Lung Cancer Runs in the Family
Genes May Play Role in Who Develops Lung Cancer
April 11, 2003 - Smokers whose parents or siblings have lung cancer appear to face much higher risks of developing lung cancer themselves. A new study suggests that genes may play a role in raising the risk of lung cancer.
Smoking is the single largest risk factor for lung cancer, but researchers say only about 15% of all smokers develop lung cancer.
"In families of those smokers, our belief is that it is more likely other family members will be just as susceptible if they also smoke," says researcher Carol Etzel, PhD, of the department of epidemiology at the University of Texas M.D. Anderson Cancer Center, in a news release.
"We all are familiar with someone who smoked for years and never got lung cancer, while another person who didn't smoke much developed the disease," says Etzel. "It is those individual differences, expressed in genetic tendencies, that we are exploring."
Etzel's study, published in the Proceedings of Annual Meeting of the American Association for Cancer Research, compared histories of lung cancer among the families of some 800 lung cancer patients and 660 healthy people. Most of the lung cancer patients were over 60 and were either current or former smokers.
Fathers of lung cancer patients were more than two and a half times as likely also to have had lung cancer. Siblings of the lung cancer patients were nearly twice as likely also to have had lung cancer.
But this higher risk of lung cancer in families was seen only when the lung cancer patient was a smoker. For example, there was a 40% increase in risk for lung cancer in the family among lung cancer patients that had ever smoked. But there was no evidence of familial lung cancer among non-smoking lung cancer patients.
Researchers say if genes that affect the risk of developing lung cancer are found, it may be possible to identify people most at risk for these cancers and develop screening programs and interventions.