I'm all about bringing back older threads today...
Some cases of lung cancer are likely to have a genetic cause. I know my uncle, and probably my grandpa, who were both diagnosed with emphasema had a genetic vulnerability. Both were smokers, but both also experienced a faster progression of the disease than usual - their lung tissue was much more vulnerable to the ravages of cigarette smoke than the average person. Makes me very glad that my father quit smoking almost 30 years ago and my brother and I never started.
And my grandmother, before getting emphasema from smoking, got bladder cancer - often related to smoking. So, not only does smoking release carcinogens that can cause cancer in many areas of the body, but environmental and genetic causes of cancer are not always organ-specific. Depends on a lot of biochemistry which monkeyMD would be much more qualified to discuss than me. (eg - breast cancer occurs more frequently in women because it's associated with estrogen levels and estrogen receptors - men don't have anywhere near as much estrogen floating around, so don't develop this particular cancer as often)
"Up plus down equals flat" Pumpkin, 3 yrs, 10 mo, July '07