Survival predictors associated with signet ring cell carcinoma of the esophagus (SRCCE): A population-based retrospective cohort study

PURPOSE: Signet ring cell carcinoma of the esophagus (SRCCE) is an uncommon tumor associated with significant morbidity and mortality. There is still no consensus regarding cut-off values for tumor size, age and optimal treatment for SRCCE. Thus, we elucidated the current survival outcomes of patients with SRCCE and analyzed factors associated with prognosis. METHODS: A retrospective cohort study based on the SEER (The Surveillance, Epidemiology, and End Results) program database was conducted. We identified 537 patients (461 men and 76 women) newly diagnosed with SRCCE between January 2004 and December 2014. A multivariate Cox proportional hazards model was utilized to measure the mortality-associated risk factors in patients with SRCCE after adjusting for various variables. RESULTS: The 1-, 2- and 5-year disease-specific mortalities (DSM) were 51.6%, 67.6%, and 78.4%, respectively, and the median survival time was 12.0 months. The factors correlated with mortality hazard were marital status (unmarried versus married, Hazard Ratio (HR) = 1.443), tumor size (≥ 5 cm versus < 5 cm, HR = 1.444), tumor grade (high grade versus low grade, HR = 3.001), condition of primary tumor (T4 versus T1, HR = 2.178), regional lymph node metastasis (N1 versus N0, HR = 1.739), further metastasis (M1 versus M0, HR = 1.951) and chemotherapy (receiving chemotherapy versus no chemotherapy, HR = 0.464). CONCLUSIONS: The contemporary 5-year DSM was 78.4%. Being unmarried, having a tumor size ≥ 5 cm, a high tumor grade, a score of T4 for tumor invasion of adjacent organs, a score of N1 for regional lymph node metastasis, a score of M1 for distant metastasis and no chemotherapy were independent predictors of high DSM.