A post-surgery increase of PSA (usually three increases) is the definition for a prostate cancer recurrence. The best response after these increases is to radiate the prostate bed in hopes for stopping any stray cancer cells that had escaped prior to surgery. Using salvage radiation is the only remaining treatment modality that might allow a man to regain control the disease (sometimes referred to as a cure).
Deciding to have salvage radiation is not always an easy choice as radiation is thought to have its own toxicity issues. To evaluate how significant of these toxic effects really are there was just a study completed out of the Mayo Clinic. It is the largest single-institution study of the complications from post-surgery radiation to date. The study found few complications in prostate cancer patients treated with radiotherapy after surgery. The study will be published in the October issue of Radiotherapy and Oncology.
“There is a general fear of this kind of radiation treatment on the part of some patients and their physicians, but this study shows that it not only effectively eradicates the recurrent cancer in a substantial number of patients, but that there are few serious side effects,” says the study’s lead investigator, Jennifer Peterson, M.D., from the Department of Radiation Oncology at Mayo Clinic in Florida.
“It is really important that patients and their doctors watch PSA levels after a radical prostatectomy, which is a complete removal of the prostate,” she says. In men who have an intact prostate, a PSA test can indicate either an enlarged prostate gland or development of cancer in the prostate, says Dr. Peterson. “But in men without a prostate, a rising PSA level indicates that cancer has recurred. After a recurrence is detected, there is only a narrow window of time during which radiotherapy will be beneficial in controlling their cancer.”
This study was designed to document those side effects. It followed 308 men with a median follow-up of 60 months after salvage external beam radiotherapy. Only one man had a serious (grade 4) complication and three others had a less serious (grade 3) side effect. None of these effects was fatal, and all were treated. Milder side effects were seen in an additional 37 men, the researchers say, and all were successfully treated for these complications. Urinary leakage, a concern of many patients who choose not to use radiation, was not a common side effect of treatment.
Improved techniques in the administration of salvage external beam radiotherapy since the study began in 1987 likely would mean the rate of side effects today, compared to those in the study, would be much lower, said Dr. Buskirk. “We can do a better job today with delivering radiation precisely where we want to, while minimizing dose to surrounding normal tissues,” he says.
“In our experience at Mayo Clinic, the side effects of salvage radiotherapy in patients treated after a radical prostatectomy are minimal,” says Dr. Peterson. “Even more importantly, it is the only potential curative treatment possible in these patients once cancer has recurred.”
The Mayo Clinic funded this study
Joel T Nowak, MA, MSW