ベースラインPSA値による検診間隔の個別設定は前立腺癌スクリーニングの効率を改善する : 数理モデルを用いた社会経済学的考察

Abstract

In prostate specific antigen (PSA) -based prostate cancer mass screening, the optimal re-screening interval is still in question, although guidelines suggest that a prolonged interval would be safe and costsaving. We examined the socioeconomic feasibility of prolonged re-screening interval based on individual baseline PSA values. Markov decision-analytic models of prostate cancer screening were established for cost-effectiveness comparison of prolonged re-screening in men with low (≦1 ng/ml) PSA level (metainterval strategy) and annual re-screening in every participant (control strategy). Effectiveness and socioeconomic feasibility were evaluated according to quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER ; Δcost per ΔQALY), respectively. As a result, outcomes including cancer detection rates and stage shift suggested that these models well recapitulated actual prostate cancer mass screening. The meta-interval strategy was more cost-effective than the control strategy. The ICER for the control strategy with respect to the meta-interval strategy exceeded US$62, 000/QALY through the sensitivity analyses for every assumption. The meta-interval strategy was more effective and less expensive if the trade-off of impaired clinical outcomes caused by delayed detection was small. In conclusion, our models suggest that the meta-interval strategy is more cost-effective than annual screening. It can be even more effective if the interval is determined appropriately such that cancer can be detected within the therapeutic window.