PD-L1 expression patterns in oral cancer as an integrated approach for further prognostic classification

Author(s)

Miranda-Galvis, Marisol ^{[1, 2]} ; Rumayor Pina, Alicia ^[3] ; Sales de Sa, Raisa ^[1] ; Almeida Leite, Amanda ^[1] ; Agustin Vargas, Pablo ^[1] ; Calsavara, Vinicius Fernando ^[4] ; Lopes Pinto, Clovis A. ^[5] ; Teng, Yong ^{[2, 6]} ; Kowalski, Luiz Paulo ^{[7, 1, 8]}

Affiliation

^[1] Univ Estadual Campinas, Piracicaba Dent Sch, Oral Diag Dept, UNICAMP, Piracicaba - Brazil

^[2] Augusta Univ, Dept Oral Biol & Diagnost Sci, Dent Coll Georgia, Augusta, GA - USA

^[3] Autonomous Univ Coahuila, Fac Dent, Saltillo, Coahuila - Mexico

^[4] AC Camargo Canc Ctr, Dept Epidmiol & Stat, Sao Paulo - Brazil

^[5] AC Camargo Canc Ctr, Dept Anat Pathol, Sao Paulo - Brazil

^[6] Augusta Univ, Med Coll Georgia, Georgia Canc Ctr, Dept Biochem & Mol Biol, Augusta, GA - USA

^[7] Univ Sao Paulo, Med Sch, Head & Neck Surg Dept, Sao Paulo - Brazil

^[8] AC Camargo Canc Ctr, Dept Head & Neck Surg & Otorhinolaryngol, Rua Prof Antonio Prudente 211, BR-01509900 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: ORAL DISEASES; v. 27, n. 7, p. 1699-1710, OCT 2021.
• Web of Science Citations: 2

Abstract

Background Despite the well-known role of programmed cell death ligand 1 (PD-L1) in promoting immune resistance in oral squamous cell carcinoma (OSCC), its potential utility as a prognostic biomarker is undetermined. We evaluated PD-L1 expression as predictor of survival in patients with OSCC and explored PD-L1 expression patterns. Methods We conducted a retrospective cohort study that assessed PD-L1 expression through immunohistochemistry in 123 surgical specimens of OSCC. A first approach evaluated tumor proportion scores (TPS) and combined proportion scores (CPS). Next, expression patterns were examined by evaluating PD-L1 localization in tumor nests, as well as the interfaces of tumor cells (TC) and immune cells (IC) in the tumor microenvironment. Results High-level PD-L1 expression determined by TPS and CPS using variable cutoffs was not associated with survival. Immunohistochemistry revealed that TC expressed PD-L1 in either patchy or diffuse patterns. The patchy pattern was an independent risk factor for overall survival. Furthermore, expression patterns in the tumor immune microenvironment showed that most cases expressed PD-L1 on both TC and IC, while PD-L1 non-expressors had the lowest overall survival. Conclusion PD-L1 expression patterns in the context of localization in tumor nests and TC-IC interactions represent antitumor immune responses better than either TPS or CPS. Our suggested classification system may have important implications for the characterization of OSCC and for the use of PD-L1 as a prognostic biomarker. (AU)

• FAPESP's process: 16/03248-1 - Mass spectometry based proteomic in oral squamous cell carcinoma in young patients
• Grantee: Marisol Miranda Galvis
• Support Opportunities: Scholarships in Brazil - Doctorate