Abstract PS2-41: Supplemental contrast enhanced mammography screening of women with elevated risk of breast cancer

Objective and Rationale: To investigate the utility of screening Contrast Enhanced Mammography (CEM) imaging as a supplemental screening tool in women at elevated risk for breast cancer. Materials and Methods: This prospective, single institution, IRB approved observational study was conducted in asymptomatic women 35 years of age or older who were deemed at elevated risk of breast cancer, defined as IBIS v.8.0 lifetime risk of breast cancer score >15% or a prior personal history of breast cancer. Enrollment started in January 2019 and is on-going. An interim data analysis was performed. Women were invited to undergo supplemental CEM screening within 180 days of negative (BI-RADS 1 or 2) conventional 2D/3D screening mammography (MG). Patients with prior screening MBI, ultrasound or MR imaging within 12 months were excluded from study participation. Outcome measures were supplemental cancer detection rates, sensitivity, specificity, positive predictive value, and negative predictive value of CEM, along with their 95% confidence intervals, as well as the biologic profiles of MG-occult, CEM detected cancers. Results: A total of 351 women were enrolled in this prospective study over a 20-month period. To date, we have 1 year follow up on 106 cases with negative follow-up MG. Average age of the participants was 56 years ± 9.44 (standard deviation); 11 patients had screening 2D MG, 333 had combined 3-D and 2-D screening MG; 309 dense and 37 non-dense breasts based on ACR BI-RADS categories. CEM depicted 8 additional breast cancers (table 1), which were otherwise MG occult, for an overall supplemental cancer detection rate of 22.7 per 1000 patients, 95% CI (9.9, 44.3). 1 false negative cancer on CEM imaging which was further detected on MR imaging only. Biopsy revealed 16 benign changes (16/28=57%), 4 high-risk lesions (4/28=14%), and 8 breast cancers (8/28=29%) (table 2). CEM imaging screening offered high specificity (0.942, 95% CI (0.917, 0.967), high NPV 0.997, 95% CI (0.991, 1.000) and moderate PPV (0.286, 95% CI (0.118, 0.453) and sensitivity (0.889, 95% CI (0.684, 1.000)). Size of CEM detected cancers ranged from 7 to 57 mm. Conclusion: This pilot trial demonstrates a supplemental cancer detection rate of 22.7 per 1000 during prevalence round of CEM screening in women at an elevated risk for breast cancer. These initial results are comparable to results reported for high-risk surveillance MR imaging. Larger, multi-institutional high-risk CEM trials are needed for those patients who are not otherwise undergoing regular supplemental surveillance MR imaging. Citation Format: Bhavika K. Patel, Victor Pizzitola, Donald Northfelt, Karen Anderson, Marina Giurescu, Gina Mazza, Roxanne Lorans, William Eversman, Richard Sharpe, Juliana Kling, Denise Millstine, Ernst Brenda, Patricia Cronin, Heidi Apsey, Jennifer Palmieri, Barbara Pockaj, Michele Halyard. Supplemental contrast enhanced mammography screening of women with elevated risk of breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-41.