To investigate the prognostic value of preoperative serum carcinoembryonic antigen (CEA) combined with peripheral platelet count (PLT) in colorectal cancer patients.

From January 2010 to May 2012, clinical-pathological data of two hundred and ninety-seven colorectal cancer patients treated in the Third Affiliated Hospital of Sun Yat-sen University who finished 5 years’ follow-up were analyzed retrospectively. The risk factors of CEA positive (CEA≥5 μg/L) and PLT positive (PLT≥350×10⁹/L) were judged by Chi-square test. The survival analysis with Kaplan-Meier regression and COX regression were done to investigate the prognostic value of CEA and PLT in colorectal cancer.

(1) Positivity of preoperative serum CEA was significantly related to vascular cancer embolus, nerve invasion, the depth of invasion, lymph node metastasis, distant metastasis and TNM stages (χ²=5.743, 5.699, 10.308, 15.543, 43.537, 21.199, P=0.017, 0.017, 0.028, <0.01, <0.01, <0.01), while gender, age, the size of tumor, tumor position, the depth of invasion and distant metastasis were significantly related to PLT positivity (χ²=13.409, 7.749, 8.496, 7.324, 9.295, 9.196, P<0.01, 0.005, 0.014, 0.007, 0.038, 0.002). (2) Survival analysis found that positive CEA, PLT and their combination suggested poor prognosis (χ²=36.926, 6.892, 34.821, P<0.01). The 5-year survival rate of neither, either and both positivity of CEA and PLT were 80.2%, 51.1%, 45.5%, while the median survival time was 69, 61, 28 months with statistical difference (χ²=36.506, P<0.01). (3) COX regression revealed that the location of the tumor, nerve invasion, distant metastasis and TNM stages were the independent risk factors for the colorectal cancer (all P<0.05).

Combination of preoperative serum CEA and peripheral PLT can provide prognostic information for patients with colorectal cancer.