Scientists have developed a noninvasive blood test that can detect signs of eight types of cancer long before any symptoms of the disease arise. The test, which can also help doctors determine where in a person’s body the cancer is located, is called CancerSEEK. Its genesis is described in a paper published Thursday in the journal Science.
The authors said the new work represents the first noninvasive blood test that can screen for a range of cancers all at once: cancer of the ovary, liver, stomach, pancreas, esophagus, colon, lung and breast.
Together, these eight forms of cancer are responsible for more than 60% of cancer deaths in the United States, the authors said.
“The goal is to look for as many cancer types as possible in one test, and to identify cancer as early as possible,” said Nickolas Papadopoulos, a professor of oncology and pathology at Johns Hopkins who led the work. “We know from the data that when you find cancer early, it is easier to kill it by surgery or chemotherapy.”
CancerSEEK, which builds on 30 years of research, relies on two signals that a person might be harboring cancer.
First, it looks for 16 telltale genetic mutations in bits of free-floating DNA that have been deposited in the bloodstream by cancerous cells. Because these are present in such trace amounts, they can be very hard to find, Papadopoulos said.
The team relied on recently developed digital technologies that allowed them to efficiently and cost-effectively sequence each individual piece of DNA one by one.
“If you take the hay in the haystack and go through it one by one, eventually you will find the needle,” Papadopoulos said.
In addition, CancerSEEK also screens for eight proteins that are frequently found in higher quantities in the blood samples of people who have cancer.
By measuring these two signals in tandem, CancerSEEK was able to detect cancer in 70% of blood samples pulled from 1,005 patients who had already been diagnosed with one of eight forms of the disease.
The test appeared to be more effective at finding some types of cancer than others, the authors noted. For example, it was able to spot ovarian cancer 98% of the time, but was successful at detecting breast cancer only 33% of the time.
The authors also report that CancerSEEK was better at detecting later stage cancer compared to cancer in earlier stages. It was able to spot the disease 78% of the time in people who had been diagnosed with stage III cancer, 73% of the time in people with stage II cancer and 43% of the time in people diagnosed with stage I cancer.
“I know a lot of people will say this sensitivity is not good enough, but for the five tumor types that currently have no test, going from zero chances of detection to what we did is a very good beginning,” Papadopoulos said.
CancerSEEK is not yet available to the public, and it probably won’t be for a year or longer, Papadopoulos said.
He said that eventually the test could cost less than $500 to run and could easily be administered by a primary care physician’s office.
The test will be conducted through a blood sample. More details here.
Dr Nickolas Papadopoulos is an Oncology Professor at the Kimmel Cancer Center of Johns Hopkins University and Director of Translational Genetics at the Hopkins’ Ludwig Center. He is considered to be an international expert in cancer diagnostics. He gained worldwide popularity for discovering the genetic basis of the predisposition to hereditary nonpolyposis colon cancer (HNPCC), one of the most common hereditary forms of cancer.
Papadopoulos started his academic studies in Greece and later obtained an M.S. from the University of Houston and a PhD from the University of Texas, before receiving his postdoctoral training at The Johns Hopkins Medical Institute, Department of Oncology. He was named Assistant Professor of Pathology at Columbia University, where he worked on cancer genetics of prostate cancer. He then moved to GMP Genetics as the Chief Scientific Officer, where he developed applications to genetic diagnosis.