Click here to see BORA BORA ISLANDLung Cancer CausesCigarette smoking is the most important cause of lung cancer. Research as far back as the 1950s clearly established this relationship. Cigarette smoke contains more than 4,000 chemicals, many of which have been identified as causing cancer.A person who smokes more than one pack of cigarettes per day has a risk of developing lung cancer 20-25 times greater than someone who has never smoked.Once a person quits smoking, his or her risk for lung cancer gradually decreases. About 15 years...