Article Text
Abstract
Introduction/Background Adjuvant treatment in endometrial carcinoma was based on classical risk stratification which included clinicopathological data. Molecular classification has been recently incorporated into risk stratification by ESGO guidelines. The aim of this study is to describe the distribution of molecular groups in our population and to evaluate its impact on indication of adjuvant treatment.
Methodology Retrospective cohort study including all newly endometrial cancer cases diagnosed between January 2021 and April 2022 with available molecular data. Immunochemistry for TP53 and MMR proteins and Sanger sequencing for POLE mutations were done on diagnostic biopsy tissue. Risk stratification and indication of adjuvant therapy followed new histomolecular groups.
Results 66 cases were included. Table 1 shows clinicopathological data.
Molecular classification yielded 6 (9.1%) POLEmut, 17 (25.8%) MMR-D, 29 (43.9%) NSMP and 14 (21.2%) p53abn. Between POLEmut, 3 (50%) were low-grade endometrioid, while the rest were high-grade. 2 (14.3%) of p53abn were low-grade endometrioid, 2 (14.3%) high-grade endometrioid and 10 (71.4%) non-endometrioid hystotype. Regarding MMR-D cases, loss of MLH1 and PMS2 expression was observed in 11/17 (64.7%), of those MLH1 promotor hypermethylation was identified in 7/11 (63.1%). Rest of cases were referred to germline testing, although no germline mutations have been identified yet.
According to final prognostic group, 25/66 (37.9%) were low risk, 9/66 (13.6%) intermediate risk, 7/66 (10.6%) high-intermediate risk, 17/66 (25.8%) high risk. Between low-risk patients, 3 would have classified as high risk if molecular classification had not been taken account, and 2 between high-risk would have classified as low-risk. Consequently, 7.6% of cases were reclassified and adjuvant therapy adjusted.
Conclusion Implementation of molecular classification is feasible in routine clinical practice. POLEmut and p53abn are identified not only in high-grade cases but also in low-grade. Molecular classification leads to a change in adjuvant therapy in a non-negligible proportion of cases.