According to the results of a study published in the British Journal of Cancer, breast cancer is present in roughly one-third of women who have a borderline result (lesion of uncertain malignant potential) on a core needle biopsy of the breast.
The suspicion of breast cancer often first arises when a lump is detected in the breast during breast examination or a suspicious area is identified during screening mammography. In order to diagnose the cause of the suspicious area or lump in the breast, a physician will perform a biopsy. A biopsy can be performed on an outpatient basis. During a biopsy a physician removes cells or tissue for examination in the laboratory to determine whether cancer is present.
For some women, the results of the biopsy will be borderline (not clearly positive or negative for cancer). In the case of core needle biopsy, for example, results may be coded as “lesions of uncertain malignant potential.” Women who receive this result may undergo removal of additional tissue (excision biopsy) in order to definitively establish the presence or absence of breast cancer.
To provide information about the likelihood of breast cancer among women who receive a borderline result on core needle biopsy, researchers in Italy conducted a study among 328 women with a borderline result. Following the core needle biopsy, 279 of the women underwent an excision biopsy and the remainder received other follow-up.
- Breast cancer was found 35% (98 out of 279) of the women who underwent excision biopsy. The breast cancer was ductal carcinoma in situ (DCIS) in 61 women and invasive cancer in 37 women.
- Among all study participants (those who underwent excision biopsy as well as those who received other follow-up), 30% were found to have breast cancer.
- Risk of breast cancer was highest among women whose core needle biopsy indicated atypical ductal hyperplasia or lobular intraepithelial neoplasia.
The researchers conclude that for many women with a borderline result on breast core biopsy, the risk of breast cancer is high enough to warrant excision biopsy. Risk of breast cancer varies, however, and research is underway to better understand the risk of breast cancer in particular subgroups of women with a borderline result on core needle biopsy.
Reference: Houssami N, Ciatto S, Bilous M, Vezzosi V, Bianchi S. Borderline breast core needle histology: predictive values for malignancy in lesions of uncertain malignant potential (B3). British Journal of Cancer2007; 96:1253-1257.