Active surveillance may expose men with intermediate-risk prostate cancer to adverse outcomes that could be avoided by immediate intervention, according to the findings of a large cohort study.

The study, “Adverse Pathologic Findings for Men Electing Immediate Radical Prostatectomy,” was published in the journal JAMA Oncology.

Active surveillance is currently recommended to patients with very-low-risk (VLR) and low-risk (LR) prostate cancer. But more recent clinical guidelines have suggested that active surveillance also may be considered in men with low-volume intermediate-risk (LVIR) disease, a decision that remains controversial.

In active surveillance, patients do not undergo immediate radical treatment, which includes surgery or radiation therapy. Instead, they are monitored carefully over time for signs of disease progression.

Now, researchers at Johns Hopkins University School of Medicine performed a retrospective cohort study and compared the rate of signs of disease among VLR, LR, and LVIR men undergoing radical prostatectomy and evaluated retrospectively at Johns Hopkins Hospital.

Specifically, researchers asked, “Is there a subset of men with Gleason 3+4=7 intermediate-risk prostate cancer with favorable characteristics to minimize risk of adverse pathologic findings at surgery?”

In total, the study included 1,264 men with clinically localized VLR, 4,849 with LR, and 608 with LVIR, as defined by National Comprehensive Cancer Center (NCCN) criteria.

Researchers found that the rate of adverse pathologic findings was significantly higher for LVIR disease when compared to those with LR or VLR disease, at 24.7%, 5.8%, and 4.7%, respectively.

This means that men with LVIR had almost a 4.5-fold increase in the risk of adverse pathologic findings compared with men who had LR disease, and a 5.2-fold increase compared with men with VLR disease.

According to current NCCN guidelines, some LVIR patients may consider active surveillance, but the practice is controversial.

“Our observations suggest use of active surveillance may place similar men with Gleason 3+4=7 (GG2) cancer at risk of adverse outcomes that could have potentially been avoided with immediate intervention. This study could have important implications for men with LVIR prostate cancer electing [active surveillance], and further study is clearly needed,” researchers wrote.

In an attempt to stratify the risk of the LVIR group, researchers analyzed both preoperative clinical and pathologic criteria. However, none of these could define a favorable subgroup within the LVIR group with a rate of adverse pathologic findings as low as those of VLR and LR patients.

Overall, these results do not support the presence of a “favorable” subgroup among men with intermediate-risk prostate cancer.

“Men with Gleason 3+4=7 prostate cancer otherwise eligible for curative intervention should be fully informed as to the avoidable risk associated with use of active surveillance,” the study concluded.