Patient and Disease Characteristics, Treatment Practices and Oncologic Outcomes among Patients with Colorectal Cancer: a Population-Based Analysis.

Background:The incidence of colorectal cancer (CRC) is increasing among young adults. We sought to report on patient and disease characteristics, treatment practice patterns and outcomes in this population. Methods:We conducted a retrospective cohort study using administrative health data from the Alberta Cancer Registry (2004-2015), including demographic and tumour characteristics, and treatment received. Outcome measures included overall and cancer-specific deaths. We used Cox regression and Kaplan-Meier curves to assess for factors associated with survival. Results:We included 18 070 patients with CRC (n = 1583 [8.8%] < 50 yr, n = 16 487 [91.2 %] >= 50 yr). Younger patients were more likely to present with locally advanced disease (21.0% v. 18.0%, p < 0.0001), stage III (16.4 % v. 14.6%, p < 0.0001) or metastatic (16.7% v. 13.8%, p < 0.0001) involvement. Younger patients were more likely to receive surgery (87.2% v. 80.9%, p < 0.0001), chemotherapy (59.6% v. 34.1%, p < 0.0001) or radiation therapy (49.5% v. 37.2%, p < 0.001). At 5 years, overall and cancer-specific survival was better among younger patients than older patients (30.6% v. 51.5% overall deaths, 27.5% v. 38.4% cancer-specific deaths, p < 0.0001). Conclusion:Despite higher stage and higher grade disease, young patients with CRC had more favourable oncologic outcomes than stage-matched older patients, which may be related to younger patients receiving more aggressive treatment. Further investigation should focus on optimal treatment patterns for young patients with CRC.