Beyond the Guidelines: Evaluating BI-RADS 3 Lesions in a High-Suspicion Breast Cancer Population: Outcomes and Clinical Implications.

Objective

BI-RADS category 3 lesions are typically benign (<2% malignancy risk), managed with follow-up imaging, but their upgrade to BI-RADS 4 may indicate malignancy, particularly in high-risk patients. This study evaluates malignancy risk and predictors among BI-RADS 3 lesions upgraded to BI-RADS 4 in a cohort with a high prevalence of breast cancer history.

Methods

We retrospectively analyzed 352 patients undergoing breast ultrasound from June 2021 to June 2023, with 123 categorized as BI-RADS 3. Of these, 17 patients (18 lesions) were upgraded to BI-RADS 4 and biopsied. Data included age, prior breast cancer history (100/123, 81.3%), lesion characteristics (size, number, morphology), and histopathology. Descriptive statistics, binomial tests, Fisher's exact tests, and logistic regression were used to assess upgrade rates, malignancy rates, and predictors, with significance at p=0.05. RESULT The upgrade rate was 13.8% (17/123; 95% CI: 8.5-21.0%), significantly exceeding the ACR's <2% benchmark (p=0.05). Among upgraded lesions, 11.1% (2/18; 95% CI: 1.4-34.7%) were malignant (recurrent breast cancer, lymphomatous lymph node), also surpassing the <2% benchmark (p=0.05). Benign outcomes mainly included stromal fibrosis (38.9%) followed by benign lymphadenopathy (27.8%), and fibroadenoma (22.2%). Lesion size (OR=1.15 per mm, p=0.05) and multiple lesions (OR=3.2, p=0.05) predicted malignancy, while age, cancer history, and morphology were not significant (p>0.05).

Conclusion

The high upgrade and malignancy rates in this high-risk cohort suggest that BI-RADS 3 lesions with larger size or multiple foci, particularly in breast cancer survivors, may warrant earlier biopsy to detect malignancy, thereby emphasizing the need for refined surveillance criteria.