Hans Bjarke Rahr

Background: Variations in treatment choices have been reported in colorectal cancer (CRC). In the context of national recommendations, we aimed to elucidate predictors and between-hospital variations in refraining from curatively intended surgery and adjuvant chemotherapy in potentially curable colorectal cancer. Methods: A total of 34,116 patients diagnosed with CRC from 2009 to 2018 were included for analyses on non-curative treatment in this register-based study. Subsequently 8006 patients were included in analyses on adjuvant treatment. Possible predictors included patient-, disease-, socioeconomic- and perioperative-related factors. Logistic regressions were utilized to examine the predictors of a non-curative aim of treatment and no adjuvant chemotherapy. Results: The predictors of non-curative treatment were high age, poor performance, distant metastases and being underweight. Predictors for no adjuvant treatment were high age, poor performance, kidney disease, postoperative complications and living alone. For both outcomes we found between-hospital variations to be present. Conclusions: Non-curative overall treatment and refraining from adjuvant chemotherapy were associated with well-known risk factors, but the former was also associated with being underweight and the latter was also associated with living alone. Marked between-hospital variations were found and should be examined further.