COMMENTS AND RESPONSES Observation Versus Initial Treatment for Prostate Cancer

TO THE EDITOR: In their cost-effectiveness analysis of treatment versus observation for low-risk prostate cancer, Hayes and colleagues (1) conclude that watchful waiting is less costly and more effective in terms of quality-adjusted life expectancy than the standard treatment of surgery or radiation. Their base-case results depend heavily on a hazard ratio (HR) for prostate cancer–specific death of 1.48 for treat-ment versus watchful waiting, which was obtained from an HR ob-served in the low-risk subgroup in PIVOT (Prostate Cancer Inter-vention Versus Observation Trial). However, the 95 % CI on this HR was extremely wide (0.42 to 5.24) because only 10 deaths from prostate cancer occurred in PIVOT in this subgroup (6 in the treat-ment group vs. 4 in the watchful waiting group). That such a pivotal parameter in the model was derived from such an unstable estimate should make readers cautious in interpret-ing the model’s findings. Furthermore, the point estimate used, be-sides being unstable, lacks credulity. As the authors stated, it is al-ready controversial that men with low-risk prostate cancer, who comprise up to 70 % of men with clinically localized disease and have less than a 6 % risk for prostate cancer–specific death through 15 years, are being routinely treated with radiation or surgery, given the fact that these treatments are known to greatly reduce quality of life (impotence and incontinence) and consume substantial health care resources. However, if it were widely accepted that such treat-ments also were associated with a 50 % increase in the risk for pros-tate cancer death (or death from treatment for this condition) com-pared with observation only, this situation would move well past controversial—it would be one of the greatest medical scandals in the United States in recent decades. Solid evidence for such an increased risk is clearly not available yet