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 low-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.