Fluorescent Antibody Studies of Human Breast Cancer<xref ref-type="fn" rid="FN1">1</xref><xref ref-type="fn" rid="FN2">2</xref>

Abstract

Indirect immunofluorescence studies with sera from breast cancer patients were conducted on cell lines derived from human breast cancers. A new antigen was demonstrated in 2 primary cell cultures of 11 primary and established lines of breast carcinoma studied. Eighty-five percent of cells per field demonstrated an intense granular cytoplasmic fluorescence. Thirty-five additional cell lines of primary and established cultures derived from normal cells and from tumors of non breast origin including 7 human sarcoma cultures were negative where tested with positive sera. Ninety-one percent (22/24) of sera of breast cancer patients free of metastatic disease obta ined 7–10 days after surgery were positive for antibody, whereas only 20% (4/20) of sera of age- and parity-adjusted normal donors were positive. Absorption studies with extracts of cell cultures of sarcomas and of a cell culture AIAb of breast origin (antigen negative) did not remove fluorescent antibody activity. A titer as high as 1 : 160 was found in the serum of one breast cancer patient. The antibody class was identified as predominantly IgG.