Claudio Ceccarelli

An Analysis of Clinical, Surgical, Pathological and Molecular Characteristics of Endometrial Cancer According to Mismatch Repair Status. A Multidisciplinary Approach

Since 2016, our hospital has applied tumor testing with immunohistochemistry (IHC) in endometrial cancer in order to detect mutations of mismatch repair genes (MMR). All cases with MMR deficiency proteins expression are sent for genetic testing, except those with MLH1 protein deficiency, in which case genetic testing is performed if negative for promoter hypermethylation. The primary aim of this study was to investigate the ability of our algorithm to identify Lynch syndrome (LS). The Secondary aims were to investigate the relationship between MMR status and clinicopathological features and prognosis of primary endometrial cancer (EC). From January 2016 to December 2018, 239 patients with EC were retrospectively analyzed and subdivided according to MMR status. Patients were divided in three groups: MMR proficient, LS and Lynch-like cancer (LLC). LS was characterized by a lower age and BMI, more use of contraceptive and less use of hormonal replacement therapy, nulliparity and a trend versus a better prognosis. LLC appeared more related to MMR proficient than LS and exhibited a more aggressive behavior. Our multidisciplinary approach permitted a correct diagnosis of germline mutation in patients with newly diagnosis EC and it confirmed clinicopathologic and prognostic characteristics of LS.

Endometrial carcinoma and immune escape: prognostic relevance of HLA class I loss in NSMP subtype

Aims This study aims to define and characterize human leukocyte antigen class I (HLA‐I) expression in a consecutive series of molecularly classified endometrial carcinomas (ECs), and to evaluate its association with clinicopathologic features, spatial cancer–immune phenotypes and patient prognosis, with a focus on the NSMP (no specific molecular profile) subtype. Methods and results HLA‐I expression was assessed by immunohistochemistry on whole tissue sections from 208 ECs, classified into POLE ‐mutated, MMR‐deficient (MMRd), p53‐abnormal (p53abn) and NSMP subtypes. Loss of HLA‐I was identified in 31% of cases and was associated with adverse features including high‐grade, aggressive histotypes, deep myometrial invasion, substantial lymphovascular space invasion (LVSI), extensive tumour necrosis and an ‘excluded’ immune phenotype. While HLA‐I loss showed no significant prognostic impact in POLE , MMRd or p53abn tumours, it significantly correlated with worse disease‐free survival in NSMP tumours ( P  < 0.001). Multivariate analysis confirmed HLA‐I loss as an independent prognostic factor in early‐stage NSMP ECs, in addition to substantial LVSI, presence of lymph node metastases and spatial cancer–immune phenotypes. Integration of HLA‐I status improved the performance of predictive models over time. Conclusions HLA‐I loss defines a biologically aggressive subgroup within NSMP ECs and is associated with adverse clinicopathologic and immune features. Assessment of HLA‐I expression could refine risk stratification in NSMP ECs, a group traditionally lacking robust prognostic markers and may help identify patients who could benefit from intensified clinical surveillance and future immunomodulatory treatment strategies.