How can stress spread cancer?

New research conducted in mice may reveal how chronic stress can promote the spread of cancer. Studies have found evidence that stress may cause changes in certain immune cells that inadvertently make it easier for cancer cells to metastasize and invade other parts of the body. Scientists say the findings emphasize the need to manage stress after a cancer diagnosis and may also help efforts to find new treatments.

The research was led by scientists at Cold Springs Harbor Laboratory in New York. Chronic stress has long been considered a risk factor For many health problems like heart disease, headache and insomnia. there is something there too Research There is evidence suggesting that stress may increase cancer risk or worsen outcomes in people already diagnosed, although much remains unclear about this relationship. Since stress can make us more likely to develop other unhealthy habits, such as drinking excess alcohol, for example, it may indirectly increase our susceptibility to cancer.

The study authors decided to see if they could detect obvious biological changes in cancer-stricken mice exposed to long-term stress. Mice were made to grow cancerous tumors in their breast tissue, and then some of the cells were transported to the lungs, mimicking the process of metastasis.

The researchers found that cancer grew much faster in the lungs of stressed mice, compared to control mice. And when they looked closer, they found evidence that stress hormones were affecting the behavior of neutrophils, immune cells that are one of the first lines of defense against infection and other physical threats. Specifically, stress induces the formation of spider web-like structures called NETs (neutrophil extracellular traps). NETs are typically used by neutrophils to engulf microbes, but the team believes they may also somehow create a friendly home for cancer cells to metastasize.

To test their hypothesis, the team conducted various experiments that cleared out neutrophils or NETs from mice, or made their neutrophils completely unresponsive to stress hormones. And in all of these scenarios, they found that stress no longer acted as a catalyst for cancer in the mice, providing more evidence that neutrophils and their NETs are the key factors behind this relationship. They also found evidence that NETs may make lung tissue in general more fertile ground for cancer, even in mice without cancer.

“Together, our data show that glucocorticoids released during chronic stress cause NET formation and establish a microenvironment that promotes metastasis,” the authors write in their paper. published Thursday in the journal Cancer Cell.

Before we can conclusively link neutrophils and NETs to the crime scene, the findings must be validated by other research, especially in humans. And it is possible that there are other mechanisms involved that allow stress to aid in cancer formation and spread. But the results support the idea that keeping stress under control is especially important for cancer patients. And going forward, researchers speculate that it may be possible to safely develop NET-destroying drugs that could slow or stop cancer from growing out of control.

“Stress reduction should be a component of cancer treatment and prevention,” said senior study author Mikaela Egeblad. statement From Cold Springs Harbor Laboratory.