Hope of improving cure rates for 8 common cancers have been raised as researchers at Johns Hopkins Kimmel Cancer Center in the U.S. have developed a single blood test which can screen for eight different types of cancer and pinpoint the location.
CancerSEEK is a unique, noninvasive test that simultaneously evaluates levels of eight common cancer proteins and the presence of cancer gene mutations from DNA circulating in the blood. The cancers that the test screens for—cancers of the ovary, liver, stomach, pancreas, esophagus, colorectum, lung, or breast—account for more than 60 percent of cancer deaths in the United States. Five of the cancers covered by the test currently have no screening test.
CancerSEEK will be relatively inexpensive and in theory will be able to be undertaken by GPs alongside other blood work.
“This test represents the next step in changing the focus of cancer research from late-stage disease to early disease, which I believe will be critical to reducing cancer deaths in the long term.”
Nickolas Papadopoulos, senior author and professor of oncology and pathology at Johns Hopkins added:
“The use of a combination of selected biomarkers for early detection has the potential to change the way we screen for cancer, and it is based on the same rationale for using combinations of drugs to treat cancers.”
The findings were published online Thursday by Science.
“Circulating tumor DNA mutations can be highly specific markers for cancer. To capitalize on this inherent specificity, we sought to develop a small yet robust panel that could detect at least one mutation in the vast majority of cancers,” says Joshua Cohen, an MD-PhD student at the Johns Hopkins University School of Medicine and the paper’s first author. “In fact, keeping the mutation panel small is essential to minimize false-positive results and keep such screening tests affordable.”
The investigators initially explored several hundred genes and 40 protein markers, whittling the number down to segments of 16 genes and eight proteins. They point out that this molecular test is solely aimed at cancer screening and, therefore, is different from other molecular tests, which rely on analyzing large numbers of cancer-driving genes to identify therapeutically actionable targets.
In this study, the test had greater than 99 percent specificity for cancer. The test was used on 812 healthy controls and produced only seven false-positive results.
“Very high specificity was essential because false-positive results can subject patients to unnecessary invasive follow-up tests and procedures to confirm the presence of cancer,” says Kenneth Kinzler, professor of oncology.