Antibiotic bowel preparation prior to epithelial ovarian cancer surgery does not impact infectious or oncologic outcomes (494)

Abstract

<b>Objectives:</b> Antibiotic therapy has been associated with worse oncologic outcomes in women with epithelial ovarian cancer (EOC) receiving platinum chemotherapy. The objective of this study was to identify whether antibiotic bowel preparation impacts progressionfree survival (PFS) and overall survival (OS) in women with epithelial ovarian cancer (EOC). <b>Methods:</b> An IRB-approved, retrospective single-institution cohort study was performed in women who underwent cytoreductive surgery (CRS) for EOC from 2008 to 2017. Type of bowel preparation was defined as <i>1)</i> none, <i>2)</i> mechanical bowel preparation alone, or <i>3)</i> antibiotic with or without mechanical bowel preparation. Infectious wound outcomes were defined using Centers for Disease Control definitions: superficial incisional SSI, deep incisional SSI, and organ/ space infections. The impact of bowel preparation type upon incidence of SSI was assessed using univariate models. Cox regression was used to determine the impact of bowel preparation on progression-free survival (PFS) and overall survival (OS). <b>Results:</b> Of 560 women, 174 (31.1%) received no bowel preparation, 354 (63.2%) received mechanical bowel preparation, and 32 (5.7%) received antibiotic bowel preparation, either alone or in combination with mechanical bowel preparation. The superficial SSI rate was 12.6% (<i>n</i>=22), 10.2% (<i>n</i>=36), and 6.3% (<i>n</i>=2) for patients with no bowel preparation, mechanical bowel preparation and antibiotic bowel preparation, respectively (p=0.48). Similarly, there was no difference in pelvic or intra-abdominal abscess rate between the groups: 8.6% (<i>n</i>=15), 4.0% (<i>n</i>=14), and 3.1 % (<i>n</i>=1), respectively (p=0.069). On univariate analysis, there was no difference in PFS between no bowel preparation versus mechanical bowel preparation (17.5 vs 20.5 months, HR: 0.98, 95% CI: 0.79-1.20, p=0.82) or no bowel preparation versus antibiotics bowel preparation (17.5 vs 14.9 months; HR: 1.09, 95% CI: 0.70-1.69, p=0.70). Similarly, there was no statistically significant difference in OS between the three groups (60.9 months vs 54.3 months vs 48.0 months, p=0.30 and p=0.49, respectively). <b>Conclusions:</b> In women with EOC undergoing CRS, the type of bowel preparation does not impact infectious or oncologic outcomes. Given recent studies showing negative impacts of antibiotics on chemotherapy response in EOC, further investigation is needed to understand how timing and delivery of antibiotics may impact outcomes.