Many things...cancer (as I am sure you know) is an overgrowth of normal cells, usually a mutation. Simply staying too long out in the sun can cause the ultra violet rays to burn your skin and cause your cells to mutate and grow too rapidly, causing skin cancer. Other things would include radiation exposure, or viral or bacterial infection that could cause cancer. And if I am correct, it can also be easier obtained by relatives having it as well which is a factor that causes cancer.
-- they showed that smoking causes cancer :) kymmie
smoking
The cancer society's view on smoking is that smoking causes at least 80% of lung cancer deaths
causes lung cancer
smoking
smoking
smoking/lungcancer
Lung cancer and mouth cancer, definitely.
Any smoking you do whatsoever has the potential to cause cancer, smoking for longer just increases your risk of it.
Smoking causes cancer and heart attacks.
they showed that smoking causes cancer
It is caused by sun and smoking