Prognostic implications of signet ring cell histology in esophageal adenocarcinoma

Signet ring cell esophageal adenocarcinoma histology has been difficult to study in single institution series because of its relative rarity, yet has an anecdotal reputation for poor prognosis. The Surveillance, Epidemiology, and End Results (SEER) database was examined to assess the prognostic implications of this esophageal adenocarcinoma subtype.

All patients with esophageal adenocarcinoma in the SEER database from 2004 to 2009 were included. Univariate and multivariate analyses examining the relationship of signet ring cell histology with overall survival were performed in all patients, as well as those undergoing surgical resection.

A total of 596 of 11,825 (5%) study patients had signet ring cell histology. Patients with signet ring cell histology were similar in age, race, and sex distribution, but had a higher grade (P <  .001) and higher stage (P <  .001) at diagnosis. In both the all-patient group as well as those undergoing surgical resection, univariate analyses showed a worse survival in patients with signet ring cell esophageal cancer (hazard ratio [HR] = 1.24; 95% confidence interval [CI] = 1.13-1.36 and HR = 1.57; 95% CI = 1.29-1.93, respectively). In multivariate analyses adjusting for covariates, patients with signet ring cell cancer had a worse prognosis than those without (HR = 1.18; 95% CI = 1.07-1.30). In surgically resected patients, this remained a trend, but did not reach statistical significance (HR = 1.16; 95% CI = 0.94-1.42).

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.