Serum p53 auto-antibodies: incidence in familial breast cancer.

Inactivation of the p53 gene, which codes for a tumour suppressor protein, is known to occur in the majority of human malignancies. An ELISA technique has been developed which has detected auto-antibodies to p53 in the serum of 25.6% of 176 women with breast cancer, considerably higher than previously reported with an immunoblotting technique. The incidence of auto-antibodies in those cases with a family history of breast cancer was 9.1%, compared to 29.4% in those with no family history (P = 0.029). In women without clinical breast cancer, 4 out of 36 (11.1%) of those with a positive family history were seropositive, compared to 1 out of 73 control women. Auto-antibodies were more frequently seen in the serum of breast cancer patients whose biopsies demonstrated overexpression of p53 protein. We conclude that auto-antibodies to p53 may have a role in the molecular characterisation of familial breast cancer.