Li Y, et al. - Based on Surveillance, Epidemiology and End Results (SEER) data, researchers conducted a retrospective population-based study to investigate the prognostic effect of tumor sidedness by subgroup survival analyses, according to histology and tumor grade in stage I-IV colorectal cancers (CRCs). From 1975 to 2014, the 5-year cause-specific survival for all subgroups of CRCs improved. Investigators observed that out of 238,826 patients, 44.2% had right-sided cancer. Findings suggested that patients with right-sided cancer were more likely to be older, to be women, to have disease of mucinous or signet-ring cell histology, to have more poorly differentiated tumors, and to be diagnosed with a more advanced disease stage. Particularly for stage III disease, the association between sidedness and prognosis in CRCs depends on stage and histopathologic characteristics.