How Medical Research Can Tackle the Deadly Legacy of Asbestos

Post world war two, the UK had the difficult task ahead of rebuilding cities decimated during the blitz. Asbestos was well known for its insulating and fire retardant properties, so during the massive re-development, asbestos saw extensive use. Unfortunately, unbeknownst to users at the time, asbestos is uniquely carcinogenic.

Decades later, people who had previously worked with Asbestos contracted a range of asbestos-related diseases, including pleural thickening, asbestosis and Mesothelioma. Of all the cancers, Mesothelioma is one of the most difficult to treat as it doesn’t respond well to current cancer treatments, meaning that newly diagnosed sufferers only live for a further 12-21 months after hearing the bad news.

The way mesothelioma presents is also a challenge, as the only early symptom tends to be a chronic cough which is commonly mistaken for other less frightening illnesses.

The problem with Mesothelioma’s presentation is that the serious symptoms are only evident when it’s too late to treat. For victims who have their condition discovered by accident, early surgery can be helpful, but for many, cancer spreads too far for surgery to be effective, leaving typical chemotherapy as the only treatment which is only thought to extend life by up to six months.

Immunotherapy

Given Mesothelioma’s rarity, it doesn’t get the same level of time, attention and resources as those cancers that are more common. Breakthroughs, therefore, have been slow to appear, but recently some initial success has been demonstrated by experimental immunotherapy treatments.

In June of 2017, French researchers published results from a phase II clinical trial where out of 108 mesothelioma patients, roughly half of them responded well to a combination therapy comprising nivolumab (Opdivo) and ipilimumab (Yervoy). The results were so positive that the research group have already designed a phase III trial to test the drug combination on a larger group of patients.

In another 2017 study by Penn Medicine, researchers were able to shrink the tumours of 14 patients in a sample of 25 who had been diagnosed with pleural mesothelioma. The drug used in the trial is known as Keytruda, where initial findings suggest that the survival rates of patients were extended to an average of 18months compared to the 12months experienced by those treated only by chemotherapy.

Gene Therapy

Gene therapy is an extension of immunotherapy. Gene therapy has already been shown to produce positive outcomes for sufferers of blood cancers, where white blood cells known as ‘T-cells’ are reprogrammed to recognise and successfully attack cancer cells.

In this case, a gene known as ‘CAR’ is introduced to T-cells so they can target a protein known as mesothelin, which is produced by mesothelioma tumours. This approach is still being investigated, so it isn’t openly available to patients, but this path may lead to a greater variety of options for future mesothelioma sufferers.

Nanocells

Another technique introduced by Australian researchers in 2015 is reported to show potential. This approach takes nanocells from bacteria and modifies them to deliver anti-cancer treatments. In a phase I study, microRNA was used to encourage the human immune system to attack mesothelioma tumours. Again, results were positive, and further research continues into further phases.

The Battle Continues

The UK sees an average of 2,700 new cases of mesothelioma diagnosed every year. Fortunately, it’s felt that this number has plateaued and that it ought to decline in the coming years, echoing the rise and fall of asbestos use some decades earlier. This will be of little comfort to present victims of mesothelioma, and the problem is much worse outside of the UK.

Cancer Research UK notes that 80% of the world’s population live in countries where asbestos is still used. Among these developing nations, they might expect to see a similar trend to the UK as mesothelioma rates begin to rise.

It’s estimated that 2million tonnes of asbestos are still produced each year, so with so few effective treatments currently available, there’s a real concern that in decades to come there may be a mesothelioma epidemic as asbestos users in developing nations begin to experience the symptoms of this deadly disease.