Exploring the Diagnostic Potential of IHC and Next-Generation Sequencing Approaches for Endometrial Carcinoma Detection and Classification

Background: Globally, in 2018 endometrial cancer (EC) regarded as the sixth most commonly diagnosed cancer and the fourteenth leading cause of cancer with more deaths in females. Nowadays classical and modern classifications can be performing for diagnosing various types of cancers including endometrial cancer. Based on this our Objective of study is to determine the effectiveness of immunohistochemical observation, a quick and easy method for determining MSI and/or other types of EC which based on modern classification. As molecular study takes more cost we want to compare the both methods and showing the possibility of doing IHC instead of molecular study. Methods: This study designed to establish a small gene panel of Next Generation Sequencing NGS of endometrial cancer patients targeting 12 genes; MSH6, MLH3, MSH3, CDH1, PTEN, MSH2, MLH1, PMS2, FGFR2, BRCA1, MUTYH and AREL1. By using DNBSEQ-G400 Platform, Human Core Exome kit and Python software for analysis is used. At the same time, Dako kit used to performing IHC for six primary antibodies used to detect each of MSH6, MSH2, MLH, PMS2, PTEN and CDH1. The primary antibodies were applied on 5 µm formalin- fixed paraffin- embedded (FFPE). Results; histopathological examinations showed that all patients were at stage II endometrioid endometrial carcinoma. The FIGO classification were Ia and Ib. Microsatellite instability (MSI), nuclear staining immunoreaction for PTEN antibodies and membranous E- cadherin immunoreactions observed through IHC study. The molecular studies detected several polymorphisms which have clinical significant and some of them have conflict interpretations. Conclusions; we considered that, simply immunoreaction staining procedure can be use as alternative method for MSI phenotype detection rather than any type of more expensive and complex method of NGS. Concerning PTEN and ECAD1 antibodies reactions, also could be dependable in diagnosis and treatment and performing them if molecular diagnosis not available.