Scientists' understanding of the progression of cancer has long been based on streamlined models where cancer is driven by mutations in only a few genes, according to the background information in an article published in PLoS Computational Biology. The researchers have shown how tumour progression can be driven by hundreds of genes. They say that as many as 20 different mutated genes may be responsible for driving an individual tumour's development.
During the research, a case of colon cancer was studied. Cancer progression proceeds stochastically from a single genetically altered cell to billions of invasive cells through a series of clonal expansions.
According to the researchers' model, cancer progression is driven by mutations in many genes, each of which confers only a small selective advantage. The researchers have found that the time that a benign tumour takes to transform into a malignant tumour is dominated by the selective advantage per mutation and the number of cancer genes, whereas tumour size and mutation rate have smaller impacts.
Niko Beerenwinkel, a member of the research team, says that the new mathematical model may help explain the large amount of variation between individual tumours that has long puzzled researchers and clinicians.