Racial inequality with radiation oncology referral and treatment in metastatic colorectal cancer.

Abstract

470 Background: Black patients with colorectal cancer have worse outcomes compared to white patients, however the underlying source of this racial disparity remains unclear. This population-based study evaluates the impact of race on referral patterns and subsequent treatment with chemotherapy or radiotherapy in metastatic colorectal cancer. Methods: This study used the Surveillance, Epidemiology, and End Results–Medicare linked database to identify 11,125 patients with stage IV colorectal cancer diagnosed between 2000-2007. Patient demographic data were abstracted from the SEER database, and referral and treatment information were derived from Medicare claims data. Multivariate logistic regression models determined the impact of race on 1) consultation patterns with medical oncology and radiation oncology, and 2) subsequent treatment with chemotherapy and radiation therapy. Results are presented as adjusted odds ratios (OR) that control for potential confounding factors including age, comorbidity, socioeconomic status, geography, gender, marital status, and year of diagnosis. Results: Of the entire patient cohort, 2,025 (18%) were seen in consultation by a radiation oncologist, and among these patients, 1,221 (60%) ultimately received radiotherapy. Black patients had significantly lower rates of consultation with a radiation oncologist compared to white patients (OR=0.79, 95% CI=0.65-0.96; p=0.016). Among patients with a radiation oncology consultation, fewer black patients were subsequently treated with radiotherapy (OR=0.67, 95% CI=0.46-0.99; p=0.046). There was no difference between black and white patients in time from diagnosis to radiation treatment, and no difference in radiation treatment duration. We found no race-related difference in medical oncology consultation rates (p=0.24), nor in subsequent treatment with chemotherapy (p=0.95). Conclusions: This study shows racial disparity in radiation oncology consultation rates, and in radiation therapy treatment. Further research evaluating these barriers to care will help us achieve equality in treatment of metastatic colorectal cancer.