J. K. Ewing1, J. J. Cabo1, X. Shu2, X. O. Shu2, M. Tan1, K. Idrees1, C. E. Bailey1 1Vanderbilt University Medical Center,Department Of Surgery, Division Of Surgical Oncology And Endocrine Surgery,Nashville, TN, USA 2Vanderbilt University Medical Center,Division Of Epidemiology,Nashville, TN, USA
Introduction: Some studies show that care at an academic center (AC) improves survival for patients with advanced stage colon cancer (CC). However, it remains unclear which patients have the greatest survival benefit from treatment at AC. The primary aim of this study is to determine which patients have the most improvement in overall survival (OS) from treatment at AC, relative to other treatment facilities (TF).
Methods: A retrospective cohort study of adults with histologically confirmed CC was performed using the National Cancer Database (2004-2014). TF were classified as community cancer programs (CCP; 100-500 cases/year), comprehensive community cancer programs (CCCP; >500 cases/yr), academic centers (AC; >500 cases/yr with residency training program), or integrated network cancer programs (INCP; multi-center organizations). Demographic and clinical factors were compared according to TF. Kaplan-Meier curves and log-rank tests were used for univariate survival analysis. Cox proportional hazard models were used to assess the impact of TF on OS after adjusting for patient, tumor, and treatment characteristics. Subgroup analyses were performed stratifying by stage, age, and race.
Results:The cohort included 433,997 patients with median age of 69(Interquartile range: 59-78). Most were white(83.8%), had Medicare(55.4%) or private insurance(34.8%), and were treated at CCCP(49.1%) or AC(26.5%). Median OS was greatest for patients treated at AC(107.1 months), compared to INCP(98.5 mo), CCCP(95.9 mo), and CCP(90.2 mo) (P<0.001). On multivariate analysis, there was no significant difference in OS between patients with stage IV CC treated at CCCP or INCP relative to those treated at CCP. However, an improvement in OS was observed for patients with stage IV CC treated at AC(Hazard ratio [HR] 0.85, 95% Confidence Interval [CI] 0.83-0.87, P<0.001) (Figure 1A). Similarly, among patients younger than 70, patients treated at CCCP or INCP had similar OS relative to those treated at CCP, whereas those treated at AC had improved OS relative to those treated at CCP(HR 0.86, 95% CI 0.84-0.88, P<0.001) (Fig. 1B). Finally, for African American (AA) patients, treatment at CCCP and INCP had similar OS compared to treatment at CCP, whereas improved OS was observed for AA patients treated at AC(HR 0.88, 95% CI 0.84-.91, P<0.001). A similar pattern was observed for non-white, non-AA patients (Fig. 1C).
Conclusion:Treatment at AC is especially beneficial for patients with stage IV CC, patients younger than 70, and non-white patients. For these patients, treatment at AC was independently associated with 12-15% reduced mortality relative to treatment at CCP. Further work is needed to examine why certain groups benefit more from care at AC.
