Serum CEA as a predictor for response to preoperative chemoradiation in rectal cancer

Abstract

[한글]

[영문]Recent data suggest that good responders to preoperative chemoradiation have favorable prognosis in rectal cancer patients. The aim of this study was to determine the predictive value of the selected clinicopathologic factor including serum carcinoembryonic antigen for response to preoperative chemoradiation.

Ninety five patients with rectal adenocarcinoma underwent preoperative radiation therapy and 5-FU based chemotherapy followed by curative resection. Pretreatment clinical stage was determined by endorectal ultrasound, abdominiopelvic computed tomography scan and

or magnetic resonance imaging. The outcome parameters were recurrences, 5-year cancer specific survival and 5-year disease free survival. Pretreatment clinicopathologic features including age, gender, location of tumor, cT classification, cN classification, and serum CEA level were investigated as possible predictive factors for response to preoperative chemoradiation.

A pathologic complete and near complete response occurred in 10 (11%) and 8 patients (8%), respectively. Partial or no response occurred in the remaining 77 (81%). Twenty one patients had recurrent disease. All of these patients were included in partial or no response group (100%), while no patients with complete or near complete response showed recurrence (P = 0.012). Patients with complete or near complete response had higher 5-year cancer specific survival (100% vs. 68.3%, P = 0.0478) and disease free survival (100% vs. 60.0%, P = 0.0134) than those with partial or no response. Univariate analysis revealed that cN classification and pretreatment serum CEA can predict for response to preoperative chemoradiation. Using logistic regression analysis, pretreatment serum CEA (≤ 5ng/mL vs. ＞5ng/mL) was the only predictor for response (Odd ratio = 3.32, Confidence interval = 0.97-10.14, P = 0.04).

Patients with complete or near complete response to preoperative chemoradiation showed favorable prognosis compared with partial or no response. Pretreatment serum CEA was found to be a predictor for response to preoperative chemoradiation in rectal adenocarcinoma.