Multicancer blood test feasible for routine clinical care, could guide intervention
A minimally invasive, multicancer blood test demonstrated the potential to screen and guide management of individuals with no cancer history, according to results of a prospective study presented at the virtual American Association for Cancer Research Annual Meeting.
Use of the test, which can be incorporated safely into routine clinical care, could lead to surgery with curative intent among asymptomatic individuals, researchers noted.
“Many cancers, unfortunately, are detected too late after they have metastasized,” Nickolas Papadopoulos, MD, professor of oncology at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, said during a presentation. “The questions we looked to answer were whether a multicenter blood test can prospectively detect cancer in individuals whose cancer was not previously detected by other means, whether such a test can be used to intervene in the tumor progression process, whether this test can be incorporated into routine clinical care without discouraging patients to forgo standard-of-care screening, and whether the test can be performed safely without incurring a large number of futile, invasive follow-up tests.”
Liquid biopsies could help reduce cancer-specific morbidity and mortality through earlier detection. However, there is debate on how to effectively screen large populations for cancer, including individuals who do not have symptoms or history of the disease.
Papadopoulos and colleagues analyzed the multicancer, multianalyte screening DETECT-A blood test, which incorporates DNA and protein markers, among 10,006 women aged 65 to 75 years with no prior history of cancer —a population with a high degree of compliance with standard-of-care screening.
Women with a positive DETECT-A result received an imaging test, usually PET-CT, to localize the putative cancer.
Results showed the DETECT-A blood test in combination with standard-of-care screening doubled the number of cancers detected by screening.
The blood test effectively identified women with multiple types of cancer, with a positive predictive value higher than existing noninvasive screening tests for individual cancers. No screening tests exist for seven of the 10 different types of cancer identified by DETECT-A.
Overall, blood testing detected 26 different cancers. Of these, 15 underwent PET-CT imaging and nine were surgically excised.
Twenty-four additional cancers were detected by standard-of-care screening and 46 by neither approach. One percent of participants underwent PET-CT imaging based on false-positive blood tests, and 0.22% underwent a futile invasive diagnostic procedure.
Nearly two-thirds (65%) of cancers detected by the test were considered local or regional disease. The most common alterations identified in plasma included somatic mutations in TP53, BRAF, KRAS and PIK3CA.
In all cases with available tumor tissue, the mutations detected in plasma were confirmed to be present in the primary tumor.
“It is feasible for a minimally invasive blood test to safely detect several types of cancers in patients not previously known to have cancer, which enables treatment with intent to cure in at least a subset of individuals,” Papadopoulos said. “This advance informs the design of randomized trials to establish clinical utility, cost effectiveness and benefit-to-risk ratio of future tests.” – by John DeRosier
Papadopoulos N, et al. Abstract CT022. Presented at: AACR Annual Meeting; April 27-28, 2020 (virtual meeting).
Disclosures: Papadopoulos reports stock ownership in Cage Pharma, NeoPhore, PGDx and Thrive Earlier Detection Corp. Please see the abstract for all other researchers’ relevant financial disclosures.