Gram-positive targeting antibiotics are associated with progression and death in women with platinum-sensitive recurrent high grade epithelial ovarian cancer

OBJECTIVE: To evaluate oncologic outcomes in women with recurrent platinum-sensitive ovarian cancer (OC) receiving antibiotics (ABX) during platinum-based chemotherapy. METHODS: A retrospective, single-institution cohort study was performed in women undergoing platinum chemotherapy for recurrent platinum-sensitive OC from 2009-2017. ABX for >48 hours, including anti-gram-positive antibiotics (G+ ABX), were recorded. The impact of ABX on time to second progression (PFS2), time to platinum resistance, and overall survival (OS) were assessed using univariate and multivariable Cox regression models. RESULTS: Of 261 women with recurrent platinum-sensitive OC, 80 (30.7%) received ABX during platinum chemotherapy, and 20 (7.7%) received G+ ABX. On univariate analysis for PFS2, there was no difference for ABX versus none (13.1 vs. 12.3 months: hazard ratio [HR]=1.23, 95% confidence interval [CI]=0.93-1.62, p=0.15), but this was decreased for G+ ABX versus none (10.2 vs. 12.3 months: HR=1.71; 95% CI=1.05-2.77; p=0.03). There was no difference in OS for ABX versus none (30.8 vs. 33.5 months: HR=1.01; 95% CI=0.73-1.39; p=0.97), but G+ ABX were associated with decreased OS compared to no ABX (26.4 vs. 33.4 months: HR=2.13; 95% CI=1.28-3.57; p=0.004) and other ABX (26.4 vs. 37.9 months: HR=2.43; 95% CI=1.34-4.41; p=0.003), respectively. On multivariable analysis, no ABX were associated with improved PFS2 (HR=0.54; 95% CI=0.33-0.88; p=0.014) and OS (HR=0.49; 95% CI=0.29-0.81; p=0.006) versus G+ ABX. CONCLUSION: This retrospective study of women with recurrent platinum-sensitive OC treatment with G+ ABX during platinum chemotherapy was associated with decreased PFS2 and OS.