It was genetic, the reports I'm hearing (and heard when she announced the cancer diagnosis)are saying cancer ran in her family.
I'm sure the stress of Christopher's death didn't help matters any.
Now their, son who I believe is only 12, has to deal with both of his parents being dead.
Lung Cancer kills more women in the US than any other type of cancer - an estimated 1 in 4 cancer deaths are from lung cancer and women are 1.5 times more likely to die from it than men. 87% of lung cancer deaths are smoking related - she was in the unfortunate 13%.