Cancer is among
the leading causes of death worldwide. In 2012, there were 14 million new cases
and over 8 million deaths annually. The number of new cases is expected to rise
to 22 million annually within the next two decades. Sadly, a very high percentage
of these cases are diagnosed in later stages, leading to lower survival rates.
Detecting cancer at an early stage dramatically increase probability of
treatment success and long-term survival.
The startup GRAIL is determined to decrease global cancer mortality rates by enabling early detection in asymptomatic individuals through a blood screen. Powered by Illumina’s ultra-deep sequencing technology, Grail is developing a screening test that measure circulating tumor DNA (ctDNA) in the blood. It has been identified that tumors shed their DNA into the bloodstream, and that the concentration of ctDNA in blood increase as cancer stage increase. This make it a direct measurement of cancer, in contrast to current diagnostics that measure indirect effects of cancer.
Scientists have been trying for years to identify a non-invasive cancer biomarker. ctDNA is not only non-invasive, but free from radiation exposure, making it very low risk with no limitation to frequency of testing. In addition, a test measuring ctDNA is applicable to a wide range of cancer types. This give the possibility of detecting most cancers at an early stage before symptoms appear, meaning it could be used as an extremely effective and advantageous screening method to increase chances of survival. And while some might raise questions regarding ethics of treating asymptomatic people, the test could function as guide to which individuals that need careful attention.
More than 60 percent of the world’s new cases occur in Africa, Asia and Central and South America. These regions also account for 70% of the world’s cancer deaths. Developing a test that is able to detect cancer early could significantly improve survival rates in these regions, and ctDNA might be more suitable for a rapid global scale than current diagnostics. However, it is difficult to imagine that it could reach rural resource-poor settings that lack health facilities, workers, and even proper technology. Targeting these resource-poor settings is key in order to dramatically decrease global cancer mortality rates. Sadly, it might not be possible without investing in public health.
Although the startup specify that they will not pursue other applications of ctDNA and only focus on the challenges of early detection, it could be applied to multiple stages of cancer patient care. It could be used to estimate a patient’s stage of cancer, survival chances, cancer progression and even monitoring the response to targeted drug treatments. This not only show the immense potential of ctDNA to improve early detection and treatment of cancer, but also of GRAIL and the impact they could have on cancer care and improving survival rates in the near future.