Histopathological response after preoperative radiochemotherapy in rectal carcinoma is associated with improved overall survival

BACKGROUND: Recent studies showed improved local control after preoperative radiochemotherapy (RCTX) in patients with locally advanced rectal carcinoma, but failed to demonstrate a survival benefit. Our aims were to determine outcome and impact of histopathological response after preoperative RCTX. METHODS: One hundred four patients with uT3 rectal carcinoma were treated with preoperative RCTX of 45 Gy and continuous 5-FU infusion between 1997 and 2001 (group I). Histopathological response was evaluated in all specimens after tumor resection. Group II consisted of 114 patients with uT3 rectal carcinoma treated with postoperative RCTX between 1988 and 1997. RESULTS: Group I showed a 6.1% 5-year local recurrence rate compared to 15.3% in group II (P = 0.023). Overall survival rates did not differ significantly between both groups (P = 0.225). Histopathological responders had a significantly improved 5-year overall survival with 89.1 (7.8)% compared to 68.7 (6.7)% of the non-responders (P = 0.008) and were identified as an independent prognostic factor. CONCLUSIONS: Significant improvement of overall survival was observed for histopathological tumor responders after neoadjuvant radiochemotherapy. Our protocol of preoperative radiochemotherapy confirms the results of the multi-center studies in regard to local control and overall survival.