Histologic tumor type and the rate of complete response after neoadjuvant therapy for esophageal cancer.

A review of the literature demonstrated that clinical evaluation cannot be used to determine 'complete response'. The different classification systems of the histopathologic response grading after neoadjuvant radiochemotherapy of esophageal carcinoma are summarized in this report. A systematic review of studies analyzing preoperative chemoradiation of squamous cell carcinoma (SCC) or adenocarcinoma (AC) of the esophagus demonstrated no significant difference in pathologic complete response (pCR) rates between the AC and SCC studies. Analyzing only the applied dose of radiation demonstrated that patients with AC required a higher dose than patients with SCC to achieve complete response. Incorporating chemotherapy administration does not markedly change the difference in required radiation dose. However, when the tumor does respond, the rate of pCR with increasing dosage of chemoradiotherapy increases more rapidly in AC patients than in SCC patients.