Do high or low White Blood cell counts cause cancer?
Decreased white counts predispose the body to infections it was once able to fight off. Some of these infections can cause cancer when the immune system is not able to contain them.
The key to understanding this pathology is to realize that there are some infections that your body is unable to get rid of. Sometimes, these infectious organisms are good at hiding from your immune cells; and other times, your immune system is just not able to kill them. Some good examples include:
- Epstein-Barr Virus (causes mononucleosis)
- the Herpesviruses
- Mycobacterium tuberculosis (obviously causes tuberculosis)
However, even though your immune system cannot permanently eliminate these viruses/bacteria, it is still very effective at halting the infection so that it does not spread throughout and damage the body. But if someone has decreased white blood cells (like we see in people with AIDS), the body loses its ability to stop these infections from damaging the body again.
When some diseases are no longer limited by the immune system, their uninhibited spread throughout the body can lead to cancer cells. Epstein-Barr Virus, for example, infects B cells of the immune system, which is why AIDS victims sometimes get extremely rare leukemias or lymphomas - the immune system is not there to stop it.
Hope this helps!