Differences in PD-L1–Expressing Macrophages and Immune Microenvironment in Testicular Germ Cell Tumors. Issue 3 (5th December 2019)

• Record Type: Journal Article
• Authors: Sadigh, Sam; Farahani, Sahar J; Shah, Abhishek; Vaughn, David; Lal, Priti
• Is Part Of: American journal of clinical pathology. Volume 153:Issue 3(2020)
• Page Start: 387
• Page End: 395
• Publication Date: 2019-12-05
• Subjects: PD-L1 -- Testicular germ cell tumors -- Immune microenvironment; Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqz184
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Objectives: To characterize the tumor microenvironment of testicular germ cell tumors (GCTs) using immunohistochemical markers. Methods: Seventy-seven orchiectomies, including 36 nonmetastatic (NM) seminomas, 15 metastatic (M) seminomas, 13 nonmetastatic nonseminomatous germ cell tumors (NSGCTs), and 13 metastatic NSGCTs, were studied with PD-1, PD-L1, FOXP3, CD68, CD163, and mismatch repair (MMR) immunohistochemistry. FOXP3+ and PD-1+ tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) expressing CD68 and CD163 were enumerated. PDL-1 expression was evaluated on tumor cells and macrophages. Results: GCTs primarily express PD-L1 on TAMs, except choriocarcinoma, where true tumor cell positivity was noted. Seminomas reveal increased intratumoral PD-L1+ TAMs compared with NSGCTs ( P < .05). Activated TILs are increased in NM-seminomas compared with M-seminomas ( P < .05). All GCTs retained MMR expression. Conclusions: Robust PD-L1+ TAMs are significantly expanded in seminomas compared with NSGCTs. Among all GCTs, only choriocarcinoma cells reveal true positivity for PD-L1. These findings expand the realm of potentially targeted treatments for GCTs.