We now understand that cancer is not one disease but many, and that for example breast cancer and lung cancer should be treated differently. However, it now looks like things are a lot more complicated than that: cancer could indeed be thousands of different diseases. What’s more, cancer could be thousands of different diseases within the same person. Because cancer cells are damaged, they grow faster than healthy cells and don’t carry out all the necessary controls for copying DNA; as a result, cancer daughter cells can be quite different from their mothers. Cancer cells are highly variable because of their genetic instability, and then the application of a selective pressure decides which cells come out victorious.

Source: The Irish Times March 29, 2018 03:56 UTC