Purpose: Geographic access to care may be associated with receipt of chemotherapy but has not been fully examined. This study sought to evaluate the association between density of oncologists and travel distance and receipt of adjuvant chemotherapy for colon cancer within 90 days of colectomy.
Patients and methods: Patients in the National Cancer Data Base with stage III colon cancer, diagnosed between 2007 and 2010, and age 18 to 80 years were selected. Generalized estimating equation clustering by hospital service area was conducted to examine the association between geographic access and receipt of oncology services, controlling for patient sociodemographic and clinical characteristics.
Results: Of 34,694 patients in the study cohort, 75.7% received adjuvant chemotherapy within 90 days of colectomy. Compared with travel distance less than 12.5 miles, patients who traveled 50 to 249 miles (odds ratio [OR], 0.87; P=.009) or ≥250 miles (OR, 0.36; P<.001) had decreased likelihood of receiving adjuvant chemotherapy. Density level of oncologists was not statistically associated with receipt of adjuvant chemotherapy (low v high density: OR, 0.98; P=.77). When stratifying analyses by insurance status, non-privately insured patients who resided in areas with low density of oncologists were less likely to receive adjuvant chemotherapy (OR, 0.85; P=.03).
Conclusion: Increased travel burden was associated with a decreased likelihood of receiving adjuvant chemotherapy, regardless of insurance status. Patients with nonprivate insurance who resided in low-density oncologist areas were less likely to receive adjuvant chemotherapy. If these findings are validated prospectively, interventions to decrease geographic barriers may improve the timeliness and quality of colon cancer treatment.
© 2015 by American Society of Clinical Oncology.