Molecular classification of endometrial carcinoma-a short summary for clinical use

Background: Histopathological examination is still the backbone for the diagnosis and treatment decision making in endometrial carcinoma (EC). The binary classification of EC into type 1 (mostly endometrioid) and type 2 (mostly serous), although still helpful, showed overlapping clinical, morphological and molecular features and was not very prognostic discriminatory for all subtypes of EC.Methods: Analysing the most recent studies dealing with the molecular classification of EC and the recommendations of the German S3-guidelines for EC.Results and conclusion: Based on the comprehensive molecular study of The Cancer Genome Atlas Project (TCGA) four distinct molecular subtypes have been identified: EC with POLE mutation (POLEmut), with loss of mismatch repair proteins (MMR deficiency; dMMR), or with TP53 mutation (p53mut) and without any of these alterations, termed NSMP (no specific molecular profile). The molecular classification of EC presents a morphomolecular approach, based on histopathological evaluation (tumor diagnosis, subtyping, grading), immunohistochemistry (MMR, p53) and molecular analyses for POLE. The incorporation of this molecular classification is recommended for clinical use by the World Health Organisation (WHO) as well as many national guidelines and international societies. Due to the heterogeneity of NSMP-EC, which is the largest molecular group, additional research is indicated to further characterise these tumors.