World Cancer Day 2017: global lung cancer rates reveal tobacco’s dark shadow is looming

In the first of our 4-part series for this year’s World Cancer Day we take a look at lung cancer rates in different parts of the world. Thankfully in some countries rates are falling, but as our interactive map shows, other regions are facing an increasing challenge in the years to come.

Lung cancer kills more than a million and a half people every year worldwide.

That’s more than 4,000 deaths each day from this single type of cancer. And even that pales in comparison to the total number of deaths caused by the biggest risk factor for lung cancer – tobacco smoking – which is responsible for a staggering 6 million deaths each year worldwide.

Professor Sir Richard Peto, a Cancer Research UK expert on smoking and cancer, said “Although some smokers don’t get lung cancer and some lung cancers aren’t caused by smoking, more than 80% of lung cancers are caused by tobacco smoking.”

Smoking is also linked with a number of other cancers and is the single biggest preventable cause of cancer. We know from countries that have introduced tobacco control measures that falling smoking rates are reflected in cancer trends. That means worldwide efforts to curb smoking have the potential to make a monumental difference to global cancer rates.

Let’s take a look at what’s going on.

The smoking gun

If we rewind more than 100 years to 1900, smoking wasn’t a common habit across the globe. But during the first half of that century smoking rates began to climb rapidly in developed regions, first in men and then in women.

“Women in the UK and US took up smoking in high numbers and later than men,” says Professor David Phillips, a Cancer Research UK expert on environmental causes of cancer.

“Men took up smoking in a big way during World War I; whereas for women it was post-World War II.”

The peak of women’s smoking rates, which came decades later than that of men, was never as high

– Professor David Phillips

By 1950, around 8 in 10 men and 4 in 10 women were smokers in the UK. And following this increase in popularity, lung cancer rates began to soar; firstly in men because they had been smoking for longer than women. This startling rise in lung cancer rates prompted researchers to search for a cause. And in 1950, several prominent publications proved the relationship between smoking tobacco and lung cancer.

“1950 was really the ‘big bang’ year for smoking and lung cancer,” says Peto. “From then onwards it was clear that the evidence was too strong for this to be anything except a real cause and effect relationship.”

Doctors then took the health risks posed by smoking seriously, advising people to stop. But tobacco companies had other tricks up their sleeves. As smoking rates steadily dropped among men in high-income countries, tobacco companies began specifically targeting women.

“In America during the ‘60s and ‘70s advertising and marketing of cigarettes were heavily aimed at women,” says Phillips. “Some brands were exclusively marketed to women, and they were very successful. But the peak of women’s smoking rates, which came decades later than that of men, was never as high.”

Setting an example

Because it takes many years of accumulating damage from tobacco smoke for lung cancer to develop, the effects of changing smoking rates on cancer rates don’t become apparent for several decades. And this is clearly reflected in the trends we have seen over the years and continue to observe today.

“When it comes to tobacco smoking and lung cancer patterns within a population, we can see a 100-year cycle that countries tend to go through,” says Phillips. A rise in smoking rates is usually followed by a 30-40 year lag before lung cancer rates start to climb, he adds. These rates then peak in the third quarter of the century.

According to Phillips, smoking rates fall “as people become wise to the effects of smoking”. A fall in lung cancer rates will follow later. “You can track this same pattern across different sections of the world,” he adds.

The effects of pretty much all the known causes of lung cancer are greatly aggravated by smoking

– Professor Sir Richard Peto

Looking back at the map above, the countries with the highest rates of lung cancer today (largely Europe and North America) are countries where smoking rates were high decades ago, rather than reflecting current trends of smoking.

Unfortunately, this also means that countries in which smoking rates are now beginning to skyrocket will see a catastrophic rise in lung cancer rates decades from now. As the majority of these countries are in the developing world, such as Asia and sub-Saharan Africa, they are less able to cope with such a strain on public health.

These areas may also be burdened with other risk factors for lung cancer, like air pollution and diseases such as tuberculosis, which make matters worse by heightening the risk from smoking even further.

“The effects of pretty much all the known causes of lung cancer are greatly aggravated by smoking,” says Peto.

“The most obvious is radiation. If a woman with breast cancer is treated with radiotherapy for example, the chance of her developing lung cancer as a side effect from the therapeutic radiation is much higher if she smokes than if she doesn’t.”

Smoking kills, stopping works

While the picture painted so far may sound bleak, the good news is that something can be done.

“Many people believe that once they have been smoking for many years, the damage is already done,” says Peto. “But that’s not necessarily true. Studies like the Million Women Study have shown the extraordinary extent to which stopping works.”

This Cancer Research UK-funded study, which looked at 1.2 million women in the UK, found that the extra risk of dying from smoking almost disappears if people stop smoking before the age of 30, while quitting before 40 avoids more than 90% of it.

Many people believe that once they have been smoking for many years, the damage is already done. But that’s not necessarily true

– Professor Sir Richard Peto

So there’s clearly an incentive for people to stop smoking. But, given the money governments make from taxing tobacco, what’s the government’s incentive to support reducing smoking rates?

“Governments worldwide make $300 billion [£237 billion] each year from tobacco,” Peto says. “The UN has a target of reducing smoking by one-third by 2030. If tobacco prices stay the same but that target is met, governments will lose $100 billion each year.

“But, if governments instead doubled the price of tobacco through raising excise taxes, the number of people smoking would be reduced by about a third, so the same number of lives would be saved, and governments would gain $100 billion a year.”

This type of strategy can work: between 1990 and 2005, France tripled their cigarette prices through taxes, which halved smoking rates and doubled government profits from tobacco. South Africa also achieved the same success over a similar period

Taking control

But it will take more than hiking up taxes to curb smoking effectively. That’s why we’re working hard to make sure the UK government launches a comprehensive tobacco plan (although it’s already a year late). And we’re supporting similar schemes worldwide.

For example, we strongly support the Framework Convention on Tobacco Control (FCTC), an international public health treaty negotiated by the World Health Organisation (WHO). This lays out steps for governments to take to tackle smoking, such as banning tobacco advertising, introducing smoke-free areas and packaging requirements.

But less developed countries often don’t have the resources to follow suit, so we’ve teamed up with the American Cancer Society to fund a new programme (PROACTT) that will help them introduce some of these measures.

Most developed countries, including the UK, have laws that protect people from tobacco marketing and nationwide programmes to support people to quit smoking. In the most recent step forward, we followed Australia in introducing plain, standardised packaging for cigarettes, banning previous marketing and glitzy design features.

And it was our scientists who helped provide the evidence in the UK that eye-catching tobacco packaging is attractive to children and young people, and we led the campaigning to get this law introduced.

But even with new measures, it’s vital we don’t drop the ball on this. Cuts to public health budgets are threatening Stop Smoking Services in England, which are the most effective way for people to quit.

So there is much to be done to achieve our ambition of a Tobacco-free UK and to help others countries follow suit. But through continued effort, smoking can be controlled and lives will be saved.

Justine