People in silhouette

Our researchers have found that height can affect cancer risk

Today, Cancer Research UK scientists have published research showing that taller people seem to be have a higher risk of cancer.

This may seem alarming, but tall people needn’t be too worried about these results.

The results only point to a small increase in risk, and most people aren’t so much taller than average that their height would have a strong effect on their chances of developing cancer.

Let’s have a look at what the researchers found.

Height and cancer in context

Researchers have been studying the links between height and breast cancer risk since the 1970s. This study is the latest in a long line of studies that have linked being taller to a higher risk of cancer, including testicular and ovarian cancer.

The latest results come from the Million Women Study, which involves so many people that the researchers were able to investigate the relationship between height and a range of different cancers including some less common types of cancer.

They found links between height and bowel, skin, breast, ovary, womb, kidney, and brain cancers, as well as leukaemia and non-Hodgkin’s lymphoma.

The Million Women Study has given us a huge amount of useful information about cancer risk in the past. Linking even small amounts of alcohol to cancer risk, providing groundbreaking results about the effects of hormone replacement therapy, and studying weight, reproductive history and diet, the results from the study have helped us understand more than ever before about what affects cancer risk.

Why might they be linked?

Although it seems that height and cancer risk are fairly clearly linked, with a 16 per cent higher relative risk for every extra 10cm (4 inches) of height, researchers are stumped about the reasons why this might be happening. But there are several theories.

It could be that taller people simply are made of more cells, so there’s more potential for one of them to go wrong and become cancerous.

Our genetic make-up also affects our adult height, and one recent study by Cancer Research UK scientists, looking into certain genetic changes in prostate cancer risk, found that one particular change was associated with being taller, and also linked to a higher risk of prostate cancer.

There are also things in early childhood that affect how tall we’ll be as adults. Diet, hormone levels, illnesses, and how affluent or deprived we are can all have an impact. And some of these things can be linked to cancer risk as well – so height could simply be a ‘marker’ for something else that’s causing the increase.

But at the moment, there’s little evidence to support any of these possible mechanisms.

It’s likely that future research, aimed at discovering more about how height and cancer risk are linked will give us some useful insights into how these cancers start and develop – insights that may lead to ways to improve treatment and care.

How big is the risk?

Let’s take breast cancer as an example. In this study, the researchers found that every extra 10cm (or 4 inches) of height was associated with a 17 per cent higher risk of the disease.

Drinking alcohol increases breast cancer risk: every extra unit per day increases the risk by 12 per cent (and a large glass of wine is about three units).

Comparing that to the effect of weight, the risk for women with the highest BMIs is 40 per cent higher than for the slimmest women.

Having children also has an effect. Women with no children have a 43 per cent higher risk of this disease than those who have had children.

So in comparison with these risks, the effect of height seems to be much smaller.

Controlling cancer risk

There are things we can’t control about cancer risk: getting older, the genes we were born with, and our height – to name a few.

But there’s also a lot we can do to reduce the risk of developing cancer in the first place.

Experts estimate that up to half of all cancers could be prevented by lifestyle changes. Being a non-smoker, cutting down on alcohol, keeping a healthy weight, being active, eating a healthy balanced diet and enjoying the sun safely can all reduce the risk of developing cancer.

And tall people, just as much as short, can benefit from living healthily – not just by lowering their risk of cancer, but of lots of other diseases too.

It’s also important for all of us to get to know our bodies, and what’s normal for us. That way, we’re more likely to notice if anything changes.

If you do notice any persistent or unusual changes, it’s a good idea to get it checked out by a doctor. It probably won’t be cancer, but if it is, getting it checked is the best thing you could have done – spotting cancer early means that treatment is more likely to be successful.