Autoantigens in breast cancer tissue.

Two antigens in specimens of human breast cancer have been identified as autoantigens. One antigen appears to be an IgG Fc fragment; the other, an IgG Fab fragment. Antibodies in sera of cancer patients directed against these antigens have also been identified. These autoantibodies occur in patients with breast cancer as well as other cancers, and rarely in patients with non-cancerous disease or in people screened in a detection center for breast diseases. The breast cancer patient found to have antibody directed against the IgG Fab antigen falls into a group that has improved two-year survival statistics over groups of patients who lack this antibody.