Utilization of radiotherapy for prostate cancer according to urologists’ practice patterns.

Abstract

11 Background: Physician practices that offer ancillary medical services may refer their patients for such services, a process known as self-referral. Self-referral for radiation therapy according prostate cancer risk and cost of care is not known. We evaluated how utilization and cost of care differ for men diagnosed with prostate cancer in a self-referring urologic practice (SRP) compared to a traditional urologic practice. Methods: 17,982 men 66 years and older diagnosed with localized prostate cancer from 2006 to 2009 were identified from the Texas Cancer Registry. Disease was classified as favorable if low-grade and clinical T1 or T2. The diagnosing urologist was classified as being affiliated with a SRP if their practice owned a linear accelerator. Multilevel logistic regression models evaluated the odds of receiving a specific type of treatment adjusted for diagnosis year, age, comorbidities, race/ethnicity, income, education, clinical tumor stage, and tumor grade. Cost of care was calculated from Medicare expenditures within 12 months of diagnosis. Results: Diagnosis in a SRP increased from 2.2% of prostate cancers in 2004 to 24.5% in 2009 (p< 0.001). Men diagnosed in SRPs were more likely to receive upfront treatment (vs. watchful waiting/active surveillance) than men diagnosed by traditional practices (92.7% vs. 89%; AOR 1.61, p<0.001) and were more likely to be treated with external beam radiation (47.4% vs. 34.1%; AOR 1.59, P<0.001). This persisted for both favorable and unfavorable risk cancer. Men diagnosed in SRPs were more likely to receive upfront treatment (favorable: 92.9% vs. 87.1%; AOR 1.89, p<0.001; unfavorable: 97.9% vs. 95.0%; AOR 2.07, p=0.002) and more likely to be treated with EBRT (favorable: 41.2% vs. 31.1%; AOR 1.45, p=0.002; unfavorable: 49.0% vs. 38.1%; AOR 1.53, p<0.001). Median annual prostate cancer care cost was $2,460 (95% CI $1,663-$3,368) higher for men diagnosed by SRPs. Conclusions: Older men diagnosed with prostate cancer in SRPs are more likely to undergo upfront treatment and to receive radiation treatment. This may increase appropriate treatment of unfavorable disease but contribute to overtreatment of favorable disease.