Cancer rates worldwide are expected to increase by 75% by 2030, according to the first analysis to examine global cancer patterns according to individual countries’ development levels. In some of the world’s poorest countries, the analysis indicates that cancer rates could increase by more than 90%.
The study, published online in Lancet Oncology, is based on incidence and mortality estimates for 27 cancers in 184 countries that the International Agency for Research on Cancer (IARC) compiled in 2008. Researchers led by the IARC’s Freddie Bray, PhD, grouped the countries into 4 socioeconomic development levels: very high (the United States, Canada, Western Europe, Scandinavia, Australia, and New Zealand), high (Mexico, much of South America, Eastern Europe, Russia, Saudi Arabia, Turkey, and Libya), medium (China, India, much of Southeast Asia, and countries in the north and southern tip of Africa), and low (much of sub-Saharan Africa and Afghanistan).
Several patterns emerged after accounting for such variables as changes in population size, aging populations, and trends in cancer screening and early detection, the researchers said. They reported that as living standards improve in some low-development nations, rates of infection-related cancers such as cervical cancer and Kaposi sarcoma will decrease, only to be replaced by cancers more commonly linked with Western lifestyles—breast, prostate, and colorectal cancers.
Additional trends reported in the study include the following:
• In most medium- to very high–development countries, rates of prostate cancer and breast cancer in women are increasing while stomach and cervical cancers are decreasing.
• Lung cancer will become a leading cancer in low-development nations if tobacco smoking isn’t effectively controlled in these regions.
• In 2008, nearly 40% of cancer cases occurred in very high–development countries even though just 15% of the world’s population lives in these regions.
“Cancer is already the leading cause of death in many high-income countries and is set to become a major cause of morbidity and mortality in the next decades in every region of the world,” said lead author Bray.