Inactivation of the p53 gene, which codes for a tumour suppressor prot
ein, is known to occur in the majority of human malignancies. An ELISA
technique has been developed which has detected auto-antibodies to p5
3 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 b
reast cancer was 9.1%, compared to 29.4% in those with no family histo
ry (P=0.029). In women without clinical breast cancer, 4 out of 36 (11
.1%) of those with a positive family history were seropositive, compar
ed to 1 out of 73 control women. Auto-antibodies were more frequently
seen in the serum of breast cancer patients whose biopsies demonstrate
d overexpression of p53 protein. We conclude that auto-antibodies to p
53 may have a role in the molecular characterisation of familial breas
t cancer.