p53 and follow-up of colorectal adenocarcinomas

Circulating p53 antibodies (ELISA method), p53 genetic alterations (SSCP), and protein overexpression (immunohistochemistry) were studied in 41 patients with colorectal adenocarcinomas and 10 control patients. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA 19-9) were evaluated in parallel. Ten patients with p53 antibodies and p53 overexpression were selected. Tumor DNA extracts from these 10 patients were analyzed by SSCP. Of all 41 patients, 10 (24%) showed significant levels of p53 antibodies, and p53 accumulation was detected in 20 (48%) patients. In six patients, p53 antibody concentrations decreased rapidly after surgery; in two patients, these levels returned to normal values. Of the 10 selected tumors, eight revealed TP53 gene mutations. Only two patients with high values of both CEA and CA 19-9 developed p53 antibodies. In conclusion, beside classical tumor markers, circulating p53 antibodies may be considered as additional markers for the management of patients with colorectal adenocarcinomas.