The Study of p53 Expression and DNA Ploidy in Colorectal Carcinoma

Lee, Ji Shin; Cheon, Kwang Soo; Park, Chang Soo

Abstract

Mutation of the p53 gene frequently results in overexpression of the p53 protein and loss of its tumor-suppressing properties. The overexpression of the p53 gene could be an indicator of rapid proliferation, poor differentiation, advanced stages, or poor prognosis. The prognostic value of the overexpression of the p53 gene in colorectal carcinoma is equivocal. The presence of DNA aneuploidy has been described as a powerful adverse prognostic indicator in relation to survival. To investigate the prognostic significance of p53 expression, and the relationship with DNA ploidy, 92 cases of colorectal carcinomas were analyzed. The overexpression of p53 gene product was present in 50(54.4%) of 92 cases. p53 expression only correlated with recurrence or metastasis during the follow-up periods (p=0.045). DNA aneuploidy was observed in 32(39.1%) of 82 cases. DNA ploidy was strongly associated with lymph node invasion(p=0.005), Dukes' stage(p=0.003), TNM classification (p=0.003), and recurrence or metastasis during the follow-up periods (p=0.045). The frequency of DNA aneuploidy was higher in the p53-positive colorectal carcinomas(58.3%) than in the p53-negative colorectal carcinomas (21.6%) (p=0.003). p53-positive colorectal carcinomas had a higher rate of cell proliferation than p53-negative cases(p<0.001). These results suggest that checking the p53 expression and DNA ploidy could be useful prognostic indicators of colorectal carcinoma.