Papillary Serous Carcinoma of the Peritoneum Coexisting with or after Endometrial Carcinoma

Abstract Objective. Papillary serous carcinoma of the peritoneum (PSCP) coexisting with, or after, endometrial carcinoma (EC) is an extremely rare condition with no documented patient series. The aim of this investigation was to describe our experience in treating five patients diagnosed with PSCP synchronously with EC and two others who developed PSCP metachronously after EC. Methods. In this retrospective study, we reviewed and analyzed the clinical and pathological data of seven patients diagnosed and managed over a 10-year period. The diagnosis of PSCP was mostly based on the inclusionary criteria of the Gynecologic Oncology Group [1]. Disease stages were determined using the FIGO criteria for epithelial ovarian cancer (EOC) and endometrial carcinomas [2]. The treatment for PSCP was similar to that for advanced EOC and immunohistochemical studies were performed using archival material for PSCP and EC in order to determine p53, Bcl-2, HER2, and estrogen and progesterone receptor (ER, PR) status. Germline mutation analyses were performed for the two most common mutations pertaining to BRCA1 and the one most common mutation pertaining to BRCA2 genes only. Results. Five patients with PSCP and synchronous EC initially underwent surgical treatment. The remaining two underwent surgery originally for EC and, thereafter, for metachronous PSCP. All seven patients had advanced stages (III or IV) of PSCP and stage I only EC. At the time of analysis, four patients were alive. p53, Bcl-2, ER, and PR were found to have been expressed in various rates in both or one of the neoplasms. However, no HER2 was found to have been expressed, either in PSCP or in EC. All germline mutation analyses were negative. Conclusions. The results obtained in this study show that PSCP can occur either synchronously or metachronously with lower stage EC that is associated with advanced disease stages. We suggest that this clinical form of PSCP with synchronous or metachronous EC is a very aggressive and lethal clinical form and differs markedly from the vast majority of multiple gynecologic neoplasms of the upper genital canal diagnosed in the ovarian–endometrial group, of which EOC are mostly diagnosed as stage I diseases with high-rate cures.