[The differences between three distinct locations of colorectal cancers based on clinicopathological characteristics...

To investigate the differences of clinical characteristics and molecular features among colorectal cancer subsides and provide evidence for colorectal cancer protection, diagnosis and treatment.

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.

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)).

There are specific characteristics in right-sided colon cancers. The difference of molecular features between right-sided colon and rectal cancers are more significant.