This article is more than 5 years old. Information may no longer be current.
Smokers with lung cancer have more genetic mutations than never-smokers
Click Here to Manage Email Alerts
Smokers with lung cancer have 10 times more genetic mutations in their tumors than never-smokers with the disease, according to results of sequencing-based study.
Lung cancer is the leading cause of cancer-related death worldwide. Approximately 10% to 40% of patients diagnosed with lung cancer report no history of smoking tobacco, according to background information in the study.
“None of us were surprised that the genomes of smokers had more mutations than the genomes of never-smokers with lung cancer,” Richard K. Wilson, PhD, director of the Genome Institute at Washington University, said in a press release. “But it was surprising to see 10-fold more mutations. It does reinforce the old message — don’t smoke.”
For the study, Wilson and researchers identified 3,726 point mutations and more than 90 indels across 17 patients with non–small cell lung cancer, the most common type of lung cancer. NSCLC accounts for approximately 85% of all lung cancer cases.
For the study, researchers examined 12 patients with a history of smoking and five with none.
The genomic landscape identified significant differences between smokers and never-smokers.
Researchers identified distinctive sets of mutations in never smokers (epidermal growth factor receptors mutations and ROS1 and ALK fusions) and smokers (KRAS, TP53, BRAF, JAK2 and JAK3), according to the study.
In each non-smoker, the researchers found at least one mutated gene that can be targeted with drugs currently on the market for other diseases or available through clinical trials, the study found.
In total, researchers identified 54 mutated genes potentially targetable with currently available drugs.
“Whether these drugs will actually work in patients with these DNA alterations still needs to be studied,” said RamaswamyGovindan, MD, oncologist in the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University. “But papers like this open up the landscape to understand what’s happening. Now we need to drill deeper and do studies to understand how these mutations cause and promote cancer and how they can be targeted.”
Govindan and Wilson were also involved in a larger genomic study recently reported in Nature, of 178 patients with squamous cell carcinoma. The study was part of The Cancer Genome Atlas project, a national effort to detail the genetics of common cancers.
Based on genetic research detailing common mutations across different cancer types, the field may reach a point in which doctors label and treat a tumor based on mutated genes rather than the affected organ. Instead of lung cancer, they may call it EGFR cancer, Wilson said.
Mutations in EGFR have been found in multiple cancers, including lung, colon and breast.
“For example, if genome sequencing revealed that a lung cancer patient has a mutation known to be sensitive to a drug that works in breast tumors with the same genetic alteration, you may want to use that agent in those lung cancer patients, ideally as part of a clinical trial,” Wilson said. “In the coming years, we hope to be treating cancer based more on the altered genetic make-up of the tumor than by the tissue of origin.”
For more information:
Govindan R. Cell. 2012;150;1121-1134.
The Cancer Genome Atlas Research Network. Nature. 2012;489;519-525.
Disclosure: Govindan and colleagues report no relevant financial disclosures.