Incidence and risk factors for surgical complications in breast and gynecologic cancer surgery: a retrospective observational study

Abstract

This dissertation evaluates perioperative morbidity following oncologic surgery in patients with breast cancer and gynecologic malignancies. The primary aim was to systematically analyze intraoperative complications by incidence and type and postoperative complications by incidence and severity, and to identify independent risk factors for both. A retrospective single-center cohort study was conducted at the Department of Gynecology, Medical University of Graz. Two patient cohorts were analyzed: a breast cancer cohort including 234 patients and a gynecologic oncology cohort comprising 127 patients who underwent a total of 175 surgical procedures. Postoperative complications were graded according to the Clavien–Dindo classification. Demographic, clinical, and procedure-related variables were assessed, and potential predictors of perioperative morbidity were evaluated using logistic regression analyses. In the breast cancer cohort, postoperative complications occurred in 44% of patients. The highest complication rates were observed after mastectomy with immediate breast reconstruction. Axillary surgery and surgical technique remained independent risk factors for postoperative complications. In the gynecologic oncology cohort, intraoperative complications occurred in 9.7% of procedures, while postoperative complications were observed in 14.9%. Increased surgical complexity, prolonged operating time, and perioperative blood transfusion were associated with a higher risk of complications. Overall, the findings demonstrate that procedural characteristics, particularly surgical extent and complexity, are the main determinants of perioperative morbidity in both breast and gynecologic oncology surgery, whereas patient- and tumor-related factors play a less prominent role. Standardized complication grading provides a reliable framework for perioperative risk assessment and supports informed surgical planning and quality assurance in oncologic care.

Date of Award	2026
Original language	English
Awarding Institution	Medical University Graz
Supervisor	Vesna Bjelic-Radisic (Supervisor), Thomas Gary (Supervisor) & Daniela Gold ehem Ulrich (Supervisor)