Cytokines foreshadow brain tumor 5 years before typical diagnosis

By John Murphy, MDLinx
Published January 13, 2016

Key Takeaways

Researchers have found that certain serum cytokines are inversely related to glioma and can be detected years before brain tumor diagnosis. This discovery offers the possibility of a blood test for early screening of glioma.

Currently, “clinicians don’t have any way to detect the tumors until patients have symptoms, which is typically 3 months before diagnosis. I see something 5 years before,” said the study’s lead author Judith Schwartzbaum, PhD, associate professor of epidemiology at The Ohio State University (OSU), in Columbus, OH. The study was published online September 9, 2015 in PLOS ONE.

Prior research had already shown that allergy is inversely related to glioma risk. Dr. Schwartzbaum’s group previously reported that people whose blood samples contained allergy-related antibodies had an almost 50% lower risk of developing glioma 20 years later compared with to people without signs of allergies.

In this study, Dr. Schwartzbaum and colleagues sought to determine whether prediagnostic allergy-related serum proteins could be associated with glioma. They obtained serum samples from the Janus Serum Bank Cohort in Oslo, Norway, and tested for 12 serum proteins in 487 people diagnosed with glioma (315 of which were glioblastoma) and 487 age- and sex-matched controls. The serum samples had been taken an average of 15 years before those who had developed tumors were diagnosed.

When researchers compared the allergy-related proteins with people subsequently diagnosed with glioma, the analysis showed these immune system proteins sent fewer signals to each other as long as 5 years before diagnosis. This suggests that the tumor is starting to suppress local immune activation. Among healthy controls, though, the interactions did not weaken. The findings indicate that early tumor development could lead to detectable immune function changes years before the cancer diagnosis.

“The changes we see in immune function suggest there are localized changes long before the usual time of tumor diagnosis,” said Dr. Schwartzbaum, also an investigator in Ohio State’s Comprehensive Cancer Center. “I can’t say which are the most important cytokines because they’re all related to each other and they don’t act alone. But I see a weakening of all of their relationships in glioma patients within 5 years before diagnosis, and nothing like that among controls.”

Among the entire group of blood samples, researchers found one other cytokine relationship that suggested allergies protect against this specific type of tumor. As long as 20 years before diagnosis, the analysis showed that higher levels of the protein IL4, which is overproduced in people with allergies, was associated with reduced likelihood of developing a glioma later in life. The association held when considering a partner protein and interactions between the two.

“This could mean this cytokine interaction has a preventive effect 20 years before a tumor would be likely to develop,” Dr. Schwartzbaum said.

This discovery offers the hope of a blood test that could predict glioma years before diagnosis. “That is the long-term goal, but we are not near that goal yet. I would say the first priority is to attempt replication of the findings in another data set,” Dr. Schwartzbaum said.

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