Positive predictive value of breast lesions of uncertain malignant potential (B3): Can we identify high risk patients? The value of a multidisciplinary team and implications in the surgical treatment

Background and aim: The use of conventional needle core biopsy for palpable masses and vacuum-assisted needle core biopsy for microcalcifications has significantly increased the preoperative diagnosis rate, but the strategy for those patients with lesions of uncertain malignant potential (B3) still remains controversial. The aim of this study was to evaluate the positive predictive value (PPV) of the malignancy of B3 lesions in order to establish their correct management in the setting of a multidisciplinary care pathway.

Methods: Data from all patients who had a Needle Core Biopsy (NCB) or a Vacuum-Assisted Needle Core Biopsy (VANCB) between 2005 and 2014 were retrospectively collected and analyzed. The B3 patients were discussed by the Multidisciplinary Team (MDT) deciding for surgery or for follow-up, based on a score in which clinical-instrumental factors and environmental factors were considered. The PPV of malignancy of all surgically excised B3 lesions was calculated.

Results: One hundred and seventy-eight B3 NCBs were included in the study and Atypical Epithelial Proliferation of Ductal Type (AEDPT) was the most represented subcategory. The final histopathology report of the 128 patients operated on showed 94 benign and 34 malignant lesions. The PPV of B3 patients referred to surgery was 26.5%.

Conclusion: B3 patients should be evaluated by a breast MDT in order to make the right therapeutic decision, in particular for patients with contrasting clinical/diagnostic findings. Larger prospective studies are required to assess the definitive PPV of each B3 subcategory.