Biomarker characterization in endometrial cancer in Italy: first survey data analysis

Objective: Endometrial carcinoma (EC) is the most common gynecological malignant disease in high income countries. The 2020 edition of the World Health Organization (WHO) Classification of Tumors of the Female Genital Tract underlines the important clinical implications of the new integrated histo-molecular classification system, in order to correctly define the specific prognostic risk group. This survey analysis will focus on the most commonly adopted immunohistochemical and molecular biomarkers used in daily clinical characterization of a diagnosed endometrial carcinoma in Italian labs.

Methods: An evaluation questionnaire was distributed to 41 Italian pathology laboratories. Normal habits in EC evaluation, especially regarding mismatch repair status (MMR) and microsatellite instability (MSI), were collected. A summary and a descriptive statistical analysis were used to show the current practice of each laboratory.

Results: The analysis of MMR status by immunohistochemistry (IHC) is carried out on the majority of all EC samples. The most frequent strategy for the analysis of MMR status in EC is IHC of four proteins (PMS2, MSH6, MSH2, MLH1). MSI analysis by molecular method in endometrial cancer is rarer and more restricted to some circumstances. Hypermethylation of the MLH1 promoter by methylation-specific PCR and pyrosequencing was analyzed in case of negative expression of MLH1/PMS2. Also, the analysis of p53 in EC is performed in the majority of cases. POLE mutational profiling is adopted only in a limited number of laboratories. Fifty-five percent of Italian laboratories refer to national/international guidelines when analyzing biomarkers in EC (among those, 45% use the ESGO Guidelines, 18% ASCO-CAP, 18% AIOM, 14% WHO, 5% British Association of Gynaecological Pathologist, 5% ESMO, 5% NCCN).

Conclusions: Adoption of guidelines and standardization of pre-analytical and analytical procedures are effective tools for adequate EC prognostic risk stratification and high quality standard of care.