Expression of p16 in serous ovarian neoplasms.

PURPOSE We aimed to examine p16 protein expression in ovarian serous neoplasms along with normal ovarian tissues. MATERIALS AND METHODS P16 expression was immunhistochemically evaluated in 86 ovarian serous neoplasms (21 cystadenomas, 20 borderline tumors and 45 carcinomas) and 21 non-neoplastic ovarian tissue. The results were also compared with histopathological grade in serous adenocarcinomas. RESULTS P16 expression rates for benign, borderline ovarian tumors and ovarian cancer were 14.2%, 85% and 86.6%, respectively. It was significantly higher in carcinomas (p < 0.001) and borderline tumors (p < 0.001) compared to cystadenomas. No immunoreactivity was found in the non-neoplastic ovarian surface epithelial cells. The percentage of p16 expression did not change significantly with histological grade in carcinomas. CONCLUSION P16 expression is strong and widespread involving most tumor cells in serous papillary ovarian carcinomas, and is probably an early event.