The study, conducted between 1988 and 1995, enrolled 473 men suffering from advanced stage prostate cancer. After the patients underwent surgery to remove their tumor, they were randomly split into two groups, one that was observed and one that immediately began receiving radiation therapy. Researchers found that the 213 patients undergoing radiation therapy had significantly improved five- and 10-year prostate cancer-free survival rates compared to their counterparts.
At both five and 10 years, radiation reduced the risk of recurrence by 25 percent. The adjuvant radiation also reduced the risk of the cancer spreading to other parts of the body and overall survival, but those differences were not statistically significant. In patients not cured by radiation, the treatment delayed the need for further treatments by four years.
"We have known for a long time that men who undergo surgery and are found to have cancer extending outside their prostate gland are at a very high risk for recurrence," said Gregory Swanson, M.D., a radiation oncologist for the Genitourinary Committee of the Southwest Oncology Group, which was the main sponsor of the study. "To see a 25 percent reduction in recurrence of any cancer is considered a major breakthrough as cancer doctors, we should be quite impressed. Prostate cancer patients clearly deserve a discussion with their physician about whether adding a course of radiation after surgery is right for them, their cancer and their lifestyle."
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Contact: Beth Bukata
American Society for Therapeutic Radiology and Oncology