Factors associated with malignant biopsy results for newly detected lesions within one year after breast cancer surgery.

Rationale and objectives: This study aimed to identify the factors associated with malignant biopsy results for new lesions within one year after breast cancer surgery.

Materials and methods: This retrospective study included 192 lesions from 186 patients who underwent biopsy for newly developed breast lesions within one year of breast cancer surgery. All patients underwent breast ultrasound (US) at 6 months and breast US with mammography one year after surgery. We analyzed the biopsy results, patient age, characteristics of previous cancers (histologic type, stage, molecular subtype, histologic and nuclear grade, Ki-67 index, extensive intraductal component, lymphovascular invasion (LVI)), history of neoadjuvant chemotherapy (NAC), adjuvant therapy, and characteristics of biopsied lesions (location, mode of detection, imaging features, and Breast Imaging Reporting and Data System category). Multivariate logistic regression was performed to predict malignant results after a biopsy of the new lesion in the early postoperative period.

Results: The mean patient age was 49.0 (range, 28-82) years. During follow-up, 137 lesions developed in the ipsilateral remnant breast or mastectomy bed, and 55 lesions developed in the contralateral breast. In total, 37 (19.3%) of the biopsied lesions were malignant, and the following conditions were associated with malignant results in the newly detected lesions: irregularly shaped hypoechoic mass with increased vascularity, presence of previous LVI, history of NAC, and no history of adjuvant radiotherapy or hormone therapy in the indicated patients.

Conclusion: Active biopsy may be warranted for new lesions with suspicious imaging findings in the breast or operation bed of patients with LVI, a history of NAC, and no history of adjuvant radiotherapy or hormone therapy, even within one year of breast cancer surgery.