Hepatology Communications (Mar 2020)

Novel Liquid Biopsy Test Based on a Sensitive Methylated SEPT9 Assay for Diagnosing Hepatocellular Carcinoma

  • Yurika Kotoh,
  • Yutaka Suehiro,
  • Issei Saeki,
  • Tomomi Hoshida,
  • Masaki Maeda,
  • Takuya Iwamoto,
  • Toshihiko Matsumoto,
  • Isao Hidaka,
  • Tsuyoshi Ishikawa,
  • Taro Takami,
  • Shingo Higaki,
  • Ikuei Fujii,
  • Chieko Suzuki,
  • Yoshitaro Shindo,
  • Yukio Tokumitsu,
  • Hiroaki Nagano,
  • Isao Sakaida,
  • Takahiro Yamasaki

DOI
https://doi.org/10.1002/hep4.1469
Journal volume & issue
Vol. 4, no. 3
pp. 461 – 470

Abstract

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Liquid biopsies are not used in practice for hepatocellular carcinoma (HCC). Epi proColon is the first commercial blood‐based test for colorectal cancer screening based on methylated DNA testing of the septin 9 gene (SEPT9). However, Epi proColon has some disadvantages, including the requirement of a large amount of blood and lack of quantitative performance. Therefore, we previously developed a novel liquid biopsy test that can quantitatively detect even a single copy of methylated SEPT9 in a small amount of DNA. In the current study, we evaluated the application potential of this assay for diagnosing HCC. Study subjects included 80 healthy volunteers, 45 patients with chronic liver disease (CLD) without HCC, and 136 patients with HCC (stage 0, 12; stage A, 50; stage B, 31; stage C, 41; and stage D, 2), according to the Barcelona Clinic Liver Cancer staging system. For the assay, DNA was treated with methylation‐sensitive restriction enzymes in two steps, followed by multiplex droplet digital polymerase chain reaction. The median copy number of methylated SEPT9 was 0.0, 2.0, and 6.4 in the healthy control, CLD, and HCC groups, respectively, with significant differences among the groups (HCC vs. healthy control, P < 0.001; HCC vs. CLD, P = 0.002; CLD vs. healthy control, P = 0.008). Assay sensitivity and specificity were 63.2% and 90.0%, respectively (cutoff value, 4.6 copies), in detecting HCC when compared with healthy subjects. The positive rate of methylated SEPT9 increased with HCC progression (stage 0, 41.7%; stage A, 58.0%; stage B, 61.3%; stage C, 75.6%; and stage D, 100%). Conclusion: We developed a sensitive methylated SEPT9 assay that might serve as a liquid biopsy test for diagnosing HCC.