(RxWiki News) To find out if a lung cancer prevention drug is effective, scientists may follow thousands of patients for more than a decade. A recent discovery of a molecular response may significantly shorten these trials.
Typically, tests of medications that can prevent lung cancer can require up to 15 years of study to see if they have a benefit. Scientists recently found that they might be able to predict patient response to drug therapy early on based on how one particular molecule reacts.
"If you have ever smoked, ask your doctor about lung cancer screening."
Fred R. Hirsch, MD, PhD, investigator at the University of Colorado Cancer Center and professor of medical oncology and pathology at the CU School of Medicine in Denver, led research examining microRNA expression in patients taking the potential chemopreventive medication iloprost (Ventavis). Chemopreventive medication is intended to prevent the development of cancer.
Iloprost, which is used to treat pulmonary hypertension, has shown promise in preventing lung cancer in former smokers. In a June 2011 study, investigators followed 152 current and former smokers—75 took iloprost and 77 received a placebo. The researchers noted no lung tissue improvement in current smokers taking iloprost, but significant improvement in former smokers.
Using data from this research, Dr. Hirsch and his team examined MicroRNA, or miRNA, expression for the current study. MiRNAs are molecules that control gene expression. They have been linked with the earliest steps in lung squamous cell cancer development.
Dr. Hirsch and his team found that the expression of one particular miRNA (microRNA-34c) was down after six months of treatment. These patients had improvement in bronchial changes indicating benefit from iloprost. In patients who showed no benefit, microRNA-34c expression remained unchanged.
Dr. Hirsch told dailyRx News, “Our preliminary results suggest that microRNA-34c could provide an intermediate [or substitute] end point for new chemoprevention studies.”
“Instead of waiting for an endpoint 15 years in the future, we could potentially discover the effectiveness of chemopreventive agents only six months after treatment,” he said. “It would speed up the pace of discovery and eventually bring new chemopreventive agents much faster to the market.”
Dr. Hirsch next intends to looks at miRNAs as a possible means for diagnosing screen-detected nodules.
CT scans and x-rays may show nodules in patients, but the readings are incorrect 9 out of 10 times, according to Dr. Hirsch.
Dr. Hirsch told dailyRx News, “We need a better measure to tell if nodules are benign [not harmful] or malignant [cancerous].”
MiRNAS might provide a less invasive diagnostic method because they may be analyzed from blood or sputum samples.
The study was published in January in the journal Cancer Prevention Research.