Prognostic implications of signet ring cell histology in esophageal adenocarcinoma: A SEER database analysis

4067 Background: Signet ring cell esophageal adenocarcinoma histology has been difficult to study in a single institution series because of its relative rarity, yet has an anecdotal reputation for poor prognosis. We examined the Surveillance Epidemiology and End Results (SEER) database to assess the prognostic implications of this esophageal adenocarcinoma subtype. Methods: All patients with esophageal adenocarcinoma in the SEER database from 2004 – 2009 were included. Characteristics of patients with signet ring cell histology were compared to those without it. Univariate and multivariate analyses examining the relationship of signet ring cell histology with overall survival (censored at 72 months) were performed in all patients, as well as those undergoing surgical resection. Results: 597 of 11,838 (5%) study patients had signet ring cell histology. Patients with signet ring cell histology were similar in age, race, and gender distribution, but had a higher grade (p<0.001) and higher stage (p<0.001) at diagnosis. In both all-comers as well as those undergoing surgical resection, univariate analyses showed a worse survival in patients with signet ring cell esophageal cancer (HR = 1.24; 95% CI 1.13-1.37 and HR = 1.57; 95% CI 1.29-1.92 respectively). In multivariate analyses adjusting for age, gender, grade, stage, and race, patients with signet ring cell cancer had a worse prognosis than those with non-signet ring cell adenocarcinoma (HR = 1.20; 95% CI 1.09 -1.33). In surgically resected patients, this remained a trend, but did not reach statistical significance (HR = 1.16; 95% CI 0.94-1.42). Conclusions: This large study of esophageal adenocarcinoma confirms the clinical impression that signet ring cell variant of adenocarcinoma is associated with an advanced stage at presentation and a worse prognosis independent of stage of presentation.