SLUG expression is an indicator of tumour recurrence in high-grade endometrial carcinomas

To investigate how SNAIL and SLUG were involved in the nature of high-grade endometrial carcinomas (grade 3 endometrioid carcinoma, serous carcinoma and clear cell carcinoma), we analysed the correlation of their expression status with clinicopathological characteristics and evaluated their prognostic significance.

We performed immunohistochemical staining in 52 high-grade endometrial carcinomas. Expression status of SNAIL and SLUG was classified into a high expression (positive in more than 50% of the tumour cells) and a low expression. Thirteen cases (25%) showed a high expression of SLUG, whereas all 52 cases showed a low expression of SNAIL. High expression of SLUG was correlated significantly with tumour recurrence (P = 0.0203) and aberrant p53 expression (P = 0.000559). Overall survival was worse in patients with high SLUG expression at all stages (P = 0.0327) and in those who underwent adjuvant therapy (P = 0.00963). Among the patients with complete tumour resection, high SLUG expression was associated with worse recurrence-free survival (RFS) in the patients at all stages (P = 0.00264), at stages III/IV (P = 0.0146), and who underwent adjuvant therapy (P = 0.000743). SLUG expression was identified as an independent factor of RFS by multivariate analysis (hazard ratio 5.938, 95% confidence interval 1.251-28.18, P = 0.025).

SLUG expression could be correlated with TP53 mutational status and could be involved in therapeutic resistance resulting in tumour recurrence. A high expression level of SLUG can be an indicator of recurrence and a therapeutic target for long-term remission in high-grade endometrial carcinomas.