In a respite from coronavirus news, there’s some positive development in the battle against cancer. A new blood test that can check over 50 types of cancer, often before any signs or symptoms, is undergoing trials. While not a “cure for cancer” per se, this can be huge for diagnosing tumors sooner rather than later, thus making them much easier to deal with.
So far during its trials, the overall specificity of the test was 99.3%, meaning that only 0.7% of the results incorrectly indicated that cancer was present.
So far the data shows that this new blood test is better at diagnosing more advanced conditions but isn’t as accurate with conditions in their early stages.
How does the new blood test work?
The test aims to diagnose the telltale chemical changes in certain bits of genetic code. This cell-free DNA is what leaks from tumors into the bloodstream. This is also what makes the test better at catching mostly tumors in their later stages – because they produce more of this cell-free DNA.
The researchers working on this project come from many prestigious institutions around the world – Harvard Medical School, the Dana-Farber Cancer Institute, the University College of London, and the Francis Crick Institute. Over 4,000 samples from patients with and without cancer have been used in this study.
The test doesn’t just perform well at detecting the presence of tumor cell-free DNA but it has also shown a 96% accuracy at identifying the exact type of cancer the patient is suffering from. The 50+ types of cancer that this test can check for include some of the most dangerous ones such as lung cancer, ovarian cancer, and bowel cancer.
If early detection can indeed be improved even for just these three types of cancer this can lead to hundreds of thousands of lives saved every year.
Lung cancer, for example, is the second most common type of cancer (not counting skin cancer) in both men (second behind prostate cancer) and women (second to breast cancer).
For bowel (or colon) cancer, it’s estimated that there will be 104,610 new cases in 2020 and 43,340 deaths.
The numbers for ovarian cancer are 21,750 cases and 13,940 deaths.
And those are just 3 out of the 50+ types of cancer this new blood test might be able to accurately detect.
What are the experts’ predictions for the test?
This blood test is funded by Grail, a major scientific investor that’s dedicated to cancer prevention, detection, and treatments. According to their own and one of the lead researchers on the project, Prof Geoff Oxnard:
“This blood test seems to have all the features needed to be used on a population scale, as a multi-cancer screening test.
“Everyone asks when will a test like this will be ready for use.
“Based upon this successful clinical validation in thousands of patients, the test has actually now been launched for limited use on clinical trials.
“But before this blood test is used routinely, we will probably need to see results from clinical studies like this to more fully understand the test performance.
“Certainly the field is moving quickly and it makes us hopeful that blood-based cancer detection will be a reality.”
Dr David Crosby from Cancer Research UK and an early detection head on the project also adds that:
“Detecting cancers at their earliest stages, when they are less aggressive and more treatable, has a huge potential to save lives and we sorely need tech innovations that can turn this potential into reality.
“Although this test is still at an early stage of development, the initial results are encouraging.
“And if the test can be fine-tuned to be more efficient at catching cancers in their earliest stages, it could become a tool for early detection.
“But more research is needed to improve the test’s ability to catch early cancers and we still need to explore how it might work in a real cancer-screening scenario.”