A new global cancer report by a leading US health organization estimates that cancer will kill 7.6 million people worldwide this year (about 20,000 cancer deaths a day), and more than 12 million people will find out they have the disease.
The report is called the Global Cancer Facts and Figures 2007, and is published by the American Cancer Society.
Using data from the Globocan 2002 database compiled by the International Agency for Research on Cancer (IARC), report co-author, Dr Ahmedin Jemal, an epidemiologist with the American Cancer Society, and colleagues, showed there were significant disparities in the cancer rates between the developed and the developing world.
Jemal and colleagues estimate that 5.4 million cancers and 2.9 million cancer related deaths will be in economically developed countries, while in the less developed world there will be 6.7 million cases and 4.7 million deaths.
Infection appears to play a greater part in cancer incidence in the developing world (26 per cent of all cancers) where the incidence of infection-related cancer is some 3 times higher than in the developed world (8 per cent of all cancers).
Also, in the less developed nations, among men, the most commonly diagnosed cancers are those of the stomach, lungs, and liver, and for women, breast, cervical and stomach cancer were the most commonly diagnosed.
In the developed nations, among men, prostate, lung, and colorectal cancers are the most commonly diagnosed, and for women it is breast, colorectal, and lung cancers.
In the developing world, infection with the Helicobacter pylori (H. pylori) bacteria is considered to be the main cause of stomach cancer; infection by the human papillomavirus (HPV) is thought to be the main risk factor for cervical cancer; and hepatitis B and C infections, which the report describes as rampant in Africa and East Asia, are thought to be the main link to liver cancer.
Jemal and colleagues said lack of prevention, early detection and treatment facilities were probably the reason for the less developed world having lower cancer survival rates.
As an example they cited the 5-year survival rate for children with cancer, which is about 75 per cent in Europe and North America, but only 48 to 62 per cent in Central America. This was also based on the IARC figures.
The report estimates that if the growing use of tobacco products persists in developing countries, there will be 2 billion smokers in the world by 2030.
In 2000 there were 5 million deaths linked to smoking, of which 1.42 were from cancer, said the report.
According to the World Health Organization (WHO), over 80 per cent of the 1.3 billion smokers in the world live in developing countries.
There are 350 million smokers in China alone, more than the whole of the US population.
Overall, tobacco was responsible for around 100 million deaths worldwide in the 20th century, and will be responsible for more than 1 billion deaths worldwide in the 21st century, said the report authors. Most of the deaths will be in the developing world, and the authors said stopping the rapid spread of tobacco in developing countries should be a top global health priority.
The cancer burden is on the rise said Jemal, because developing nations are increasingly adopting a western lifestyle, characterized by “cigarette smoking, higher consumption of saturated fat and calorie-dense foods, and reduced physical activity”.
Written by: Catharine Paddock