New model explains how our immune system sometimes helps cancer spread

Mathematicians at the University of Alberta have developed a model that explains how the immune system interacts with cancer—and in some cases, may help cancer spread to other areas of the body.

"Past research has shown that sometimes, the immune system has the opposite effect of what we might expect," said Thomas Hillen, a mathematical biologist at the U of A and member of the Cancer Research Institute of Northern Alberta.

"There are many different mechanisms through which this can happen," explained Adam Rhodes, a Ph.D. student studying under Hillen's supervision and lead author on the study.

"In general, the tumor tricks the immune system into thinking that it is part of a healthy body system. The immune system can help provide blood supply and growth factors to the tumor. It can fend off other immune cells from damaging the cancer, allowing it to spread."

The pair analyzed hundreds of studies on many types of cancer, then developed a mathematical model that can explain the mechanisms through which the immune system can support metastasis—and give insight into how to prevent and treat the disease.

"For example, our research suggests that inflammation and injury can contribute to cancer metastasis," noted Rhodes. "So it is justified to study the effect of anti-inflammatory treatments on metastasis."

Although the research team does not work directly with patients, they said their work could add valuable insight and information into clinical practice.

"Mathematics is the only way to combine the vast number of studies done on cancer into one cohesive framework," said Hillen.

"This model applies to many different kinds of cancer—from prostate cancer to breast cancer to lung cancer. Without a tool for analyzing all these data from studying myriad types of cancer, it is difficult to move forward."

The study, "A Mathematical Model for the Immune-Mediated Theory of Metastasis," was published in the Journal of Theoretical Biology.