Pathology and Laboratory Medicine International (Apr 2024)
PD-L1 Expression and Its Association With p16 in Head and Neck Squamous Cell Carcinoma in Southwestern Uganda
Abstract
Rita Nabulya,1 Raymond Atwine,1 Brian Ssenkumba,1 Yekosani Mitala,1 Jamilah Nabukenya2 1Department of Pathology Mbarara University of Science and Technology, Mbarara City, Uganda; 2Department of Ear, Nose and Throat Mbarara University of Science and Technology, Mbarara City, UgandaCorrespondence: Rita Nabulya, Department of Pathology Mbarara University of Science and Technology, Mbarara City, Uganda, Email [email protected]: Head and Neck squamous cell carcinoma (HNSCC) is the seventh most common cancer in the world. The prognosis of patients with HNSCC remains unsatisfactory, with a 5-years survival rate of only approximately 50%. In western Uganda, the 1-year survival rate is only 1%. Programmed cell death ligand 1 (PD-L1) and p16 have been shown to predict the progression of HNSCC lesions, prognosticate survival, reveal new therapeutic targets, and predict response to therapeutic agents. HNSCC patients with positive PD-L1 expression have been reported to benefit from immunotherapy; however, data on PD-L1 expression in HNSCC in Uganda and Africa are still lacking. This study aimed to determine the expression of PD-L1 in HNSCC and its association with p16 expression in Southwestern Uganda.Patients and Methods: We retrospectively studied 165 formalin-fixed paraffin-embedded specimens from the head and neck region with a previous histological diagnosis of squamous cell carcinoma (SCC). The specimens were retrieved from June 2012 to June 2022. Hematoxylin and eosin (H&E) staining was performed to confirm the diagnosis, followed by immunohistochemical (IHC) staining for PD-L1 and p16 using the laboratory developed technique.Results: Of the 165 specimens included in the study, 80% of source patients were male and the majority (51.5%) were older than 60 years. The oral cavity was the predominant site (51.52%). PD-L1 was expressed in 32.1% (95% C.l: 25.4– 39.68) of the specimens, whereas p16 was expressed in 16.36% (95% C.l: 11.4– 22.9). There was a statistically significant association between PD-L1 and p16 expression.Conclusion: The prevalence of PD-L1 expression in HNSCC in southwestern Uganda is low, implying that a number of patients with HNSCC can benefit from immunotherapy. PD-L1 expression may predict p16 expression and therefore HPV infection in HNSCC.Keywords: head and neck squamous cell carcinoma, PD-L1, p16, Uganda
