Does diabetes mellitus influence pathologic complete response and tumor downstaging after neoadjuvant chemoradiation for esophageal and gastroesophageal cancer? A two-institution report.

BACKGROUND Esophageal carcinoma is an aggressive disease that is often treated with neoadjuvant therapy followed by surgical resection. Diabetes mellitus (DM) has been associated with reduced efficacy of chemoradiation (CRT) in other gastrointestinal cancers. The goal of this study was to determine if DM affects response to neoadjuvant CRT in the management of gastroesophageal carcinoma. METHODS We retrospectively reviewed the esophageal cancer patient databases and subsequently analyzed those patients who received neoadjuvant CRT followed by surgical resection at two institutions, Thomas Jefferson University (TJUH) and Fox Chase Cancer Center (FCCC). Comparative analyses of rates of pathologic complete response rate (pCR) and pathologic downstaging in DM patients versus non-DM patients was performed. RESULTS Two hundred sixty patients were included in the study; 36 patients had DM and 224 were non-diabetics. The average age of the patients was 61 years (range 24-84 years). The overall pCR was 26%. The pCR rate was 19% and 27% for patients with DM and without DM, respectively (P = 0.31). Pathologic downstaging occurred in 39% of study patients, including of 33% of DM patients and 40% of non-DM patients (P = 0.42). CONCLUSIONS Although the current analysis does not demonstrate a significant reduction in pCR rates or pathologic downstaging in patients with DM, the observed trend suggests that a potential difference may be observed with a larger patient population. Further studies are warranted to evaluate the influence of DM on the effectiveness of neoadjuvant CRT in esophageal cancer.