Use of Recommended Radiation Therapy in the Rural U.S.

Research center:
Lead researcher:
Project funded:
September 2007
Project completed:
October 2012

Radiation therapy specifically is recommended as primary or adjunctive therapy for many cancers. Recent WWAMI RHRC research found that nearly 40% of colorectal cancer patients in small and isolated small rural areas and 30% in large rural areas must travel over 50 miles to receive radiation oncology consultation, raising concerns about the adequacy of cancer treatment for rural populations requiring radiation therapy.

The goal of this project is to identify the degree to which rural cancer patients meet the recommended guidelines for radiation therapy as primary or adjunctive treatment for cancers. This research also will determine whether rural county characteristics (e.g., poverty level, adjacency to urban areas, presence of radiation oncologist), cancer characteristics, patient characteristics, and contextual factors are associated with radiation therapy use.

Using 2004 data from 303 rural and 165 urban counties in 10 states with Surveillance, Epidemiology, and End Results (SEER) cancer registries, we will conduct a cross-sectional analysis of rural cancer patients' use of recommended radiation therapy. SEER data provide detailed chart-abstracted information on cancer type/stage, extent of disease, and initial treatment (e.g., surgery, radiation); Federal Information Processing Standards (FIPS) county codes, allowing geographic categorization into urban and different levels of rural using Urban Influence Codes; demographic characteristics (e.g., age, sex, race/ethnicity); and contextual characteristics (e.g., ZIP code-based median household income). We will link radiation oncologist availability in each county from the Area Resource File to these data. We will first use the National Comprehensive Cancer Network (NCCN)-published clinical oncology practice guidelines to define the cancer types and stages for which radiation therapy is recommended as primary and adjuvant cancer treatment. Next, we will compare unadjusted radiation therapy use rates between different types of rural and urban areas overall and for different cancer types, then, using hierarchical logistic regression models to account for clustering by county, examine the influence of different geographic, demographic, contextual, and health systems factors on radiation therapy use in rural areas.