While we don't yet know of any definitive causes of CLL, CLL does put us at a higher risk of secondary cancers, due to CLL reducing our immune system's effectiveness at detecting and eliminating precancerous cells caused by DNA damage from carcinogens such as ionizing radiation.
For the first time, the signatures of mutations arising in human tissues following exposure to ionizing radiation, have been documented in 12 radiation-associated second malignancies of different tumour types.
Article in Nature Communications:
nature.com/ncomms/2016/1609...
Easier to read NewAtlas overview of above article:
newatlas.com/radiation-fing...
"This is the first time that scientists have been able to define the damage caused to DNA by ionising radiation," said professor Adrienne Flanagan, a collaborating cancer researcher from University College London and Royal National Orthopaedic hospital. "These mutational signatures could be a diagnosis tool for both individual cases, and for groups of cancers, and could help us find out which cancers are caused by radiation. Once we have better understanding of this, we can study whether they should be treated the same or differently to other cancers."
Neil
Photo: Beach Sunset. Remember our sun puts out over 1kilowatt of radiative power per square metre at midday at the equator. That's well over 1 Megawatt of power over the area of an Olympic sized swimming pool. Thankfully Earth's atmosphere filters out most of the ionizing radiation, but UV radiation can still give us painful sunburn - and set us up for secondary skin cancers...