Comparative analysis of clinical, treatment, and survival characteristics of signet ring cell and adenocarcinoma of esophagus.

Abstract

Signet ring cell carcinoma (SRC) is a rare pathological subtype of mucinous adenocarcinoma (AC). Clinical features, prognosis, and especially treatment methods between SRC and AC of the esophagus remain controversial. Thus, we conducted this study to explore the differences in clinicopathological characteristics and treatment modalities between SRC and AC of the esophagus. A retrospective cohort study based on the Surveillance, Epidemiology, and End Results (SEER) program database was conducted. Patients diagnosed with SRC or AC not otherwise specified (NOS) were selected between 2004 and 2018. We investigated the prognosis of SRC and AC in terms of overall survival (OS). A subgroup analysis was performed according to the stage and different treatment methods. A total of 24,987 patients were enrolled, including 1,147 with SRC and 23,840 with AC. In the multivariate Cox analysis of the whole cohort, SRC, tumor site, differentiation, metastases, American Joint Committee on Cancer (AJCC) 6th edition staging, treatment, tumor size, lymph nodes examined, and positive lymph nodes were independent risk factors. The results of the subgroup analysis showed that surgery alone was associated with better OS for AC at the early stage, but was not significantly different for SRC (P=0.896). Surgery plus adjuvant therapy was the best treatment for SRC and AC at the late stage. In the multivariate Cox analysis, the treatment of surgery plus adjuvant therapy had a tendency towards better OS at the early stage [hazard ratio (HR): 0.64, 95% confidence interval (CI): 0.39-1.1, P=0.08]. SRC is an independent risk factor, with a higher grade of differentiation, later stage, larger tumor size, more positive lymph nodes, and poorer prognosis compared with AC. Surgery plus adjuvant therapy seems to be useful for SRC at the early stage, but further research is needed.