Abstract PS1-05-16: Patient understanding and impact on quality of life of serial minimal residual disease testing in patients with early-stage breast cancer

Abstract Background: There are no standard guidelines regarding radiographic or laboratory monitoring for patients with early-stage breast cancer (EBC) in the adjuvant setting. Detecting minimal residual disease (MRD) through circulating tumor DNA (ctDNA) is associated with significantly higher probability of later distant recurrence, although clinical utility data are lacking. To date, patient understanding and emotional burden of serial MRD testing are understudied. Here we evaluate the impact of MRD surveillance on quality of life among patients with EBC through investigating anxiety, depression, fear of recurrence, and patient comprehension. Methods: This IRB-approved prospective study enrolled patients with EBC undergoing ctDNA surveillance testing at Washington University in St. Louis. All patients underwent blood collection for Signatera MRD testing (Natera Inc.) and plasma-biobanking at up to 8 serial timepoints over 4 years. Baseline testing was prior to neoadjuvant treatment (n=12) or after surgery prior to adjuvant therapy (n=29). Testing results were shared with the patient and the treating oncologist. Surveys were conducted to assess patient understanding of the rationale for ctDNA testing, Fear of Recurrence (FCR4), Hospital Anxiety and Depression Scale (HADS), and level of comfort with ctDNA testing, at baseline blood collection and again 12 months after the initial MRD testing. Qualitative data were obtained through free-response survey items. Descriptive statistics were used to summarize the data. Results: 41 patients with triple-negative (n=17) or HR+ HER2- (n=24) EBC completed the baseline surveys with 26 patients completing both the baseline and 12-month assessments as of July 1st, 2025. The cohort included 31 (75.6%) White, 8 (19.5%) Black, and 2 (4.9%) Asian patients with a median age of 50 years. Qualitative analysis demonstrated patients had a strong understanding of the use of ctDNA surveillance with 30 of 35 (85.7%) patients who responded to the free text question accurately describing it as a tool for early detection of cancer in the blood. At 12 months, 88.5% of patients (n=23 of 26) answered that they would consider starting treatment based on results of ctDNA testing if recommended by their oncologist; however, 42.3% of patients (n=11 of 26) expressed financial concern with ctDNA testing if not covered by insurance. Among patients with longitudinal survey data (n=26), 10 patients had at least one positive MRD test and one patient had serially positive MRD testing prior to 12-month surveys. For patients with negative MRD testing at all timepoints (n=16), the mean FCR4 score did not significantly change from baseline to 12 months. Similarly, for those with positive MRD testing (n=10), FCR4 score did not significantly change at 12 months. The average HADS-anxiety score decreased from 5.15 at baseline (n=40) to 4.54 at 12 months (n=26), while the average HADS-depression score increased from 1.89 to 2.52; however, this change was not significant, including in the subset of patients with positive MRD testing. On a 0-5 scale of evaluating future attitudes toward use of ctDNA testing, the average rating was 4.1, indicating a favorable opinion of undergoing MRD testing. Conclusion: This prospective study demonstrated that the rationale for MRD testing was well understood and viewed favorably by patients. Regardless of MRD testing results, fear of recurrence and levels of anxiety or depression remained relatively stable from baseline to 1 year, indicating that testing was not associated with significant psychological stress in our study. Nearly half of patients expressed concerns about costs associated with testing if not covered by insurance. Larger, confirmatory studies are needed to further evaluate the impact of MRD surveillance on quality of life of patients with EBC. Citation Format: S. Tapiavala, I. Grigsby, N. Bagegni, F. Fa'ak, F. Ademuyiwa, K. Clifton, E. L. Podany, C. Cheng, A. J. Medford, C. Gianni, L. Gerratana, M. Lipsyc-Sharf, A. Bardia, M. Cristofanilli, C. X. Ma, A. A. Davis. Patient understanding and impact on quality of life of serial minimal residual disease testing in patients with early-stage breast cancer abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-05-16.