The alteration of p16 protein in invasive cervical cancer

Objective : Recently p16 gene has been found as a new factor for cervical carcinogenesis. The purpose of this study is to investigate the p16 protein alteration in invasive cervical cancers, and to find the correlation with the p53 protein overexpression, HPV infection and the clinicopathologic prognostic parameters, as well as to predict the prognosis by examining the influences of the p16 gene, p53 gene, HPV to the survival rate. Material & Methods : We examined 29 invasive cervical cancer patients who visited and operated in Obstetrics & Gynecology department of Kosin University Gospel Hospital from Jan. 1994 to Dec. 1995. We investigated clinicopathologic parameters and p16 protein alteration, p53 protein overexpression, HPV 16, 18 infection in these patients. p16 protein and p53 protein were examined by immunohistochemistry method and HPV was done by PCR method. The survival rate was examined by Kaplan-Meier method. Results : The rate of p16 protein alteration, p53 protein overexpression, HPV infection were respectively 31% (9/29), 72.4% (21/29), 80.6% (26/29), and all of these factors had no statistical correlations with the clinicopathologic parameters (p>0.05). Among the 21 positive cases for p53 protein overexpression, p16 protein alteration was positive in 6 (28.6%), negative in 15 (71.4%) cases and among the 8 negative cases for p53 overexpression, p16 showed positive in 3 (37.5%), negative in 5 (62.5%). Finally among the 26 positive cases of HPV infection, p16 alteration was positive in 9 (34.6%) and negative in 17 (65.4%) and all of the 3 HPV infection negative cases showed no p16 alteration. The p16 alteration had no significant correlation with the p53 overexpression and HPV infection. The total 5 years survival rate in 29 cases of invasive cervical cancer patients was 86.2%. In the negative group of p16 protein alteration the survival rate was 80% and the positive group was all alive. In the positive groups of p53 protein overexpression and HPV infection the survival rate were 80.9% and 84.6% respectively and the negative groups were all alive. And these factors had no significant correlation with the survival rates. Conclusion : This results indicate that p16 protein alteration had no correlation with clinicopathologic prognostic parameters and survival rates in invasive cervical cancer. In addition p16 protein alteration had no correlation with p53 protein overexpression and HPV infection respectively.