Feb 17 2005
Deaths from mesothelioma, an asbestos-related lung cancer, will peak within ten years in the UK and then fall to a much lower level, according to new figures published in this week's British Journal of Cancer.
Mesothelioma is a type of cancer in the lining of the lungs or the lining of the abdomen. It is thought that the majority of cases are the result of exposure to asbestos, but the disease can take up to sixty years to develop.
Mortality in Britain rose from 153 deaths in 1968 to 1,848 in 2001 and is still increasing, but the new study suggests the rate will begin to decline by 2015.
Researchers from the Health and Safety Executive (HSE), together with Professor Julian Peto of the London School of Hygiene and Tropical Medicine and The Institute of Cancer Research, have improved on previous forecasts by taking account of the changing patterns of exposure to asbestos following the sharp reduction in asbestos use around 1980.
Professor Peto says: "The peak in mesothelioma deaths will be earlier and at a lower number than formerly thought. The abrupt reduction in asbestos exposure in 1980 has altered the lifelong patterns of exposure that people have experienced. This makes the previous age-related models inaccurate.
"Our new model for predicting mesothelioma mortality rates is more complex and takes account of the varying exposure to asbestos of different age groups at different times of their lives."
For example, men born around 1920 who entered the construction industry would have had an increasing level of exposure to asbestos throughout their career. But for men born around 1950 the pattern of exposure would have been completely different.
Early in their career, exposure would have been higher than in earlier generations, but their exposure would have abruptly dropped at about the age of 30 when asbestos use virtually ceased.
Mortality from mesothelioma in younger men has already been observed to be lower than in previous generations, which adds weight to the accuracy of the new model. However, uncertainties remain as to the future of mesothelioma mortality beyond 2020.
Professor Peto explains: "We've assumed that exposure to asbestos has now reached a negligible level, but we don't know that for certain and it won't be clear from the statistics for thirty years.
"We are currently starting a study of lung samples from young men operated on for a collapsed lung. This will give us a snapshot of the current asbestos exposure without having to wait."
The study predicts the peak in mortality will come between 2011 and 2015, the highest number of deaths per year being between 1,950 and 2,450. After this peak, the mortality rate is expected to fall rapidly to a background level, depending on what residual exposure to asbestos, if any, still persists.
Professor Robert Souhami, Executive Director of Policy and Communication at Cancer Research UK, which owns the British Journal of Cancer, says: "A key part of our work is to monitor incidence and mortality rates for different types of cancer. It helps us to anticipate the future cancer burden, which is essential for planning in the health services.
"Mesothelioma is a devastating disease. This study suggests that mesothelioma will be a much rarer disease for the next generation, and it clearly highlights the benefit of preventing cancers by removing specific risk factors such as exposure to asbestos."