Study: changes detectable in blood 5 years before brain cancer diagnosis

New research has found that interactions among proteins that relay information from one immune cell to another are weakened in the blood of brain cancer patients within five years before the cancer is diagnosed.

The changes in immune activity, according to lead researcher Judith Schwartzbaum, an associate professor of epidemiology and member of Ohio State University's Comprehensive Cancer Center, appear to signal a growing brain tumor five years before symptoms arise, and could one day lead to earlier diagnosis of brain cancer.

Published in the journal PLOS ONE, the study focused on gliomas, which make up about 80 percent of brain cancer diagnoses. Average survival time for the most common type of glioma is 14 months. Symptoms vary and include headaches, memory loss, personality changes, blurred vision and difficulty speaking. On average, the cancer is diagnosed three months after the onset of symptoms and when tumors are typically advanced.

Schwartzbaum evaluated blood samples from 974 people, half of whom went on to receive a brain-cancer diagnosis in the years after their blood was drawn. Building on previous research, Schwartzbaum was interested in the role of cytokines, proteins that communicate with one another and with immune cells to spark immune responses. In the new study, the researchers evaluated 277 cytokines in the blood samples and found less cytokine interaction in the blood of people who developed cancer.

"There was a clear weakening of those interactions in the group who developed brain cancer and it' s possible this plays a role in tumor growth and development," Schwartzbaum was quoted as saying in a news release from the Ohio State University.

In addition to discovering the weakening of cytokine interactions in the blood of future cancer patients, the researchers found a handful of cytokines that appear to play an important role in glioma development.

Cytokine activity in cancer is especially important to understand because it can play a good-guy role in terms of fighting tumor development, but it also can play a villain and support a tumor by suppressing the immune system.

However, Schwartzbaum acknowledged that the results of this study must be confirmed and further evaluated before it could translate to changes in the earlier diagnosis of brain cancer.