Background: Genomic analyses describe significant differences between R and L sided CCa. Four distinct Consensus Molecular Subtypes (CMS1-4) have recently been described: CMS1 is predominantly R, stage II and appears to do well in early stages, but has inferior SAR. CMS2 is predominantly L and has a more favorable SAR. We hypothesize that RFS and SAR outcomes are different in R versus L CCa. Methods: Patients diagnosed with stage I-III CCa were identified from the BC Cancer Agency GI Cancers Outcomes Unit. Disease location, demographic, pathologic, treatment, recurrence and mortality information was prospectively collected. R included cecal to transverse tumors; L included splenic flexure to sigmoid tumors. Kaplan Meier survival analysis was performed by stage and stratified by use of adjuvant chemotherapy. RFS was measured from date of surgery until recurrence and censored at death or last follow-up. SAR was measured from relapse, until death or last follow-up. Cox-proportional hazard models were used to control for baseline clinicopathologic characteristics. Results: Of 5378 patients with stage I-III CCa, 46% were R and 54% L. The median age was 67. Compared to L, R sided was significantly associated with females (52 vs 43%), grade 3 (23 vs 10%), stage II (39 vs 35%), > 12 lymph nodes sampled (60 vs 45%) and no adjuvant chemotherapy (54 vs 47%). 5Y survival outcomes and hazard ratios (HR) are listed. In multivariate analysis, R was associated with superior RFS for only stage II disease, while L experienced better SAR overall and in stages II and III. Conclusions: R vs L sided CCa has a prognostic impact in both early stage and relapsed disease, independent of adjuvant therapy. Until better molecular classification is available, R versus L CCa may be a meaningful reflection of molecular subtypes and represent relevant stratification and prognostic factors.