Right-sided vs left-sided colorectal cancer.

AV In the analysis of the Cancer and Leukemia Group B (CALGB)/SWOG 80405 trial that we presented at the 2016 annual meeting of the American Society of Clinical Oncology (ASCO), we defined right-sided colon cancer as cancer of the cecum and the ascending colon up to the hepatic flexure. Left-sided colon cancer comprises cancer of the splenic flexure and cancer in regions distal to the splenic flexure, including the rectum. The transverse colon connects the left and right sides and on average is appreciably shorter than the right and left sides. Fewer cancers occur there, and for clarity, we omitted patients with cancer of the transverse colon from our analysis. In fact, the addition of these cases to either the left side or the right side did not change our results.