GPs and oncologists: Partners in managing asbestos-related disease

Use of asbestos as a building material has been banned in Australia since 31 December 2003, but the country still has one of the highest rates of asbestos-related diseases (ARDs) in the world.
 
This includes mesothelioma, a type of lung cancer that is caused only by exposure to asbestos; Australia has the second-highest death rate from this disease internationally, and approximately 19,400 cases are expected to be diagnosed before the end of the century.
 
‘I would say that mesothelioma would not be amongst the rarest [cancers in Australia] any more,’ Dr Melvin Chin, a clinical academic medical oncologist who works at Sir Charles Gairdner Hospital in Perth, told newsGP.
 
‘We see at least a case every fortnight. It waxes and wanes, but we do see it frequently.’
 
These high rates are partly due to the wide use of asbestos in the Australian building industry during the latter half of the 20th century. Another factor is that the mineral was mined in Australia, much of it in Western Australia in places like the now-notorious town of Wittenoom – which is why WA has the highest rates of ARDs, including mesothelioma, in the country.
 
‘We saw approximately 100 cases of mesothelioma in Western Australia during 2014,’ Dr Chin said.
 
‘While that doesn’t sound like a very big number on its own, compared to other countries, it is high.
 
‘If we were to view the United States, for instance, they probably diagnose about 3000 cases per year, but that’s across a much larger and broader population.
 
‘We have a high incidence of [mesothelioma] because of our increased exposure.’
 
Not everyone who is exposed to asbestos will go on to develop ARDs or mesothelioma. But for those who do, the prognosis is almost always poor.
 
‘Unfortunately our treatment of mesothelioma is rarely curative,’ Dr Chin said. ‘The prognosis, even with first-line chemotherapy and a fit patient, would usually be less than 12 months.
 
‘The reason for this is because it is usually diagnosed too late for surgical treatment. So in most circumstances our approach to treating the disease is to alleviate symptoms such as pain, cough and shortness of breath, and to give some control of the disease with chemotherapy and supportive management.’
 
While this type of treatment is administered by oncologists, Dr Chin has found that GPs are vital at every stage of the mesothelioma patient’s journey.
 
‘Usually these patients present with symptoms such as shortness of breath, they may be fatigued, lose appetite, present with fluid on the lungs, with pleural effusion,’ he said. ‘And their GPs are the first ones who refer them on to the correct specialties such as the respiratory physicians, in order to investigate that further.
 
‘GPs often also pick up that some of their patients with ARD might be developing another consequence of asbestos exposure such as mesothelioma, by flagging symptoms such as weight loss, developing fluid on the lungs, feeling unwell.
 
‘GPs also really help manage the symptoms after the chemotherapy, and pick up patients who are vulnerable to infection during chemotherapy, and treat those infections before they become bad enough for the patient to admitted into hospital.
 
‘And finally, GPs have an important role to play in assessing the pain associated with mesothelioma and managing it with prescriptions, and teaching patients about coping strategies for pain and referring to occupational therapy, physiotherapy. They are also important in engaging and liaising with palliative care in the community when the symptoms become significant.
 
‘Essentially, GPs participate in the entire journey from diagnosis, active treatment, and when the symptoms become significant in the disease process.’
 
ARD and mesothelioma in particular can have quite a long dormancy period, so the origins of many of the cases that Dr Chin and his colleagues are treating now may lie many years in the past.
 
‘There is a significant lag-time between where a person is exposed to asbestos and the time when the disease manifests,’ Dr Chin explained. ‘So for many of our patients, the exposure to asbestos can be traced back as far back as 40 years ago.
 
‘In most cases, when they’ve done the epidemiological studies, it seems to be at least 15 years down the track when they start to develop the illness.’
 
This lag-time in the emergence of ARD symptoms means it is anticipated that doctors in Australia will see many more cases in the years to come, in what is described as a ‘third-wave’ of disease largely caused by do-it-yourself renovations to older home that contain asbestos.
 
‘I don’t think we’ve hit the so-called maximum incidence yet in terms of the number of cases diagnosed per year, because [asbestos is] still in some of the old houses we still see today, and we’re also still in that life-stage for patients who have been exposed and have yet to be diagnosed with the disease,’ Dr Chin said.
 
In the case of ARD, there is no question that prevention is the best cure, and Dr Chin hopes that a combination of legislation and awareness-raising about the health issues caused by asbestos will help reduce the number of cases in the future.
 
‘I think it will decline over time. There’s much more awareness now as to the dangers of asbestos exposure,’ he said.

asbestos related disease cancer care mesothelioma oncology