Analysis of prognostic factors in patients with colorectal mucinous adenocarcinoma after radical surgery

Objective To explore the prognostic factors of patients with colorectal mucinous adenocarcinoma （MA） after radical surgery. Methods Eighty-one patients with colorectal MA undergoing radical surgery were recruited. Disease-free survival （DFS） and overall survival （OS） were analyzed using the Kaplan-Meier method. The prognostic factors of patients with colorectal MA were identified by using univariate and multivariate Cox’s regression analyses. Results The 5-year DFS of colorectal MA, colonic MA and rectal MA were 55%, 57% and 47% respectively. The 5-year OS were 60%, 62%, 51%, respectively. Univariate Cox’s regression analysis found that T4（HR = 2.174）, N2（HR = 3.592）, TNM stageⅢ（HR = 2.435）, CA199≥34 U/ml（HR = 3.33） were the risk factors for DFS of patients with colorectal MA. The operation time > 200 minutes （HR = 2.594）, T4 （HR = 2.465）, N2 （HR = 5.413）, TNM stage Ⅲ （HR = 3.275）, CA199≥34 U/ml（HR = 4.150） and CEA≥5 ng/ml（HR = 2.636） were the risk factors for OS of colorectal MA patients. Multivariate Cox’s regression analysis demonstrated that N2 and CA199 ≥ 34 U/ml were the risk factors for the prognosis of colorectal MA patients. The HR of DFS and OS for N2 were 2.763 and 4.113. The HR of DFS and OS for CA199≥ 34 U/ml were 2.560 and 2.948. Stratified analysis revealed that N2（HR = 5.628）was the risk factor for DFS of colonic MA. N2（HR = 7.547） and CA199 ≥ 34 U/ml （HR = 2.947） were risk factors for OS of colonic MA. Adjuvant chemotherapy was a protective factor for the prognosis of rectal MA patients, the HR of DFS and OS were 0.063 and 0.182 （both P < 0.05）. Conclusions N2 stage and CA199≥34 U/ml are the risk factors for clinical prognosis of patients with colorectal MA. Adjuvant chemotherapy is a protective factor for clinical prognosis of patients with rectal MA.