Tumour-infiltrating immune cells in tonsillar cancer: no tissue-level signs of inflammageing in the elderly

BACKGROUND: Age-related immunosenescence, also known as 'inflammageing', may impact the elderly's ability to mount immune responses against cancers and compromise the effectiveness of immune checkpoint inhibition (ICI). In this context, data on tonsillar cancer (TC), a subset of head and neck squamous cell cancer (HNSCC), are lacking. AIMS/OBJECTIVES: To compare the presence/distribution and features of immune cells in TC, and of bulk RNA-seq in HNSCC, between the young and the elderly. MATERIAL AND METHODS: TC tissue microarrays (TMAs) characterised by GeoMx digital spatial profiling were revisited and analysed, focusing on quantification and location of CD8⁺ and CD11c⁺ immune cells. De novo analyses of the TMAs targeted CD68⁺/CD163⁺ macrophages. Bulk RNA-seq and clinical data from patients with HNSCC were sourced from the Cancer Genome Atlas (TCGA). For all data, patients were stratified into age groups. RESULTS: Immune-cell characteristics in TC were similar across young and elderly individuals, although the elderly exhibited higher PD-1 levels. TCGA data revealed increased immune checkpoint molecules PD-L1 and LAG-3 in the elderly, alongside immunosuppression. CONCLUSION AND SIGNIFICANCE: In the elderly, key immune cells are present in TC, and immune checkpoint molecules are overexpressed. This may be relevant to the stratification of patients for ICI.