The report estimates that 5.4 million of those cancers and 2.9 million deaths will occur in economically developed countries, while 6.7 million cases and 4.7 million deaths will occur in economically developing countries. These projections were based on incidence and mortality data from the Globocan 2002 database compiled by the International Agency for Research on Cancer (IARC).
In economically developed countries, the three most commonly diagnosed cancers in men are prostate, lung, and colorectal cancer. Among women, they are breast, colorectal, and lung cancer. In contrast, the three most commonly diagnosed cancers in economically developing countries are cancers of the lung, stomach, and liver in men, and cancers of the breast, cervix uteri, and stomach in women. In developing countries, two of the three leading cancers in men (stomach and liver) and in women (cervix and stomach) are related to infection. In both economically developed and developing countries, the three most common cancer sites are also the three leading causes of cancer death.
Approximately 15 percent of all cancers worldwide are infection-related, with the percentage of cancers related to infection about three times higher in developing than in developed countries (26 percent versus 8 percent). "The burden of cancer is increasing in developing countries as deaths from infectious diseases and childhood mortality decline and more people live to older ages when cancer most frequently occurs," said Ahmedin Jemal, PhD, American Cancer Society epidemiologist and co-author of the report. "This cancer burden is also 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."
The International Agency for Research on Cancer (IARC) estimates that in 2002 there were approximately 24.6 million people worldwide who had been diagnosed with cancer in the past five years. Survival rates for many cancers are poorer in economically developing countries than in developed countries largely because of lack of availability of early detection and treatment services. For example, overall five-year childhood cancer survival rates are around 75 percent in Europe and North America, compared to three-year survival rates of only 48 to 62 percent in Central American countries.
Special Section: The Tobacco Epidemic
The publication includes a special section on tobacco’s increasing toll. An estimated five million people worldwide died from tobacco use in the year 2000. Of these, about 30 percent (1.42 million) resulted from cancer, with 850,000 deaths from lung cancer alone. Overall, tobacco was responsible for about 100 million deaths around the world during the 20th century, and it is projected to kill more than 1 billion people in the 21st century, with the great majority of these deaths occurring in developing countries. The report says halting the rapid diffusion of tobacco consumption to developing countries is an urgent global health priority.
The World Health Organization (WHO) estimates that approximately 84 percent of the approximately 1.3 billion smokers in the world live in countries with a developing or transitional economy. In China alone, there are 350 million smokers, more than the entire population of the U.S. If current smoking prevalence patterns continue, there will be two billion smokers worldwide by the year 2030, half of whom will die of smoking-related diseases if they do not quit.
Click here to download the whole report.