As health authorities make increasing headway in treating infectious diseases in the developing world, they may be trading one problem for another. As people in those countries live longer, they become more likely to develop chronic diseases such as cancer, heart disease and diabetes. A new report by the World Health Organization's International Agency for Cancer Research (IARC) suggests that the incidence of cancer worldwide will grow by 75% by the year 2030, nearly doubling in some of the developing countries. Those increases will put a much larger burden on the poorly developed healthcare systems in such countries because care of cancer is much more expensive than care for infectious diseases.
Dr. Freddie Bray of the International Agency for Research on Cancer in Lyon, France, and his colleagues used data from IARC's GLOBOCAN database to compile estimates of cancer incidence and mortality in 2008 in 184 countries. They determined how various types of cancer relate to the standard of living in each country -- as determined by the Human Development Index -- then projected how the rates would change as living standards improved. The researchers reported their findings in the journal Lancet Oncology.
The team found that cancers typically associated with infections -- such as cervical, stomach and liver cancer and Kaposi's sarcoma -- are declining in the developing countries as infections become better controlled. But the cancers that are most common in the most developed countries -- including lung, breast, prostate and colorectal cancer -- are increasing at a faster rate. In 2008, almost 40% of the number of cancers worldwide occurred in countries with the highest standard of living, even though those regions account for just 15% of the world's population. As living standards increase elsewhere, the number of such cancers will continue to grow, the authors said. In countries with medium standards of living, such as South Africa, China and India, the cancer rate will grow by 78% by 2030, the team predicted. In countries that currently have the lowest standards of living, the rate will grow by 93%.
The seven most common types of cancers worldwide are lung cancer, breast cancer, colorectal cancer, stomach cancer, prostate cancer, liver cancer and cervical cancer.