Tumor volume doubling time as a potential predictor of prognosis in clinical stage I lung squamous cell carcinoma

Background: Tumor volume doubling time (VDT) has been shown to predict prognosis in various nonsmall cell lung carcinoma with scant evidence for lung squamous cell carcinoma (SCC). The purpose of this study was to investigate the prognostic value of tumor VDT in resected lung SCCs. Methods: In this study, subjects were 51 patients who underwent lobectomy for clinical stage I SCC of the peripheral lung at our institution between January 2006 and April 2020. Univariable and multivariable analyses of overall survival (OS) and recurrence-free survival (RFS) were performed using the Cox proportional hazards model. The Kaplan-Meier method was used to create OS and RFS curves and to determine statistical significance. The cut-off value of VDT was defined by receiver operating characteristic (ROC) curve analysis on survival. Results: Multivariable analysis found only VDT (HR, 0.990; 95% CI: 0.979-0.997) to be an independent predictor of OS. Also, only VDT (HR, 0.989; 95% CI: 0.978-0.995) was an independent predictor of RFS. The 5-year OS rates were 88.4% and 30.4% in the long (>_150 days) and short (<150 days) VDT groups, respectively (P=0.002). The 5-year RFS rates were 88.8% and 26.5% in the long (>_150 days) and short Conclusions: Tumor VDT was found to be a useful prognostic predictor in clinical stage I lung SCC in this study.