Molecular classification and clinical significance in high risk endometrium cancer

The aim of this study was to determine the molecular characteristics of high-risk endometrial adenocarcinoma (EC) and fertility sparing approach (FSA) patients and to examine the relationship between molecular classification and clinical-pathologic prognostic factors. Among the 132 cases, there were 16 FSA, 33 grade 3 endometrial carcinoma, 50 type 2 EC (37 serous EC and 13 clear cell EC) and 33 recurrent cases. Clinical information, degree of myometrial invasion (MI), lymph node metastasis (LNM), lymphovascular invasion (LVSI), stage and adjuvant treatment status were determined. Mismatch repair (MMR) and p53 status were evaluated by immunohistochemical methods. Cases were divided into three molecular groups (MMR deficient-MMRd, p53 mutant-p53abn and p53 wild type-p53wt). The prognostic features of the molecular groups and the relationships between clinical and pathological features were analyzed by statistical analysis. In the FSA group, all cases were in the p53wt group. When the high-risk groups were evaluated together, 29 cases (25%) were in the MMRd group, 43 cases (37%) in the p53abn group and 43 cases (37%) in the p53wt group. Only one cases have MMRd and P53abn. There was no significant difference between the groups in terms of LVSI, MI, LNM and stage. There was a significant difference between the groups in terms of OS (p=0.004). There was no statistically significant difference between the groups in terms of DFS. MI ≥50%, LVSI, recurrence and p53abn were found to be independent poor prognostic factors in high-risk groups. In high-risk group, being in the p53abn group reduced life expectancy by 5.9-fold. In high-risk and relapsing cases, molecular classification plays a critical role not only prognostically but also in determining management. Therefore, molecular classification by examining p53 and MMR with İHK is recommended in this group of cases. Keywords: Endometrioid Adenocarcinoma; Fertility-Sparing Approach; High Grade Endometrioid Adenocarcinoma; Molecular Classification; Recurrent Endometrioid Adenocarcinoma.