The report, based on data compiled by the International Agency for Research on Cancer (IARC), reveals disparities in how cancer affects the developed and developing world. Infection plays a greater role in shaping cancer incidence in developing countries, where the number of infection-related cancers is 3 times higher than in developed nations.
In developing countries, stomach, lung, and liver cancer were named as the three most commonly diagnosed cancers among men, and cancers of the breast, cervix, and stomach showed up the most frequently among women. Infection with Helicobacter pylori (H. pylori), a type of bacteria, is thought to be a major cause of stomach cancer, whereas infection by the human papillomavirus (HPV) is known to be a strong risk factor for cervical cancer. Liver cancer is linked to hepatitis B and C infections, both rampant in Africa and East Asia. In the developed world, by contrast, the most commonly diagnosed cancers in men are prostate, lung, and colorectal, while breast, colorectal, and lung cancer were the three most common in women.
Survival rates are lower in less developed parts of the world, reflecting a lack of prevention, early detection, and treatment resources. For example, the IARC found that 5-year survival rates for children with cancer were around 75% in Europe and North America, but only 48% to 62% in Central America.
Global Cancer Facts and Figures 2007 also includes data on growing tobacco use in developing countries, warning that if current patterns continue, the number of smokers worldwide will reach 2 billion by 2030. In 2000, an estimated 5 million people died from diseases related to smoking, and of these, about 1.42 million were from cancer. Approximately 84% of the nearly 1.3 billion smokers worldwide live in developing countries, says the World Health Organization.
There are other factors at play, too. 'The cancer burden is “increasing as people in the developing countries adopt western lifestyles such as cigarette smoking, higher consumption of saturated fat and calorie-dense foods, and reduced physical activity," said Ahmedin Jemal, PhD, American Cancer Society epidemiologist, and co-author of the report.
You can download a copy of Global Cancer Facts and Figures 2007 here.