An immunohistochemical analysis of CD3, PD-L1, and CTLA-4 expression in carcinosarcomas of the gynecological tract and their metastases

Abstract Background Carcinosarcoma of the gynecological tract is a rare tumor with a dismal prognosis. Its immune micro-environment has not been sufficiently studied. Aim of the study To study the immune micro-environment of gynecological carcinosarcomas. Material and methods Sixty-nine surgical specimens from 37 different patients, including 34 primary tumors and 35 metastases, were immunohistochemically studied for the expression of CD3, PD-L1, and CTLA-4. Clinical and histological features were recorded and correlated with immunohistochemical factors. Results Twenty-two cases involved the uterine corpus, 1 the uterine cervix, and 14 the adnexa. The overall survival ranged from 2 to 156 months, with a median survival of 16 months. CD3 expression was more frequent at the sarcomatous than the carcinomatous component. CTLA-4 expression was higher at the carcinomatous than the sarcomatous component. PD-L1 was negative in all cases studied. Tumor relapse, metastasis presence, metastasis localization, and overall survival did not correlate with CD3 or CTLA-4 expression. Conclusion PD-L1 expression is not a feature of gynecological carcinosarcomas, despite a relatively frequent lymphocytic reaction. CTLA-4 expression is sometimes found in these tumors.