One of the biggest threats to the health of the American public is cancer. Each year, approximately 600,000 people succumb to at least one form of this disease, and about three times as many people receive a cancer diagnosis. Even if cancer goes into remission, it can make an unwelcome return. According to a recent study, stress could a reason for its return.

Under the Microscope

Authored by an international team of contributors, this study sought to develop a better picture of cancer through creating dormant lung cancer cells in a laboratory setting. Once their cells had been created, the research team mixed them with either B immune cells or T immune cells. Neither of these types of immune cells caused the cancer cells to resume growing.

The story was quite different when the artificial cells were exposed to neutrophils, a type of white blood cell. Under normal circumstances, neutrophils are a crucial part of the body’s immune system, acting as the body’s first line of defense against various microscopic threats. The presence of cancerous tumors, however, effectively hijacks these cells, causing them to foster the growth and spread of cancer.

So how does stress come into the picture? The authors found that two specific stress hormones, known as adrenaline and norepinephrine, had the effect of forcing neutrophils to secrete specific proteins. In turn, these proteins caused the neutrophils to release lipids that restarted the growth and development of the previously dormant lung cells. It also bears mentioning that the same response occurred with cells that had been earlier neutralized with chemotherapy.

A Chain Effect

The study’s senior author, Michela Perego, PhD., offered a succinct explanation of her team’s findings. In short, Perego described the process as a “a type of cascade,” and stressed that “one component of this cascade alone doesn’t work. Neutrophils alone, S100A8/A9 alone, and stress hormones alone don’t work to wake up dormant cells. But when you have this chain of events…it reawakens dormant cells.”

As noteworthy as the report’s findings are, they shouldn’t be taken to mean that stress will automatically lead to a second bout of cancer. “There could be many different ways to wake dormant cells. We’ve shown one mechanism, but I’m very confident this is not the only one,” stated Perego.