THE RELATIONSHIP BETWEEN SERUM P53 AUTOANTIBODIES AND CHARACTERISTICSOF HUMAN BREAST-CANCER

Sera from 182 newly diagnosed breast cancer patients were assayed for antibodies to p53 using an enzyme-linked immunosorbent assay (ELISA) m ethod, and antibodies were detected in 48 (26%) compared with 1 out of 76 (1.3%) normal control volunteers (P = 0.0001). In breast cancer pa tients, autoantibodies were found in all stages of disease progression : carcinoma in situ, primary invasive breast cancer and in metastatic disease. In the subset of patients in whom sequential sera were assess ed over a 6 month period, changes in the p53 antibody titres were obse rved. The presence of antibodies to p53 correlated positively with hig h histological grade (P = 0.0012) and a history of second primary canc er (six positive out of eight cases). The incidence of autoantibodies was lower in those patients with a first-degree relative with breast c ancer (P = 0.046). Out of 68 patients, there was a significant correla tion between positive p53 autoantibody status and the detection of p53 protein in the tissue sections by immunocytochemistry (P=0.002). In t he seronegative patients, positive p53 tumour staining was strongly as sociated with a family history of breast cancer (P=0.009). The p53 pro tein overexpressed in heritable breast cancers may therefore be less i mmunogenic. The presence of p53 autoantibodies provides important addi tional information to immunochemistry and may identify patients with a ggressive histological types of breast cancer.