Correlation between p53 expression and
 hepatocellular carcinoma differentiation grade

Abstract

Relevance: Hepatocellular carcinoma (HCC) is one of the world’s most common liver cancers and fatal malignant neoplasms. According to GLOBOCAN 2018, liver cancer ranks sixth in incidence (842,000 new cases) and fourth in mortality
 (782,000 deaths) globally. In Kazakhstan, there is an increase in HCC incidence from 879 cases in 2016 up to 984 cases in 2017,
 which amounted to 5.5 cases per 100 000 population. In 2017, the five-year survival rate was 23.7%.
 The mutations in the p53 gene that encodes the p53 protein are most frequent in HCC (35.2%). A high level of nuclear expression of p53 and a decrease in apoptosis of tumor cells with a simultaneous increase in their proliferative activity, noted in
 HCC cells, are important for the prognosis of the disease. There is a correlation between poor prognosis, a decreased survival of
 patients with HCC, and high expression of the p53 oncoprotein in HCC.
 U. Nzeako et al. have revealed a strong correlation of HCC histological differentiation with the patient survival rate. Therefore, a study of the correlation between p53 expression and HCC differentiation grade is very relevant.
 The purpose of this study was to analyze the correlation between p53 expression and HCC differentiation grade.
 Results: p53 was overexpressed in 18% of HCC cases; the expression was high in 62% and low in 20% of HCC cases. In
 well-differentiated HCC (G1), the p53-immunopositive nuclei expression was low in 10 cases and high in 2 cases. In moderately
 differentiated HCC (G2), p53 was highly expressed in 21 cases and overexpressed in 2 cases. In poorly-differentiated HCC (G3),
 p53 was overexpressed in 7 cases and highly expressed in 8 cases of HCC. The analysis of the correlation between p53 expression and HCC differentiation grade by Spearman showed a high correlation (r=0.79, p<0.01), evidencing a direct dependence
 of p53 expression level on HCC gradation.
 Conclusion: HCC differentiation grade highly correlates with p53 expression level in immunopositive nuclei of HCC cells.
 The obtained data evidences a dependence between p53 expression level and HCC gradation.