Blood Test for Liver Cancer Shows Promise

Exact Sciences test that uses DNA methylation biomarkers is more sensitive than alpha-fetoprotein.

As with many cancers, early detection of hepatocellular carcinoma, the most common type of liver cancer, improves the chances for curative treatment. Current guidelines recommend that some people at high risk of developing liver cancer — those with cirrhosis and some hepatitis B virus carriers — be screened for possible signs of the disease with ultrasounds of the liver. Tests alpha-fetoprotein levels in the blood may also be ordered with a high level possibly indicative of hepatocellular carcinoma.

But this approach to hepatocellular carcinoma has shortcomings, including relatively low sensitivity — the tests miss cancer that is present.

Exact Sciences, which developed Cologuard, the test that detects colon cancer DNA markers in stool, has developed a blood test for hepatocellular carcinoma, that depends on three methylation biomarkers in combination in with alpha-fetaprotein.

In a study published earlier this month in Clinical Gastroenterology and Hepatology, a team of researchers led by Naga P. Chalasani of Indiana University School of Medicine reported findings that showed that the Exact Sciences test had overall sensitivity of 88% compared with a sensitivity of 58% for an alpha-fetaprotein test. The difference in sensitivity was even greater for early-stage disease (82% vs. 40%). However, the alpha-fetaprotein test was more specific than the Exact Sciences test (100% vs, 87%), which could mean more false positives with the Exact Sciences test

Exact Sciences is selling the test under name Oncoguard Liver test (or solution). In the research paper, it was called multitarget HCC blood test (mt-HBT). Exact Sciences funded the study, although the authors had guarantees of independence.

“The mt-HBT may significantly improve early-stage HCC (hepatocellular carcinoma) detection for patients undergoing HCC surveillance, a critical step to increasing curative treatment opportunities and reducing mortality,” reads the conclusion of the abstract of the study published in Clinical Gastroenterology and Hepatology.

In DNA methylation, a methyl group “sticks” to the DNA and affects which genes get expressed into protein. The Exact Sciences liver cancer test combines information from three methylation markers (HOXA1, TSPYL5, and a reference marker, B3GALT6), a test for alpha-fetaprotein and the patient’s sex.

Chalasani and his colleagues reported the results of two research projects in Clinical Gastroenterology and Hepatology. The first involved developing an algorithm of the test, the second validating it in a group of 156 hepatocellular cases and a control group of 245. The validation study, the test had an overall sensitivity of 88%, a sensitivity of 82% in the early-state hepatocellular carcinoma, and a specificity of 87%.