How Can Biopsy Miss Breast Cancer


If an abnormal mammogram turns up, a breast biopsy is the preferred follow-up procedure even though other options are available. Biopsy has long been considered the “gold standard” in the diagnosis of breast cancer.

Even a biopsy may not be 100 percent accurate. Research has shown that the false-negative rate for core biopsy, a type of needle biopsy, can be as high as 8 percent. Needle biopsies, in particular, are relatively inaccurate compared to surgical biopsies. A core needle biopsy, for example, may miss a cancerous tumor and take a sample of normal tissue instead.

In the case of fine needle aspiration, the evaluation may potentially be inaccurate because the tissue sample taken is very small. When used alone, up to about 10% of breast cancers may be missed. Consequently, when a fine needle aspiration does not find cancer, it may still need to be followed up with another type of biopsy, such as a core needle or surgical biopsy.