Mapping expanded prostate cancer index composite to EQ5D utilities to inform economic evaluations in prostate cancer: Secondary analysis of NRG/RTOG 0415.

PURPOSE: The Expanded Prostate Cancer Index Composite (EPIC) is the most commonly used patient reported outcome (PRO) tool in prostate cancer (PC) clinical trials, but health utilities associated with the different health states assessed with this tool are unknown, limiting our ability to perform cost-utility analyses. This study aimed to map EPIC tool to EuroQoL-5D-3L (EQ5D) to generate EQ5D health utilities. METHODS AND MATERIALS: This is a secondary analysis of a prospective, randomized non-inferiority clinical trial, conducted between 04/2006 and 12/2009 at cancer centers across the United States, Canada, and Switzerland. Eligible patients included men >18 years with a known diagnosis of low-risk PC. Patient HRQoL data were collected using EPIC and health utilities were obtained using EQ5D. Data were divided into an estimation sample (n = 765, 70%) and a validation sample (n = 327, 30%). The mapping algorithms that capture the relationship between the instruments were estimated using ordinary least squares (OLS), Tobit, and two-part models. Five-fold cross-validation (in-sample) was used to compare the predictive performance of the estimated models. Final models were selected based on root mean square error (RMSE). RESULTS: A total of 565 patients in the estimation sample had complete information on both EPIC and EQ5D questionnaires at baseline. Mean observed EQ5D utility was 0.90±0.13 (range: 0.28-1) with 55% of patients in full health. OLS models outperformed their counterpart Tobit and two-part models for all pre-determined model specifications. The best model fit was: "EQ5D utility = 0.248541 + 0.000748*(Urinary Function) + 0.001134*(Urinary Bother) + 0.000968*(Hormonal Function) + 0.004404*(Hormonal Bother)- 0.376487*(Zubrod) + 0.003562*(Urinary Function*Zubrod)"; RMSE was 0.10462. CONCLUSIONS: This is the first study to identify a comprehensive set of mapping algorithms to generate EQ5D utilities from EPIC domain/ sub-domain scores. The study results will help estimate quality-adjusted life-years in PC economic evaluations.

Cost-Effectiveness of Primary Radiation Therapy Versus Radical Prostatectomy for Intermediate- to High-Risk Prostate Cancer.

PURPOSE: To compare, using a cost-effectiveness analysis, the quality-adjusted life expectancy (QALE) and cost between the 2 treatment options for intermediate- to high-risk prostate cancer: (1) radiation (RT) with androgen deprivation therapy (ADT) or (2) radical prostatectomy (RP) followed by adjuvant RT for patients with risk factors. METHODS AND MATERIALS: Our Markov model allowed patients to transition between health states with yearly probabilities of developing cancer recurrence and/or toxicity. Probabilities were assigned according to favorable intermediate, unfavorable intermediate, or high-risk prostate cancer groups. The primary analysis examined outcomes for patients aged 65 years, whereas secondary analyses explored the effects of younger age, elevated baseline cardiovascular risk, and the use of salvage therapy. One-way and probabilistic sensitivity analyses were performed. RESULTS: Across all primary and secondary analyses, and using a wide-range of assumptions, RT + ADT was the preferred treatment strategy for men with intermediate- to high-risk prostate cancer. The QALE was higher after RT + ADT by 0.5 to 1.14 quality-adjusted life years, compared with RP. Radiation plus ADT was cost-effective in all situations, falling beneath a threshold of $100,000 per quality-adjusted life year. Among all risk groups, a greater proportion of patients undergoing RP experienced single or multiple treatment toxicities. CONCLUSIONS: Radiation plus ADT may result in improved QALE compared with RP for intermediate- to high-risk prostate cancer. Although biochemical failure is similar between treatment groups, there is a higher rate of developing multiple toxicities among patients treated with upfront RP.

Longitudinal Trends in Costs of Palliative Radiation for Metastatic Prostate Cancer.

BACKGROUND: In recent years, palliative treatment of prostate cancer metastases has been characterized by the use of more complex radiation treatment, despite a lack of evidence demonstrating a clinical benefit of these technologies in the palliative setting. The impact of adoption of these technologies on the costs of palliative radiation treatment in patients with metastatic prostate cancer remains poorly understood in the general patient population. METHODS: The study was a retrospective analysis of Surveillance, Epidemiology and End Results (SEER) Medicare data of men aged 66 and older who died from metastatic prostate cancer between 2000 and 2007 and received radiation therapy for bony metastases in the last year of life. Direct costs were obtained from Medicare carrier and outpatient facility payments for all radiation treatment claims and adjusted to 2008 dollars. RESULTS: A total of 1705 men met study inclusion criteria. Total Medicare payments for radiation therapy for bony metastases in the last year of life increased by 44.4% from an average of $2,763 in 2000 to $3,989 in 2007, with the proportion of all payments accrued within hospital-based settings increasing from 48% to 57%. Complexity of radiation therapy techniques over the same period was characterized by use of less simple (30.1% to 23.3%) and more complex (59.9% versus 66.7%) radiation therapy. From 2000-2003 to 2004-2007, the use of shorter treatment courses (≤5 fractions) decreased from 22% to 14%, and the use of single fraction treatment courses decreased by half (6.3% to 2.9%; P≤.001). CONCLUSIONS: Between 2000 and 2007, palliative radiation therapy for bony prostate cancer metastases was characterized by the use of more advanced treatment technologies and prolonged radiation treatment courses. Further research investigating barriers to cost-effective palliation is warranted.

Changes in initial treatment for prostate cancer among Medicare beneficiaries, 1999-2007.

PURPOSE: In the absence of evidence from large clinical trials, optimal therapy for localized prostate cancer remains unclear; however, treatment patterns continue to change. We examined changes in the management of patients with prostate cancer in the Medicare population. METHODS AND MATERIALS: We conducted a retrospective claims-based analysis of the use of radiation therapy, surgery, and androgen deprivation therapy in the 12 months after diagnosis of prostate cancer in a nationally representative 5% sample of Medicare claims. Patients were Medicare beneficiaries 67 years or older with incident prostate cancer diagnosed between 1999 and 2007. RESULTS: There were 20,918 incident cases of prostate cancer between 1999 and 2007. The proportion of patients receiving androgen deprivation therapy decreased from 55% to 36%, and the proportion of patients receiving no active therapy increased from 16% to 23%. Intensity-modulated radiation therapy replaced three-dimensional conformal radiation therapy as the most common method of radiation therapy, accounting for 77% of external beam radiotherapy by 2007. Minimally invasive radical prostatectomy began to replace open surgical approaches, being used in 49% of radical prostatectomies by 2007. CONCLUSIONS: Between 2002 and 2007, the use of androgen deprivation therapy decreased, open surgical approaches were largely replaced by minimally invasive radical prostatectomy, and intensity-modulated radiation therapy replaced three-dimensional conformal radiation therapy as the predominant method of radiation therapy in the Medicare population. The aging of the population and the increasing use of newer, higher-cost technologies in the treatment of patients with prostate cancer may have important implications for nationwide health care costs.