Factors predicting long-term survival in colorectal cancer patients with a normal preoperative serum level of carcinoembryonic antigen.

purposeThe aim of this study was to determine which clinicopathological factors influenced the long-term survival after potentially curative resection of colorectal cancer patients with a normal preoperative serum level of carcinoembryonic antigen (CEA).

methodsA total of 1,732 patients who underwent curative surgery for primary nonmetastatic colorectal cancers from 1997 to 2009 were analyzed. Of these patients, 1,128 (65.1 %) had normal level of preoperative CEA (<5 ng/mL). The predicting factors for survival were analyzed.

resultsWhen the serum CEA cutoff value was set at 2.4 ng/mL (median value), the high CEA groups displayed a higher percentage of older patients, males, large-diameter tumors, advanced T and N categories, and positive perineural invasion, compared to the low CEA groups. Multivariate analysis revealed that age, T category, N category, number of lymph nodes retrieved, operative method, lymphovascular invasion, perineural invasion, postoperative chemotherapy, and preoperative serum CEA level ≥ 2.4 ng/mL were independent predictors for 5-year overall survival, while tumor location, tumor size, T category, N category, lymphovascular invasion, and perineural invasion were independent predictors for 5-year disease-free survival.

conclusionsEven if patients with colorectal cancer have a normal preoperative CEA before surgery, CEA may be useful for prognostic stratification using 2.4 ng/mL as the cutoff.