Cost-Effectiveness of Adjuvant Immunotherapy in Cancer Treatments

Importance: Adjuvant immunotherapy is increasingly integrated into cancer care to reduce recurrence and improve survival. However, its high cost raises critical concerns regarding affordability and economic value across diverse health system contexts. Objective: To synthesize published economic evaluations of adjuvant immunotherapy and assess cost-effectiveness outcomes, quality-adjusted life-year (QALY)/life-year (LY) gains, and methodologic approaches. Evidence Review: A systematic search was conducted of PubMed, Scopus, Embase, and Web of Science for full economic evaluations published between January 1, 2015, and January 31, 2025. Eligible studies included cost-effectiveness or cost-utility analyses of adjuvant immunotherapy across any cancer type. Data were extracted on cancer type, treatment strategy (single vs combination therapy), treatment line, model structure, health utility instruments, funding sources, and cost-effectiveness outcomes. Methodologic quality was appraised using the Criteria for Health Economic Quality Evaluation 2023. Due to heterogeneity of health systems, findings were narratively synthesized. Findings: The analysis included 69 studies covering a range of cancer types, most frequently non-small cell lung cancer and melanoma. Of these, 46 (67%) evaluated first-line therapy with single-agent checkpoint inhibitors. Higher QALY/LY gains were consistently reported among the adjuvant immunotherapy group (63 [91%]), particularly for non-small cell lung cancer, industry-funded studies, and combination regimens. More than half of the evaluations (40 [58%]) concluded that adjuvant immunotherapy was cost-effective, although results varied by cancer type, model assumptions, drug pricing, funding organizations, and country-specific thresholds. Markov modeling was the dominant analytic approach (46 [67%]) and EuroQol 5 Dimensions was the most commonly used health utility instrument (56 [81%]). Conclusions and Relevance: This systematic review found that adjuvant immunotherapy was frequently associated with meaningful QALY/LY improvements and was often considered cost-effective in high-risk or first-line settings. However, economic value remains context-specific, shaped by treatment strategy, drug costs, and modeling assumptions. These findings support the selective, value-based adoption of adjuvant immunotherapy and underscore the need for transparent, standardized economic evaluations to guide reimbursement and policy decisions.