Cigarette smoking is probably the most closely related link to developing lung cancer. A person who smokes two packs or more of cigarettes per day has a one in seven chance of developing lung cancer. Those that smoke one pack of cigarettes per day have a twenty-five times greater chance of developing lung cancer than a non-smoker. In addition, those people that smoke a pipe or cigar have a five times greater chance of developing lung cancer than a non-smoker.