New Delhi, Dec. 17: Developing countries are beset by increasing burdens and deaths from cancers amid low survival rates, a report released today by the American Cancer Society said.
The report estimated that 4.7 million people would die from cancer in 2007 in developing countries, and 2.9 million in developed countries. The number of new cases is also higher in developing countries.
The findings based on data from the International Agency for Research on Cancer suggest that the cancer burden is rising in developing countries as infectious diseases and childhood mortality decline and more people live to older ages.
The report estimated there would be over 12 million new cancer cases and 7.6 million cancer deaths worldwide (20,000 per day) during 2007.
Worldwide, cancer kills more people than AIDS, malaria and tuberculosis combined and is the third leading cause of death in developing countries after heart disease and diarrhoeal infections.
This burden is also increasing as people adopt western lifestyles such as smoking, high consumption of saturated fat, calorie-dense foods, and reduced physical activity, said Ahmedin Jemal, an epidemiologist with the American Cancer Society and co-author of the report.
The survival rates for many types of cancer are poorer in the developing countries largely because of lack of availability of early detection and treatment services, the report said.
Indian cancer specialists said the late diagnosis is only one factor among many that can contribute to lower survival rates. But the rates vary widely within India.
In top hospitals, survival rates would be comparable to those in the West, said Purvish Parikh, an oncologist with the Tata Memorial Hospital, Mumbai.
But lack of infrastructure, lack of supportive care, and higher chance of infection from the environment can also contribute to low survival rates, Parikh said.
In developed countries, the most common cancers are prostate, lung and colorectal in men, and breast, lung and colorectal in women. In developing countries, the top cancers are lung, stomach and liver in men, and breast, cervix and stomach in women.
The report said five-year survival rates (the proportion of patients surviving five years after diagnosis) in childhood cancers are about 75 per cent in Europe or North America, in contrast to figures ranging from 48 to 62 per cent in developing countries in central America.
In developing countries, many children who have cancer are never diagnosed, diagnosed too late, or diagnosed where treatment is limited or not available, it said.
In a special section on tobacco, the report said tobacco will kill one billion people during the 21st century, 10 times its toll in the 20th century.
The great majority of the future deaths from tobacco are expected to occur in the developing countries where tobacco consumption has been rising.
If current smoking trends continue, the world will have two billion smokers by the year 2030. Among the world's current smokers, about 50 per cent or 650 million people, will die from their habit each losing an average of about 20 years of life, the report warned.
In countries such as India and China, the tobacco epidemic seems to be unfolding as it did in the US and Europe some 40 years ago, it said.
About 15 per cent of all cancers worldwide are related to infections and percentage of these cancers is three times higher in the developing countries than in the developed countries, the report said.