Decision analyses in consideration of treatment strategies for patients with biochemical failure after curative therapy on clinically localized prostate cancer in the prostate-specific antigen era

BACKGROUND: The introduction of prostate-specific antigen (PSA) testing has not only shortened the time required to make diagnosis but changed the treatment strategies of localized prostate cancer. We conducted the decision analysis on its treatment focusing on patients with biochemical failure. METHODS: We developed a Markov model to calculate life expectancy (LE) and quality-adjusted life expectancy (QALE) stratified by age, comorbidity and tumor characteristics in patients with newly diagnosed prostate cancer or biochemical failure after curative therapy. For newly diagnosed patients, three treatment strategies were considered as primary managements: radial prostatectomy (RP), external beam radiotherapy (EBRT) and watchful waiting (WW). Managements considered for biochemical failure were: after RP, salvage radiotherapy (SRT), salvage hormonal therapy (SHT) and WW; and after EBRT, SHT and WW. Transition probabilities in the Markov model were derived from published studies. Quality of life (QOL) data to estimate QALE score were derived from 323 patients with prostate cancer. RESULTS: For patients with Gleason 2-6 cancer at diagnosis, WW yielded the greatest number of QALE. For patients with Gleason 7 cancer, it was controversial whether curative therapy was the preferred strategy. For patients with Gleason 8-10 cancer, curative therapy yielded the greatest number of QALE in younger patients without severe comorbidity. Patients' benefit from salvage therapy for biochemical failure after curative therapy depended on age, comorbidities, tumor characteristics and QOL effect. CONCLUSIONS: Our findings support the need for various treatment options, taking into consideration the patient's age, comorbidity and the QOL effect in the aging society.