You are right. Don't forget Linda McCartney died of breast cancer, and she was a clean living, thin vegetarian. But that doesn't stop groups from claiming that it's caused by hormones in meat.The fact is we don't always know what causes some people to develop cancers. Cancer arises in all organs of the body. Why in the case of lung cancer does it HAVE to be because of tobacco?
Linda McCartney was a notorious pot smoker and she did smoke tobacco too. She did not live a "healthy lifestyle."