Cost-Effectiveness Analysis of No Adjuvant Therapy Versus Partial Breast Irradiation Alone Versus Combined Treatment for Treatment of Low-Risk DCIS: A Microsimulation

PURPOSE:Adjuvant therapy in patients with ductal carcinoma in situ who undergo partial mastectomy remains controversial, particularly for low-risk patients (60 years or older, estrogen-positive, tumor extent < 2.5 cm, grade 1 or 2, and margins ≥ 3 mm). We performed a cost-effectiveness analysis comparing three strategies: no adjuvant treatment after surgery, a five-fraction course of accelerated partial breast irradiation using intensity-modulated radiation therapy (accelerated partial breast irradiation [APBI]-Alone), or APBI plus an aromatase inhibitor for 5 years.MATERIALS AND METHODS:Outcomes including local recurrence, distant metastases, and survival as well as toxicity data were modeled by a patient-level Markov microsimulation model, which were validated against trial data. Costs of treatment and possible adverse events were included from the societal perspective over a lifetime horizon, adjusted to 2019 US dollars and extracted from Medicare reimbursement data. Quality-Adjusted life-years (QALYs) were calculated based on utilities extracted from the literature.RESULTS:No adjuvant therapy was the least costly approach ($5,744), followed by APBI-Alone ($11,070); combined therapy was costliest ($16,052). Adjuvant therapy resulted in slightly higher QALYs (no adjuvant, 11.320; APBI-Alone, 11.343; and combination, 11.381). In the base case, no treatment was the cost-effective strategy, with an incremental cost-effectiveness ratio of $239,109/QALY for APBI-Alone and $171,718/QALY for combined therapy. The incremental cost-effectiveness ratio for combined therapy compared with APBI-Alone was $131,949. Probabilistic sensitivity analyses found that no therapy was cost effective (defined as $100,000/QALY of lower) in 63% of trials, APBI-Alone in 19%, and the combination in 18%.CONCLUSION:No adjuvant therapy represents the most cost-effective approach for postmenopausal women 60 years or older who receive partial mastectomy for low-risk ductal carcinoma in situ.