New study findings suggest there is no “favorable” subset of patients with intermediate-risk prostate cancer (PCa) likely to benefit from active surveillance (AS).
In a retrospective cohort study, the rate of adverse findings was 24.7% among patients with low-volume intermediate-risk (LVIR) disease compared with 5.8% and 4.7% for those with low-risk (LR) and very-low-risk (VLR) disease, respectively, Hiten D. Patel, MD, MPH, and colleagues at Johns Hopkins University School of Medicine in Baltimore reported in JAMA Oncology. Men with LVIR had a 4.5-fold greater risk of adverse pathologic findings compared with men who had LR disease and 5.1-fold greater risk compared with those who had VLR disease.
The study included 1264 men with clinically localized VLR, 4849 with LR cancer, and 608 with LVIR as defined by National Comprehensive Cancer Center (NCCN) criteria: Gleason pattern 3+4, T2a-b, 1-2 positive cores, and PSA below 20 ng/mL. Of the 150 LVIR patients with adverse pathologic findings at RP, 141 (94%) were upgraded to at least Gleason 4+3 PCa or Gleason Group (GG) 3. Just a few had the other pre-specified features: seminal vesicle invasion or positive lymph nodes. Age, race, family history of PCa, and cancer volume did not appear to play a role in outcomes. Results held when analyses were repeated using updated patient numbers in the various risk categories.
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Among 508 men with LVIR men (83.6%) who met all LR criteria other than biopsy grade, 108 (21.3%) were found to harbor adverse pathologic findings. Of the 271 men with LVIR (44.6%) who met all VLR criteria beside biopsy grade, 50 (18.5%) demonstrated adverse surgical pathologic findings.
According to current NCCN guidelines, some LVIR patients may consider AS, but the practice is controversial.
“Our observations suggest use of AS 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,” Dr Patel and colleagues wrote. “This study could have important implications for men with LVIR prostate cancer electing AS, and further study is clearly needed.”
The team attempted additional risk stratification of the LVIR group using preoperative clinical and pathologic criteria, but none defined a favorable subgroup with rates of adverse pathologic findings as low as those of VLR and LR patients. According to multivariate analysis, PSA density predicted adverse pathologic findings, but Gleason score had the greatest impact.
Lack of magnetic resonance imaging and molecular and/or genetic test results prevented additional risk stratification of patients, which was a study limitation.
“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,” Dr Patel and colleagues noted .
Reference
Patel HD, Tosoian JJ, Ballentine Carter H, Epstein JI. Adverse Pathologic Findings for Men Electing Immediate Radical Prostatectomy Defining a Favorable Intermediate-Risk Group. JAMA Oncol. doi:10.1001/jamaoncol.2017.1879 [Epub July 13, 2017].
