RON, ROR1 and SUSD2 expression in tissues of endometrial carcinoma patients. Clinicopathological and prognostic implications

Introduction
Endometrial carcinoma is now considered a common female gynecologic cancer with increasing incidence, with 13–25% of patients being still liable to recurrence and metastasis, which needs further studies to detect novel targets and new therapies. The aim of the study was evaluate tissue expression of RON, ROR1 and SUSD2 in endometrial carcinoma and atypical endometrial hyperplasia using immunohistochemistry and correlate their expression with clinical, pathological and prognostic parameters of patients.

Material and methods
We included samples from 100 patients with endometrial carcinoma. Sections from paraffin blocks were stained with RON, ROR1 and SUSD2 using immunohistochemistry. Correlations between marker expression, clinicopathological features and prognostic samples were evaluated.

Results
Upregulation of RON and ROR1 and downregulation of SUSD2 expression were found in endometrial carcinoma more than atypical endometrial hyperplasia (p < 0.001). High RON and ROR1 expression levels were significantly associated with high grade (p < 0.001), presence of lymph node metastases (p = 0.003), distant metastases (p = 0.009), advanced International Federation of Gynecology and Obstetrics stage (p = 0.002), poor response to therapy (p = 0.046), and lower recurrence-free survival (RFS) rate (p = 0.002), progression-free survival (PFS) rate (p = 0.008), distant metastasis-free survival (DMFS) rate (p = 0.019) and overall survival rate (p < 0.001). Low SUSD2 expression was significantly associated with older patient age (p = 0.002), large tumor size (p = 0.003), high grade (p = 0.005), presence of adnexal invasion (p = 0.023), presence of lympho-vascular invasion (p = 0.021), extent of myometrial invasion (p = 0.002), lower RFS rate (p = 0.008), lower PFS rate (p = 0.023), and lower DMFS rate (p < 0.001).

Conclusions
Upregulation of RON and ROR1 and downregulation of SUSD2 lead to promotion of endometrial cancer cell proliferation, migration, epithelial-mesenchymal transition, and invasion.