Chickenpox Linked To Reduced Risk Of This Common Brain Cancer, Major Study Indicates

In one of the largest studies completed so far, an international consortium has reported that children who have a history of catching chickenpox may be less likely to develop a type of brain cancer known as glioma. The research was led by scientists in the Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine and mirrors earlier, but smaller, studies that found an inverse relationship between brain cancer and cases of childhood chickenpox.

Dr. Melissa Bondy, associate director for cancer prevention and population sciences at Baylor College of Medicine, said that the research demonstrated a significant enough link between children having acquired chickenpox and their reduced likelihood of developing brain cancer that the results shouldn’t be dismissed as coincidence.

“It provides more of an indication that there is some protective benefit from having the chicken pox. The link is unlikely to be coincidental.”

The Baylor College of Medicine report calls chickenpox “one of those pesky illness that affects kids and pains their parents,” but reported that chickenpox may actually offer some positive health benefits later in life.

According to John Hopkins Medicine, gliomas are a common type of tumor. Carrie Treadwell, chief research officer at the National Brain Tumor Society, a nonprofit organization dedicated to helping Americans with brain cancer, said that there are not enough good medical options for people diagnosed with gliomas. She told NBC News that gliomas are hard to extract with surgery, because they “are more like fingers” that creep into healthy brain tissue.

“You can only do so much. You don’t want to destroy that patient completely. So you can’t be as aggressive as you can be with other organs because (if so), you’re compromising the very essence of who they are,” Treadwell explained. “You’re never going to get all of the (glioma) tumor. It is impossible to get every single tumor cell. Recurrence is inevitable.”

The glioma study’ authors, led by the researchers at the Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine, reported their findings in the journal Cancer Medicine last month, though the information was virtually ignored by the media. The international consortium reported a 21 percent reduced risk of developing glioma in people who had a positive history of chickenpox. Importantly, the protective effect of the chickenpox virus was greater in more serious, higher grade gliomas.

According to a study published in Nature Clinical Practice Neurology,“Gliomas account for almost 80% of primary malignant brain tumors, and they result in more years of life lost than do any other tumors.”

The researchers said that chickenpox is, so far, the only virus known to consistently show a link to lowered incidences of this brain cancer.

“Varicella zoster virus (VZV) is a neurotropic α-herpesvirus that causes chickenpox and establishes life-long latency in the cranial nerve and dorsal root ganglia of the host. To date, VZV is the only virus consistently reported to have an inverse association with glioma. The Glioma International Case-Control Study (GICC) is a large, multisite consortium with data on 4533 cases and 4171 controls collected across five countries.”

Chickenpox, or varicella, is a highly contagious viral illness. Before the chickenpox vaccine was added to the childhood vaccine schedule in the 1990s, nearly all children in the United States contracted the virus. For most children, chickenpox was just a part of childhood, but in rare instances, especially among children with immune system issues, serious health conditions and even death could come from complications of chickenpox, according to the CDC. Before vaccination began in the United States, chickenpox was associated with just over 100 deaths each year in the United States. Now, according to the CDC, that number has dropped to only about 20 deaths per year in the United States.

The CDC reports that “Antiviral medications are recommended for people with chickenpox who are more likely to develop serious disease.” The most commonly prescribed antiviral used against chickenpox was patented in 1979.

According to the text of the study, researchers are considering the chickenpox virus as a possible candidate for glioma treatment.

“Furthermore, because of its ability to replicate rapidly and lyse malignant glioma cells in vitro, VZV has even been proposed as a novel candidate for glioma virotherapy”

The Glioma International Case-Control Study (GICC) involved data from researchers at “Brigham and Women’s Hospital (Boston, MA, USA), Case Western Reserve University (Cleveland, Ohio, USA), Columbia University (New York, NY, USA), Danish Cancer Society Research Centre (Copenhagen, Denmark), The Gertner Institute (Tel Hashomer, Israel), Duke University (Durham, NC), University of Texas MD Anderson Cancer Center (Houston, TX, USA), Memorial Sloan Kettering Cancer Center (New York, NY, USA), Mayo Clinic (Rochester, MN, USA), North Shore Health System (Chicago, IL, USA), Umeå University (Umeå, Sweden), University of California, San Francisco (San Francisco, CA, USA), University of Southern California (Los Angeles, CA, USA), and The Institute of Cancer Research (London, United Kingdom),” according to the paper.

The consortium stated that previous studies showed similar findings. One such study, published in the American Journal of Epidemiology, had already suggested that future studies should examine the impact of the chickenpox vaccine on glioma incidence and whether or not the vaccine offers similar against gliomas as the wild-type chickenpox virus seems to demonstrate against this type of brain cancer.

[Photo by Dominic Sayers | Flickr | CC 2.0 | Cropped]