Genes That Are Associated With Tobacco Dependence and Lung Cancer

Blog Post created by dr_hurt on May 13, 2011

You may have seen the news about the genes that may be associated with lung cancer.  Hold on – that is only part of the story so read on further.  Basically, the studies showed a smoker who inherits one copy of this particular gene has a 25% increased risk of developing lung cancer while a smoker who inherits two copies of the gene (one from each parent) has an 80% chance of developing lung cancer.  Whether this is due to the greater level of tobacco dependence and heavier smoking among smokers with two sets of the gene is unclear.  However, finding genes that are related to nicotine points to the biologic basis of tobacco dependence.  It really is in your genes, and not simply a problem of character or will power. 

As a smoker, is it important for you to know if you have one or two copies of this gene?  Probably not, and furthermore, this test is going to be a while in the making.  The reason it is not so important is because we know the main cause of lung cancer is smoking.  So stopping smoking reduces the risk of developing lung cancer regardless of your genetic makeup.  And if you do not have this gene, is it okay to continue to smoke?  Of course not.  Remember that lung cancer is only one of a myriad of tobacco caused diseases.  As these articles point out a minority of smokers develop lung cancer in the first place.  Smokers who do not have this gene and are at less risk for developing lung cancer certainly can develop heart disease, emphysema, and other forms of cancer like laryngeal cancer, pancreatic cancer, bladder cancer, etc.  So, if the genetic marker of the smoker indicates a lower risk for lung cancer would that mean we should be less aggressive in helping that smoker to quit smoking?  Absolutely not.  We should help all smokers stop smoking because it dramatically reduces their chances of dying from a tobacco caused disease, and that’s basically a 50/50 proposition.  In other words, smokers who continue to smoke through their adult lives, over half of them will die of a tobacco-caused disease. 

The bottom line is that this research adds to our understanding of the genetics of tobacco dependence and lung cancer but stopping smoking always gets back to you the smoker.  So dig in, get your plan in place, and go for it.  Stopping smoking is your best chance of avoiding lung cancer.