Abstract:

Objective To investigate the differences in survival characteristics and prognostic factors of postoperative patients with left⁃side and right⁃side colonic mucinous adenocarcinoma（MA）. Methods A total of 13 594 patients with colonic MA after surgery from 2006 to 2015 were collected in the Surveillance，Epidemiology， and Final Results（SEER）database. They were divided into right⁃side MA group（n = 9 824）and left⁃side colonic MA group（n = 3 770）. Overall survival（OS）of the two groups was estimated using the Kaplan⁃Meier method and stratified analysis was conducted by stage and degree of differentiation. The prognostic factors of patients with left⁃ side and right ⁃side colonic MA were evaluated using multivariate COX regression analyses. Results There were differences in the tumor characteristics of the left⁃side and right⁃side colonic MA patients. The 5⁃year survival rates of the left⁃side and right⁃side MA were 51.6% and 55.0%，respectively，and there was no difference in overall sur⁃ vival between the two groups（P = 0.234）. Stratified analysis revealed there was no difference in the OS between the left⁃side and right⁃side colonic MA in the AJCC staging stage Ⅰ（P = 0.203），stage Ⅱ（P = 0.156），stage Ⅲ （P = 0.08），well differentiated（P = 0.091），moderately differentiated（P = 0.252）and undifferentiated（P = 0.946）. The OS of the left⁃side group was better than that of the right⁃side group in stage Ⅳ colonic MA（P < 0.001）. However，the OS was better in the right⁃side group compared with that in the left⁃side group in poorly differentiated colonic MA（P = 0.001）. Multivariate COX analysis showed that male，aged over 60，single or unmarried，wid⁃owed，stage T3，stage T4，stage N1，stage N2，stage M1，poorly differentiated，undifferentiated，number of lymph nodes less than 12，CEA positive，and no chemotherapy were independent risk factors of postoperative patients with left⁃side or right⁃side colonic MA. Moderately differentiated was also an independent risk factor for the prognosis of postoperative patients with left colonic MA. Conclusion The survival differences are not completely the same between the right⁃side and left⁃side colonic MA with different differentiations and stages. The independent risk factors for the prognosis of postoperative patients with left ⁃side and right ⁃side colonic MA are not completely the same. 

Key words:

 , left?side and right?sided colon cancer, mucinous adenocarcinoma, tumor stage, tumor differentiation, prognosis, SEER database