Blood test detects common cancers
A blood test can detect the presence of eight common cancer types, long before symptoms of the disease arise. CancerSEEK detects tiny amounts of DNA and proteins released into the bloodstream from tumours.
Sequenced parts of just 16 genes often mutated in different types of cancer. They then added eight known protein biomarkers characteristic of specific kinds of cancer.
In blood samples from 1,005 patients with eight types of tumours that had evidently not yet metastasised, the test detected between 33% and 98% of cases, depending on the tumour type. The sensitivity was 69% or higher for ovarian, liver, stomach, pancreatic, and oesophagal cancers — all types that are difficult to detect early.
Known as a liquid biopsy, the test is distinctly different to a standard biopsy, where a needle is put into a solid tumour to confirm a cancer diagnosis. CancerSEEK, is also far less invasive. It can be performed without even knowing a cancer is present, and therefore allow for early diagnosis and more chance of a cure.
How the test works?
Often long before causing any symptoms, even very small tumours will begin to release minute amounts of mutated DNA and abnormal proteins into blood. While DNA and proteins are also released from normal cells, the DNA and proteins from cancer cells are unique, containing multiple changes not present in normal cells.
The newly developed blood-based cancer DNA test is exquisitely sensitive, accurately detecting one mutated fragment of DNA among 10,000 normal DNA fragments, literally “finding the needle in the haystack”.
The test has been shown to reliably detect early stage and curable cancers. It has also been found to rarely be positive in people who don’t have cancer.
This prevents significant anxiety and further invasive tests for those who don’t need them.
Large trials are now underway in the US, with Cancer SEEK testing being offered to thousands of healthy people. Cancer incidence and outcomes in these people will be compared to a control group who do not have testing. Study results will be available in the next three to five years.