Detection of a status of microsatellite instability in tumors of patients with endometrioid adenocarcinoma of the ovaries and/or of uterine corpus

Introduction. Multiple primary malignant neoplasms of female reproductive organs are a rare pathology. However, over the past decades, there has been an upsurge of interest in the study of this phenomenon in oncology. This is particularly the case for the diagnosis of synchronous endometrioid adenocarcinoma of the ovaries and uterine corpus, which histogenetically belong to the same germ layer and have similar histological structure. Until recently, clinicians relied only on morphological examination in these cases, but with the development of molecular genetic technologies, new diagnostic possibilities have emerged. Aim. Is the detection of the status of microsatellite instability in tumors of patients with endometrioid adenocarcinoma of the ovaries and/or uterine corpus. Materials and Methods. A pilot retrospective molecular genetic study ( n = 48) was conducted to determine the status of microsatellite instability (MSI) in the tumors of the ovaries and/or uterine corpus: it involved 33 patients with solitary endometrioid ovarian cancer and 15 patients with synchronous endometrioid adenocarcinoma of the ovaries and uterine corpus. Microsatellite instability status was detected using PCR method with subsequent fragment analysis performed on ABI PRISM 3500 genetic analyzer (8 capillaries, Applied Biosystems). DNA was isolated from paraffin blocks of surgical specimens using DNAsorb B extraction kit (AmpliSens, Russia), according to the manufacturer’s manual. DNA concentration was estimated fluorometrically using Qubit 2.0 (Life Technologies, USA). The obtained data were analyzed using GeneMapper program (Thermo Fisher, USA). In case of polymorphism of two and more markers high-level microsatellite instability (MSI-H) was observed. Results. The incidence of MSI-H in solitary endometrioid ovarian cancer ( n = 33) was 12,1 % (4 cases), while in synchronous ovarian and uterine corpus tumors ( n = 15) MSI-H incidence made up 20 % ( n = 3). Herewith, there have been only cases of a combination of endometrioid histotypes of ovarian and endometrial cancer with identical status of microsatellite instability. Thus, the incidence of MSI-H in synchronous endometrioid adenocarcinoma of the ovaries and uterine corpus (20 %) is comparable to that in solitary endometrial cancer. Conclusion. Our pilot study became a significant complement to the previously published materials, as it allowed to confirm the clonal origin of tumors in patients with endometrioid adenocarcinoma of the ovaries and uterine corpus, that can affect the stratification of treatment strategy for this category of patients.