It is well known that some cancers, such as ovarian cancer and colon cancer, run in families. Even though the role of heredity in lung cancer is not as well-known, having a family history of lung cancer does increase our risk to some degree. Hereditary lung cancer is higher in women, nonsmokers and those with early onset lung cancer (lung cancer that occurs before the age of 60). Overall, it has been estimated that 1.7% of lung cancers up to the age of 68 are hereditary. Several factors are associated with hereditary lung cancer, including:
How Closely a Family Member is Related
Having a first-degree family member (parent, sibling or child) with lung cancer roughly doubles the risk of developing lung cancer. This risk is more for women and less for men and stronger in nonsmokers than smokers. Having a second-degree relative (an aunt, uncle, niece or nephew) with lung cancer raises your risk to around 30%.Smoking Status, Lung Cancer and Heredity
Smokers who develop lung cancer are less likely to have a family history than nonsmokers that develop lung cancer. That said, however, for those who have a genetic predisposition to lung cancer, smoking appears to amplify that risk.Type of Lung Cancer and Heredity
Studies vary in the types of lung cancers that have the greatest hereditary component, but those with nonsmall cell lung cancers are more likely to have a family history of lung cancer than those with small cell lung cancers.Race, Lung Cancer and Heredity
Blacks with first-degree relatives have a greater risk of early onset lung cancer than whites. This risk increases in smokers.Other Cancers and Hereditary Lung Cancer
In general, having a family history of cancers other than lung cancer, does not appear to increase the risk that you will develop lung cancer. On the other side of the equation, though, those that develop more than one primary lung cancer are significantly more likely to have a genetic predisposition contributing to their cancer.What Should I Do if I Have a Family History of Lung Cancer?
Progress is being made to determine if CT screening for lung cancer is beneficial, although the American Cancer Society does not recommend screening at this time. Before we despair about those genes passed on to us by Mom and Dad, we need to keep in mind that many causes of lung cancer are preventable. Quitting smoking (if you smoke), testing your home for radon, eating a healthy diet and exercising can all help lower your risk of developing lung cancer whether you have a family history or not.Sources:
Cote, M. et al. Risk of lung cancer among white and black relatives of individuals with early-onset lung cancer. Journal of the American Medical Association. 2005. 293(24):3036-42.
Hemminki, K., and X. Lix. Familial risk for lung cancer by histology and age of onset: evidence for recessive inheritance. Experimental Lung Research. 2005. 205-15.
Jonsson, S. et al. Familial risk of lung cancer in the Icelandic population. Journal of the American Medical Association. 2004. 292(24):2977-83.
Lix, X., and K. Hemminki. Familial multiple primary lung cancers: a population-based analysis from Sweden. Lung Cancer. 2005. 47(3):301-7.
Lix, X.,and K. Hemminki. Inherited predisposition to early onset lung cancer according to histological type. International Journal of Cancer. 2004. 112(3):451-7.
Nitadori, J. et al. Association between lung cancer incidence and family history of cancer: data from a large-scale population-based cohort study, the JPHC study. Chest. 2006. 130(4):936-7.
