New Studies on Genetic Predisposition to Tobacco Addiction and Lung Cancer in Smokers




Several new studies have identified genetic links to developing tobacco addiction and increasing the smokers’ risk of lung cancer. Specific genetic variations have been found to influence a susceptibility to cigarette addiction. The same genes may be involved in making current and ex-smokers more predisposed to contracting lung cancer.

Three independent teams of scientists investigating genetic connections with tobacco consumption and smoking-induced diseases have found that certain deviations of chromosome 15 can hold key to an increased incidence of lung cancer among cigarette addicts. The study results have recently been reported by the journals Nature Genetics and Nature.

Although the identified genetic variations are commonly found among the population, only former and current smokers with deviated chromosome 15 run an increased risk of lung cancer. Particularly susceptible are those who carry two copies of genetic alterations from both maternal and paternal lines. It is estimated that carrying a double set of the responsible genetic variations can almost double the risk of lung cancer in smokers, while carrying one copy of each deviation elevates the risk of about one third.

The largest study has been carried out by an Icelandic team from deCODE Genetics. Their results have shown that the chromosomal deviations also make people more prone to be addicted to tobacco, once they begin smoking. Another team that included researchers from different countries working for the Johns Hopkins University, the University of Cambridge and the Institute of Cancer Research, has found an unquestionable link between the genetic variants and elevated risks of lung cancer in people exposed to tobacco smoke.

How exactly the identified chromosomal alterations affect lung cancer is still unclear. Some researchers believe that nicotine from tobacco smoke can trigger cancer-inducing cellular changes in genetically susceptible individuals.

Each group of the scientists examined the DNA of many thousands of volunteers – both former and current smokers. The results also showed that smokers who do not have the dangerous genetic alterations still run an increased risk of lung cancer, which is estimated at about 10 percent, against only one percent in non-smokers.

Lung cancer is the second most common type of malignant tumour observed in the industrialized countries, after breast cancer. At that, nine out of every ten lung cancer cases are diagnosed in people who have been exposed to tobacco smoke. Male smokers are more susceptible to contracting lung cancer than women, but the rates of lung cancer in female smokers have currently been on the rise. Approximately half of all smokers tend to die due to smoking-induced diseases, including lung cancer, and roughly 50 percent of them die until the age of 69.

Jimmy Edwards

Related Posts

Posted on April 25, 2008 
Filed Under Smoking and Health, Tobacco Research

Comments

Leave a Reply