Association Between Travel Distance and Use of Post-Operative Radiation Therapy Among Men With Prostate Cancer: Does Geography Influence Treatment Decisions?

Abstract

Following radical prostatectomy (RP), men with a persistent post-operative PSA and select men with adverse pathologic features are candidates for postoperative radiation therapy (PORT). However, travel distance to radiation therapy facilities may negatively affect patient access to PORT. In this study, we investigated disparities in rates of PORT in men with high risk prostate cancer according to their distance from the treatment facility. Using the National Cancer Database, we identified 510,665 men with prostate cancer diagnosed 2004-2015 who have received RP. Multivariable logistic regression defined adjusted odds ratios (AORs) with 95% confidence intervals (95CI) of receiving PORT as the primary dependent variable and distance from the treatment facility as the primary independent variable. Patients were defined as living “far” from the treatment facility if they lived beyond the median distances of 9.1 miles for metro counties, 38.1 miles for urban counties, and 52.9 miles for rural counties; all others were categorized as “near.” Analyses were stratified by the presence of adverse pathologic features (pT3 disease or positive surgical margins) and type of county (rural vs urban vs metro). Patients living far from the treatment facility received PORT less frequently than those living near a treatment facility (3.98% vs 6.33%, AOR 0.58, 95CI 0.56-0.60, P<0.001). These trends persisted in patients with adverse features (far vs near: 11.36% vs 17.94%, AOR 0.58, 95CI 0.56-0.60, P<0.001) and those with no adverse features (1.51% vs 2.62%, AOR 0.58, 95CI 0.55-0.60, P<0.001). When stratifying by county type, patients living far from a treatment facility had lower rates of PORT compared to those living near a treatment facility in metro (4.10% vs 6.16%, AOR 0.62, 95CI 0.61-0.64, P<0.001), urban (3.39% vs 7.42%, AOR 0.39, 95CI 0.36-0.42, P<0.001), and rural (3.26% vs 6.87%, AOR 0.41, 95CI 0.34-0.50, P<0.001) counties. For men with prostate cancer managed with surgery, patients living farther from their treatment facility were 38-61% less likely to receive PORT relative to those living near the treatment facility, regardless of the presence of adverse pathologic features and county type. While the decision to use PORT depends on many patient-specific factors, these findings raise the possibility that the geographic availability of radiation treatment facilities influences the treatment decision. As alternative payment models in radiation oncology are being explored, attention should be given to supporting community-based radiation treatment centers to ensure accessibility of care for patients with prostate cancer.Tabled 1Abstract 2941; TableOR95% CIP>|z|% PORTFarNearMetro0.620.610.640.0004.16.16Urban0.390.360.420.0003.397.42Rural0.410.340.500.0003.266.87 Open table in a new tab