Today, adenocarcinomas make up about 80% to 85% of all lung cancers, says one expert
Since the introduction of ventilation holes in cigarette filters, this type of lung cancer has proportionally increased
Light cigarettes falsely ease smokers’ fear of lung cancer, say researchers from the Ohio State University.
Evidence suggests that ventilation holes in the filters of these cigarettes contribute to increased lung adenocarcinoma rates and risks, according to a study published Monday in Journal of the National Cancer Institute.
Adenocarcinoma is a type of lung cancer that arises in the periphery or farther reaches of the lung and is difficult to treat, the researchers say.
Based on the study results, the authors recommend that the US Food and Drug Administration investigate whether the use of filter ventilation in cigarettes should be prohibited.
Cigarette makers began to incorporate ventilation holes in filters in the mid-1960s to dilute the smoke; the holes meant smokers drew in air along with the burning tobacco. At the time, this was believed to make cigarettes safer.
“The evidence shows that more modern cigarettes are more risky for lung cancer,” said Dr. Peter G. Shields, a co-author of the study, deputy director of the Comprehensive Cancer Center at James Cancer Hospital and a professor at the Ohio State University. “It is pretty clear that the only plausible explanation is changes in cigarette designs over the last 40-plus years.”
A shift in lung cancer
“There are three or four types of lung cancers based on what they look like under the microscope,” said Dr. Norman H. Edelman, senior scientific adviser at the American Lung Association.
He explained that unlike adenocarcinoma, squamous-cell carcinoma tends to arise in the central part of the lung. There are also small-cell lung cancers and undifferentiated lung cancers.
“Two, three generations ago or so,” Edelman said, squamous-cell made up about a third of all lung cancers and adenocarcinoma another third, and the remaining two types combined to make up the final third.
Around that time, cigarette companies began to make and promote filters on their cigarettes.
The ratios of lung cancers have since shifted. Today, adenocarcinomas make up about 80% to 85% of all lung cancers, said Edelman, who was not involved in the new study.
“We don’t quite know cause and effect between the use of filters and the change of the cell type,” he said, but the fact that there’s a relationship between the two is well-known by the general scientific community.