Why are cancers common in the lung?

I'm unable to find any medical reference to the incidence of right lung cancer being greater than the incidence of left lung cancer. There are cancers that begin in the lung (primary cancer) and those that have originated in another part of the body and

travelled to the lungs (secondary cancer). If cancer is present in an area near to the right lung, it will become infected before the left lung. Lung cancer is very serious, although symptoms may not be apparent until the condition has progressed. Cancers can arise in any part of the lung, but by far the most arise from the epithelial cells, the cells lining the bronchi and bronchioles; That is why lung cancers are sometimes called bronchogenic cancers or bronchogenic carcinomas.

A cancer growing right at the top of the lung is called a pancoast tumour. These tumours cause a very specific symptom: a severe shoulder pain, or pain that travels down the arm.