How Much Delay Matters? How Time to Treatment Impacts Overall Survival in Early Stage Lung Cancer

OBJECTIVES To identify drivers of time from diagnosis to treatment (TTT) of surgically resected early stage non-small cell lung cancer (NSCLC) and determine the effect of TTT on post-resection survival. SUMMARY BACKGROUND DATA Large database studies that lack relevant comorbidity data have identified longer TTT as a driver of worse overall survival. METHODS From 1/1/2014-4/1/2018, 599 patients underwent lung resection for clinical stage I and II NSCLC. Random forest classification, regression, and survival were used to estimate likelihood of TTT=0 (tissue diagnosis obtained at surgery), > 0 (diagnosis obtained pre-resection), and effect of TTT on all-cause mortality. RESULTS Patients with TTT > 0 (n=413) had median TTT of 42 days [25-75th percentile: 27-59 days]. Patients with TTT=0 (n=186) had smaller tumors and higher percent predicted forced expiratory volume in one second (FEV1%). Patients with history of stroke, oncology consultation, invasive mediastinal staging, low and high extremes of FEV1% had longer TTT. Higher clinical stage, lack of preoperative stress test, anemia, older age, lower FEV1% and diffusion lung capacity, larger tumor size, and longer TTT were the most important predictors of all-cause mortality. One- and five-year overall survival decreased when TTT was longer than 50 days. CONCLUSION Preoperative physiologic workup and multidisciplinary evaluation were the predominant drivers of longer TTT. Patients with TTT=0 have more favorable presentation and should be considered in TTT analyses for early stage lung cancer populations. The time needed to clinically stage and optimize patients for resection is not deleterious to overall survival until resection is performed after 50 days from diagnosis.