Nov 9, 2010 13:15 GMT  ·  By

In a new investigation, researchers have determined that lung cancer which develops in smokers has different traits than the one that appears in non-smokers, hinting that the two are in fact different disorders.

If the discovery turns out to be real, then it could lead to a paradigm shift in how patients are treated. Custom treatments that differentiate between smokers and non-smokers could be used to boost each group's chances of survival.

The discovery was made when researchers figured out that the number of DNA mutations in the tumors of non-smokers was nearly two times higher than that in cancer cells of patients who smoke.

The investigation was conducted by PhD candidate Kelsie Thu, who is based at the BC Cancer Research Center in Canada, LiveScience reports. She believes that oncologists are in fact dealing with two forms of cancer.

“We think this finding provides evidence that never-smoker and smoker lung cancers are different, and suggests they arise through different molecular pathways,” the research scientist says.

“Never-smokers might be exposed to a carcinogen, not from cigarettes, that causes their tumors to have more DNA alterations and promotes lung cancer development,” she goes on to add.

This idea is nothing new. Back in 2007, two extensive reviews – one published in Nature and the other in the Journal of Thoracic Oncology – showed that the two conditions most likely arise by means of different mechanisms.

But those reviews were limited in scope, in the sense that they only looked at mutations in a single gene. The recent study finds that an entire section of genetic material are different in the two forms of lung cancer.

Details of the new study were presented yesterday, November 8, in Philadelphia, at the American Association for Cancer Research (AACR) Frontiers in Cancer Prevention Research Conference.

“By improving what we know about how lung cancer develops in never smokers, our results will help us better understand the biology underlying lung cancer development in never smokers, ultimately leading to the development of better diagnostic and treatment strategies,” Thu explains.

Her team collected samples from a group of 83 people, 30 of whom never smoked. Of the remaining group, 39 were smokers at the time of the investigation, and 14 had quit smoking. The team harvested both lung tumors and noncancerous tissue from all of the participants to arrive at their conclusion.