Patient preferences for duration of adjuvant trastuzumab for HER2+ breast cancer.

Abstract

e12518 Background: A recent meta-analysis of reduced duration adjuvant trastuzumab trials demonstrated that 6 months was noninferior to 12 months for early HER2+ breast cancer. However, US oncologists usually prescribe 12 months despite permissive NCCN guidelines indicating “up to 12 months.” Given apparent clinical equipoise, this treatment option could be an exemplar for patient choice and shared decision-making (SDM) in the clinic. Thus, we elicited patient preferences on adjuvant trastuzumab duration when presented with data from the meta-analysis and the PERSEPHONE trial as infographics with either point or range estimates of efficacy and toxicity. Methods: We surveyed women with breast cancer from December 2024 to June 2025 who were diagnosed within 5 years or receiving active treatment at the University of Chicago. Surveys presented an infographic that was developed through patient feedback and included 5-year disease-free (DFS) and overall survival (OS) from the meta-analysis for 6 vs 12 months. Surveys also presented data on cardiotoxicity causing trastuzumab to be discontinued permanently and severe fatigue during treatment, both from PERSEPHONE data. Out-of-pocket (OOP) cost estimates were based on simulations (Table). Patients were randomized to see efficacy and toxicity attributes as either point or range estimates. Patients indicated their binary choice for 6 or 12 months and their percent chance of choosing 6 months. Multivariable regression models were used to adjust for clinical factors. Results: Of 208 respondents, 65% had Stage I / II disease, 22% were HER2+, and 6% were receiving trastuzumab at the time of the survey. Most patients (70%) preferred 6 months in the discrete choice, and the median probability of choosing 6 months was 80% (IQR 50-95%). While patients did not differ in their percent chance of choosing 6 months when presented with point vs range estimates, patients who saw the range estimate had higher odds of making the binary choice of 6 months (aOR 2.27, p=0.01). Conclusions: When reviewing a patient-friendly infographic of trial data, most patients chose 6 months of adjuvant trastuzumab rather than 12 months. This suggests that an absolute difference of 1% in DFS and OS was not large enough for patients to prefer 12 months. This preference was even stronger when the infographic included uncertainty around efficacy and toxicity through range estimates. Oncologists wishing to actively engage in SDM with their patients could use this preference elicitation methodology to ensure that adjuvant trastuzumab duration aligns with patients’ preferences and values. Infographic attributes. Point Estimates Range Estimates 6 Months 12 months 6 Months 12 Months 5-Year DFS 85% 86% 84%-86% 85%-87% 5-Year OS 92% 93% 91-93% 92-94% Heart problems-trastuzumab stopped 3% 8% 2-4% 7-9% Severe Fatigue (during treatment) 9% 12% 8-10% 11-13% OOP Cost (estimated) $4,000 $8,000 $4,000 $8,000 Number of Appointments 9 18 9 18