Influence of Geography on Prostate Cancer Treatment

Purpose: Several definitive treatment options are available for prostate cancer, but geographic access to those options is not uniform. We created maps illustrating provider practice patterns relation to patients and assessed the influence of distance to treatment receipt. Methods and Materials: The patient cohort was created by searching the National Medicare Database for patients diagnosed and treated for prostate cancer from 2011 to 2014. The provider cohort was created by querying the American Medical Association Physician Masterfile to identify physicians who had treated patients with prostatectomy, intensity modulated radiation therapy (IMRT), brachytherapy, stereotactic body radiation therapy (SBRT), or proton therapy. Maps detailing the location of providers were created for each modality. Multivariate multinomial logistic regressions were used to assess the association between patient-provider distance and probability of treatment. Results: Cohorts consisted of 89,902 patients treated by 5518 physicians. Substantial numbers of providers practicing established modalities (IMRT, prostatectomy, and brachytherapy) were noted in major urban centers, whereas provider numbers were reduced in rural areas, most notably for brachytherapy. Ninety percent of prostate cancer patients lived within 35.1, 28.9, and 55.6 miles of a practitioner of prostatectomy, IMRT, and brachytherapy, respectively. Practitioners of emerging modalities (SBRT and proton therapy) were predominantly concentrated in urban locations, with 90% of patients living within 128 miles (SBRT) and 374.5 miles (proton). Greater distance was associated with decreased probability of treatment (IMRT –3.8% per 10 miles; prostatectomy –2.1%; brachytherapy –2%; proton therapy –1.6%; and SBRT –1.1%). Conclusions: Geographic disparities were noted for analyzed treatment modalities, and these disparities influenced delivery.