Lung cancer may have genetic link

Though exposure to tobacco and smoke is the dominant cause of lung cancer, the disease appears to have a genetic link to it. The strongest family link was found in the relatives of patients who developed the disease at age of 60 years or younger. The parents of such people had nearly a three and a half times higher risk of developing the disease as compared to the general population. There was a more than three times risk for the siblings and a slightly less for the children of these patients. Researchers from the Landspitali-University Hospital in Reykjavik, Iceland, found that the genetic risk may extend beyond the immediate family as well. Aunts, uncles, cousins, nieces and nephews of lung cancer victims of any age also run a higher risk, though at lower levels than the immediate family. The researchers traced the genetic links by looking at 2,756 patients diagnosed with lung cancer and linked them with an genealogical database containing all living Icelanders and most of their ancestors since the settlement of the country.The nationwide genealogy database used in the study provided a means for uncovering the familial component by revealing more connections between patients, missed in most other populations. While the higher risk in immediate families may be related to second-hand smoke as well as genetics, the higher risk found in persons outside the immediate family provides further evidence of a genetic link.