Professor John Cherrie at Heriot-Watt University in the United Kingdom believes future treatment advances and improved patient outcomes for mesothelioma rests with a formula to better identify and screen high-risk patients.
It could make an early diagnosis of the asbestos-related cancer much more common.
Cherrie said the current standard — which typically results in a late-stage diagnosis and a poor prognosis — prevents novel treatment studies and the development of any pre-emergent strategy to combat the aggressive cancer.
“We don’t pretend to have a medical cure that will help immediately, but until we can start identifying patients earlier, we can’t even try out what might work,” Cherrie, an occupational medicine specialist in the School of Engineering and Physical Sciences at Heriot-Watt, told Asbestos.com. “The patients are usually too sick. It’s tough to make progress that way.”
Cherrie is the lead author in a study published recently in the International Journal of Hygiene and Environmental Health, detailing the asbestos-exposure formula he believes would work.
“Right now, we don’t have a way of identifying early-stage disease,” he said. “Usually by the time it is diagnosed, it’s virtually untreatable. We want to find a way to change that.”
Pre-Emergent Treatment Strategies
Mesothelioma is caused almost exclusively by exposure to toxic asbestos, typically in long-term occupational settings.
Cherrie believes a reliable, standardized assessment of asbestos exposure history and the development of a comprehensive screening program would lead to healthier clinical trial participation and novel chemoprophylaxis strategies that are not yet used with mesothelioma.
Chemoprophylaxis, which is being studied closely with breast, prostate and colorectal cancers, involves preventative therapy that may reduce disease incidence or slow its growth with early molecular modification.
It would be practical, though, only if there are little or no side effects and the high-risk patients can be accurately identified.
“If we could better categorize the amount of exposure over a lifetime, we could better predict what the chances were of getting the disease,” he said. “That’s a start, a first step to a better screening tool.”
Identifying the High-Risk Mesothelioma Population
The method used in Cherrie’s study is based on a model of exposure that involves substance emission potential, activity emission potential and the effectiveness of any local control measures.
- Substance emission potential includes the intrinsic property of the material being handled. For example, the type and proportion of asbestos.
- Activity emission potential includes the amount of energy exerted to the material to disperse the asbestos.
- Local control measures include general dilution ventilation and efficiency of any respiratory protection.
The three factors, along with various other parameters, can be calculated to form an estimate of exposure level, providing a more accurate identification of high-risk candidates.
The method also would be suitable for reconstructing exposure measurements in civil litigation and for epidemiological studies.
Progress Can Be Made
Once the highest-risk population is identified properly, screening tools such as chest X-rays, low-dose computed tomography and accompanying medical exams can be used more effectively.
Novel identifiers such as biomarker technologies, soluble proteins in blood and molecules in exhaled breath could be more easily studied.
Early identification of mesothelioma also would lead to more effective use of immunotherapy — which works best with lower tumor volume — and minimally invasive techniques such as pleurodesis and indwelling pleural catheters.
“Early detection will accelerate the development of new treatments and should be pursued aggressively,” the authors wrote in the study.
Cherrie believes the lack of a definitive cure for mesothelioma and continued skepticism are reasons a more aggressive early identification program has yet to be embraced.
“There still is a lingering mindset that this tumor is untreatable, so why would they want to know about it and treat it earlier? It’s a nothing can be done attitude,” he said. “People don’t always see the possibility of improving the situation. We’re not saying this is a solution, but we see it as a way forward that is worth exploring.”