Comparison of Long-Term Oncological Results in Young Women with Breast Cancer between BRCA-Mutation Carriers Versus Non-Carriers: How Tumor and Genetic Risk Factors Influence the Clinical Prognosis

Background: Breast cancer (BC) is very uncommon in young women (YW) and it is unclear whether a BRCA mutation has prognostic implications. Our aim was to evaluate the characteristics of YW with BC by comparing the long-term oncological results between BRCA-mutation carriers and non-carriers. Methods: We retrospectively reviewed all the consecutive YW (aged 18-40 years) diagnosed with BC. Endpoints were disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS). Results: 63 YW with a BRCA mutation were compared with 339 YW without BRCA mutation. BRCA-mutation carriers were younger (60.3% versus 34.8% if age = 35 years, p = 0.001) and presented with more aggressive tumors (66.7% versus 40.7% if G3, p = 0.001; 57.2% versus 12.4% if biological subtype triple-negative, p = 0.001; 73.0% versus 39.2% if Ki67 = 25%, p = 0.001). Non-carriers presented significantly better DFS, DDFS, and OS compared with BRCAmutation carriers. Neoadjuvant chemotherapy was found to be an independent protective factor for OS in BRCA-mutation carriers. Conclusions: BC is more likely to present at a younger age (= 35 years) and with more aggressive characteristics (G3, triple-negative, Ki67= 25%) in YW with BRCA mutation compared with their non-mutated counterparts. Young BRCA-mutation carriers showed a poorer prognosis in terms of recurrence and survival compared with non-carriers. The implementation of neoadjuvant chemotherapy may improve survival in YW with BC and BRCA mutation.