AB013. SOH21AS104. Five years follow up of patient with uncertain malignant potential in the breast (B3 lesions): single centre study

Background: B3-breast lesions comprise a heterogeneous group of lesions with unknown malignant potential. Due to improvement in diagnostics, the incidence is increasing, while their value as a predictive factor for malignancy has steadily fallen. The treatment of this heterogeneous group varies with expertise and tools available. To assess the outcome of patients with B3 lesion, risk of malignancy and need for surgery.

Methods: This is a retrospective study included 63 patients histopathological proven B3 lesions on core needle/vacuum-assisted biopsy who subsequently underwent diagnostic excision biopsy-between January 2013 to December 2015—followed for more than 5 years. Rate of malignancy were reported for B3 in general and all B3 sub-categories. Logistic regression analysis identified associations between B3-subgroups and outcome after excision biopsy.

Results: A total of 63 patients were analyzed. The most commonly recorded subtype was intraductal papilloma with 46 patients (60.9%). Forty-seven percent of patient discharge after excision with no need for further follow up while 18% were upgraded to malignancy after surgical excision immediately; 4.76% developed it later within 2–3 year from the operation with initial B3 show evidence of atypia or high-risk patients (family history).

Conclusions: B3 lesions are mostly benign and operation should be considered if high risk patient or histopathology show evidence of high risk (atypia or atypical).

Keywords: Breast lesions; breast cancer; lesions of uncertain malignant potential