Abstract 1436: ABCF1 and ABCF2 genetic variants in association with hepatocellular carcinoma (HCC) risk

Abstract Background/Aims: ATP-binding cassette (ABC) transporters have been shown to regulate tumor initiating cells in various cancer types and specific genotype associated with cancer risk. ABCF1 was on priority among the ABC transporters because the gene located at 6p21, the chromosome region associated with a number of HCC risk genetic loci including the HLA genes. Its family member ABCF2 was also examined as their expression levels were highly correlated and associated with HCC recurrence. Subjects and Methods: A total of 300 HCC and 300 healthy blood samples (99.3% and 94.7% Chinese respectively) were prospectively collected with informed consent. All patients had been diagnosed with primary HCC and underwent partial hepatectomy. Clinical information including sex, age, tumor stage and survival outcomes were collected prospectively. Genomic DNA were extracted from blood samples and SNPs were examined by TaqMan genotyping assay, Sequenom MassARRAY platform and direct sequencing. Results: Sixteen SNPs and three INDELs were examined in ABCF1 and ABCF2 in the germline DNA of 300 HCCs and 300 healthy individuals. Among the 19 loci investigated, ABCF1 rs1264440 (916-99A>G) and rs4148252 (*1delA), ABCF2 rs3823589 (-43+219C>A) and rs75100208 (368-94C>A) were significantly associated with HCC risk (OR: 1.424, 95%CI: 1.03-1.97, P=0.032; OR: 1.446, 95%CI: 1.04-2.00, P=0.026; OR: 1.635, 95%CI: 1.09-2.46, P=0.018; OR: 1.479, 95%CI: 1.09-2.18, P=0.049, respectively). Patients with any two of the four variant genotype, compared with those with all wild type, revealed elevated HCC risks (OR: 1.657, 95%CI: 1.16-2.37, P=0.006). Importantly, patients with all four variant genotypes demonstrated augmented HCC risk (OR: 2.295, 95%CI: 1.27-4.15, P=0.006). Conclusions: ABCF1 genetic variants rs1264440, rs4148252 and ABCF2 genetic variants rs3823589, rs75100208 were associated with significantly increased HCC risk. Augmented cancer risk was observed among patients possessed all four variant genotypes in ABCF1 and ABCF2. Further mechanistic studies are warranted to comprehend the underlying mechanisms. Citation Format: Philip Chun Yeung, Kelvin Kwok Chai Ng, Tan To Cheung, Charing Ching-Ning Chong, Paul Bo San Lai, Siu Tim Cheung. ABCF1 and ABCF2 genetic variants in association with hepatocellular carcinoma (HCC) risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1436.