Comparison of Clinical Stage, Therapy Response, and Patient Outcome Between Squamous Cell Carcinoma and Adenocarcinoma of the Esophagus

Abstract

To analyze the differences in clinical stage, pathologic response to chemoradiotherapy, patterns of failure, and overall survival (OS) between patients with squamous cell carcinoma (SCC) and adenocarcinoma (ACA) of the esophagus. We stratified patients by two histologies, ACA and SCC, and statistically compared their clinical stage, post-therapy pathologic response, patterns of failure, and OS. Of the 235 patients who underwent preoperative chemoradiotherapy, 42 (18%) had SCC and 193 (82%) had ACA. Among the ACA patients, a significantly larger proportion was male (93% vs 7%; p <0.001), whereas sex was distributed similarly among SCC patients (55% male vs 45% female; p = 0.5). A significantly larger percentage of SCC patients were classified as lower TN and overall stage than ACA patients (T2 = 41% vs 28%, p <0.0001; N0 = 69% vs 48%, p = 0.01; stage II = 76% vs 55%, p <0.001). A significantly greater portion of SCCs was categorized as pathologic N0 after treatment (71% vs 65%; p = 0.02). Among the pathCR patients in clinical stage II, there were significantly greater proportion of SCC patients (77% vs 63%; p <0.001) than ACA patients. Among the pathCR patients in clinical stage III patients, a significantly greater proportion were ACA patients (38% vs 23%; p <0.001) than SCC patients. The median and 5-yr OS was 53 +/- 11 mo and 39% for ACA patients and 35 +/- 14 mo and 37% for SCC (median OS, p = 0.3). Among pathCR patients, median OS of ACA patients (133 mo) was longer than that of SCC patients but nonsignificant (29 mo; p = 0.07); results were similar for non-pathCR patients. DFS results were similar in all subgroups. Among the whole cohort, incidence of local-regional recurrence and distant metastases did not vary significantly. The median time to distant metastases did not vary significantly for pathCR and non-pathCR patients. We believe this is the first study that compares failure outcome of ACA and SCC patients with similar clinical stage after trimodality therapy. Our data suggest that significant differences in clinical stage and post-therapy pathologic stage exist between ACA and SCC. Frequent presence of malignant nodes in the resected specimens of ACA patients resulted in a shorter time-to-metastases suggesting that ACA patients need better systemic control.