IT’S normal and inevitable to get bursts of stress – if you’re late to an appointment, interviewing for a new job or worried about a friend.
But long-term stress that seems to be a lingering undercurrent to your life can take a toll on your health.
Research has linked chronic stress to an increased of risk of heart disease and stroke.
A 2017 study published The Lancet found links between stress and cardiovascular disease episodes.
Another published in 2022 found that a major stressful life event could increased the risk of a first stroke by 17 per cent.
There isn’t any evidence that stress can directly increase your risk of cancer, according to Cancer Research UK.
“But it can be harder for some people to keep healthy during stressful times, which can lead to an increased risk of cancer,” the charity explained.
Now, new research has shown that stress can make it more likely for cancer to spread if you’re already suffering from the disease – and uncovered the mechanisms behind it.
Xue-Yan He, a former postdoc in Cold Spring Harbor Laboratory (CSHL), acknowledged: “Stress is something we cannot really avoid in cancer patients.
“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.”
CSHL researchers discovered that stress causes certain white blood cells called neutrophils to form sticky web-like structures.
These make body tissues more susceptible to metastasis – the spread of cancer cells from the place where they first formed to another part of the body – they said.
This new finding could help find new treatment strategies that stop cancer’s spread in its tracks, researchers added.
The CSHL team used mice for their study, mimicking the effects of chronic stress to see how it would affect the rodents’ cancer.
They first removed tumors that had been growing in mice’s breasts and spreading cancer cells to their lungs.
Next, they exposed the mice to stress.
Researchers observed a “scary increase in metastatic lesions in these animals”.
Adjunct Professor Mikala Egeblad said: “It was up to a fourfold increase in metastasis.”
The team found that stress hormones called glucocorticoids acted on the neutrophils.
These “stressed” neutrophils formed spider-web-like structures called NETs (neutrophil extracellular traps), which form when the white blood cells expel DNA.
Normally, neutrophils can defend the body against invading microorganisms.
But in the cancer-ridden mice, the NETs created a metastasis-friendly environment.
Dr He performed three tests to confirm that stress triggers NET formation, which can lead to increased metastasis.
First, she removed neutrophils from the mice using antibodies.
Next, she injected a NET-destroying drug into the animals.
Lastly, she used mice whose neutrophils couldn’t respond to glucocorticoids.
Similar results were observed in all three tests.
“The stressed mice no longer developed more metastasis,” Dr He said.
The team also found that chronic stress caused NET formation to modify lung tissue even in mice without cancer.
Dr Egebald explained: “It’s almost preparing your tissue for getting cancer.”
CSHL Professor Linda Van Aelst said the findings had a clear implication: “Reducing stress should be a component of cancer treatment and prevention.”
The research team said future drugs preventing NET formation could benefit patients whose cancer hasn’t yet metastasized, helping to slow or stop the disease’s spread.
Stress is the body's reaction to feeling threatened or under pressure.
Our body body releases a hormone called adrenaline when we’re stressed, also referred to as the ‘fight or flight hormone’.
But too much stress can affect our body and mood in multiple ways and even spread into our relationships.
Meanwhile, experiencing long-term stress or severe stress can lead to feeling physical, mental and emotional exhaustion, often called “burnout”.
Here are some ways to combat it:
