Oligorecurrent prostate cancer has historically been treated with indefinite androgen deprivation therapy (ADT), although many patients and providers opt to defer this treatment at time of recurrence given quality-of-life and/or comorbidity considerations. Recently, metastasis-directed therapy (MDT) has emerged as a potential intermediary between surveillance and immediate continuous ADT. Simultaneously, “advanced” systemic therapy, in addition to ADT, has also been shown to improve survival in metastatic hormone-sensitive disease. This study aimed to compare the cost-effectiveness of treating oligorecurrent patients with upfront MDT prior to standard-of-care systemic therapy.
A Markov-based cost-effectiveness analysis was constructed comparing three strategies: (1) upfront MDT → salvage abiraterone acetate plus prednisone (AAP)+ADT → salvage docetaxel+ADT, (2) upfront AAP+ADT → salvage docetaxel+ADT, and (3) upfront docetaxel+ADT → salvage AAP+ADT. Transition probabilities and utilities were derived from the literature. Using a 10-year time horizon and willingness-to-pay threshold of $100,000/quality adjusted life year (QALY), net monetary benefit (NMB) values were subsequently calculated for each treatment strategy.
At 10 years, base case revealed total cost of $141K/$167K/$136K with QALYs of 4.63/4.89/4.00 – reflecting NMB of $322K/$322K/$263K for upfront MDT, upfront AAP+ADT, and upfront docetaxel+ADT, respectively. On probabilistic sensitivity analysis (PSA) utilizing Monte Carlo simulation (1,000,000 simulations), upfront MDT was the cost-effective strategy in 53.6% of simulations. PSA revealed 95% confidence intervals for cost ($76K-180K/$124K-224K/$103K-181K) and utility in QALYs (3.85-6.12/3.91-5.86/3.02-5.22) for upfront MDT, upfront AAP+ADT, and upfront docetaxel+ADT, respectively.
At 10 years, upfront MDT followed by salvage AAP+ADT is comparably cost-effective compared to upfront standard-of-care systemic therapy and may be considered a viable treatment strategy – especially in patients wishing to defer systemic therapy for quality-of-life or comorbidity concerns. Additional studies are needed to determine whether MDT causes a sustained meaningful delay in disease natural history, and whether any benefit exists in combining MDT with upfront advanced systemic therapy.
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