Scientists discover why stress helps spread cancer – offering new hope for prevention and treatment
It could also help find new treatments.
Scientists have made a major breakthrough in preventing and treating cancer by proving how stress helps the disease spread.
Stress is hard to avoid in life, but is magnified and multiplied following a cancer diagnosis.
Doctors have long suspected stress enables cancer to spread around the body – known as metastasis – triggering a vicious circle, but exactly how it worked was a mystery.
Now however, US-based scientists have cracked the code.
The team discovered that when stressed, white blood cells known as neutrophils eject DNA and form sticky, web-like structures. These sticky webs, known as neutrophil extracellular traps, or Nets, are usually an essential part of the immune system, and usually help bind and kill invading microorganisms.
But when it comes to cancer, they appear to create a metastasis-friendly environment.
‘Stress is something we cannot really avoid in cancer patients,’ said co-author Dr Xue-Yan He.
‘You can imagine if you are diagnosed, you cannot stop thinking about the disease or insurance or family. So it is very important to understand how stress works on us.’
The team made the discovery by mimicking chronic stress in mice with cancer. First they removed tumours that had been spreading cancer cells to their lungs, then exposed them to stress.
‘[We] saw this scary increase in metastatic lesions in these animals,’ said co-author Professor Mikala Egeblad, from Cold Spring Harbor Laboratory in New York. ‘It was up to a fourfold increase in metastasis.’
Further investigation showed that stress hormones called glucocorticoids act as a trigger on the neutrophils, prompting them to expel DNA and create the Nets.
The study also found that chronic stress even caused Net formation to modify lung tissue in healthy mice.
‘It’s almost preparing your tissue for getting cancer,’ said Professor Egeblad.
The startling results highlight the damaging effects of stress.
Co-author Professor Linda Van Aelst said: ‘Reducing stress should be a component of cancer treatment and prevention.’
The team hopes that future drugs that prevent Net formation could slow or stop cancer spreading in patients.
The study is published in the journal Cancer Cell.