Signet Ring Cells in Esophageal Adenocarcinoma Predict Poor Response to Preoperative Chemoradiation

Background. The purpose of this study was to examine the significance of signet ring cell histology to predict response to preoperative chemoradiotherapy in patients with esophageal adenocarcinoma. Methods. Two groups of patients with locoregional esophageal adenocarcinoma treated with neoadjuvant chemoradiation and surgery were studied: those with signet ring cell adenocarcinoma (n = 85) and a reference group (n = 638) with usual and other types of adenocarcinoma. Surgical specimens were reviewed for degree of pathologic response and pathologic stage. Cox regression models were used to assess the effects of clinicopathologic variables on survival. Results. Tumors from patients in the signet ring cell group had a lower rate of complete pathologic response (9% versus 26%, p < 0.001) and more frequent positive margins (24% versus 10%, p < 0.001) compared with tumors from the reference group. Median overall survival (22 versus 48 months, p = 0.003) and disease-free survival (16 versus 35 months, p = 0.007) were shorter in the signet ring cell group than in the reference group. Signet ring cell histology and high pathologic stage were significant predictors of decreased overall survival and disease-free survival. Survival durations for patients whose resected specimens showed downstaging after neoadjuvant chemoradiation did not significantly differ from survival durations of patients whose specimens did not show downstaging in the signet ring cell group, unlike the reference group. Conclusions. Signet ring cell histology on pretreatment biopsy predicts a decreased likelihood of complete pathologic response and survival for patients with esophageal adenocarcinoma treated with preoperative chemoradiation and surgery. (C) 2014 by The Society of Thoracic Surgeons