DNA flow cytometry applied to fine needle sampling of human breast cancer

Breast cancer cells can be obtained directly from the patient with minimal trauma by fine needle sampling (FNS). A method was developed that enabled us to prepare tumor cell nuclei for ploidy determination by flow cytometry (FCM). Fine needle sampling was performed on 235 patients with clinically suspected malignancy. Two hundred sixteen specimens (92%) produced enough material for assessment; 206 were diagnosed as cytologically malignant. In 41 patients surgical specimens from the same tumors were available. Thirty-eight of these specimens (93%) were classified according to ploidy. No significant correlation was found between aneuploidy and clinical stage (size and lymph node involvement). The comparison of DNA histograms from 21 primary breast tumors and homolateral axillary lymph nodes showed mostly similar patterns. On the contrary, eight of nine synchronous bilateral cancers were shown to have different ploidy. Flow-cytometry-derived DNA histograms of fine needle samples could be a valuable tool in the management of breast cancer.