Methods & Results
The authors examined the incremental costs and quality-of-life outcomes of chemoprevention with 5-α reductase inhibitors (5ARIs) using a Markov modeling approach, focusing on men at high risk of developing prostate cancer (CaP). Their base models begin at 50 years of age and compare men with a variety of risk factors, ranging from a 10-year cumulative risk of developing CaP of 41.5–96.6%, as well as average-risk men with a 10-year cumulative risk of 2.4%.[2,3]
Their models allow men with different risk profiles and different starting ages to either be treated or untreated with 5ARIs for 10 years and estimate the time they spend in six health states: healthy without benign prostatic hyperplasia (BPH) or CaP, BPH alone, CaP at risk for recurrence within 10 years of diagnosis, CaP with recurrence, or CaP with no risk of recurrence. In contrast to prior studies that quantified years of life saved over a lifetime horizon, this study focuses on quality-adjusted life years (QALYs) spent in the model's health states within 10 years of initiation of chemoprevention. Notably, the utility estimates were 0.92 for 50–59-year-olds, 0.91 for 60–79-year-olds, 0.96 for BPH, 0.84 for men with a diagnosis of low-grade CaP and 0.79 for high-grade CaP.
Key costs include 5ARI treatment (US$982 per year), costs of CaP work-up, initial cancer treatment costs, and cost of BPH treatment, including α-blockers and costs of transurethral resection of prostate (TURP). Many health state probabilities varied by age, such as the probability of experiencing BPH, which ranged from 0.075 for men aged 40–49 years, and 0.65 for men aged over 70 years. The model included rates of adverse events associated with CaP, including urinary and bowel incontinence, impotence and erectile dysfunction.
The primary finding was that the cost–effectiveness of 5ARI chemoprevention varied by risk of CaP. For men starting at 50 years of age with a 10-year cumulative risk estimate of CaP of 2.4%, the average increase in costs was US$7421 per patient for a gain of 0.086 QALYs. The incremental cost–effectiveness ratio (ICER) for chemoprevention relative to no chemoprevention was US$86,511. The authors observed much more favorable cost–effectiveness profiles among men with multiple risk factors. In one subgroup of men with prior negative biopsy, elevated prostate-specific antigen (PSA) and other risk factors associated with a 10-year cumulative risk of CaP of 63%, the average costs were US$2761 per patient for average gain of 0.149 QALYs. This yielded an ICER of US$18,490. In sensitivity analyses, the authors report that starting at age 40 years increased the ICER to US$313,471 among men with multiple risk factors.
Among the average risk population, the authors indicate that the only parameter that the model was sensitive to was the utility associated with reducing BPH with 5ARI chemoprevention. When the baseline BPH utility with 5ARI chemoprevention was varied by ±20%, the ICER ranged from US$62,100 to $142,500. Among the high-risk men, the model was mostly sensitive to risk-reduction estimates of 5ARI chemoprevention, the utilities associated with CaP and BPH, and cancer treatment costs.
Expert Rev Pharmacoeconomics Outcomes Res. 2010;10(5):505-508. © 2010 Expert Reviews Ltd.
Cite this: Cost–Effectiveness of Prostate Cancer Chemoprevention among High-risk Men - Medscape - Oct 01, 2010.