Eight in one
Researchers from Johns Hopkins Kimmel Cancer Center have developed a single blood test that is able to identify eight common types of cancer at an early stage and determine the localization of the tumor.
Source: Elizabeth Cook and Kaitlin Lindsay.
The blood test, called CancerSEEK, evaluates the levels of eight cancer proteins and the presence of mutations in circulating DNA. Cancers that can be diagnosed at an early stage with CancerSEEK, in total, account for 60% of all cancer deaths in the United States. Five of the eight species currently have no screening method at all for early detection.
To implement their idea, the researchers analyzed several hundred genes and 40 protein markers, eventually reducing their number to 16 genes and eight proteins. The aim of the work was to create a screening test, therefore, the analysis of a large number of genes necessary for therapeutic purposes was not performed.
The test developed in the study had a specificity of more than 99%, which means that the probability of false positive results leading to unnecessary expensive and invasive diagnostic interventions for patients is minimized. The test was tested among 812 healthy patients and showed only seven false positive results.
CancerSEEK sensitivity was tested among patients suffering from non-metastatic cancer (stage I-III) of the ovaries, liver, stomach, pancreas, esophagus, rectum, lungs and breast. The study involved 1005 people. The average overall sensitivity, that is, the test's ability to detect cancer, was 70% and ranged from 98% for detecting ovarian cancer to 33% for detecting breast cancer. For five types of cancer that do not have screening methods (ovarian, liver, stomach, pancreatic and esophageal cancers), the sensitivity was 69-98%.
The novelty of the method is that CancerSEEK combines the determination of mutations in circulating DNA and levels of marker proteins. Another advantage is the possibility of machine learning, which will allow the test to determine the localization of the tumor in 83% of patients.
The potential of the CancerSEEK test is limited. This is due to the fact that the inclusion of more mutations in circulating DNA in the test will lead to a decrease in specificity. The more DNA bases you have to analyze, the higher the probability of finding a mutation, but this will eventually lead to the detection of insignificant changes, obtaining too much information and increasing the percentage of false positive results. That is why it was decided to include in the test only those mutations that have high specificity.
The ability of the CancerSEEK test to detect cancer at an early stage will lead to timely treatment, which in the future will be manifested by a decrease in mortality from cancer.
Conducting the test itself does not require high professional skills, it can be performed by a link providing first aid.
The cost of the CancerSEEK test is currently estimated at $500.
Research on the test continues.
Article by Joshua D. Cohen et al. Detection and localization of surgically resectable cancers with a multi-analyte blood test is published in the journal Science.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on Johns Hopkins Medicine: Single Blood Test Screens for Eight Cancer Types.