A novel risk stratification system for primary small-cell carcinoma of the esophagus: indication for prognostication and staging.

Background: Primary small cell carcinoma of the oesophagus (PSCCE) is a gastrointestinal tumour of rare onset. The current study was to investigate the role of a novel risk stratification system (RSS) for PSCCE.

Methods: The study included patients with PSCCE attending any of five medical institutions in China in 2008-2021, four of which served as a training set (n = 422) for construction of the RSS while the other served as a separate cohort (n = 256) for validation of the model. The RSS was established based on covariates associated with overall survival (OS) with a two-sided -value of < 0.05 in multivariable regression. Survival discrimination of RSS was assessed.

Results: In the training cohort, multivariate regression analysis revealed age, Eastern Cooperative Oncology Group score, and initial lymph node metastasis to be independent prognostic factors for OS in non-distant metastatic PESCC; concurrent hepatic metastasis was the only significant predictor of distant metastatic PESCC. Accordingly, the RSS was developed and could classify patients into four subgroups: low-risk localized disease (LLD, defined as non-distant metastasis PESCC without risk factors, n = 58); high-risk localized disease (HLD, defined as non-distant metastasis PESCC with ≥ 1 risk factor, n = 199); low-risk metastatic disease (LMD, defined as metastatic PESCC without concomitant liver metastases, n = 103); and high-risk metastatic disease (HMD, definded as metastatic disease with synchronous liver metastases, n = 63). Three-year OS rates were 52.5%, 29.5%, 14.4%, and 5.7% for LLD, HLD, LMD, and HMD, respectively. When compared with the tumor-node-metastasis (TNM) system, RSS showed a consistently superior ability to predict OS in both the training and validation cohorts.

Conclusion: The RSS is a reliable stratification model that could be used to optimize treatment for PESCC.