Five key facts about cancer

With nearly 10 million deaths and nearly 20 million new cases in 2022, cancer remains one of the world’s biggest killers, according to a report on Thursday by the World Health Organization.

Here are five key facts about the disease ahead of World Cancer Day on Sunday:

– One in five people –
Cancer — a disease that causes abnormal cells to multiply and spread — affects humans and virtually all other animal species, with traces found in human skeletons dating from prehistoric times.

There are more than 100 types of cancer, each with its own diagnosis and treatment. Around one in nine men and one in 12 women will die from cancer.

An estimated 9.74 million people died from cancer in 2022 and 19.96 million new cases were recorded, according to a report by the WHO’s International Agency for Research on Cancer (IARC) published on Thursday.

On average, one person in five will develop some form of cancer in their lifetime, with the number of global cases growing by over 25 percent between 2009 and 2019, according to the US-based Institute for Health Metrics and Evaluation.

The IARC predicted the number of new cases of cancer recorded in the year 2040 would be 50 percent higher than the 19.96 million recorded in 2022.

In 2050, the number is predicted to be 77 percent higher than in 2022.

“There is a large increase in the cancer burden,” said Dr Freddie Bray, head of the IARC’s cancer surveillance unit.

– Lung, breast, colon most common –
The three most common cancers are lung cancer (12.4 percent of new cases in 2022), breast cancer (11.6 percent) and colon cancer (9.6 percent.

In terms of deaths, lung cancer is by far the deadliest, accounting for 18.7 percent of deaths, ahead of colon cancer (9.3 percent), liver cancer (7.8 percent) and breast cancer (6.9 percent).

– Europe disproportionately hit –
Around half of the new cases in 2022 were in Asia, which is home to more than half the world’s population.

What is more surprising is that Europe, including Russia, accounted for a quarter of all the new cases, although it represents under 10 percent of Earth’s inhabitants.

“Many countries in Europe have among the highest incidence rates of common cancers worldwide such as prostate and female breast,” Bray told AFP.

By contrast, fewer than six percent of cancer cases in 2022 were in Africa, home to one in five people but which has the youngest population in the world.

Africa’s youthfulness can explain the low prevalence of many types of cancer, apart from cervical cancer, where is particularly prevalent in sub-Saharan Africa.

– Age a big factor –
Three-quarters of all the new cancer cases in 2022 were among people aged over 55.

Under-29s accounted for fewer than three percent of the cases despite accounting for nearly 50 percent of the world’s population.

The risk of cancer rises steeply as people age because cells in the body become damaged over time and start to behave differently, leading in some cases to cancer.

Some of the damage happens by chance but some is caused by external factors such as drinking, smoking and exposure to UV radiation.

– Men more at risk –
Cancer kills more men than women, with men accounting for 56 out of every 100 cancer deaths, compared to 44 for women.

The fact that men are bigger smokers, which makes them more at risk of lung cancer — the deadliest of all cancer types — is chiefly blamed for the disparity.

But women “endure almost the same burden of cancer overall and disproportionately so at younger ages”, Bray told AFP.