Roles of fine-needle aspiration and core needle biopsy in the diagnosis of breast cancer

Background There is controversy regarding which of the two biopsy methods, fine-needle aspiration (FNA) or core needle biopsy (CNB), should be routinely employed for diagnosis of breast cancer. The aim of this study was to evaluate the efficacy of FNA compared to CNB and to explore the value of performing both FNA and CNB. Methods Two hundred eighty-one patients with breast cancer received FNA alone (group 1: n = 182), CNB alone (group 2: n = 56), or a combination of FNA and CNB (group 3: n = 43). In group 3, FNA was combined with CNB because of an inadequate smear of FNA on immediate cytological examination. Subsequently, the patients underwent definitive surgery or open surgical biopsy based on the clinical findings, and the tumors were pathologically confirmed to be noninvasive or invasive breast cancer. Results There was no significant difference in the absolute sensitivity between group 1 (93% for FNA alone) and group 2 (86% for CNB alone). In group 3, on the other hand, the absolute sensitivity was significantly improved to 72% when FNA and CNB were combined (P<0.05), although it was only 42% for FNA alone and 63% for CNB alone. Conclusions The absolute sensitivity of FNA was equivalent to that of CNB when excluding patients who were converted from FNA to CNB based on immediate cytological examination. In the latter patients, however, it was improved by combining FNA and CNB. Therefore, these two techniques should be considered complimentary to one another.