Scientists have found a genetic alteration that occurs in a common type of lung cancer in smokers, which they say provides a target for developing much-needed new drugs against the often deadly tumors.
In a study published in the journal Science Translational Medicine, a German-led team of researchers said a gene known as FGFR1 was "a new suspect" in squamous cell lung cancer and their findings may lead to targeted drugs for patients whose current treatment options are limited.
"Until now, the news for patients with such cancers has not been good," said Nicholas Turner at Institute of Cancer Research in London, who wrote a commentary in the same journal. He said, however, that this study provided "the first glimmer of hope."
Lung cancer is the leading cause of cancer death worldwide, killing up to 1.3 million people a year, according to the World Health Organization. The vast majority of cases are caused by smoking.
Non-small cell lung cancer accounts for around 80 percent of cases and is divided roughly equally into two main groups -- adenocarcinomas and squamous carcinomas. Squamous cell lung cancer tends to respond poorly to both chemotherapy and radiotherapy, and there are as yet no targeted drugs for it.
The researchers, led by Roman Thomas at the Max Planck Institute for Neurological Research in Germany, created gene profiles of a large set of lung cancer cells and found that squamous cell lung cancer samples contained more copies of the FGFR1 gene than other cancer types.
"We tested a huge cohort of lung cancer patients of all kinds, and we specifically saw this sub-type only in this particular group of squamous cell lung cancer patients," Thomas said in a telephone interview.
He said that more than 20 percent of squamous cell lung cancer samples showed multiple copies of the FGFR1 gene.
Thomas said the findings suggest that drugs known as FGFR inhibitors, designed to block the function of this gene, could prove useful against this type of squamous cell lung cancer.
Several drug firms, including Novartis and AstraZeneca, are developing FGFR inhibitors and have experimental medicines in early stage clinical trials for other types of cancers such as breast cancer and myeloma.
After identifying the gene clue, Thomas' team used experimental mice to test an FGFR inhibitor drug and found that it shrank the tumors.
"What was really striking to us was that it was only the tumors with the (gene) amplification that showed this extreme sensitivity to the FGRF inhibitor," Thomas said.
The researchers said that if further clinical trials of these types of drugs in human patients go well, they could be available for use within five years.