The findings of this study, based off of over 2500 tumours, have provided new knowledge that can help identify cancer earlier than currently thought possible. Identifying which specific mutations lead to the onset of cancer has become a key part of cancer research, as early detection of cancer can lead to better patient outcomes.
The study is the first to present a large-scale genome-wide history of tumour evolution and provides key information regarding the timeline of tumour formation.
A human's DNA experiences billions of mutation throughout their lifetime, but only mutations in specific genes (such as genes involved in cell suicide) lead to the formation of cancerous tumours.
“What’s extraordinary is how some of the genetic changes appear to have occurred many years before diagnosis ... and perhaps even in apparently normal tissue.”- Clemence Jolly, one of the co-authors of the study
One of the co-authors of the study, Clemency Jolly, describes the findings, “What’s extraordinary is how some of the genetic changes appear to have occurred many years before diagnosis, long before any other signs that a cancer may develop, and perhaps even in apparently normal tissue.”
The study identified nine genes which account for half of the earliest mutations that lead to tumour formation, but do not lead to any immediate symptoms. This opens the door to screening for cancer-causing mutations through analysis of the cell-free DNA present within a patient's urine.
A particularly exciting part of this research is it's findings within "biological dark matter". As Lincoln Stein, a member of the project's steering committee explains, "The vast majority of work so far has been on the protein coding portion of the genome. That’s a mere 1%."
The non-coding segments of DNA (the 99%) have been described as "dark matter DNA" and has been an area of interest for modern geneticists, as the function of these regions is not understood. This study identified several genes within the biological dark matter that act as indicators for early onset cancer, which Stein believes will greatly help identify those with an early tumour.
While this study does not allow for any immediate improvements to current cancer screening techniques, it provides a solid foundation for future work to build off of.