[Clinical pathologic factors predicting tumor response after preoperative neoadjuvant therapy for rectal cancer]

To identify the clinical pathologic factors predicting tumor response of preoperative neoadjuvant therapy in patients with rectal cancer.

Seventy-nine patients with rectal cancer underwent neoadjuvant therapy before surgery from July 2000 to July 2009 were included in this study. Clinical pathologic factors were retrospectively analyzed to check the predicting effect of tumor response to the neoadjuvant therapy.Pathologic complete response (pCR) and T down-staging were the study endpoints.

Of the 79 patients, 10 cases (12.7%) got pCR after the neoadjuvant treatment. T down-staging was achieved in 41 patients (51.9%). The colonoscopy showed that the tumor occupied < or = 1/3 proportion of the bowel lumen in 22 patients, and 7 of them got pCR after the neoadjuvant therapy. Chi-square analysis showed that the proportion of tumor occupied in the bowel lumen was relevant to pCR rate (P < 0.05). Serum carcino-embryonic antigen (CEA) level was examined in 74 patients. Twenty-seven cases of the 46 patients with a serum CEA level < 5 microg/L got a T down-staging. Twenty-three cases of the 38 patients with a normal range of both serum CEA/CA19-9 levels got a T down-staging. Chi-square analysis showed normal range of both serum CEA/CA19-9 levels indicated better T down-staging.

It's defined some possible predictive factors for effects of neoadjuvant therapy in patients with rectal cancer. Particularly, patients with less tumor occupation of the bowel lumen and a serum CEA level < 5 microg/L seem to be more likely to get better clinical results.