[The differences between three distinct locations of colorectal cancers based on clinicopathological characteristics and molecular features].

OBJECTIVE: To investigate the differences of clinical characteristics and molecular features among colorectal cancer subsides and provide evidence for colorectal cancer protection, diagnosis and treatment. METHODS: All of 4 316 colorectal patients from Shanghai cancer center were selected for clinical character analysis, among which, 2 224 subjects for molecular feature analysis. Clinic pathological characteristics like age, gender, tumor types, histological types, differentiation and T-stage, as well as molecular features like hMLH1, hMSH2, CD44, p21, p53, COX2,E-cadherin, Her2 and Ki-67, were involved into this research. RESULTS: It showed that compared with left-sided colon and rectal cancers, right-sided cancers occurred more in women (46.0% (541/1 176); 39.2% (424/1 083); 41.2% (848/2 057), respectively, χ² = 11.85, P < 0.01), had more mucinous or signet-ring carcinoma (12.0% (128/1 064), 5.8% (56/960), 4.0% (75/1 859), respectively, χ² = 31.27, P < 0.01), poor differentiated carcinoma (32.1% (343/1 069), 19.5% (201/1 033), 19.3% (380/1 967), respectively, χ² = 72.66, P < 0.01) , and advanced T stage (87.9% (992/1 129), 83.2% (869/1 045), 72.2% (1 486/2 057), respectively, χ² = 121.44, P < 0.01). Meanwhile, the rates of hMLH1 were higher in right-sided colon cancers when compared with rectal cancers (13.4% (59/439) vs 8.5% (88/1 035), OR (95%CI): 1.67 (1.18-2.37)), as well as the rates of hMSH2 negative expression (4.9% (22/452) vs 2.4% (26/1 083), OR (95% CI): 2.08(1.17-3.71)). The rates of p53 positive expression were higher in right-sided colon cancers when compared with rectal cancers (76.2% (321/421) vs 68.4%, (776/1 134), OR (95% CI): 0.68 (0.52-0.87)). Compared with right-sided colon cancers, the rates of Her2 positive expression were higher in rectal cancers (19.3% (176/913) vs 13.2% (45/340), OR (95% CI): 1.57 (1.10-2.23)) , as well as the rates of Ki-67 expression which was positive in more than 50% cells (73.6% (840/1 141) vs 65.6% (299/456), OR (95% CI): 0.68 (0.54-0.86)). CONCLUSION: There are specific characteristics in right-sided colon cancers. The difference of molecular features between right-sided colon and rectal cancers are more significant.