Histologic subtypes as determinants of outcome in esophageal carcinoma patients with pathologic complete response after preoperative chemoradiotherapy

BACKGROUND. The current study tested the hypothesis that the clinical outcome of patients with localized esophageal carcinoma after preoperative chemoradiotherapy (CTRT) depends on histology. METHODS. The authors stratified patients by adenocarcinoma (ACA) or squamous cell carcinoma (SCC) and compared the overall survival (OS) and patterns of failure among patients achieving pathologic complete response (pathCR) and < pathCR after preoperative CTRT. A correlation between baseline clinical stage and post-therapy pathologic response was made for ACA and SCC. RESULTS. Of the 235 patients who underwent preoperative CTRT, 42 (18%) had SCC and 193 (82%) had ACA. In the ACA group, 56 patients (29%) achieved a pathCR and in the SCC group 13 patients (31%) achieved a pathCR. In the ACA group, a larger proportion of pathCR patients (n = 44; 79%) than < pathCR patients (n = 82; 60%) were alive at the time of last follow-up (P = 0.01) and pathCR patients had a longer OS than < pathCR patients (P = 0.0006). However, in the SCC group OS or proportion alive did not differ significantly between pathCR and < pathCR patients (P ≥ 0.05). In the ACA group, a greater portion of < pathCR patients (32%) than pathCR patients (16%) had distant metastases (P = 0.02) and the distant metastases-free survival of pathCR patients was longer than that of < pathCR patients (P = 0.0012). In the SCC group, the proportion or time to distant-metastases did not differ significantly. Pretreatment clinical stage did not correlate with pathologic response for either histology. CONCLUSIONS. The results of the current study suggest that the clinical Biology of SCC and ACA is different after CTRT. An investigation of molecular and patient genetics is needed to improve therapy.