Men presenting with aggressive prostate cancer - Gleason Score of 9 or 10 - comprise most of those who will die from prostate cancer worldwide, and despite surgical removal of the prostate (radical prostatectomy), their cancer will recur more than 80 percent of the time.

In a new multinational study of 639 men with a Gleason Score of 9 or 10, researchers at Brigham and Women's Hospital investigated how treatment with surgery plus the appropriate use of post-operative, low-dose radiation and hormone therapy, before cancer recurrence, fared as an option for these men.

They found that death from prostate cancer within five years following this option or the standard option of high dose radiation and hormone therapy was less than 10 percent likely as compared to 22 percent with surgery alone.

Results published today in JAMA Oncology suggest post-operative radiation and hormone therapy, before cancer recurrence, as a new prostate cancer treatment option for men with a Gleason Score of 9 or 10.

"In many cases when cancer recurs, radiation and hormone therapy are recommended, but our findings indicate that the best survival outcomes can be achieved by implementing these therapies directly after surgery and not waiting for the cancer to recur," said Anthony Victor D'Amico, MD, PhD, chief, Genitourinary Radiation Oncology at the Brigham. "While more than 75 percent of men in this study had risk factors for recurrence following surgery for which radiation and hormone therapy could have been recommended, only one-third received those treatments."

A prior study showed that the risk of death is much higher when surgery alone is performed, compared to the risk following the standard treatment option of high dose radiation and hormone therapy.

D'Amico points out that the lack of use of radiation and hormone therapy following surgery for men with Gleason Score 9 or 10 prostate cancer is largely due to concern about overtreatment.

"However, overtreatment in this population with aggressive and advanced prostate cancer is very unlikely given that prostate cancer will recur in at least 80 percent of these men within five years of surgery and require radiation or hormone therapy at that time," D'Amico said.

Researchers note additional study is needed to determine whether treating these men with post-operative low-dose radiation and hormone therapy before cancer recurrence can produce the low prostate cancer death observed in the study.

Given that no randomized trials are available to answer this question specifically for men with Gleason Score 9 or 10 prostate cancer, this is the only evidence to date supporting this new treatment option.

Source: Brigham and Women's Hospital