Family History of Lung Cancer
It is possible to inherit defective genes that lead to the development of a familial form of a particular cancer type. For example, certain genes influence a person's ability to metabolize some of the carcinogenic chemicals in cigarette smoke.(2) An individual with inherited suceptibility that chooses to smoke may be at an increased the risk of developing lung cancer compared to other smokers.
Risk is higher if an immediate family member has been diagnosed with lung cancer. The more closely related an individual is to someone with lung cancer, the more likely they are to share the genes that increased the risk of the affected individual. Risk also increases with the number of relatives affected.