1819 MANAGED CARE AND THE DIFFUSION OF INTENSITY-MODULATED RADIOTHERAPY FOR PROSTATE CANCER

1819 MANAGED CARE AND THE DIFFUSION OF INTENSITY-MODULATED RADIOTHERAPY FOR PROSTATE CANCER

Vol. 187, No. 4S, Supplement, Tuesday, May 22, 2012 THE JOURNAL OF UROLOGY姞 Source of Funding: Bruce Jacobs is supported in part by the American Can...

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Vol. 187, No. 4S, Supplement, Tuesday, May 22, 2012

THE JOURNAL OF UROLOGY姞

Source of Funding: Bruce Jacobs is supported in part by the American Cancer Society Postdoctoral Fellowship Grant (121805-PF-12-008-01-CPHPS) and by the National Institutes of Health T32 Training Grant NIH 5 T32 DK007782-12. Brent Hollenbeck is supported by the American Cancer Society Pennsylvania Division–Dr. William and Rita Conrady Mentored Research Scholar Grant (MSRG-07-006-01-CPHPS).

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Source of Funding: Bruce Jacobs is supported in part by the American Cancer Society Postdoctoral Fellowship Grant (121805-PF-12-008-01-CPHPS) and by the National Institutes of Health T32 Training Grant NIH 5 T32 DK007782-12. Brent Hollenbeck is supported by the American Cancer Society Pennsylvania Division–Dr. William and Rita Conrady Mentored Research Scholar Grant (MSRG-07-006-01-CPHPS).

1819 MANAGED CARE AND THE DIFFUSION OF INTENSITY-MODULATED RADIOTHERAPY FOR PROSTATE CANCER Bruce L. Jacobs*, Yun Zhang, Brent K. Hollenbeck, Ann Arbor, MI INTRODUCTION AND OBJECTIVES: Intensity-modulated radiotherapy (IMRT) for the treatment of prostate cancer has rapidly disseminated over the last decade. Its improved targeting capabilities and delivery of higher doses of radiation are thought to result in numerous patient benefits, including reduced bowel and urinary toxicity and improved cancer control. However, IMRT is expensive. How this affects its dissemination in markets with varying degrees of managed care remains unknown. We examined the relationship between managed care penetration and IMRT utilization. METHODS: Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, we identified a retrospective cohort of men diagnosed with prostate cancer between 2001 and 2007 who underwent treatment with radiation (n⫽ 57,749), of which 23,545 received IMRT. We aggregated these data to the market level, defined as a Hospital Service Area (HSA). HSAs represent local healthcare markets for hospital care. For a given year, we excluded HSAs with ⬍ 10 patients treated with radiation, which resulted in 684 HSA-years. We used the Area Resource File to obtain the managed care penetration for each HSA. Then, we compared markets with high and low managed care penetration. Our primary outcome was the adjusted proportion of IMRT use among those patients receiving radiation. RESULTS: Over this 7-year period, the proportion of IMRT utilization substantially increased across all markets. After adjusting for income, education, race, and diagnosis year, the overall proportion of IMRT use was 38% and 39% in markets with low and high managed care penetration, respectively (p⬍0.01). Patients living in markets with higher managed care penetration used IMRT more frequently. CONCLUSIONS: Despite IMRT’s high cost, its overall dissemination was not deterred by managed care penetration. While statistically significant, the effect of managed care penetration on IMRT utilization appears small.

1820 CLINICAL OUTCOMES FOLLOWING PRIMARY ANDROGEN DEPRIVATION THERAPY AMONG MEN WITH LOCALIZED PROSTATE CANCER Grace Lu-Yao*, Dirk Moore, Weichung Shih, Yong Lin, Robert DiPaola, Hui Li, New Brunswick, NJ; Peter Albertsen, Farmington, CT; Siu-Long Yao, New Brunswick, NJ INTRODUCTION AND OBJECTIVES: Primary androgen deprivation therapy (PADT) is commonly used among elderly patients despite uncertainty about its impact on disease progression. This study assessed the impact of PADT on further use of cancer therapy and risk of metastasis among men with localized prostate cancer (T1/T2) not undergoing local therapy. METHODS: Medicare claims data linked to the Surveillance, Epidemiology and End Results (SEER) data were used to assemble a cohort of men over age 66 years diagnosed with T1/T2 prostate cancer in 1992-2007 without local therapy. To overcome potential biases associated with unmeasured confounding variables, we used instrumental variable analysis (IVA), a pseudo-randomization technique, to control for overt and hidden biases. Health service areas (HSAs) were used to define the instrumental variable. Low risk patients had Gleason scores ⬍ 7 in 2003-2007 and Gleason scores 2-7 in 1992-2002. RESULTS: The population-based cohort consisted of 29,775 men, of which 39% received PADT. For the low-risk group, PADT was not associated with lower use of any cancer therapy (Hazard Ratio [HR] ⫽1.02, 95% C.I.0.94-1.11) and was associated with increased usage of palliative cancer treatments (Hazard Ratio [HR] ⫽1.15, 95% C.I. 1.03-1.29), chemotherapy (HR⫽1.23, 95% CI 1.00-1.51), and risk of metastases (HR⫽1.24, 95% CI 1.00-1.53). For the high risk group, there was a trend toward lower utilization of future cancer treatments and metastases, but the differences were not statistically significant. CONCLUSIONS: For men over 66 years of age with low-risk prostate cancer, PADT does not reduce the risk of metastases or lower the usage of palliative treatments. The adverse effects of ADT should be weighed with the potential benefits when making treatment decisions. Source of Funding: This study was supported in part by NCI grant # R01 CA116399 and CINJ core grant NCI CA-72720-10.