Association of NCCN guideline adherence with improved survival in high-risk stage II and stage III colon cancer.

Abstract

543 Background: Evidence-based treatment guidelines have been proposed as a quality metric for cancer care. There is significant variability in the treatment of high-risk stage II (defined by tumor depth, histologic grade, margin status, and # of nodes retrieved) and stage III colon cancer patients in the National Cancer Database (NCDB). This study examines whether adherence to guidelines is associated with improved outcomes. Methods: Patients with colon adenocarcinoma (1998-2002) were identified from the NCDB. The stage-specific NCCN guidelines were used to classify patients into two groups based on adherence to guidelines (adherent or non-adherent). Overall survival (OS) and relative survival (RS) were calculated for both groups. Relative survival was used as a surrogate for disease-specific survival and calculated using the methods of Dickman et al. Results: A total of 77,350 patients were included in the analytic cohort. Stage-specific outcomes were compared and stage is an independent predictor of survival. As reported in our previous analyses, nonadherence as a result of omission of chemotherapy, was noted in 64.3% and 26.4% of high-risk stage II and stage III patients, respectively. Nonadherence was associated with decreased OS and RS with a hazard ratio for death of 1.43 (95% CI: 1.33, 1.54) for high-risk stage II and 1.89 (95% CI: 1.82, 1.95) for stage III (p < 0.001, Table) RS. Additionally, regression analysis demonstrated that gender, age, race, insurance, income, and type of facility were associated with differences in RS. Conclusions: Guideline-based practice, particularly for high-risk stage II and stage III colon cancer, is associated with improved survival outcomes. Therefore, these guidelines may be appropriate as a metric of performance comparable across various institutions. Additionally, factors associated with deviations from guidelines can be used to focus improvements in the access to and delivery of cancer treatment. [Table: see text]