In Australia, each state and territory collects data about people newly diagnosed with malignant mesothelioma. Data about how old a person is, their sex, the area that they live in, the type of mesothelioma they have, and how they were diagnosed is collected for each new case. These data are then combined so that we can see the total number of people diagnosed with malignant mesothelioma in Australia.
Australian data on the number of new mesothelioma cases has been collected since 1982 which means we can look at changes over time in how many new cases of mesothelioma there are each year.
Since the late 1990s, approximately 600 people a year have been newly diagnosed with malignant mesothelioma in Australia. The total number of new mesothelioma cases in Australia between 1982 and 2009 is 11,667 .
It is also important to look at the rate of malignant mesothelioma in the Australian population. This is because looking just at the number of people with mesothelioma does not take into account how the overall Australian population is changing over time.
The rate of mesothelioma in the Australia population in 2012 was 2.4 per 100,000 , or for every 100,000 people you would expect to see 2.4 cases of mesothelioma in that year. This rate is for males and females combined. However, the rates are different when you split the data by sex. The male rate was 4.3 per 100,000 and the female rate was 0.8 per 100,000. This difference between males and females is because of the levels of occupational asbestos exposure experienced by men in the previous decades.
There is a long time between asbestos exposure and the occurrence of mesothelioma, with this ‘lag’ time estimated to be between 20 and 40 years.
Collecting data about asbestos exposure in people diagnosed with malignant mesothelioma is important because it provides us with information about when they were exposed, how long they were exposed for, and in what situation they were exposed. To date, most people with mesothelioma in Australia have been exposed to asbestos in their workplace. However, more recent information suggests people might also be exposed to asbestos in other settings.
The recently established Australian Mesothelioma Registry has been set up to help investigate any changes in the types of asbestos exposure.
Each state and territory collects data for their region on a person’s date and cause of death. Data at the national level is also collected because some people die outside of the state or territory that they would normally live in. Combining this data gives a more accurate estimate of how many have died from malignant mesothelioma, but this process can take several years.
In 2009, 584 people died from malignant mesothelioma in Australia . The total number of people who have died from mesothelioma between 1997 and 2009 in Australia is 6,492.
Because of the rapid disease course of mesothelioma, the mortality rate is closed to the rate of newly diagnosed cases.
Data about how long people survive after a malignant mesothelioma diagnosis are collected from clinical trials as well as from the total number of mesothelioma cases and deaths in Australia.
Compared to other cancers, we know that malignant mesothelioma is an aggressive disease resulting in death shortly after diagnosis, with a median survival time of between 9 and 12 months. However, there is evidence about a group of patients who survive for much longer than the median survival time.
Some of the factors that might influence whether a mesothelioma patient has longer-term survival are age, sex, blood results, type of tumour, stage at diagnosis, and the type of treatment received. Researchers at ADRI are looking at these important factors to better understand what factors contribute to longer-term survival in MPM patients.
From the Australian population data , we also know that there is a less than 10% chance of surviving up to 5 years following a mesothelioma diagnosis. Unfortunately, and despite many research efforts into different treatment options, there has been little change in this probability of survival over the last two decades.