Can stress cause cancer?

Doctor with medical file

Does stress cause cancer?

The shortest answer to that question is “currently, it's not believed so”. At least, probably not directly.

But there are numerous links between cancer and stress which can't be ignored...

Most of these are due to the fact that stress – whatever the cause – is not a healthy condition for your body to experience for extended periods of time.

Let's take a look at the whole question of whether stress can cause cancer in a little more detail:

What is stress?

Stress – also known as the stress response or “fight or flight” reflex – is a normal part of the way your body works.

When you perceive yourself to be under threat, the response is triggered. Hormones like cortisol are released and your nervous system amps up.

This does things like boost your heart rate, blood pressure and reaction times. This is very handy if you're facing down a predator or in some other kind of dangerous situation.

But not so handy in other circumstances...

When stress is bad for you

Unfortunately, when the stress response is triggered too often or on a regular basis, this is not good.

Your body isn't designed to operate on a constant “fight or flight” hair trigger for long periods of time. Having all of those hormones floating around and pathways in your nervous system lit up like this all of the time simply isn't healthy.

It's why conditions like acute stress and chronic stress can cause such bad physical and mental health problems.

Can stress cause cancer?

Stress can cause many health problems, some of which can be extremely serious. But can stress cause cancer?

Well, the jury still seems to be out...

Recent studies which have been done on the links between cancer and stress have shown that:

  • A 2013 study found no links between workplace stress and overall cancer risk or risk of specific cancers.
  • A 2016 study found no links between stress factors and risk of breast cancer in over 100 000 women.
  • A 2017 study did find associations between higher levels of previous workplace stress and a higher risk of prostate cancer in the 2000 men studied.

But, while direct links between stress and cancer as cause and result have not yet been proven without a doubt, there are other questions to answer:

Doctors examining x-rays

Can stress cause cancer to spread faster?

Whether stress causes cancer might not yet be clear. But can stress cause cancer to spread faster?

The answer might be a guarded “yes”.

Stress hormones may speed up tumour growth and metastasis (when cancer spreads from its original location):

  • A 2016 study on mice with pancreatic cancer found that stressed mice had larger tumours and weaker immune systems by the end of the experiment.
  • A 2019 study on mice implanted with human breast cancer cells found suggestions that in locations where metastasis occurred, stress hormones receptors were increasingly active.

Are there any other links between cancer and stress?

As well this potential stress-cancer link, there are other potential direct or indirect ties between the two:

  • Stress can weaken your immune system: some types of cancer can exploit the weakened immune system which stress can lead to.
  • Stress can result in poor life choices: common responses to stress include smoking, drinking alcohol to excess and poor eating habits (including both under and over-eating). These are all lifestyle factors which can increase the risk of developing cancer.

Plus – while, again, it isn't and doesn't prove any direct link – there was also a study in which women with breast cancer were asked whether they used beta-blockers or not. Beta-blockers are a type of medication sometimes prescribed for depression – and which affect some stress hormones.

Women who reported that they did use beta-blockers had a slightly better chance of not suffering a relapse during their cancer treatment than those who didn't.

However, the use of beta-blockers didn't seem to be an indicator that someone's treatment would be more likely to be successful.

Cancer Cells

Can stress cause cancer cells to grow?

The above studies seem to suggest that stress can increase the chance that a tumour might grow or metastasize to other parts of the body.

There have been a number of experiments on mice which show similar findings:

That when the mice were stressed, there was a much greater chance of the cancer spreading. This seems to be because of the presence of norepinephrine (the stress hormone).

Having quantities of stress hormones like norepinephrine around are also thought to potentially lead to DNA damage or impair DNA repair.

Obviously, neither of these are ideal for anyone.

So, does stress cause cancer?

There is currently no confirmed evidence that stress will directly affect the outcome for someone who has cancer.

However, most of the studies above – and a great deal of research on stress besides – suggests that stress, in general, is not good for you.

It can contribute or exacerbate a whole range of conditions, so you should take whatever steps you can to reduce your stress levels.

If you are suffering from cancer, needless to say, this might be easier said than done...

Woman Meditating

How to reduce stress

Whether stress can cause cancer directly or exacerbate it indirectly, it still contributes to a huge number of poor health outcomes.

This means that if you are suffering from stress, finding any way you can to reduce your stress levels will pay dividends in the end.

You might try taking up exercise, trying a new sport or meditation, experimenting with any of the many stress relief products which are available these days – from calming environment apps and devices to bands which stimulate nerve nexuses – or simply trying to do less and get a little time to yourself.

If you feel like you may suffer from acute or chronic stress – no matter the cause – you should always consider consulting your doctor too.

Henry Warren I am a professional writer and health & wellness enthusiast.