The immunologic tumor microenvironment in endometrioid endometrial cancer in the morphomolecular context: mutual correlations and prognostic impact depending on molecular alterations

• Published in: Cancer Immunology, Immunotherapy Vol. 70; no. 6; pp. 1679 - 1689
• Main Authors: Willvonseder, Barbara, Stögbauer, Fabian, Steiger, Katja, Jesinghaus, Moritz, Kuhn, Peer-Hendrik, Brambs, Christine, Engel, Jutta, Bronger, Holger, Schmidt, Georg Philipp, Haller, Bernhard, Weichert, Wilko, Keller, Gisela, Noske, Aurelia, Pfarr, Nicole, Boxberg, Melanie
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2021; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Biomarkers; Biomarkers, Tumor - genetics; Cancer Research; Carcinoma, Endometrioid - genetics; Carcinoma, Endometrioid - immunology; Carcinoma, Endometrioid - pathology; Endometrial cancer; Endometrial Neoplasms - genetics; Endometrial Neoplasms - immunology; Endometrial Neoplasms - pathology; Endometrium; Female; Follow-Up Studies; Humans; Immunogenicity; Immunohistochemistry; Immunology; Infiltration; Killer cells; Lymphocytes; Lymphocytes T; Lymphocytes, Tumor-Infiltrating - immunology; Medicine; Medicine & Public Health; Metastases; Microsatellite Instability; Middle Aged; Mismatch repair; MLH1 protein; Morphology; MSH2 protein; MSH6 protein; Mutants; Mutation; Oncology; Original; Original Article; p53 Protein; Prognosis; Retrospective Studies; Survival Rate; Tumor microenvironment; Tumor Microenvironment - immunology; Tumor-infiltrating lymphocytes; Endometrioid endometrial cancer; Immunologic microenvironment; Molecular subgroups; Prognostic impact
• ISSN: 0340-7004; 1432-0851
• DOI: 10.1007/s00262-020-02813-3

Objective POLE-mutant, microsatellite-instable (MSI), p53-mutant and non-specific molecular profile (NSMP) are TCGA-defined molecular subgroups of endometrial cancer (EC). Hypothesizing that morphology and tumor immunology might differ depending on molecular background concerning composition and prognostic impact, we aimed to comprehensively interconnect morphologic, immunologic and molecular data. Methods TCGA-defined molecular groups were determined by immunohistochemistry and sequencing in n  = 142 endometrioid EC. WHO-defined histopathological grading was performed. The immunologic microenvironment (iTME) was characterised by the quantification of intraepithelial and stromal populations of tumor-infiltrating lymphocytes (TIL: overall T-cells; T-Killer cells; regulatory T-cells (Treg)). Immunologic parameters were correlated with WHO-grading, TCGA-subgroups and prognosis. Results High density TIL were significantly more frequent in high-grade (G3) compared to low-grade (G1/2) EC in the whole cohort and in the subgroup of POLE-wildtype-/microsatellite-stable-EC. MSI was associated with high-level TIL-infiltration when taking into account the type of mismatch repair defect (MLH1/PMS2; MSH2/MSH6). Prognostic impact of biomarkers depended on molecular subgroups: In p53-mutant EC, Treg were independently prognostic, in NSMP, the unique independently prognostic biomarker was WHO-grading. Conclusions EC morphology and immunology differ depending on genetics. Our study delineated two molecularly distinct subgroups of immunogenic EC characterized by high-density TIL-infiltration: MSI EC and high-grade POLE-wildtype/microsatellite-stable-EC. Prognostic impact of TIL-populations relied on TCGA-subgroups indicating specific roles for TIL depending on molecular background. In NSMP, histopathological grading was the only prognostic biomarker demonstrating the relevance of WHO-grading in an era of molecular subtyping.