Combined analysis of ploidy and cell kinetics on fine-needle aspirates from breast tumors

DNA ploidy and cell kinetics determined by flow-cytometric (FCM) analysis have provided relevant information on the natural history of breast cancer. These highly feasible and evaluable assays are particularly appropriate for small samples from fine-needle aspirates (FNA) to complement cytologic information for diagnosis of breast lesions.

DNA content and the percentage of cells in the cell cycle phases were evaluated on FCM DNA histograms from 281 consecutive FNA of benign and malignant breast lesions.

FCM analysis was possible in 93% of FNA. Qualitative concordance in DNA content between FNA and surgical specimens was observed in 82% of the patients. Of the 145 aneuploid FNA, 144 (99%) were histologically diagnosed as carcinomas. The presence of only diploid clones was observed in 115 FNA: rapidly proliferating (S+G2M > 12%) diploid lesions proved to be histologically malignant in 67% of patients, and slowly proliferating diploid lesions were histologically benign in 79% of patients. False-positive results of ploidy and cell kinetics were observed in 1 and 10 patients, respectively. Of the 163 cancers evaluable for cytology and FCM, 158 were positive at cytology. The presence of aneuploid or of diploid rapidly proliferating clones in cytologically false-negative aspirates resulted in the detection of four additional cancers.

Flow cytometric analysis of ploidy and cell kinetics on FNA could be a valuable tool complementary to cytology for breast cancer diagnosis.