LAUSR

Background: Clinical guidelines are generated to preserve high‐quality evidence‐based care. Data on the implementation of guidelines into clinical practice are scarce, despite that guideline adherence prevents over‐ and undertreatment and correlates with survival. Therefore, we investigated guideline adherence for the systemic treatment in high‐risk stage II and stage III colon cancer and metastatic colorectal cancer. Patients and Methods: In all Dutch hospitals (n = 88) 1 medical oncologist involved in colorectal cancer care was approached to participate. An online survey was conducted regarding the local standard of care for adjuvant chemotherapy in high‐risk stage II and stage III colon cancer and first‐line treatment regimens in metastatic colorectal cancer. Frequency tables were provided for categorical variables and compared for differences in guideline adherence according to hospital type (academic/teaching/regional). Results: The overall response rate was 70% (62 of 88). Reported guideline adherence was at least 60% of all presented settings. For high‐risk stage II and stage III colon cancer, treatment strategies agreed with national guidelines in 66% and 84% of hospitals, and overtreatment patterns were identified in 28% and 13%, respectively. Targeted therapy was not routinely administered as first‐line treatment in metastatic colorectal cancer (range from 63% to 71% in different settings). No differences in guideline adherence were observed among different hospital types. Conclusion: Guideline adherence as reported by medical oncologists in The Netherlands is suboptimal. Possible explanations include unawareness or disagreement with the guidelines, or local financial restrictions. Our results recommend additional support of guideline implementation and monitoring in clinical practice, and investigating underlying causes in case of nonadherence. Micro‐Abstract: Guideline adherence for the systemic treatment of (metastatic) colorectal cancer was surveyed among oncologists in The Netherlands. Reported overtreatment patterns (adjuvant setting) and undertreatment patterns for targeted therapies (metastatic setting) were identified, possibly explained by unawareness or disagreement with the guidelines, or local financial restrictions. Additional support for guideline implementation and monitoring besides investigating underlying causes for nonadherence is recommended.