title: PD-1/PD-L1 expression in chromophobe renal cell carcinoma: An immunological exception?
abstract: Immune checkpoint inhibitors targeting the inhibitory cross talk between tumor and immune cells have been approved for therapy in renal cell carcinoma (RCC). In contrast to clear cell RCC, little is known on PD-1/PD-L1 expression patterns in rarer RCC subtypes. The aim of this study was to evaluate the prevalence, distribution and prognostic impact of PD-1 and PD-L1 expression in chromophobe (ch)RCC. Patients who underwent renal surgery due to chRCC were retrospectively evaluated. Tumor specimen was analyzed for PD-1 and PD-L1 expression by immunohistochemistry. Expression data were correlated with clinic-pathological parameters including patient survival. Eighty-one chRCC patients were eligible for analysis, thereof 25 (30.9 %) and 11 (13.6 %) patients were positive for PD-1+tumor-infiltrating mononuclear cells (TIMCs) and tumoral PD-L1+expression, respectively. No significant associations were found for PD-1+TIMC or tumoral PD-L1+expression and clinical attributes. In addition, no differences in 5- and 10-year overall survival for PD-1-TIMC compared to PD-1+TIMC (90.5 and 72.2 vs. 100 and 75 %; p = 0.41) and for PD-L1-tumors compared to PD-L1+tumors (91.9 and 76.4 vs. 100 and 50 %; p = 0.48) were observed. In conclusion, to our knowledge this is the first study to evaluate the prognostic impact of PD-1 and PD-L1 in chRCC. PD-L1 does seem to be expressed in a minority of all chRCC, likewise only a minority of chRCC was infiltrated by PD-1-positive inflammatory cells. Neither PD-1+TIMC nor tumoral PD-L1+expression was associated with parameters of aggressiveness or survival.
authors.affiliation: Institute of Pathology, Technical University Munich (TUM), Trogerstraße 18, 81675, Munich, Germany. f.erlmeier@tum.de.
authors.forename: Franziska
authors.initials: F
authors.lastname: Erlmeier
authors.affiliation: Institute of Pathology, University Erlangen-Nuernberg, Erlangen, Germany.
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Autenrieth
authors.affiliation: The Munich Cancer Registry of the Tumorzentrum Munich, Institute of Medical Information Processing, Biometry and Epidemiology (IBE), Ludwig-Maximilians-University (LMU) Munich, Munich, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Wiedemann
authors.affiliation: Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ivanyi
authors.affiliation: Clinic for Urology and Pediatric Urology, University Hospital Muenster, Muenster, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Steffens
authors.affiliation: Institute of Pathology, Technical University Munich (TUM), Trogerstraße 18, 81675, Munich, Germany.|The German Cancer Consortium (DKTK), Heidelberg, Germany.
authors.forename: Wilko
authors.initials: W
authors.lastname: Weichert
mesh_terms: D000328:Adult; D000368:Aged; D060890:B7-H1 Antigen / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D061026:Programmed Cell Death 1 Receptor / Q000378:metabolism*
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: Chromophobe histology; PD-1; PD-L1; Renal cell carcinoma; Survival