Serological and immunohistochemical determinations of p53 protein in diagnosis of endometrial cancer: a comparative...

The role of different methods for the determination of p53 protein was evaluated for the detection of endometrial cancer in humans.

p53 antigen was detected immunohistochemically in the cell nuclei of endometrial tumors and serologically in the serum of the same patients. The high performance liquid chromatography (HPLC) technique was used to measure serum levels of p53 protein after its partial purification on gel fiberglass affinity chromatography columns.

Image analysis of cellular concentrations of p53 protein revealed an increase from 12% in hyperplastic endometrium to 74% in adenocarcinomas. Image analysis has also revealed a strong correlation between cellular concentrations of p53 antigen and tumor grade (r = 0.54). Visual cell determination of p53 antigen was effective mainly among patients with benign lesions (r = 0.61). There was a positive correlation between cellular concentration of p53 protein in tumor tissue and its serum level in cancer patients (r = 0.44). The serum level of the cytoplasmic form of p53 antigen significantly increased in cancer patients (3 mg/ml) compared to the concentration in patients with benign disorders (0.7 mg/ml); a consequence of its higher concentration in tumor cells. Serum level of p53 antigen was highly active both in patients with non-cancerous lesions (r = 0.42) and in patients with cancer (r = 0.51). Diagnostic significance of tissue concentrations of estrogen and progesterone applies only to cancer patients: coefficients of correlation between these parameters and tumor gradation were 0.58 and 0.89, respectively.

Serum determination of cytoplasmic p53 antigen can reveal this oncoprotein in the early stages of cancer, or even foretell its development.