Antihistamine Use Tied to Brain Tumors
Glioblastoma Risk Not Affected continued...
The study also confirmed that people with allergies or asthma are less likely to develop brain tumors. They were 36% less likely to have glioblastoma, 53% less likely to have anaplastic astrocytomas, and 37% less likely to have low-grade gliomas than people without the conditions.
Results also lined up with previous reports that both anti-inflammatory drugs and chickenpox confer protection against glioblastoma, Scheurer says.
"Once you have the chickenpox, the virus that causes it stays with you forever, lying dormant in the brain," he says. "It's hypothesized that the latent virus causes low levels of inflammation. And inflammation has been linked to the development of a variety of cancers."
To arrive at their findings, the researchers combined data from two studies in which participants were asked about their use of antihistamines and anti-inflammatory drugs. A total of 610 people with brain tumors and 831 people without cancer were included in the final analysis.
John D. Potter, PhD, senior vice president of the Fred Hutchinson Cancer Research Center in Seattle and moderator of a news conference to discuss the findings, stresses that people who take antihistamines should not panic or stop taking the drugs when needed.
"This study adds to information we have showing that inflammatory processes are important in the development of cancer. It does not tell us that drugs like antihistamines cause cancer," he tells WebMD.
"It's a mechanism we should be exploring, not a risk factor we should be modifying," Potter says.
Scheurer agrees. One hypothesis he hopes to explore is to determine whether antihistamines work in concert with as-yet undetermined genetic factors to raise brain cancer risk.
"It could be that some people are predisposed to develop the tumors and antihistamine use is just speeding it up," he says. "That's a topic for future research."