Differences in gene mutations according to gender among patients with colorectal cancer

The incidence, site distribution, and mortality rates of patients with colorectal cancer differ according to gender. We investigated gene mutations in colorectal patients and wanted to examine gender-specific differences.

Gene mutations in BRAF, MSI-high status, and N-ras differ according to gender among patients with colorectal cancer.

A total of 1505 patients who underwent surgical intervention for colorectal cancer were recruited from March 2000 to January 2010 at Taipei Veterans' General Hospital and investigated for gene mutations in K-ras, N-ras, H-ras, BRAF, loss of 18q, APC, p53, SMAD4, TGF-β, PIK3CA, PTEN, FBXW7, AKT1, and MSI.

There were significant differences between male and female patients in terms of tumor location (p < 0.0001) and pathological stage (p = 0.011). The female patients had significantly more gene mutations in BRAF (6.4 vs. 3.3%, OR 1.985, p = 0.006), TGF-β (4.7 vs. 2.5%, OR 1.887, p = 0.027), and revealed a MSI-high status (14.0 vs. 8.3%, OR 1.800, p = 0.001) than male patients. Male patients had significantly more gene mutations in N-ras (5.1 vs. 2.3%, OR 2.227, p = 0.012); however, the significance was maintained only for mutations in BRAF (OR 2.104, p = 0.038), MSI-high status (OR 2.003 p = 0.001), and N-ras (OR 3.000, p = 0.010) after the groups were divided by tumor site.