Oct. 22, 2008 -- A huge study funded by the National Institutes of Health triples the number of genes linked to lung cancer and points toward new treatments.
The study analyzed DNA sequences from 623 genes in tumor samples from 188 patients with lung adenocarcinoma, the most common form of lung cancer.
The study turned up 26 genes mutated at high frequency in lung cancer tumors. Previously, 10 gene mutations had been linked to lung cancer -- and only five of them were known to be mutated at high frequency.
Tumors from smokers carried as many as 49 mutations. No tumor from nonsmokers had more than five mutations.
More than two-thirds of the tumors carried a mutation in a gene affecting a chemical pathway called mitogen-activated protein kinase or MAPK. This suggests that a group of compounds that affect the MAPK pathway -- the MEK inhibitors -- may be particularly effective. These compounds show promise in a mouse model of colon cancer.
The findings also raise hopes for an existing drug. Rapamycin, approved for use in organ transplants and kidney cancer, affects the mTOR chemical pathway. Nearly a third of the lung tumors analyzed in the gene study affected the mTOR pathway.
"Our work uncovered many new targets for therapy of this deadly disease," MIT and Harvard researcher Matthew Meyerson, MD, PhD, says in a news release.