Micrograph showing prostatic acinar adenocarcinoma (the most common form of prostate cancer) Credit: Wikipedia, CC BY-SA 3.0

Monitoring prostate cancer (PC) by active surveillance (AS), with the expectation to initiate treatment if the cancer progresses, is a preferred initial option for men with low-risk PC and a life expectancy of at least 10 years. According to the results of a new study conducted at Brigham and Women's Hospital (BWH), there is evidence to also support AS as an initial approach for men with favorable intermediate-risk of PC (men with no evidence of the cancer spreading beyond the prostate, a Gleason score of 3+4 or less and PSA, prostate-specific antigen, under 20). These findings are published online by JAMA Oncology.

"We found that men with favorable intermediate-risk prostate cancer did not have significantly increased risks of death compared to men with ," said Ann Caroline Raldow, MD, first author of the study and resident physician at BWH and the Harvard Radiation Oncology Program. "The clinical significance of our findings is that men with favorable intermediate-risk prostate cancer may also be able to avoid, or at least defer the side effects of, , and enter an active surveillance program as an initial approach."

Researchers estimated and compared the risk of PC-specific mortality (PCSM) and all-cause mortality (ACM) following brachytherapy, a high dose radiation treatment, among men with low-risk and favorable intermediate-risk PC in a prospective cohort study of 5,580 men (median age 68 years) at the Prostate Cancer Foundation of Chicago between 1997 and 2013. Men with favorable intermediate-risk PC, who had no more than half of all prostate biopsies containing PC, were included in the study and were treated with alone.

The researchers found that men with favorable intermediate-risk did not have significantly increased risk of PCSM and ACM when compared to men with low-risk PC after a median follow up of 7.69 years. Additionally, the absolute estimates of PCSM were less than one percent in men with low-risk and favorable intermediate-risk PC, sugggesting that men with favorable intermediate-risk PC may also be candidates for active surveillance.

To date, no direct comparison has been made between favorable intermediate-risk and low-risk with respect to PCSM or ACM following brachytherapy.

"While awating the results of ProtecT, a randomized trial comparing with treatment, our findings provide evidence to support a discussion of AS as an initial approach to men with favorable intermediate-risk PC," said Anthony Victor D'Amico, MD, PhD, senior author of the study and chief, BWH Genitourinary Radiation Oncology.