[Clinicopathological features and prognostic impact of MELF pattern in 512 endometrioid adenocarcinoma]

Objective: To investigate the relationship of microcystic elongated fragmented (MELF) and clinicopathological features of patients with low grade endometrial endometrioid carcinoma, and to analyze its impact on prognosis. Methods: The clinical pathological data of 512 cases with low grade endometrial endometrioid adenocarcinoma were collected. The MELF invasive pattern in all of the sections were reappraised. The correlations between MELF pattern and clinicopathological features were analyzed by chi-square test, and the independent risk factor of lymph node metastasis were evaluated by Logistic multivariate regression analysis. Survival curves was drawn by Kaplan-Meier method, and Log-rank test was used to compare progression free survival (PFS) between patients with or without MELF pattern. Disease progression-related multivariate analysis was carried out by Cox proportional hazards model. Results: MELF pattern was observed in 12.9% (66/512) low grade endometrioid adenocarcinoma. It was significantly associated with cervical stroma invasion, more than half of the depth of myometrial invasion, lymph node metastasis and vessel invasion (P<0.05). In addition, MELF pattern was an independent risk factor for lymph node metastasis (P<0.05). The 5-year PFS of patients with and without MELF pattern were 95.0% and 96.0% respectively (P>0.05). Conclusions: The patients with MELF pattern are more likely accompany with cervical stroma and deeper myometrium invasion, vessel invasion, and lymph node metastasis, and it is an independent risk factor of lymph node metastasis. However, MELF pattern has no significant impact on prognosis of patients with endometrioid carcinoma.