Tumours are made up of different “populations” of cancer cells which all carry different genetic mutations. The more diverse these mutations are, the more that tumours can evolve and gain resistance to treatments.
The researchers found that specific patterns of genetic mutations in cell populations enable the cancer to return in a patient quicker -- within 1 year of surgery.
These patterns of mutations also indicate whether a tumour is more likely to spread to other areas of the body beyond the lungs and chest.
Armed with this information, doctors could one day predict if someone with early-stage cancer, who should be treated successfully with surgery, may end up seeing their cancer return.
In another discovery, researchers found that the genetic diversity of cell populations within a tumour not only stems from genetic changes, but also from the way that genes are expressed.
Changes in gene expression can affect important aspects of cancer biology, including whether a tumour will return after surgery.
In this instance, the researchers suggest that doctors treating lung cancer patients could intervene early by identifying those whose cancer is most at risk of returning after surgery and following up with further treatment, to help prevent the cancer from coming back.