Abstract: Objective To correlate the efficacy of neo-adjuvant chemoradiotherapy in phase Ⅱ and Ⅲ rectal cancer patients with expression of Ku70，telomerase and hTERT proteins. Methods Expression levels of Ku70，telomerase and hTERT were analyzed by immunohistochemistry in rectal cancer patients who responded effectively to neoadjuvant chemoradiotherapy（XELOX regimen，n=27） and in patients in whom such therapy was ineffective（n=18）.Levels in the two groups were compared before and after neoadjuvant chemoradiotherapy. Results Expression of hTERT was significantly lower in patients who responded effectively to therapy than in those who did not（P<0.05）.The two patient groups showed similar expression of Ku70 and telomerase（P>0.05）.In each of the patient groups， expression levels of hTERT， telomerase and Ku70 differed significantly before and after chemoradiotherapy （P<0.05）.Efficacy of neoadjuvant chemoradiotherapy did not correlate with sex， age， pathological type or KPS score（P>0.05）. Conclusion Expression of hTERT in phase Ⅱ and Ⅲ rectal cancer patients may correlate with the efficacy of neoadjuvant chemotherapy combined with radiotherapy.

Key words:  Rectal neoplasm, Ku70, Telomerase, hTERT, Neoadjuvant chemoradiotherapy, Efficacy