Expression of B7-H4 in endometrial cancer and its impact on patients' prognosis.

Objectives: The aim of the study was to evaluate the B7-H4 expression in endometrial cancer cells and to investigate its relationship with patient prognosis and clinicopathological features of the disease.

Material and methods: We performed a single-center, retrospective cohort study that included endometrial cancer patients treated between 2012 and 2019. B7-H4 expression in specimens obtained from 63 patients was examined by immunohistochemical staining. The evaluation of B7H4 immunoreactivity was assessed using Immunoreactivity Scoring (IRS) system.

Results: B7-H4 reactivity was observed in all, except one, endometrial cancer patients (98%). Staining intensity: no reaction in one case, weak in 16 (24%) patients, moderate in 25 (37%), and strong in 22 (35%). Twenty-nine (46%) patients showed B7-H4 immunoreactivity in more than 60% of cells, while, in 18 (29%) cases and 16 (25%) patients, the percentages were 30-60% and < 30% respectively. Median IRS was 2 (range 0-6). We found a significantly worse overall survival (OS) rate for patients with high versus low B7-H4 IRS (p = 0.03), however, in multivariate analysis, the difference in patient survival was close to the significance level (p = 0.052). B7-H4 expression was not related to histopathological type of the tumor, tumor grade, lymph node metastases, or the FIGO stage of the disease.

Conclusions: Our result suggests that B7-H4 expression might be a useful prognostic factor in endometrial cancer.