The effect of delays in cancer surgery due to the COVID-19 pandemic on cancer resectability and postoperative mortality in different tumor entities

Background: During the COVID-19 pandemic, prioritization of COVID-19 patients led to delays in oncological surgery, potentially impacting patient outcomes. This analysis examines the effects of surgical delays in various tumor entities on resectability and postoperative mortality. Methods: Data from the COVIDSurg Cancer Collaborative, an international prospective cohort study with 19,676 patients, collected between March 26, 2020, and September 16, 2020, were analyzed. Postoperative mortality and complete resection (R0) were the outcomes, with tumor entity, stage and delay to surgery as key exposures. Results: 17,486 patients underwent surgery during the study period, at a median time of three weeks after decision to operate (IQR = 4). 172 (1.0%) patients died within 30 days postoperatively. 15,143 (90.5%) patients had an R0 resection, 1352 (8.1%) an R1 resection and 230 (1.4%) had an R2 resection. Postoperative mortality was highest for oesophageal cancer (3.9%) and UICC stage IV (1.5%). For the overall population, there was no association between delay to surgery and resectability. There was an association between delay to surgery and postoperative mortality (p < 0.001), with the highest 30-day postoperative mortality observed for operations within two weeks following surgical decision. Conclusion: Tumor resectability and postoperative mortality in oncological surgeries are influenced by various factors. During the COVID-19 pandemic, moderate delays in surgeries were observed, with differences across tumor types, UICC stages and regions. While no tangible effects on resectability were found, postoperative mortality was higher after a shorter delay to surgery.