Pulmonary mucinous epidermoid carcinoma (PMEC) is malignant and extremely rare. With only few case reports or small case series are reported, the prognosis of PMEC is not fully understood. In this study, we aimed to evaluate the prognostic factors of PMEC and to establish a prognostic nomogram model to predict its cancer-specific survival (CSS).
Within the Surveillance, Epidemiology, and End Results (SEER) Database from its inception to December 31, 2016, patients diagnosed with PMEC were retrospectively identified. Kaplan–Meier analysis and Cox regression were performed to evaluate the CSS stratified by different covariates. A predictive model of nomograms was conducted and the Concordance index (C-index) and calibration curves were used to validate the model.
A total of 585 PMEC patients are identified. The 5-, 10-, and 20-year CSS of stage I-II PMEC were 96.0%, 91.4%, and 88.9%, respectively. The 1-, 3-, 5-, and 10-year CSS of stage III-IV PMEC were 56.5%, 39.45%, 32.1%, 29.4%, respectively. The results of survival curves showed that patients with older ages, larger tumor sizes, bilateral tumors, poorer differentiation and higher stage of T, N and M aligned with poorer prognosis. Surgical treatment significantly improved the patients’ CSS (P < 0.001). But combined therapy didn't present better CSS results than surgery alone did. The multivariate COX results revealed that the covariates of age, bilateral tumor, tumor sizes, pathological differentiation grade, T stage, N stage, M stage and therapy were independent prognosis factors for PMEC. These factors were used to construct a nomogram. The C-index of the nomogram was 0.921. The calibration curve showed that favorable consistency between the predicted PMEC CSS and the actual observation. Validation of the nomogram was conducted with the validation cohort. The C-index of validation was 0.968, and the calibration curve showed favorable consistency.
Age, bilateral tumor, tumor sizes, pathological differentiation grade, T stage, N stage, M stage, and therapy were independent prognosis factors of PMEC patients. A nomogram on predicting the CSS of PMEC was first built and validated, showing its potential value in practice.
Lingxiao Qiu.
The National Natural Science Foundation of China (No.81874042).
All authors have declared no conflicts of interest.