[Multivariate analysis of clinicopathologic factors correlated with pathological complete response following preoperative radiotherapy in rectal adenocarcinoma].

Background and objective: Patients with locally advanced rectal cancer undergoing preoperative radiotherapy have disparity in pathological tumor regression. This study was to investigate clinicopathologic factors correlated with pathological complete response (pCR) following preoperative radiotherapy in rectal adenocarcinoma.

Methods: In total 132 patients with rectal adenocarcinoma received preoperative radiation from January 2002 to June 2008 at Sun Yat-sen University Cancer Center. Pathological tumor response after radiation was evaluated, and correlations of pCR to 12 clinicopathologic factors were analyzed using logistic regression method.

Results: A total of 18 patients achieved pCR after preoperative radiation, with a pCR rate of 13.6%. Univariate analysis showed that pretreatment T stage with or without concomitant chemotherapy, pretreatment serum CEA level, and CA199 level were correlated with pCR after preoperative radiation in rectal adenocarcinoma. Multivariate analysis revealed that pretreatment serum CEA level and with or without concomitant chemotherapy were independent factors for pCR after radiotherapy in rectal adenocarcinoma.

Conclusion: Patients undergoing preoperative radiochemotherapy with a low pretreatment serum CEA level were more likely to achieve pCR.