p53 expression, p21 expression and the apoptotic index in endometrioid endometrial adenocarcinoma

Aims: Although several genetic abnormalities are known to occur in endometr ial cancer, including tp53 gene mutation, the pathogenesis of this common m alignancy remains poorly defined. We investigated the relationship between overexpression of p53 protein, p21 protein expression and apoptosis in endo metrial carcinoma, Methods and results: Sixteen cases of endometrial carcinoma in which polyme rase chain reaction analysis had demonstrated the absence of a tp53 gene mu tation were selected on the basis of p53 protein expression: p21 protein ex pression and the apoptotic index were then determined for each case, The pr oportion of cells in each case ex-pressing p53 and p21 protein immunoreacti vity was compared with the apoptotic index, Overall, no significant correla tion was demonstrated between p53 and p21 immunoreactivity, or between eith er p53 or p21 and the apoptotic index. Conclusions: Factors other than p53 are involved in the regulation of p21 e xpression and apoptosis in endometrioid endometrial adenocarcinomas without p53 mutations. Despite the small numbers used in this study, the data sugg est a correlation between low levels of p53 immunoreactivity and apoptosis. We postulate that high levels of p53 immunoreactivity may be due to abnorm al stabilization of the p53 protein. Follow-up studies are needed with a la rger data set.