The characteristics and clinical relevance of tumor fusion burden in head and neck squamous cell carcinoma.

Background: Recent studies suggest that tumor fusion burden (TFB) is a hallmark of immune infiltration in prostate cancer, the correlation of TFB with immune microenvironment, and genomic patterns in head and neck squamous cell carcinomas (HNSC) remain largely unclear.

Methods: Gene fusion, genomic, transcriptomic, and clinical data of HNSC patients from the cancer genome atlas (TCGA) database were collected to analyze the correlation of TFB with mutation patterns, tumor immune microenvironment, and survival time in HNSC patients.

Results: Human papillomavirus (HPV) (-) patients with low TFB exhibited significantly enhanced CD8+ T cells infiltration and cytolysis activity and increased level of interferon-gamma (IL-γ), human leukocyte antigen (HLA) class I, and chemokines. Moreover, TFB was positively correlated with TP53 mutation, score of gene copy number, and loss of heterozygosity (LOH), as well as the biological progress of epithelial-mesenchymal transition (EMT), metastasis, and stem cell characteristics. Further analysis revealed that HPV (-) HNSC patients with low TFB have a better prognosis.

Conclusions: Our data revealed the correlation of TFB with tumor immune microenvironment and predictive features for immunotherapy, implying tumors with low TFB may be potential candidates for immunotherapeutic agents. Moreover, the TFB low group had prolonged overall survival (OS) in the HPV (-) HNSC cohort.