Researchers at Johns Hopkins Kimmel Cancer Center in the US have developed a single blood test, called CancerSEEK, which can screen for eight common cancer types.
The non-invasive blood test simultaneously evaluates levels of eight cancer proteins and the presence of cancer gene mutations from circulating DNA in the blood.
The cancers types are: ovarian, liver, stomach, pancreatic and oesophageal cancers – all of which currently have no screening test, as well as colorectal, lung and breast.
“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,” said Professor of Oncology and Pathology, Nickolas Papadopoulos, PhD.
“Circulating tumour DNA mutations can be highly specific markers for cancer. To capitalise 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,” said MD-PhD student at the Johns Hopkins University School of Medicine, Joshua Cohen.
“In fact, keeping the mutation panel small is essential to minimise false-positive results and keep such screening tests affordable,” continued Cohen.
In a study that was published in the online journal Science last month, the blood test was proven to have more than 99% specificity for cancer. The test was used on 812 healthy controls and produced only seven false-positive results.
The test was evaluated on 1,005 patients with nonmetastatic, stages I to III cancers of the ovary, liver, stomach, pancreas, oesophagus, colorectal, lung or breast. The median 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 that have no screening tests, sensitivity ranged from 69% to 98%.
“A novelty of our classification method is that it combines the probability of observing various DNA mutations together with the levels of several proteins in order to make the final call,” said Associate Professor of Oncology and Biostatistics, Cristian Tomasetti, PhD, who developed the algorithm.
“Another new aspect of our approach is that it uses machine learning to enable the test to accurately determine the location of a tumour down to a small number of anatomic sites in 83% of patients,” continued Tomasetti.
When the team were developing the CancerSEEK test they pulled data from more than three decades of cancer genetics research generated at their Ludwig Center at Johns Hopkins, where the first genetic blueprints for cancer were created, as well as data from other institutions.
The researchers believe that their test could be used routinely for cancer screening and can, in principle, be administered by primary healthcare providers at the time of other routine blood work.
They envision that the CancerSEEK test will eventually cost less than $500.
Larger studies of the test are currently under way.