Incorporating margin status information in treatment decisions for women with ductal carcinoma in situ: a decision analysis

Abstract

To integrate margin status information into the decision to undergo radiation therapy (RT) following breast-conserving surgery (BCS) for women with ductal carcinoma in situ (DCIS). We developed a decision-analytic Markov model to project quality-adjusted life years (QALYs) for a hypothetical cohort of 55-year-old women with DCIS over a lifetime horizon treated with or without RT following BCS. We estimated the transition probabilities of local DCIS and invasive recurrences based on the margin status (free, close, or positive) from a systematic literature review. Other probability estimates and utilities were collected from the published literature. Using the conditions defined in this model, expected QALYs after BCS alone were better than those after BCS with RT under the free-margin scenario (15.72 vs. 15.58) and worse in the close-margin (15.44 vs. 15.50) and positive-margin scenarios (15.20 vs. 15.33). The probability of receiving a salvage mastectomy varied from 10 to 28%, depending on margin status and treatment. One-way sensitivity analyses showed that the optimal treatment was sensitive to patients' preferences and RT side effects. Probabilistic sensitivity analyses revealed that BCS alone would be the best strategy in 54% of the cases under the free-margin scenario, 48% under the close-margin scenario, and 44% under the positive-margin scenario. This study illustrates that margin status is able to provide supplementary information on the decision of DCIS treatment. Our analyses also highlight the importance of patients' preferences in decision making. Our findings suggest that RT is not necessary for all patients with DCIS undergoing BCS.

Management of Ductal Carcinoma In Situ Patients Receiving Postoperative Radiotherapy after Breast Conserving Surgery: Hacettepe Experience

“…As RT techniques continue to improve, such as the use of modern megavoltage regimen, small fraction sizes, and with computed tomography treatment planning exposure of nearby normal tissues is reduced also potentially decrease RT side effects. 4 We observed no serious late effects due to the RT.…”

“…[1][2][3] Three large multicenter randomized control trials (RCTs) have documented the benefits of RT after BCS with 50 to 60% reduction of the risk of local recurrence (LR). 4 However, only less than 40% of patients treated with BCS received postoperative RT. 5 Recently, several studies showed that RT after BCS is an effective option for local control with acceptable toxicity.…”