[Clinically relevant, gender-specific differences in colorectal carcinoma (CRC)]

The incidence of colorectal cancer worldwide is higher in men. Risk factors like smoking, overweight, or dietary exposures cannot explain this gender difference. In the pathogenesis of colorectal carcinoma, estrogen seems to play an important protective role. Estrogen may reduce the risk of developing colon cancer in premenopausal women. The expression of estrogen receptor ß in healthy colon is significantly decreased in the development of colon cancer. The role of estrogen in pathogenic pathways is most likely protective or might serve as a tumor suppressor. However, the exact role of estrogen in the carcinogenesis of colorectal cancer still remains unclear. Furthermore, tumor localization depends on age and gender. Therefore, in postmenopausal women there is a shift to predominantly right-sided cancers. Here, a link between tumor localization and MSI-H (microsatellite-high) status can be assumed. There are virtually no prospective randomised trials in adjuvant or palliative therapy of patients with colorectal cancer. Earlier data from registries point to a better post-operative survival of women, while men seem to benefit more from adjuvant therapy. Potentially, there may be a role of an increased toxicity to 5-FU in women. In the palliative setting, there are also only few gender-specific analyses. Women with right-sided colon cancers show a significant worse response and survival under an anti-EGFR antibody treatment compared with men and left-sided cancers. A focus on gender-specific differences should be incorporated more often in future randomised trials.