Published online Oct 26, 2021. doi: 10.12998/wjcc.v9.i30.9011
Peer-review started: March 4, 2021
First decision: June 3, 2021
Revised: June 19, 2021
Accepted: August 18, 2021
Article in press: August 18, 2021
Published online: October 26, 2021
Processing time: 231 Days and 0.4 Hours
Primary small cell carcinoma of the esophagus (PSCE) is a rare tumor, accounting for 0.05% to 3.1% of all esophageal malignancies and approximately 2% of extrapulmonary small cell carcinomas. PSCE patients seem to have earlier metastasis and a worse prognosis than those with esophageal squamous cell carcinoma, which requires a more accurate prognostic prediction model.
Several previous studies have reported the prognostic factors for PSCE with controversial results, partly due to their small sample size. To date, only one nomogram has been used to predict the overall survival probability for PSCE patients in the United States. In addition, the model did not include relevant neuroendocrine markers.
The present study aimed to build a prognostic predictive nomogram model including clinicopathological factors and neuroendocrine biomarkers for Chinese PSCE patients. It was also determined whether the nomogram model can predict overall survival (OS) more accurately than the 7th tumor-node-metastasis (TNM) staging system.
The nomogram was based on a retrospective study of 256 PSCE patients, derived from our esophageal and gastric cardia carcinoma database including 500000 cases (1973-2015), established by State Key Laboratory of Esophageal Cancer Prevention and Treatment and Henan Key Laboratory for Esophageal Cancer Research of the First Affiliated Hospital of Zhengzhou University in Henan, China. The predictive accuracy and discriminative ability of the nomogram were determined by the concordance index (C-index), calibration plot, and decision curve analysis (DCA), and the results were also compared with the 7th TNM staging.
The final nomogram model included histology type, age, tumor invasion depth, lymph node invasion, distant metastases, chromogranin A, and neuronal cell adhesion molecule 56. The C-index of the model had a prognostic superiority over the 7th edition TNM staging system in both the primary cohort [0.659 (95%CI: 0.607-0.712) vs 0.591 (95%CI: 0.517-0.666), P = 0.033] and the validation cohort [0.700 (95%CI: 0.622-0.778) vs 0.605 (95%CI: 0.490-0.721), P = 0.041]. Good calibration curves were observed for the prediction probabilities of 1-, 3- and 5-year OS in the primary and validation cohorts. DCA analysis showed that our nomogram model had a higher overall net benefit than the 7th TNM staging.
We have developed and validated a nomogram for predicting 1-year, 3-year, and 5-year OS in Chinese PSCE patients. The new nomogram classifies patients into different risk subgroups and shows a superiority of survival prediction over the 7th TNM staging.
The nomogram model can be used to predict the survival probability of PSCE patients, which might help clinicians to make individualized prognosis predictions and give better treatment recommendations for PSCE patients in China.