Genes “affect smokers’ lung cancer riskâ€
04/09/03
The ongoing research by the University of Texas MD Anderson Cancer Center suggests that aggregation of cancer in families can be due to shared exposures, shared genes or a combination of both factors.
Dr Carol Etzel, a statistician at the university’s department of epidemiology, says that among families of the 15 per cent of all smokers who develop lung cancer it is more likely that other family members will be just as susceptible to the disease if they also smoke.
The researchers looked at family cancer history and smoking habits in the relatives of 806 lung cancer patients and a group of 663 control families. Most of the patients were over the age of 60 and were current or former smokers – eliminating passive smoking as a possible factor.
They found family cancer history in 6,430 first-degree relatives of patients and 5,505 relatives of control subjects. There was a nearly twofold increased risk of lung cancer among relatives of smokers. But no evidence of an increased risk was discovered among relatives of people who had never smoked.
Dr Etzel points out that if the genes responsible for susceptibility to developing lung and other smoking-related cancers are identified it may be possible to identify high-risk subgroups of smokers and to develop tailored interventions or screening programmes.
“We all are familiar with someone who smoked for years and never got cancer, while another person who didn’t smoke much developed the disease. It is those individual differences, expressed in genetic tendencies, that we are exploring,†she says.