Molecular classification of endometrial carcinoma (EC) has represented a breakthrough ever since the TCGA (The Cancer Genome Atlas) project published it in 2013. Four distinct molecular subgroups were recognized based on somatic copy number alterations and tumor mutational burden: POLE (polymerase-epsilon) ultramutated, MSI (microsatellite instability) hypermutated (MSI-H), copy number low (CNL) and copy number high (CNH). However, implementing a standardized algorithm in current practice is

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... from being definitive. Our purpose in this study was to determine different molecular subgroups in a cohort of Romanian patients using cost effective and available immuno-histochemistry markers and outline statistical associations with different parameters. Tissue microarrays encompassing 50 cases with previously diagnosed ECs were tested for ER, PR, HER2, p53, MSH6 and PMS2 and results showed 68% MSI-H cases with statistical correlation with tumor size ] 2 cm (p=0.028) and no association with overall survival. CNH ECs were reported in 26% of cases and showed important statistical significance with TILs (p=0.041) and no correlations with overall survival. The CNL subgroup was reported in 74% of ECs cases and showed statistical significance with the histopathological subtype (p=0.006), pT (removal of primary tumor according to AJCC/UICC convention) (p=0.033), risk category according to ESMO (European Society of Medical Oncology) criteria (p=0.022) and ER expression (p=0.002). Five-year overall survival was 84%. Molecular classification is an important additional tool in current pathology guidelines for reporting ECs, but it is not currently standardized or available in all laboratories. Its importance in evolving treatment strategies for this disease is well documented so we strongly recommend routine testing for molecular prognostic factors.