Abstract
Heterozygosity at human leukocyte antigen (HLA) loci may improve lung cancer immunosurveillance by increasing recognition of the tumor by the immune system. Previous studies utilizing data from population-level biobanks, such as the United Kingdom Biobank and FinnGen, have identified an association between germline HLA class II (HLA-II) heterozygosity and reduced lung cancer risk in smokers. In the present study, we evaluate the association between HLA heterozygosity and lung cancer in a large case-control study (15,302 cases and 14,580 controls) with imputed HLA allele-type information, comparing differences in HLA heterozygosity between smokers and non-smokers, among lung cancer subtypes, and at 2- and 4-digit HLA allele resolution. We identify a strong protective association of HLA-II heterozygosity in smokers compared to non-smokers, particularly at the HLA-DPB1 and HLA-DPA1 loci, and provide subtype-specific resolution. Finally, analysis of the additive effects of HLA allele heterozygosity in smokers identified significant associations with several 4-digit HLA alleles, including HLA-B∗08:01, HLA-A∗01:01, HLA-C∗07:01, HLA-DQA1∗05:01, HLA-DRB1∗03:01, and HLA-C∗03:04. Our study provides additional evidence, with added histologic subtype information, that germline HLA-II heterozygosity is inversely associated with lung cancer risk.