Upper tract urothelial carcinoma (UTUC) accounts for 5-10% of all UCs. Immune checkpoint inhibitors (ICIs) have been established for UCs. The prognostic and predictive potential of programmed cell death ligand 1 (PD-L1) expression to stratify patients benefiting from ICIs is not fully understood, and additional markers influencing the impact of PD-L1-mediated ICI response are needed. Previously, the chemokine-like MARVEL transmembrane domain-containing protein 6 (CMTM6) was identified as a positive regulator of PD-L1. Our aim was to investigate the expression profiles and impact of PD-L1 and CMTM6 protein status on the prognostic parameters and survival of UTUC patients. In this retrospective study, the combined positive score (CPS), tumor proportion score (TPS), and immune cell score (ICS) for PD-L1 and CMTM6 were determined. High PD-L1 CPS, ICS, and TPS were found in 77.4%, 58.3%, and 45.2% of cases, and high CMTM6 CPS, ICS, and TPS were seen in 52.5%, 51.5%, and 55.5% of cases, respectively. The scores of both markers had a significant positive correlation. High PD-L1 and CMTM6 expression was coupled with higher pT status, WHO grade, necrosis, and metastasis (p < 0.05, respectively). In the univariate survival analysis, patients with a PD-L1 ICS high and higher degree of intratumoral inflammation showed significantly longer overall survival. Compared to other studies on UC, our study shows a substantially higher rate of PD-L1-positive tumors. CMTM6 was associated with more aggressive tumors.
International journal of molecular sciences. 2024 Mar 20*** epublish ***
Said Kdimati, Clemens Christoph, Änne Glass, Nadja Engel, Desiree-Louise Dräger, Claudia Maletzki, Anne-Sophie Becker, Annette Zimpfer
Institute of Pathology, Rostock University Medical Center, 18057 Rostock, Germany., Institute of Biostatistics and Informatics in Medicine and Aging Research, Rostock University Medical Center, 18057 Rostock, Germany., Department of Oral, Maxillofacial and Plastic Surgery, Rostock University Medical Center, 18057 Rostock, Germany., Department of Urology, Rostock University Medical Center, 18057 Rostock, Germany., Department of Internal Medicine, Medical Clinic III-Hematology, Oncology, Palliative Medicine, Rostock University Medical Center, 18057 Rostock, Germany.