We estimate the lifetime implications of daily treatment with finasteride following the results of the Prostate Cancer Prevention Trial (PCPT). In this trial, prostate cancer prevalence was reduced by 25%; however, an increase in the number of high-grade tumors among the treatment group necessitates the long-term projection of the likely benefits and costs.

We use a Markov decision analysis model with data from the trial, the SEER program, and published literature. The model measures the cost per life-year and cost per quality-adjusted life-year (QALY) gained for a cohort of men age 55 years who initiate preventive treatment with finasteride.

Finasteride is associated with a gain of 6 life-years per 1000 men treated at an incremental cost of $1660000 per life-year gained. The quality-adjusted analysis results in 46 QALYs gained per 1000 men treated at an incremental cost of $200000 per QALY gained, due primarily to the favorable effects of finasteride on benign prostatic hyperplasia. Under the assumption that the increase in high-grade tumors observed among finasteride treated men is a pathologic artifact, the incremental costs are $290000 per life-year gained and $130000 per QALY gained.

The cost burden associated with finasteride is substantial, while its survival benefit is small and only realized many years after initiating treatment. To achieve an incremental cost below $100000 per QALY gained, the price of finasteride must be reduced by 50% from its current average wholesale price and finasteride must be shown to prevent high-grade as well as low-grade disease.