eP476 - Adherence with Staging, Treatment, and Surveillance Guidelines for Rectal Cancer Care in Ontario: A Population-Level Retrospective Cohort Study

Purpose/Background: Rectal cancer management has become increasingly complex, often necessitating several diagnostic tests, collaboration of a multidisciplinary cancer team to formulate multimodal treatments, and long-term surveillance. As a result of these nuanced approaches, fragmentation of care may occur, resulting in inconsistent delivery of care. We aimed to assess the consistency of care delivered in a single-payer, universal healthcare system by measuring population-level adherence to national staging, treatment, and surveillance guideline recommendations for rectal cancer.Methods/Interventions: This population-based study included individuals undergoing surgical resection for rectal cancer in Ontario, Canada between 2010-2019. Patients were identified in the provincial cancer registry using the International Classification of Diseases, Tenth Revision (ICD-10), codes for rectal cancer (ICD-10 20.9). Those under 18 years of age at time of diagnosis, who died on or before the date of diagnosis, and who were diagnosed with a different type of cancer within the preceding three years were excluded. Patients receiving local excision and palliative treatment were excluded. The primary outcome was adherence with guideline care as described by national cancer organizations. Secondary outcomes included five-year overall survival (OS). Adjusted Cox proportional-hazard models were fit. Analyses were stratified according to disease stage (i.e., early stage [stage I] vs. locally advanced [stage II and stage III]).Results/Outcomes: Overall, 9,352 patients were included, 2,667 patients with early stage disease (mean age: 65.7+/-12.8, 40.6% female) and 6,685 patients with locally advanced disease (mean age: 65.1+/-12.8, 36.3% female). In patients with early stage disease, 65.4%, 65.2%, 46.1% had guideline-adherent staging, treatment, and surveillance, respectively. In patients with locally advanced disease, 77.2%, 39.3%, 55.9% had guideline-adherent staging, treatment, and surveillance, respectively (Figure 1). Adjusted survival analyses suggested that non-adherence with staging (HR 1.26, 95%CI 0.97-1.73, p=0.085), treatment (HR 0.85, 95%CI 0.65-1.13, p=0.260), and surveillance (HR 0.96, 95%CI 0.67-1.37, p=0.830) was not associated with worse five-year OS for patients with early stage disease. Five-year OS was significantly worse in patients with locally advanced disease who did not receive guideline-adherent staging investigations (HR 1.19, 95%CI 1.04-1.37, p=0.013), treatment (HR 1.40, 955CI 1.20-1.62, p < 0.001), and surveillance (HR 2.17, 95%CI 1.85-2.56, p < 0.001) compared to patients receiving guideline-adherent care.Conclusion/

Discussion: Adherence to guideline recommended staging, treatment, and surveillance for rectal cancer in Ontario, Canada is poor. This can have a detrimental impact on long-term oncologic outcomes for patients with locally advanced disease. Future research and quality improvement projects aimed at improving adherence are necessary for this increasingly prevalent and complex disease process.Figure 1.Proportion of adherence with staging, treatment, and surveillance guideline recommendations by disease stage.