Impact of primary tumor site on the prognosis in different stage colorectal cancer patients after radical resection

Abstract

Objective: To analyze the effect to the prognosis of tumor site on the patients of colorectal cancer after curative resection with different stage. Methods: Clinicopathological and follow-up data of 2 097 colorectal carcinoma cases undergoing resection at Fourth Hospital of Hebei Medical University from January 2008 to March 2015 were retrospectively analyzed. There were 421 patients in left-sided colorectal cancer (LCC) group (including carcinoma in cecum, ascending colon , hepatic flexure, and transvers colon) , 386 in right-sided colorectal cancer (RCC) group (including carcinoma in splenic flexure, descending colon and sigmoid colon) and 1 290 in rectal cancer (RECC) group. Clinicopathologic features in patients with different tumor location were compared. 5-year overall survival rate were compared among the 3 groups. Patients were stratified by different stage to analyze the effect of tumor location on the prognosis. χ(2)test and Kruskal-Wallis rank-sum test were used to compare the clinicopathological features among the 3 groups, Kaplan-Meier curve and Log-rank test were used to analyze prognosis, respectively. Results: No significant differences were identified between the three groups in age, family history, N stage and intestinal obstruction. Significant difference were found in gender among LCC, RCC and RECC group (male were 62.5% vs. 54.9% vs.56.3%, χ(2)=6.040, P=0.049) . Compared with LCC group and RCC group, RECC group had more well and moderately differentiated adenocarcinoma patients (89.7% vs. 86.0% vs. 82.4%, χ(2)=10.712 and 17.385, P=0.013 and 0.001) , more stage Ⅰ patients (17.1% vs. 6.9% vs. 6.5%, χ(2)=37.459 and 37.208, P=0.000 and 0.000) , and less likely to be stage T4 (44.7% vs. 76.7% vs.78.5%, χ(2)=128.015 and 133.704, P=0.000 and 0.000), metastasis (2.6% vs. 5.7% vs. 3.6%, χ(2)=1 417.167 and 1 424.217, P=0.000 and 0.000) and intestinal obstruction (11.3% vs. 21.1% vs. 24.4%, χ(2)=25.846 and 41.141, P=0.000 and 0.000). Five-year survival rate reduced in turn in the patients with RECC, LCC and RCC(70.9%, 59.8%, 58.9%, χ(2)=11.577, P=0.009). In the subgroup of stage Ⅲ, patients with different tumor location had different overall survival (χ(2)=9.878, P=0.007). Compared to right-sided colon cancer patients, rectal ones had significantly better overall survival (χ(2)=9.271, P=0.002); but in the subgroup of stage Ⅰ, Ⅱ and stage Ⅳ, patients with different tumor location had similar overall survival (P were 0.124, 0.888, 0.263, respectively). Conclusions: Colorectal cancer patients with tumor location had different clinicopathologic features. Patients with rectal cancer had better five-year survival rate than those with left located and right located colon cancer. Tumor location had different effects on the prognosis according to the different TNM stage-subgroups.