FINE-NEEDLE ASPIRATION TECHNIQUES FOR THE CHARACTERIZATION OF BREAST CANCERS

Fine needle aspiration biopsy (FNAB) is a well established method for diagnosing breast lesions, including cancers. FNAB does not require su rgery and uses only a small amount of material. FNAB can also be used to acquire material for special studies. This is especially useful wit h small tumors (less than or equal to 1 cm) when most of the material is needed to make a histologic diagnosis. Immunostaining techniques ca n be used on FNABs to investigate proliferation by bromodeoxyuridine u ptake or Ki-67 labeling. Immunostaining techniques can also be used to identify oncoprotein expression, such as of p53. Fluorescence in situ hybridization is a technique that can be used to gather cytogenetic i nformation directly from interphase tumor cells and is well suited for use with FNAB material because the harvested nuclei are intact and no cumbersome dissociation processing is needed. Flow cytometric techniq ues can be applied to FNAB material to study DNA content and S-phase f raction. Material acquired by FNAB can also be analyzed by the polymer ase chain reaction followed by mutation detection. In this report, the authors show the applicability of these various analytic approaches t o FNAB material from primary breast cancers. They show that it is esse ntial that the FNAB harvest is representative, ample, and well prepare d for the success of these studies.