Development and validation of a prognostic nomogram for patients with laryngeal cancer with synchronous or metachronous lung cancer

The objective of this study was to examine the independent prognostic factors of laryngeal cancer with synchronous or metachronous lung cancer (LCSMLC), and to generate and verify a clinical prediction model.In this study, laryngeal cancer alone and LCSMLC were defined using the Surveillance, Epidemiology, and End Results (SEER) database. Risk factors of patients with LCSMLC were analyzed through univariate and multivariate logistic regression analysis. Independent prognostic factors were selected by Cox regression analyses, on the basis of which a nomogram was constructed using R code. Kaplan-Meier survival analyses were applied to test the application of a risk stratification system. Finally, we conducted a comparison of the American Joint Committee on Cancer (AJCC) staging system of laryngeal cancer with the new model of nomogram and risk stratification. For further validation of the nomogram, data from patients at two Chinese independent institutions were also analyzed.According to the eligibility criteria, 32 429 patients with laryngeal cancer alone and 641 patients with LCSMLC from the SEER database (the training cohort) and additional 61 patients from two Chinese independent institutions (the external validation cohort) were included for final analyses. Compared with patients with laryngeal cancer who did not have synchronous or metachronous lung cancer, age, sex, race, primary site of laryngeal cancer, grade, and stage were risk factors for LCSMLC, while marriage, surgery, radiation therapy, and chemotherapy are not their risk factors. Age, two cancers' interval, pathological type, stage, surgery, radiation, primary lung site, and primary throat site were independent prognostic predictors of LCSMLC. The risk stratification system of high-, medium-, and low-risk groups significantly distinguished the prognosis in different patients with LCSMLC, regardless of the training cohort or the validation cohort. Compared with the 6th AJCC TNM stage of laryngeal cancer, the new model of nomogram and risk stratification showed an improved net benefit.Age, sex, race, primary site of laryngeal cancer, grade, and stage were risk factors for LCSMLC. An individualized clinical prognostic predictive model by nomogram was generated and validated, which showed superior prediction ability for LCSMLC.