Metastasis creates a battle between the brain and invading cancer cells
Today, when cancer spreads from its original site to other parts of the body, a process known as metastasis, patients face an uphill battle. Treatments are poorly effective, and cures are nearly impossible. Further, incidence rates for these types of cancers are increasing – particularly for cancers that have spread to the brain.
City of Hope researchers are trying to change that scenario.
City of Hope neurosurgeon and scientist Rahul Jandial, M.D., Ph.D., assistant professor in the Division of Neurosurgery, and John Termini, Ph.D., researcher and professor in molecular medicine, want a deeper understanding of how cancer cells metastasize to the brain in order to find more effective treatments.
In the August issue of Cancer Research, the two scientists provide insight on how cancer spreads in the brain. Their review, published online in July, provides research data along with a new assessment of cancer metastases.
“Given that the brain is the most complex and dynamic biological system, there was a surprising lack of research about the brain’s response to tumor cells that arrive after migrating away from the organs in which they originated,” Jandial said.
Cancer metastases to the brain now appear in 8 to 10 percent of all cases worldwide. The increase is largely due to improved methods of detection, allowing more brain metastases to be documented. Also, more advanced treatments are allowing cancer patients to live longer, which ironically, unmasks an increase in metastatic brain disease.
The brain presents a unique environment for a wandering cancer cell, unlike any potential metastatic site in the body, Termini said. The barrier that prevents unwanted substances from entering the brain also excludes most chemotherapy drugs, which makes cancer in the brain difficult to treat.
“What we are discovering is that once they [tumor cells] cross into the brain, cancer cells begin communicating with their neighboring brain cells, tapping into their signaling pathways, stealing their endogenous growth factors, diverting neurotransmitters for the unintended purpose of providing energy, and possibly even commanding neural stem cells to assist them in their growth and colonization,” Termini said.
In order to find more definite answers on how cancer cells metastasize to the brain, additional research is needed to expand the knowledge of the biology and biochemistry of the brain.
One promising approach is to consider the parallels between the brain’s reaction to a traumatic brain injury and the brain’s response to metastatic invasion. This could dramatically increase the knowledge of brain oncology.
“Further investigation within this context may help us figure out how we can buttress the brain’s innate defense strategies against circulating tumors cells in patients undergoing treatment for cancer,” concluded Jandial.
Learn more about brain tumor treatment and research at City of Hope.