Tumors can form in any area of the body for a variety of reasons. Interestingly, the most common reason why a tumor develops in the brain is because cancer in another area of the body has spread to your brain. Cancer that develops in one area of the body and spreads to another area is called metastatic cancer, and since it’s the most common reason for brain tumor development, researchers are interested in learning if there are certain factors that lead to an increased risk of an initial cancer spreading to the brain.
Research out of McMaster University is getting closer to unlocking some of these answers. According to researchers, they have identified two genes that are associated with the spread of lung cancer through the blood-brain barrier and into the brain. The genes have been identified as SPOCK1 and TWIST2.
“Brain metastases are a secondary brain tumor, which means they are caused by cancer cells that escape from primary tumors like lung, breast or melanoma, and travel to the brain,” said Mohini Singh, the study’s lead author and a PhD candidate in biochemistry at the Michael G. DeGroote School of Medicine at McMaster. “We set out to find which genes can regulate the cells that initiate brain metastases, which we’ve termed brain metastasis initiating cells or BMICs. In other words, what are the genes that are sending the signal to these lung BMICs to leave the lung tumor, go into the blood stream, invade the blood-brain barrier and form a tumor in the brain.”
Metastatic Brain Cancer Research
The research in itself is quite fascinating. Researchers began by taking samples from lung cancer patients with brain metastases. The samples were then injected into mice, and researchers tracked tumor development and a number of genetic biomarkers. After looking at which mice developed a secondary tumor in the brain, researchers uncovered that two genes were associated with the development of a metastatic tumor in the brain.
“If you look at a set of lung cancer patients, like we did in the paper, who develop brain metastases, they all have those two genes in their primary lung cancer,” said Sheila Singh, the study’s supervisor, associate professor at the Michael G. DeGroote School of Medicine. “Patients who don’t get brain metastases don’t have these genes in their primary lung cancer.”
Not only are brain metastases the most common type of brain tumor in adults, but they are also a leading cause of death in cancer patients. However, if doctors can screen for the presence of certain genes, we may be better able to predict who is at risk for metastatic brain cancer and how to prevent problems before they occur.
“If you can identify the genes that cause metastases, then you can determine a predictive model and you can work towards blocking those genes with possible treatments,” said Mohini Singh.
This is very promising research, and I’m interested to see how it impacts brain cancer prevention and treatment in the near future.