Association of DRB1 and DRBQ haplotype 04:01~03:01 with HPV positive head and neck squamous cell carcinoma.

Abstract

6054 Background: The incidence of human papilloma virus (HPV) associated oropharyngeal head and neck cancer (HNC) is increasing rapidly in the US, Europe, and Asia. HPV16 is etiologic in 90-95% of HPV+ HNC. Sexual transmission and inability to clear infection leading to viral genome integration or chronic presence of episomal HPV16 DNA are precursors to HPV+ HNC carcinogenesis. However it remains unclear why a majority of HPV16 exposed individuals are able to clear the initial infection and avoid the risk of cancer. We hypothesized that difference in the ability eradicate infection may be mediated by certain HLA haplotypes. Methods: HPV(+) HNC patients from the TCGA cohort were HLA-typed based on available exome sequencing data. HLA typing was performed using the ATHLATES algorithm. We compared the distribution of alleles and haplotypes of classical HLA genes (A, C, B, DRB1 and DQB1) among HPV(+) HNC patients with those found in HPV(-) patients. Furthermore we evaluated enrichment of candidate alleles compared to publically available data in Caucasian non-cancer individuals. Results: Out of 528 HNC samples in the TCGA cohort, 450 were of Caucasian ancestry. The DRB1~DQB1 haplotype 04:01~03:01 was significantly increased in HPV(+) HNSCC patients compared to normal, non-cancer individuals ( p-value = 0.0045, OR = 2.52, 95% CI = 1.2–5.03). This was not the case for HPV(-) HNC patients. The number of African American samples in TCGA was comparably small (N = 48, with N = 5 being HPV+) however the frequency of DRB1~DQB1 haplotype 04:01~03:01 in the general African American population is significantly lower. Conclusions: DRB1~DQB1 haplotype 04:01~03:01 associates with an elevated risk for HPV+ HNC. Similar findings were reported 17 years ago for cervical cancer (Br J Cancer, 82(7), 1348–1352), and further validate our findings across tumor types. Mechanistic studies to understand potential DRB1~DQB1 haplotype 04:01~03:01 HPV specific immune dysfunction, as well as evaluation in different risk and racial populations are indicated.