Researchers have found that monitoring unstable chromosomes can be used to detect relapse in patients with lung cancer long before current standard tests.
Scientists participating in the TRACERx lung cancer study have analyzed tumors from 100 patients across 8 British hospitals with non-small cell lung cancer (NSCLC) and found that patients with a high proportion on unstable chromosomes in the tumor were over 4 times more likely to suffer a relapse or die from the disease within two years.
Unstable chromosomes, i.e. when whole chromosomes or parts of chromosomes are duplicated or deleted, are responsible for the great genetic diversity found within tumors. As the cells divide, instability increases. The scientists hypothesize that this drives the tumors to evolve, spread and become drug resistant faster, thus making patient treatment extremely difficult.
A second study in the same patient cohort demonstrated that this instability could be monitored in small DNA fragments found in the blood. Out of 24 patients monitored after surgery, blood analysis of the DNA could identify over 90% of those that would relapse a year before clinical imaging could confirm so.
The researchers also measured these tumoral DNA fragments after chemotherapy. When the levels were not reduced following chemotherapy, the disease returned. This is a huge discovery given that, currently, there are no clinical signs that can be used to accurately track if chemotherapy is inducing any improvement.
These are just the first results from the TRACERx study, which have been published today in the New England Journal of Medicine and Nature. The study, which involves over 225 researchers and clinicians from 19 British centers and funded with £14M (€16.5M) from Cancer Research UK, is the biggest investment in lung cancer from the charity so far.
Finding a new method to identify and monitor resistance and relapse faster than ever could have a huge impact in patients suffering from lung cancer, which is responsible for over one in five cancer deaths.
“We believe that this invaluable data generated during TRACERx will be seized upon by research teams across the world, helping us to answer more questions about lung cancer biology,” says Prof. Charles Swanton from the Francis Crick Institute in London. “We’ve only scraped the surface in terms of what is possible by looking at tumor evolution in such detail.”
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