Can Short‐term Follow‐up with Ultrasound be Offered as an Acceptable Alternative to Immediate Biopsy or Surgery for Patients with First Ultrasound Diagnosis of BI‐RADS 4A Lesions?

Abstract

AbstractObjectivesTo evaluate the relevant factors associated with malignancy in Breast Imaging Reporting and Data System (BI‐RADS) 4A and to determine whether it was possible to establish a safe follow‐up guideline for lower‐risk 4A lesions.MethodsIn this retrospective study, patients categorized as BI‐RADS 4A on ultrasound who underwent ultrasound‐guided biopsy or/and surgery between June 2014 and April 2020 was analyzed. Classification‐tree method and cox regression analysis were used to explore the possible correlation factors of malignancy.ResultsAmong 9965 patients enrolled, 1211 (mean age, 44.3 ± 13.5 years; range, 18–91 years) patients categorized as BI‐RADS 4A were eligible. The result of cox regression analysis revealed the malignant rate was only associated with patient age (hazard ratio (HR) = 1.038, p < 0.001, 95% confidence interval (CI): 1.029–1.048) and the mediolateral diameter of the lesion (HR = 1.261, p < 0.001, 95% CI: 1.159–1.372). The malignant rate for patients (≤ 36 y) with BI‐RADS 4A lesions (the mediolateral diameter ≤ 0.9 cm) was 0.0% (0/72). This subgroup included fibrocystic disease and adenosis in 39 patients (54.2%), fibroadenoma in 16 (22.2%), intraductal papilloma in 8 (11.1%), inflammatory lesions in 6 (8.3%), cyst in 2 (2.8%), and hamartoma in 1 (1.4%).ConclusionsPatient age and lesion size are associated with the rate of malignancy in BI‐RADS 4A. For patients with lower‐risk BI‐RADS 4A lesions (≤ 2% likelihood of malignancy), short‐term follow‐up with ultrasound may be offered as an acceptable alternative to immediate biopsy or surgery.