How Common is Mesothelioma?

A problem in determining mesothelioma incidence is that it has not always been accurately diagnosed. Many cases have been thought to be another form of lung cancer called adenocarcinoma of the lung, which looks very similar.

However, there is much agreement that diagnoses of mesothelioma increased between the mid-1970s and mid to late-1980s, and is now thought to be somewhere between seven and forty per million people in Western countries. In 1980 U.S. death rates from mesothelioma were approximately 2,000 per year, and by the late 1990s, they were at about 3,000 per year.

Between 1973 and 1984, pleural (lung) mesothelioma cases increased threefold in white males but remained steady among females. It most often occurs in males but can occur in anyone, even in children.

Asbestos Exposure

Between 1940 and 1979, about 27.5 million Americans were exposed to asbestos in their work place. Most often this is a background factor in those who are diagnosed with mesothelioma, but not always, as some people with mesothelioma have had no exposure to asbestos. However, incidence of mesothelioma among the family members of those who worked around it is higher than in the general population. The asbestos fibers were unwittingly brought home in the worker’s clothing and hair so that they contaminated the home and endangered the family.

Incidence Peaking

Many studies have been done and continue to be done on mesothelioma. It is thought now that mesothelioma incidence may have peaked and will decline to an ongoing level of about 500 cases each year.

The U.S. National Cancer Institute (NCI) has been assembling annual statistics on mesothelioma incidence since 1973. According to the NCI, the rise in numbers of cases corresponds to the rise and subsequent decline in use of asbestos in industry and its associated effects on workers. The decline in mesothelioma cases has been noticed since the early 1990s.

In Britain the figures form a pattern which will peak around the year 2020, as the maximum exposure to workers occurred in the 1970s. In the U.S. it occurred in the 1950s.

Male Age Breakdown

Statistics show that beginning in 1973, mesothelioma increased sharply in incidence for males aged 55 and up.

· After 1983, incidence flattened out for males aged 55 to 74

· After 1989, incidence flattened out for males aged 75 and up

· Males aged between 45 and 54 had no increase in incidence and remained relatively low

The greatest number of mesothelioma cases has always been in males aged 75 or more. The second greatest number of cases has been among males aged 65 to 74. The age brackets of 55 to 64 and 45 to 54 have never spiked as high as the higher age brackets.

In the U.S. increased awareness of the dangers of asbestos combined with the U.S. government regulations and guidance programs has greatly reduced worker exposure. Exposure is projected to remain low and to keep mesothelioma risk low in the future.