A nomogram for predicting postoperative overall survival of patients with lung squamous cell carcinoma: a SEER-based study

Abstract

Background Lung squamous cell carcinoma (LSCC) is the most common histological subtype of all lung cancer. Although the overall prognosis of lung cancer has improved, the predictable nomogram model of LSCC has not improved significantly. Our study aimed to construct and validate a nomogram model and to predict overall survival (OS) for patients with LSCC undergoing surgical treatment. Methods A total of 8,078 patients identified to have LSCC between 2010 and 2015 were selected from the Surveillance, Epidemiology and End Results (SEER) database. They were further randomly divided into training and validation cohorts. Univariable and multivariable Cox regression analyses were used to identify the risk factors affecting the prognosis for constructing the nomogram. The discrimination and calibration of the established nomogram were evaluated using receiver operating characteristic (ROC) curve, area under ROC curve (AUC), and calibration plots. In addition, decision curve analysis (DCA) was performed to evaluate the clinical utility. Finally, we plotted Kaplan-Meier survival curves and developed risk stratification systems. Results Seven variables were selected to establish the nomogram for LSCC. The AUC value in the ROC curve analysis revealed 0.658, 0.651, and 0.647 in the training cohort and 0.673, 0.667, and 0.658 in the validation cohort at 1-, 2-, and 3-year survival, respectively. The calibration curves showed satisfactory consistencies between nomogram-predicted and observed survival probability at 1-, 2-, and 3- year OS in training and validation cohorts. The DCA curve showed the established nomogram had great clinical net benefit, indicating high clinical application value. In risk stratification systems, patients were divided into three risk groups: low risk (total points༜95), middle risk (95 ≤ total points༜143), high risk (total points ≥ 143). The Kaplan-Meier survival curves indicated that significant difference in OS were observed among the three groups (P༜0.001). Conclusions A prognostic nomogram for OS of LSCC patients after surgical treatment was developed and validated, which may assist clinicians in evaluating prognosis of and facilitate doctors to provide highly individualized therapy.