Why is economic inequality linked to 19,000 cancer deaths a year?

For several years now, the economy has barely been far from the news headlines.

And recently there’s been a growing realisation that the gap between the richest and poorest in society played an important role in the recent economic malfunction.

But social inequality isn’t just an economic problem – it affects our health too: people from poorer backgrounds have higher rates of certain diseases – including cancer. And when they get them, they often fare worse than their more well-off counterparts.

So what’s the scale of this problem? How much does our unequal society affect the nation’s health? Why and how does inequality lead to health inequality? And what can we do about it?

Today, a new analysis we’ve published in partnership with the government’s National Cancer Intelligence Network, has brought this issue into even sharper focus. The impact of our unequal society is stark: it’s linked to more than 15,000 extra cases of cancer each year, and – even more alarmingly – more than 19,000 extra deaths.

To put that latter figure in some kind of context, it’s more deaths than you’d get by driving two hundred packed Double Decker buses over a cliff. Every year.

We’ll discuss how the researchers got these figures below, and what to do about them. But first, here’s a short animation that summarises the report and its findings:

• Watch the animation on YouTube

Inequality and health

We now know that poorer communities have higher rates of several diseases, including cancer, diabetes, heart disease, and strokes.

The new analysis aimed to answer the following question: given that inequality is linked to cancer, how much ‘extra’ cancer – in terms of cases and deaths – can be attributed to our unequal society?

This is a tricky thing to quantify – it’s impossible to say any particular case of cancer is caused by social inequality. So the researchers performed a clever feat of data analysis, made possible by England’s world-class cancer records, which detail all cases of cancer, and all deaths from the disease.

They analysed this data alongside information about income levels drawn from a publicly available data source called the English Indices of Deprivation – which measures deprivation in different regions of England according to several different criteria.

They then sorted these regions into five groups – or ‘quintiles’ in stats-speak – running from highest to lowest deprivation, so they could calculate how many fewer cancer cases there would be if every area of England had the same cancer rates as the most well-off quintile.

And that, in turn, allowed them to work out how many ‘excess’ cases and deaths there were due to inequality.

They were also able to look at these findings by type of cancer – and this gave them big clues as to why they found the patterns they did.

What did they find?

As well as the headline findings – 15,000 extra cases, and 19,000 extra deaths, each year – a few other facts jumped out of the data:

• Over half of the extra deaths – 11,000 each year – were due to lung cancer
• The other cancers linked most strongly to lower income areas were also linked to lifestyle
• Bucking the overall trend, rates of some cancers – notably breast cancer, prostate cancer and melanoma – were higher in more well-off areas

They also looked at how these figures changed over time – pertinent given both the 2008 financial crisis, and also the parallel focus on improving access to high-quality cancer care over the last decade and a half.

• They found that the levels of extra cases, and deaths, had barely changed over the last fifteen years.

So what’s going on?

Finding lung cancer at the heart of things is as unsurprising as it is depressing: overall it’s the UK’s biggest cancer killer. The link to inequality is driven by the fact that smoking rates are generally higher in poorer areas.

The finding that other lifestyle-linked cancers like bowel and oesophageal cancers are bigger problems in poorer areas is also hardly a surprise, given the well-established link between poverty and obesity, which is driven by many factors, including lower levels of exercise and poor diets.

There are also other factors driving the inequality gap. Poorer patients are more likely to be diagnosed later, to die following surgery for certain cancers, and there’s also lower uptake of NHS screening programmes in more deprived communities.

Finally, rates of an infection linked to stomach cancer, called H. pylori, are higher among the less well-off.

These all add up to create the startling socio-economic inequality gap among England’s cancer patients.

More counter-intuitive is the finding that some cancer types had higher rates in well-off areas.

This begins to make sense when you look at the example of prostate cancer, which is often diagnosed by the controversial PSA test. There’s evidence that men in better-off areas are more likely to ask for PSA tests than those in poorer areas, and being diagnosed with less-serious forms of the disease that didn’t actually need treatment (a phenomenon called overdiagnosis).

Making inroads

And why haven’t the figures shifted over time? On the one hand, this is depressing news – over the fifteen years the researchers looked at, we’ve seen falling smoking rates, increased political attention and priority to cancer, awareness campaigns targeted to more deprived areas, better treatment, and improved survival across the board. Yet the deprivation gap in cancer has stubbornly persisted.

But when set against the widening rates of inequality in the aftermath of the 2008 financial crisis, could it be that the above efforts have served to keep the gap static, rather than widening? This wasn’t something the report considered – but we can say that more research is clearly needed to unpick how these different forces have acted on England’s cancer rates.

What can be done?

So that’s the problem, and its likely causes. What do we do about it?

For starters – given the long shadow of lung cancer across these figures, and its link to smoking, it’s clear we need to carry on getting serious on tobacco – both in terms of measures to stop kids starting, like standard packs, high-profile awareness campaigns, and continued funding for NHS Stop Smoking Services, to help people who want to quit.

Raising tobacco taxes the most effective and cost-effective way of reducing tobacco use

We’re also backing the World Health Organisation’s calls to Raise Tobacco Tax – the focus of this year’s World No Tobacco Day this Saturday. Increased taxation is one of the clearest ways to reduce tobacco consumption (something the industry itself admits)

We also need to see more action on obesity, targeted to those who need it. And this needs to look at the social factors that are driving the nation’s obesity epidemic.

And we need to make sure all communities that need it, get access to clear, comprehensive information about cancer – whether that be its causes, its signs and symptoms, information about screening, or help during treatment. Targeting this information to less well-off areas is vital, and something we’ve begun to tackle with our Cancer Awareness Roadshows, which bring cancer information into hard-to-reach communities.

But inequality is a complex issue, with multiple overlapping causes and effects. We also want to see more research, and more focus on this issue from policy makers, so that we see more innovative policies aimed at closing the cancer inequality gap.

Nearly fifty years ago, Martin Luther King said, “of all the forms of inequality, injustice in health care is the most shocking and the most inhumane”. 19,000 avoidable deaths each year. 200 buses full of people – that’s the challenge – but also the size of the prize if we work to get this right.

Henry

• Read “Cancer by Deprivation in England 1996 – 2011” on the NCIN website

Image credit: Wikimedia Commons