High bar to reach
Approached for comment, Benjamin Weinberg, MD, assistant professor of medicine, Division of Hematology and Oncology, the Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, noted that there is “quite a ways to go before this can be clinically actionable.
“A lot of us are looking at combining methylation with circulating tumor DNA and throw the kitchen sink at it, but as the paper nicely describes, there are pros and cons to all of these,” he said.
Many tests of this type are in development. Weinberg explained that a circulating tumor DNA test for colon cancer may hit the market soon, pending FDA approval, although that test will be used in a different setting. “This is something that’s used to assess for minimal residual disease in patients who have undergone surgery and appear to be ‘cured’ of the disease,” he said. “The test is looking to see if there is any circulating tumor DNA being shed from whatever tumor is left behind.”
The type of test that has piqued the most interest is one that is “tumor informed,” meaning that the company receives tumor tissue and develops a personalized test of that tumor on the basis of tumor genetics. “That is a very targeted way of surveillance,” said Weinberg, “But it would be very difficult to use a tumor-informed test on the population described in this study because you don’t know if there is going to be a tumor or not.”
The PanSeer test may also prove difficult to use in the clinic because it detects multiple cancers, Weinberg said. “If there is a positive finding, then which cancer do you look for?” he commented. “It has an issue in that regard, and that’s the problem with this type of test, as it is easier if there is one site of origin.”
Overall, the test was fairly sensitive and specific, with a very low false negative rate. Going forward, he noted, there is a very high bar for tests used as screening tools, although the authors do say that their focus is for use in a high-risk population.
“There would have to be a randomized trial, and the test will have to show a survival benefit,” Weinberg said. He noted that it can sometimes be challenging to do so.
“Colonoscopy has been shown to be beneficial, but early mammography has become controversial, and prostate cancer is a whole different animal,” he added. “And these are established tests, and they show how difficult this can be.”
The Taizhou Longitudinal Study study was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Key Basic Research grants from the Science and Technology Commission of Shanghai Municipality, the International S&T Cooperation Program of China, the Municipal Science and Technology Major Project program, the International Science and Technology Cooperation Program of China, and the 111 Project (B13016). Funding for the DNA methylation assays was provided by Singlera Genomics. Zhang is a cofounder, equity holder, and paid consultant of Singlera Genomics, a company that is developing early cancer detection tests, including the PanSeer test. Weinberg is a speaker or a member of a speakers bureau for Taiho Pharmaceutical Co Ltd, Bayer HealthCare Pharmaceuticals, and Eli Lilly and Company; has received research grant from Novartis Pharmaceuticals Corporation; and has received travel reimbursement from Caris Life Sciences.
This article first appeared on Medscape.com.