Immunocytochemical detection of breast cancer cells: a comparison of three attachment factors

The evaluation of contaminating breast cancer cells in hematopoietic grafts is of considerable importance for monitoring the efficiency of purging procedures. We report a comparison of three systems for the in vitro detection and enumeration of metastatic breast cancer cells. Breast cancer cells from established cell lines were mixed with Daudi cells at dilutions ranging from 1:10 to 1:1,000,000, and a predetermined number were fixed in defined areas on microscope slides coated with one of the following attachment factors: (i) Cell-Tak Cell and Tissue Adhesive, (ii) 0.1% solution of Poly-L-Lysine, or (iii) Cel-Line HTC Super Cured slides. We employed a specificity-proven pancytokeratin antibody (A45-B/B3) and the alkaline phosphatase-antialkaline phosphatase (APAAP) staining technique. In multiple experiments, one breast cancer cell in 1,000,000 Daudi cells could reliably be detected in the Cell-Tak and Cel-Line systems and 1 in 100,000, with the Poly-L-Lysine system. The observed number of seeded cells showed a highly significant correlation with the number of cells seeded (p < 0.0001 in all cases). Finally, we used the Cell-Tak method to evaluate clinical material from various sources: from patients with primary carcinomas of the breast, prechemotherapy, and during various chemotherapeutic regimens, as well as from patients with metastatic disease. The system consistently detected tumor cells in bone marrow samples from these patients. All peripheral blood samples from patients with metastatic disease tested positive at incidences ranging from 5 to 19/10(6) peripheral blood mononuclear cells. This is a simple and reliable technique that allows rapid screening of large cell numbers with high resolution of positive cells.