Scientists predict that by the year 2020 there will be 15 million new cases of cancer worldwide each year, and 10 million deaths.
Statistics just released show that last year there were 10.1 million new cases of cancer, 6.2 million deaths and 22 million people living with the disease who had been diagnosed in the last five years.
Experts predict the numbers will rise significantly over the next 20 years as the world's population continues to grow, and the average age rises. Older people are most at risk of cancer.
It is likely that by 2020 some 60% of new cases of cancer will occur in developing countries.
In the year 2000 the most common cancers in terms of new cases were:
lung (1.2 million) breast (1.05 million) colorectal (945,000) stomach (876,000) liver (564,000) cervical (471,000)
Lung cancer was also the biggest killer, responsible for 17.8% of all cancer deaths. It was followed by stomach (10.4%) and liver (8.8%).
There were 5.3 million new cases of cancer among men, and 4.7 million among women.
Nearly half (46%) of cancers occurred in people aged 65 or over.
Different patterns
However, the incidence of different types of cancer varied greatly between different populations.
Dr Maxwell Parkin, of the International Agency for Research on Cancer in Lyon, France, argues this implies that lifestyle and environmental factors play a significant role in determining who gets cancer.
He said this suggests that health education programmes should have a positive impact.
Dr Parkin said that his projections for the future were based on current incidence and death rates.
He stressed that these figures for the major cancers were constantly changing.
"It is fairly certain that stomach cancer rates will continue to decrease, whereas the increasing risk of prostate and breast cancer is likely to be maintained for some time.
"The decrease in lung cancer finally being achieved in some countries will be offset by the current increases in some countries of eastern Europe, and, quite probably, but future increases in many less developed countries.
"Nevertheless, these simple projections illustrate the increasing toll that cancer will take in our ageing world populations, and highlight the need to seek and apply effective preventive measures, as well as to strive for continued improvements in the effectiveness of treatment."
Much to be done
Peter Sasieni, the Imperial Cancer Research Fund's head of mathematics and statistics, said the research comprehensively showed just how much of a burden cancer was throughout the world.
He said: "In spite of our progress in cancer prevention and treatment, there is still much to be done.
"The paper highlights the fact that so many cases of cancer are preventable.
"For example, lung cancer is the most common cancer in the world, but the number of cases could be dramatically reduced if more people gave up smoking."
The research is published in the journal Lancet Oncology.
-- Anonymous, August 31, 2001