Short-Term Outcomes of Active Surveillance for Low Risk Prostate Cancer among Men with Germline DNA Repair Gene Mutations

Abstract

Purpose: Men with germline mutations in DNA repair genes have a higher risk of prostate cancer. Active surveillance is the preferred treatment modality for low risk prostate cancer. However, many fear offering this alternative to men with germline mutations. We describe the short-term oncologic outcomes of active surveillance in a population of men with a high genetic predisposition for prostate cancer.

Materials and methods: A prospective cohort of men with germline DNA repair gene mutations were diagnosed with Grade Group 1 prostate cancer. All men were offered active surveillance. Followup consisted of prostate specific antigen every 3 months, multiparametric magnetic resonance imaging and a magnetic resonance imaging-ultrasound fusion confirmatory biopsy within 1 year of diagnosis. The primary end points included treatment and progression-free survival.

Results: Eighteen carriers of DNA repair gene mutations were diagnosed with low risk prostate cancer (BRCA1 [8], BRCA2 [6], CHEK2 [2], Lynch syndrome [2]). Of these patients 15 (83%) initiated active surveillance and 3 (17%) declined. All but 1 were fully compliant with the active surveillance protocol (93%). Overall 20% (3) had upgrading at confirmatory biopsy and were treated. At a median followup of 28 months (IQR 8.5-42) 80% of patients (12) on active surveillance are free from upgrading or radical treatment.

Conclusions: Active surveillance may be feasible among carriers diagnosed with low risk prostate cancer. If embarking on active surveillance, carriers should be very carefully monitored at a specialized clinic, optimizing patient compliance and minimizing risk. Until larger scale studies with long-term followup become available, this option should be cautiously discussed with the patient.

Keywords: DNA repair; prostatic neoplasms; watchful waiting.