(RxWiki News) Lung cancer patients who never smoked may be treated differently in the future than those who have smoked. That’s because smoking changes a person’s genes – a lot.
A recent study found that smoking increased gene mutations by 10 fold in lung cancer patients.
In the future cancer treatment may be directed at mutated genes rather than affected organs.
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Richard K. Wilson, PhD, director of The Genome Institute and Ramaswamy Govindan, MD, oncologist at Washington University in St. Louis, Missouri, led the investigation.
For the study, tumors from 17 non-small cell lung cancer (NSCLC) patients were examined for gene mutations.
Researchers were looking for the differences in cancer cell mutations among the 12 smokers and five never smokers.
A total of 3,726 mutations were identified in the genes from the NSCLC tumor biopsies.
Tests showed that smokers had an average of 10 times greater the gene mutations than never smokers.
Researchers also learned that existing medications can be used to target 54 of the mutated genes.
As a result of these findings, the researchers suggest that as a group never-smokers and smokers may need different treatment approaches. This is because their tumors are so different.
Dr. Govindan said, “Whether these drugs will actually work in patients with these DNA alterations still needs to be studied. But papers like this open up the landscape to understanding 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 for therapy.”
Currently there are ongoing studies cooperating under the Cancer Genome Atlas to closely study nearly 1,000 NSCLC patients over the next year.
Dr. Govindan believes the future of treating lung cancer will target the specific molecular biology of individual patients. This individualized or personalized therapy is already being used and may become even more common in the future.
One of the gene mutations, EGFR, found in the never smokers’ tumors also occurs in other cancer types and has a treatment medication, Iressa (gefitinib) and Tarceva (erlotinib) – that’s already on the market.
Dr. Wilson speculated that in the future, treatments will be for “EGFR cancer” not “lung cancer”. EGFR is a gene that can be altered in different cancers like colon and breast cancers.
Dr. Wilson said, “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.”
“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.”
This study was published in September in Cell.
Funding for this study was provided by grants from Washington University and the National Human Genome Research Institute.
No conflicts of interest were reported.