For anyone interested in science, epigenetics seems to imply that genetic changes are by no means the full story in blood cancers - " epigenetics implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance"(Wikipedia).
The environment in which the cells exist may play a more important part in the development of defective cells than we know.
We can't control our DNA but we do have a big say in our diet, fitness and stress responses which all influence epigenetics.