The negative predicative value of breast fine-needle aspiration biopsy: the Massachusetts General Hospital experience

Breast fine-needle aspiration biopsy (FNAB) has been increasingly accepted as an important triage tool for the evaluation of breast lumps. We examined the clinical utility and diagnostic accuracy of a negative breast FNAB result by studying 450 breast aspirates in 413 patients (average age 45 years) with a "negative" or benign cytologic interpretation performed at Massachusetts General Hospital over a 4-year period. Of these patients, 121 (29%) underwent subsequent biopsy and 17 (4%) were found to have malignancy (3% of total negative FNABs; 14% with histology). None of these 17 patients had a triple negative test. A cohort of 115 patients had documentation of negative physical, radiologic, and cytologic examinations (the triple negative), none of whom were found to have malignancy on histologic or at least 2-year clinical follow-up (negative predictive value [NPV] = 100% with a triple-negative test). Outside of the triple-negative test, the NPV of a negative breast FNAB is reduced with a false-negative rate of 7%. However, in the setting of a triple-negative test, the NPV in our patient population was 100%, reassuring the patient and clinician that clinical follow-up and not surgical intervention was sufficient for proper patient care.