Nomogram Predicting the Prognosis of Patients with Surgically Resected Stage IA Non-small Cell Lung Cancer

The American Joint Committee on Cancer (AJCC) 8th stage system was limited in accuracy for predicting prognosis of stage IA non-small cell lung cancer (NSCLC) patients. This study aimed to establish and validate two nomograms that predict overall survival (OS) and lung cancer-specific survival (LCSS) in surgically resected stage IA NSCLC patients. Postoperative patients with stage IA NSCLC in SEER database between 2004 and 2015 were examined. Survival and clinical information according to the inclusion and exclusion criteria were collected. All patients were randomly divided into the training cohort and validation cohort with a ratio of 7:3. Independent prognosis factors were evaluated using univariate and multivariate Cox regression analyses, and predictive nomogram was established based on these factors. Nomogram performance was measured using the C-index, calibration plots, and DCA. Patients were grouped by quartiles of nomogram scores and survival curves were plotted by Kaplan-Meier analysis. In total, 33,533 patients were included in the study. The nomogram contained 12 prognostic factors in OS and 10 prognostic factors in LCSS. In the validation set, the C-index was 0.652 for predicting OS and 0.651 for predicting LCSS. The calibration curves for the nomogram-predicted probability of OS and LCSS showed good agreement between the actual observation and nomogram prediction. DCA indicated that the clinical value of the nomograms were higher than AJCC 8th stage for predicting OS and LCSS. Nomogram scores related risk stratification revealed statistically significant difference which have better discrimination than AJCC 8th stage. The nomogram can accurately predict OS and LCSS in surgically resected patients with stage IA NSCLC.