Five-year survival decreases over time in patients with BRCA-mutated ovarian cancer: a systemic review and meta-analysis.

Introduction: Short-term survival rates of patients with BRCA-mutated ovarian cancer have been previously shown to be longer than those of non-carriers. We aimed to study the long-term survival rates of these patients and investigate whether the 5-year advantage decreases over time.

Methods: A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyzes (PRISMA) statement. The study protocol can be assessed at PROSPERO International prospective register of systematic reviews (http://www.crd.york.ac.uk/PROSPERO, registration number CRD42019137455). We considered for inclusion studies providing Kaplan-Meier survival curves up to and including 10 years, comparing patients with ovarian cancer with and without BRCA mutations. Our main outcome was the conditional probability of surviving an additional 5 years.

Results: A total of 13 references comprising 4565 patients was analyzed, of which 1131 BRCA1/2-mutated carriers and 3434 non-carriers were included. The expected higher 5-year survival rate in BRCA-mutated patients was observed (risk difference (RD)=14.9%, p=0.0002, risk ratio (RR)=1.36, p=0.001). Ten-year survival rates were comparatively less improved in BRCA-mutated patients (RD=8.6%, p=0.042, RR=1.25, p=0.12). After already surviving 5 years, no advantage in probability of further surviving 5 additional years was observed for the BRCA-mutated group (RD=2.9%, p=0.71, RR=0.97, p=0.78).

Conclusion: Our results provide insight into long-term survival rates and prognosis in patients with BRCA-mutated ovarian cancer which suggest that, despite the improved 5-year prognosis, the conditional probability of surviving an additional 5 years does not show the same advantage. The relatively low long-term advantage highlights the significance of epithelial ovarian cancer recurrence prevention. In the era of poly adenosine ribose inhibitors, future studies should explore the adequate follow-up and the benefit of a longer maintenance treatment phase, aiming to prolong the long-term survival of BRCA-mutated patients.