Abstract 147P
Background
It remains inconclusive whether germline BRCA mutation affects the response of neoadjuvant systemic therapy in breast cancer. Here, we present a retrospective analysis which estimated the pathologic complete response (pCR) rate in breast cancer patients according to gBRCA1/2 mutation status.
Methods
We reviewed a total of 442 breast cancer patients who underwent gBRCA1/2 tests and received neoadjuvant chemotherapy in 2 institutions between 2001 and 2022. Chemotherapy response was compared between patients with or without deleterious BRCA1/2 mutation and we assessed the association of the pCR rate and clinical characteristics of the patients. For pCR rates, the ypT0/is ypN0 definition was used as a primary end point.
Results
We detected pathogenic BRCA1/2 mutations in 145 (32.8%) of the 442 patients, 83 (18.8%) in BRCA1 and 62 (14.0%) in BRCA2. Overall pCR rate was 34.6% (153/442). The pCR rate was 37.9% (55/145) and 33.0% (98/297) for gBRCA1/2 carriers and non-carriers, respectively. Germline BRCA1/2 mutation status, mutation type and locus were not significantly different from a pCR rate (OR:0.806, 95% CI=0.533-1.219, P =0.306). With respect to the demographic and clinicopathological characteristics, higher pCR rate observed in breast cancer with hormone-receptor negative (OR:2.845, 95%CI 1.791-4.520, p<0.001) and HER2 negative (OR:2.823, 95%CI=1.6-4.984, p<0.001) tumor and high ki-67 level (OR:2.165, 95%CI 1.347-3.480, p=0.001), irrespective of gBRCA1/2 mutation.
Conclusions
In this analysis, patients with gBRCA1/2 mutations showed no significantly different response in neoadjuvant systemic therapy. Further large-scale analysis with survival data may provide robust evidence on the impact of the gBRCA1/2 mutation status for breast cancer patients.
Legal entity responsible for the study
Eun-Shin Lee.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.