Does delaying surgery following induction chemotherapy compromise survival in patients with mesothelioma?

Objective: The ideal time interval between induction chemotherapy and surgery and the impact on cancer mortality in patients with mesothelioma remains unclear. Methods: We queried the National Cancer Database (2004-2017) for patients with favorable prognostic factors considered for surgery. Immediate surgery was performed within 3 months following the start of induction chemotherapy, while delayed surgery was defined as surgery performed later than 3 months. We compared both groups to those who did not have an operation despite being surgical candidates, as well as to those who were treated with surgery only. Overall mortality was assessed using Cox proportional hazard models adjusting for covariates. Results: A total of 4,294 patients were included, with the majority of patients undergoing induction chemotherapy followed by no surgery (3,370, 78%). The proportion of patients undergoing both immediate and delayed surgery increased over the last decade, but delayed surgery continued to be more common. There were no significant differences in baseline characteristics between the immediate and delayed surgery groups. Higher comorbidity scores were significantly associated with an increased risk of death on multivariable analysis, but the timing of surgery was not. This held true with a sensitivity analysis using 6 months as the definition of delayed surgery. Conclusions: This study shows that delaying surgery following induction chemotherapy does not compromise overall survival in patients with mesothelioma.