11068 Background: A recent ASCO report highlighted improving patient access to cancer clinical trials as a fundamental priority. Although prior research found that 19% of participants in NCI-sponsored trials reside in rural areas, there is substantial heterogeneity in the classification of rurality. In addition, sociodemographic characteristics across different levels of rurality are unknown. In this analysis, we evaluated the prevalence and trends over time in trial enrollment by categories of rurality. Methods: We analyzed pooled data from phase II, II/III, and III trials conducted by the SWOG Cancer Research Network from 1992-2022. Rurality was defined by linking patient zip code to the Rural-Urban Continuum Codes, and categorized into four groups (large urban, small urban, rural, frontier). Baseline and patient demographic data were obtained from trial registration forms. Neighborhood deprivation, based on the Area Deprivation Index, was derived from patient zip code. The associations between rurality and patient characteristics were evaluated using multivariate logistic regression with covariate adjustments. Rurality enrollment was compared to corresponding overall US rurality estimates during the same period. Results: In total, N = 39,729 patients enrolled in 69 trials in brain, breast, GI, GU, gynecological, head and neck, lung, sarcoma, melanoma, and hematologic cancers were examined. Across the geographic groups, 52.2% lived in large urban, 30.9% lived in small urban, 11.6% lived in rural, and 5.4% lived in frontier areas, compared to corresponding US population estimates of 56.0% large urban, 28.6% small urban, 10.3% rural, and 5.0% frontier. Patients residing in frontier areas were nearly 80 times as likely to live in the highest versus lowest deprivation areas (OR = 78.37, 95% CI, 64.71-94.92, p < .0001). Similar though less pronounced associations were found among patients from rural and small urban areas (p < .0001). Frontier patients were more likely to be on Medicare (OR = 1.96, 95% CI, 1.66-2.30, p < .0001). Over the 30-year study period, trial enrollment among patients from frontier areas has decreased over time relative to the US population, whereas trial enrollment of patients from large urban areas has increased. Conclusions: Patients from rural and frontier areas are well-represented in SWOG clinical trials, however, enrollment among patients from frontier areas has shown a declining trend. Strong representation of patients with cancer from rural areas enhances the generalizability of trial findings. Given ongoing changes to healthcare, declining representation from frontier areas is likely to continue without targeted interventions. Further research is needed to expand access to care in these vulnerable areas and guide efforts that ensure adequate socioeconomic support for all patients, regardless of their geographic locale.
Okado et al. (Wed,) studied this question.