New Histopathological & Genetic Features to Improve Active Surveillance Selection for Low-Risk Prostate Cancer.

BACKGROUND: A recent surge in biomarkers to aid management of men with prostate cancer has occurred. Their applications are varied and not all tests are applicable to the active surveillance setting.

OBJECTIVE: To review primary evidence on genetic and immunohistochemical biomarkers, and their role on patient selection and risk stratification for men on active surveillance for prostate cancer.

EVIDENCE ACQUISITION: A PubMed electronic search using the terms (biomarker or genetic or histopathological) AND ("prostate cancer" AND "active surveillance") was performed from inception to April 2015.

EVIDENCE SYNTHESIS: Of the biomarkers reviewed, Prostate Health Index (PHI) and Oncotype DX Genomic Prostate Score (GPS), were identified to currently hold greatest potential benefit to aid risk stratification of men for AS. Higher PHI, at baseline and during follow-up, was shown to predict pathological upgrading at rebiopsy at two single institutions, but with small cohorts (n<200). The Oncotype DX GPS test has been validated on men suitable for AS but having upfront radical prostatectomy. Increase in GPS was shown to predict upgrading and upstaging at radical prostatectomy and biochemical recurrence post radical prostatectomy. Prospective validation in AS cohorts is yet to be performed.

CONCLUSIONS: PHI and Oncotype DX GPS show promise in aiding risk stratification for men on AS. However, larger prospective studies in AS cohorts are needed. Integration of biomarkers with existing clinical and imaging models remains a challenge.