One thing that most folks are generally not aware of is that there are different types of lung cancer. Some, like small cell and squamous cell, occur almost exclusively in smokers. Then there is bronchoalveolar carcinoma, which is not predisposed to smokers, and in fact occurs most frequently in non-smokers, and in women.
In addition, there are various genetic mutations that predispose one to the development of cancer, as you mention.
I thought the sometimes breast cancer can spread to the lungs as well.