Clostridium difficile Colonization in Oncologic Patients Undergoing Major Abdominopelvic Surgery: To Treat or Not to Treat? An Observational Study with Propensity Score Analysis.

Background: Clostridium difficile colonization (CDC) represents a clinical concern in oncology patients undergoing abdominopelvic surgery, particularly regarding the potential role of prophylactic antibiotics in preventing progression to active infection. Methods: We performed a single-center, retrospective, case-matched observational study of oncology patients with CDC who underwent abdominopelvic surgery between 2018 and 2023. Patients were divided into two cohorts: those who received prophylactic antibiotics and those who did not. Postoperative outcomes were compared using propensity score matching (PSM). Logistic regression and ROC curve analysis were applied to assess the predictive value of antibiotics relative to other comorbidities. Results: Ninety patients were included (62 with antibiotics; 28 without). In the unmatched cohort, patients receiving antibiotics showed a non-significant trend toward higher morbidity (32.2% vs. 21.4%, p = 0.327) and surgical site infection rates (9.6% vs. 0%, p = 0.171). After PSM (26 patients per group), morbidity remained comparable between cohorts (30.7% vs. 23.0%, p = 0.538). Notably, no patient developed active C. difficile infection during follow-up, regardless of antibiotic use. Antibiotic therapy was not an independent predictor of postoperative morbidity (OR 1.746, p = 0.297; AUC 0.549, 95% CI 0.405-0.687). Conclusions: In this study, prophylactic antibiotic use in CDC patients undergoing abdominopelvic oncology surgery was not associated with improved postoperative outcomes. While no progression to active infection was observed, the potential benefits of prophylaxis remain uncertain. Larger, prospective studies are needed to clarify the clinical role of antibiotics in this setting.