New York — Researchers at The Ludwig Center at Johns Hopkins have devised a single blood test that screens for eight common cancer types and can help identify the location of a cancer. The test, which will require further development and regulatory approval before it can be deployed in the clinic, evaluates the levels of eight proteins and the presence of cancer gene mutations in DNA shed into the blood by tumors. The tumor types it is designed to detect account for more than 60% of cancer deaths in the U.S.
“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,” says Nickolas Papadopoulos, investigator at Ludwig Johns Hopkins and senior author and professor of oncology and pathology at the Johns Hopkins Kimmel Cancer Center. The findings were published online in Science on January 18, 2018.
The researchers found their test, named CancerSEEK, had greater than 99% specificity for cancer. “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, co-director of Ludwig Johns Hopkins and professor of oncology at Johns Hopkins University.
An evaluation of the test on 812 healthy controls produced only seven false-positives. It was also run on samples from 1,005 patients with nonmetastatic, stage I to III cancers of the ovary, liver, stomach, pancreas, esophagus, colon/rectum, lung and breast. The median overall sensitivity, or the ability to find cancer, was 70% and ranged from a high of 98% for ovarian cancer to a low of 33% for breast cancer. For the five cancers for which there are no screening tests—ovarian, liver, stomach, pancreatic and esophageal cancers—sensitivity ranged from 69% to 98%.
Although CancerSEEK does not pick up every cancer, it identifies many that would likely otherwise go undetected. “Many of the most promising cancer treatments we have today only benefit a small minority of cancer patients, and we consider them major breakthroughs. If we are going to make progress in early cancer detection, we have to begin looking at it in a more realistic way, recognizing that no test will detect all cancers,” says Bert Vogelstein, who is co-director of the Ludwig Center at Johns Hopkins and the Clayton Professor of Oncology at Johns Hopkins.