Smoking is by far the leading risk factor for lung cancer , but new research suggests that common viruses, including one linked to cervical cancer , may also contribute to the development of the deadly disease.
Scientists have found evidence of the measles virus and human papillomaviruses (HPV) in samples of tissue taken from lung cancer patients, according to two early studies being presented this week at the 1st European Lung Cancer Conference in Geneva, Switzerland.
Arash Rezazadeh, MD, and colleagues from the University of Louisville in Kentucky examined lung cancer tissue samples taken from 23 patients, all smokers. Six samples tested positive for HPV, although one case resulted from cervical cancer that spread to the lungs. The remaining five HPV-positive samples comprised the following strains: HPV-16, HPV-11, and HPV-22.
"The fact that five out of 22 non-small-cell lung cancer samples were HPV-positive supports the assumption that HPV contributes to the development of non-small-cell lung cancer (NSCLC)," the study authors say in a news release.
The findings raise an intriguing question: Could an HPV vaccine similar to Gardasil, the one approved to protect women against cervical cancer, also help thwart lung cancers? Rezazadeh writes in the meeting abstract that the research "has significant implication considering the new introduction of a HPV vaccine and its potential effect on developing NSCLC."
Rezazadeh's team theorizes that HPV may play a role as a co-carcinogen, which means it increases the risk of cancer among those who smoke.
For the second study, Samuel Ariad of the Soroka Medical Center in Beer Sheva, Israel, examined tissue samples from 65 patients with non-small-cell lung cancer and found that more than half of the samples tested positive for the measles virus.
"Measles virus is a ubiquitous human virus that may be involved in the pathogenesis of lung cancer," Ariad says in a news release. "Most likely, it acts in modifying the effect of other carcinogens and not as a causative factor by itself."
The American Cancer Society estimates that more than 161,000 people in the United States will die from lung cancer in 2008.
By Kelli Stacy
Reviewed by Louise Chang
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