such patients? Should we treat a patient with radiation therapy if his PSA goes from zero to some level or he has a rising PSA level?
This is one of the most significant controversies in urologic oncology right now.
There are several important trials going on in the world that are trying address this very question. Is there a need for adjuvant radiation therapy? Or would early salvage radiation be acceptable? Can we delay the need to give these patients radiation? In general, when a patient’s PSA goes up after surgery, we consider radiation treatments to the prostate bed. That area could harbor microscopic cells. Frequently, patients who get radiation earlier, especially if they are at high risk for harboring microscopic cells in the prostate bed, can be successfully salvaged. Their PSAs could go down to zero once again. That is why close follow-up after surgery is necessary.
Of course there are many ongoing studies trying to figure out if hormonal therapy in the salvage radiotherapy setting could improve these results. Those studies are important. Hopefully, the results will become available in the near future. Radiation is also used in a recurrent setting when the disease comes back after radiation. The other option in that setting could be salvage prostatectomy, but many who do such salvage surgery procedures recognize that there is a risk of significant incontinence—from 25% to 50%.
More recently, we used seed implants to target the areas where the disease had come back based on careful imaging studies. For the last five years, we’ve been utilizing this so-called salvage brachytherapy in patients with what appears to be lower rates of incontinence. Results are comparable to what is achieved with salvage prostatectomy with lower risks of urinary incontinence.
Of course, there are other approaches such as salvage cryotherapy.
At Memorial Sloan Kettering, we are also treating patients in whom the disease has come back years later with salvage brachytherapy or salvage seeds. We tell patients that there is a risk of side effects when you add radiation on top of radiation. Fortunately, newer technologies to place seeds with image guidance and computer planning have significantly improved over the last number of years. This allows us to broaden radiation therapy options in the salvage setting.