Association of Breast Tissue Composition on Preoperative Automated Breast Ultrasound With Accuracy of Cancer Multiplicity Evaluation and Recurrence-Free Survival in Patients With Early-Stage Breast Cancer

Objective: To investigate whether breast tissue composition on preoperative automated breast ultrasound (ABUS) is associated with the accuracy of cancer multiplicity evaluation and postoperative recurrence-free survival (RFS) in patients with early-stage breast cancer.Materials and Methods: This retrospective analysis included women with early-stage breast cancer (clinical Tis, T1-2/N0) who underwent ABUS and digital mammography (DM) between October 2019 and April 2021.Tissue composition on ABUS was assessed using the Breast Imaging Reporting and Data System background echotexture (BE) (homogeneous-fat, homogeneous-fibroglandular, or heterogeneous).In a subgroup of patients with mammographically dense breasts, the glandular tissue component (GTC) on ABUS were further stratified into high (moderate or marked) or low (minimal or mild).Multivariable logistic and Cox regression analyses were used to identify factors associated with accurate cancer multiplicity categorization (unifocal, multifocal/multicentric, or bilateral) using ABUS + DM, and with RFS, respectively.Results: Among 409 women (mean age standard deviation, 50.2 8.7 years), ABUS combined with DM yielded accurate cancer multiplicity categorization in 368 patients (90.0%).Neither BE nor GTC on ABUS affected the accuracy of categorization when ABUS was combined with DM.Over a median postoperative follow-up of 3.5 years, 11 recurrences occurred.Heterogeneous BE on ABUS (hazard ratio [HR] 11.24 [95% confidence interval [CI]: 2.82-44.92];P = 0.001), BRCA mutation ]; P = 0.004), and pathologic index cancer size (HR per 1-cm increase 1. 91 [1.13-3.23];P = 0.02) was independently associated with RFS.In patients with dense breasts, heterogeneous BE (HR 14.17 [95% CI: 2.69-74.60];P = 0.002) and high GTC ]; P = 0.002) on ABUS, BRCA mutation ]; P = 0.004), and pathologic cancer size (HR per 1-cm increase 2.62 [1.50-4.59];P = 0.001) was independently associated with RFS. Conclusion:In patients with early-stage breast cancer, heterogeneous BE and high GTC on preoperative ABUS, along with larger cancer size and BRCA mutation, was associated with worse RFS.However, BE and GTC did not affect cancer multiplicity evaluation when ABUS was used in combination with DM.