EP312/#486 Comparison of HRD status before and after neoadjuvant chemotherapy in patients with advanced epithelial ovarian cancer

Abstract

<h3>Objectives</h3> Neoadjuvant chemotherapy (NACT) has been regarded as a standard treatment for those advanced epithelial ovarian cancer patients with massively disseminated tumors. The homologous recombination deficiency (HRD) status has guiding significance for the therapeutic selection of poly (ADP-ribose) polymerase (PARP) inhibitors. However, platinum may be mutagenic as a DNA cross-linker. So, the HRD status may change. Therefore, we analyze some clinical data to detect the change in HRD status before and after platinum-based NACT. <h3>Methods</h3> A total of 41 patients with advanced epithelial ovarian cancer for which biopsies were obtained before receiving NACT were enrolled. The BRCA mutation, HRD score, and HRD status of the paired samples of biopsy and surgery were tested by the AmoyDx® HRD-Focus panel. <h3>Results</h3> HRD status was defined as HRD positive for tumors with BRCA1/2 mutation or HRD scores ≥41. Before NACT, 10 patients were BRCA mutation-positive and 22 were HRD positive. While 9 patients were BRCA mutation-positive, 21 were HRD positive and 1 was not detected after NACT. There were 3 paired samples changed in BRCA mutation, and 2 of them were BRCA mutation-positive changed into BRCA mutation-negative. The other pair showed the opposite change. Among 10 paired samples of HRD status changed, HRD positive to negative accounts for half. <h3>Conclusions</h3> The HRD status of advanced epithelial ovarian cancer patients may be influenced by platinum-based chemotherapy. So, it should be detected by surgical sample after NACT.