title: PD-L1 expression in renal cell carcinoma clear cell type is related to unfavorable prognosis.
abstract: BACKGROUND
  PD-L1 is a glycoprotein from the family of T-cell co-stimulatory molecules that are constitutively expressed by macrophages. Aberrant expression of PD-L1 is observed in human cancers associated with inhibition of the tumor-directed T-cell immune response. There are few reports in the literature evaluating PD-L1 expression in association to prognosis specifically in renal cell cancer clear cell type (RCC-CC).
  
  
  METHODS
  Immunohistochemistry using a PD-L1 polyclonal antibody was performed on a tissue microarray (TMA) that contained 115 surgical specimens of RCC-CC. Cases were classified based on the absence or presence of staining intensity in the cytoplasm and membranes of the tumor cells. Statistical analysis was used to determine the association of PD-L1 expression with classic prognostic factors and tumor recurrence.
  
  
  RESULTS
  PD-L1 expression was positive in 56.5 % of tumors. The univariate analysis showed a correlation between PD-L1 expression and nuclear Fuhrman grade (p = 0.021) and microvascular tumor embolization (p = 0.039). One hundred and four patients were monitored for a mean time of 115.7 months. Seventeen patients (16.3 %) suffered tumor recurrence. Negative outcomes were associated with higher nuclear grade tumors, PD-L1 expression, and the presence of microvascular invasion.
  
  
  CONCLUSIONS
  Our findings confirm that PD-L1 expression is an important prognostic factor in RCC-CC.
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. katiaramos@uol.com.br.|Department of Molecular Biology, Genoa Biotecnologia SA, Av Dr. Arnaldo #455, room 2145, 01246-903, Sao Paulo, Brazil. katiaramos@uol.com.br.
authors.forename: Katia R M
authors.initials: KR
authors.lastname: Leite
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. sasareis@gmail.com.
authors.forename: Sabrina T
authors.initials: ST
authors.lastname: Reis
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. docjpjr@uol.com.br.
authors.forename: José Pontes
authors.initials: JP
authors.lastname: Junior
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. marcelozerati@gmail.com.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zerati
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. daniel.gomes@sbu.org.br.
authors.forename: Daniel de Oliveira
authors.initials: Dde O
authors.lastname: Gomes
authors.affiliation: Department of Molecular Biology, Genoa Biotecnologia SA, Av Dr. Arnaldo #455, room 2145, 01246-903, Sao Paulo, Brazil. lhcamaralopes@genoabiotec.com.br.
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Camara-Lopes
authors.affiliation: Department of Urology, Laboratory of Medical Research, University of São Paulo Medical School, Sao Paulo, Brazil. srougi@terra.com.br.
authors.forename: Miguel
authors.initials: M
authors.lastname: Srougi
mesh_terms: D000368:Aged; D060890:B7-H1 Antigen / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002292:Carcinoma, Renal Cell / Q000737:chemistry* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009392:Nephrectomy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D046888:Tissue Array Analysis; D016896:Treatment Outcome
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human