Blood test detects cancer before symptoms appear
A blood test can detect multiple types of cancer in people with no history or symptoms of cancer and can be safely incorporated into routine clinical care to help guide patient management in real-time, leading to early treatment, new research indicates.
Importantly, blood testing did not make participants (all women) less apt to engage in standard-of-care screening, said Dr. Nickolas Papadopoulos, of the Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, in Baltimore, Maryland.
“This was an important question for us to answer. The number of screen-detected cancers was doubled and women were not discouraged from undergoing standard-of-care screening,” he said in reporting the results April 28 at the American Association for Cancer Research (AACR) virtual annual meeting.
The results, which were simultaneously published in the journal Science, are based on 9,911 women aged 65 to 75 years with no prior history of cancer and a high-degree of compliance with standard-of-care screening enrolled in the DETECT-A (Detecting cancers Earlier Through Elective mutation-based blood Collection and Testing) study. Women with a positive DETECT-A blood test underwent an imaging test to localize the putative cancer.
Overall, 96 women developed cancer; 26 of these cancers were first detected by the blood test. An additional 24 cancers were detected by standard screening such as mammography or colonoscopy, and 46 were detected by symptoms or other means.
The blood test identified 10 different cancer types, including seven types that don’t have standard-of-care screening (lymphoma, appendix, uterine, thyroid, kidney, ovary and cancers arising from an unknown primary site). The other three types picked up by the blood test were breast, lung and colorectal cancer.
“More important,” Dr. Papadopoulos reported, 17 (65%) of the cancers first detected by the blood test were localized or regional, “which have a higher chance of successful treatment.” Twelve of these early cancers were surgically removed with intent to cure.
The positive predictive value of the DETECT-A blood test was 19.4% and increased to 40.6% when combined with imaging.
The blood test followed by PET-CT imaging was 99.6% specific for cancer. It detects the presence of known cancer gene mutations in circulating DNA and blood levels of specific cancer proteins. The genetic mutations picked up by the blood test that led to a positive test were present in the cancer 100% of the time.
Only 1.0% of women underwent imaging based on false positive blood tests, and just 0.22% underwent a futile invasive diagnostic procedure.
“This study suggests that a multicancer blood test can be complementary and additive to standard of care screening and may be a good strategy for increasing early detection of cancer,” lead author of the Science paper Dr. Anne Marie Lennon, from Johns Hopkins Kimmel Cancer Center, said in a press release.
“We believe that more than two-thirds of cancers that occur in the U.S. can eventually be screen-detected, either by blood testing or standard screening, before they cause symptoms of disease. Such earlier detection has the capacity to substantially reduce suffering and death from many cancer types,” Dr. Bert Vogelstein, co-director of the Ludwig Center at Johns Hopkins, who worked on the study, said in the release.
AACR invited discussant for the study, Dr. David Huntsman of the University of British Columbia in Vancouver, said the study serves to “move the field forward. The identification of cancers at an earlier stage across the population should be expected to increase survival if there isn’t too great a cost and the fantastic specificity data really speaks to the cost.”
Also commenting on the results, AACR President Dr. Antonio Ribas said, “This is one of the areas of cancer research that is most rapidly becoming reality in the clinic.”
“We are seeing the future in real time. I think this session (at AACR) will be remembered for when we saw the big data (showing) that these assays should be broadly applicable provided they have the appropriate regulatory agency approval. This will not take that long and it will change our practice,” said Dr. Ribas from University of California Los Angeles.
The study was supported by The Marcus Foundation; Lustgarten Foundation for Pancreatic Cancer Research; The Virginia and D.K. Ludwig Fund for Cancer Research; The Sol Goldman Center for Pancreatic Cancer Research; Susan Wojcicki and Dennis Troper; the Rolfe Foundation; The Conrad R. Hilton Foundation; The John Templeton Foundation; Burroughs Wellcome Career Award For Medical Scientists; and the National Institutes of Health.
The DETECT-A blood test is being developed by Thrive Earlier Detection Corporation. Dr. Papadopoulos and several co-investigators have financial relationships with the company.