Intravenous bags hang above young cancer patients at a hospital in California in the United States [File: Mike Blake/Reuters]

Geneva, February 2 (RHC)-- The number of new cancer cases globally will reach 35 million in 2050, 77 percent higher than the figure in 2022, according to predictions from the World Health Organization’s cancer agency.

A survey conducted by the WHO’s International Agency for Research on Cancer (IARC) cited tobacco, alcohol, obesity and air pollution as key factors in the predicted rise.  “Over 35 million new cancer cases are predicted in 2050,” the IARC said in a statement, a 77 percent increase from the some 20 million cases diagnosed in 2022.

“Certainly the new estimates highlight the scale of cancer today and indeed the growing burden of cancer that is predicted over the next years and decades,” Freddie Bray, head of cancer surveillance at the IARC, told Al Jazeera on Thursday.

There were an estimated 9.7 million cancer deaths in 2022, the IARC said in the statement alongside its biannual report based on data from 185 countries and 36 cancers.

Around one in five people develop cancer in their lifetimes, with one in nine men and one in 12 women dying from the disease, it added.  “The rapidly-growing global cancer burden reflects both population ageing and growth, as well as changes to people’s exposure to risk factors, several of which are associated with socioeconomic development. Tobacco, alcohol and obesity are key factors behind the increasing incidence of cancer, with air pollution still a key driver of environmental risk factors,” the IARC said.

The IARC also highlighted that the threat of cancer varies depending on where a patient lives.  The most-developed countries are expected to record the greatest increases in case numbers, with an additional 4.8 million new cases predicted in 2050 compared with 2022 estimates, the agency said.

But in terms of percentages, countries on the low end of the Human Development Index (HDI) – used by the United Nations as a marker of societal and economic development – will see the greatest proportional increase, up 142 percent.

Meanwhile, countries in the medium range are predicted to record a 99-percent increase, it said.  “One of the biggest challenges we are seeing is the proportional increases in the cancer burden are going to be most striking in the lower income, lower human development countries,” Bray told Al Jazeera.

“They are going to see a projected increase of well over doubling of the burden by 2050.  “And these are very much the countries that currently are ill-equipped to really deal with the cancer problem.  And it’s only going to get bigger and there are going to be more patients in cancer hospitals in the future.”

Bray said that although there are more than 100 different cancer types, the top five cancers account for about 50 percent of cases.  “Lung cancer is the most common cancer worldwide … particularly in men, whereas breast cancer is certainly the most common cancer in women,” he said.

The IARC also said different types of cancer were now increasingly affecting populations as lifestyles change.  For example, colorectal cancer is now the third most common cancer and second in terms of deaths. Colorectal cancer is linked particularly to age as well as lifestyle factors like obesity, smoking and alcohol use.

“There should be a lot more investment in the early diagnosis and screening [of cancers]. There should be a lot more investment in preventing the disease,” as well as in palliative care for people who are suffering, Bray said.