A confirmed diagnosis of mesothelioma means that the patient must have been exposed to asbestos. The success of a mesothelioma claim will rely on showing exactly where and when the victim was in contact with asbestos containing materials. A court will also consider the degree to which the exposure directly or indirectly contributed to the claimant’s development of their condition.

An exposure to asbestos has, to date, been understood to be the only known cause of a malignant mesothelioma cancer and other asbestosis diseases. However, in recent years, research has found increasing evidence, which points to a possible non-asbestos link to the development of the incurable cancer of the lung linings.

Studies suggest that there could be a connection between specific chest radiation treatments, which causes some patients to develop pleural mesothelioma. Doctors have noted that a number of middle aged females diagnosed with pleural mesothelioma were not exposed to asbestos in their home or workplace nor through “secondary exposure” during their earlier life.

X-rays are classified as cancer causing

It is widely known that radiography, the most familiar type of X-ray imaging, and CT scans, might lead to cancer as a result of the mutations caused in our DNA. For this reason, X-rays are classified as a carcinogen (cancer causing) by the World Health Organization. The risks are considered minimal compared to the benefits of medical imaging.

It is estimated that X-rays will increase the risk of cancer by just 0.6 – 1.8 per cent. A chest X-ray, for example, is equivalent to 2 days of natural background radiation. In 2016, researchers argued that there is no proof that low-level radiation causes cancer. The theoretical model which states there is “no safe dose of radiation, no matter how low the dose” ignores the human body’s ability to repair damage caused by low-dose radiation.

Recent studies of female mesothlioma patients discovered that a small but significant number had received radiation therapy to treat Hodgkin lymphoma and non-Hodgkin lymphoma, which often strikes at a young age. Lymphoma is a type of blood cancer, which affects the body’s immune system when the white blood cells divide faster than normal cells or continue beyond their natural lifespan. A lymphoma not only develops in the lymph nodes but can also eventually form a tumour in the spleen, bone marrow, blood or other organs.

Radiation therapy, of course, can be similarly used in targeting malignant mesothelioma cancer cells. While there is currently no cure for mesothelioma, radiation therapy is known to help lymphoma patients make a full recovery. However, doctors have observed that there may be an issue with radiation causing the development of mesothelioma, itself.

20 times increased risk of contracting mesothelioma

In one US study of 1,618 female mesothelioma patients over a 15 year period, it was found that 22 of the victims had received earlier radiation therapy for lymphoma disease. The group possessed an asbestos body count closer to a ‘control’ group, which had not been exposed to asbestos compared to those who were confirmed as exposed to asbestos.

In the overwhelming majority of patients, the cause of their mesothelioma could be definitely attributed to asbestos exposure, however the results of the study suggest that other causes may also be responsible. The results of the research suggest that patients with Hodgkin lymphoma have a 20 times increased risk of contracting mesothelioma after radiotherapy treatment.

The study also drew a further alarming result. Researchers point to patients with a history of lymphoma radiation therapy having an increased risk of developing multiple, second malignancies. Not only is there a fatal risk of mesothelioma, but there is the potential to contract a sarcoma – a rare cancer that can form in the soft tissue, muscles, bones, nerves, cartilage, tendons and blood vessels. The study concludes that while chest radiation therapy is not high risk for most patients, nevertheless, they should be made aware of the potential for ‘treatment-induced’ second malignancies to manifest, including non-asbestos related mesothelioma.

Inflammation link to peritoneal mesothelioma

Unfortunately, the potential for non-asbestos causes of mesothelioma has again been raised by further research into a well-known inflammatory disease. One recent study has discovered that exposure to asbestos was not a factor among a small number of patients diagnosed with the more rare peritoneal (stomach) mesothelioma – and also the inflammatory bowel disorder, Crohn’s disease.

The study analysed 3,800 mesothelioma cases to look for patients suffering with the common characteristics of inflammation in both peritoneal mesothelioma and bowel disease. The results found three patients, aged between 56 and 65 years, all with a long history of bowel disorder and an established diagnosis of Crohn’s disease of three years or more. However, the results also showed that only one of the three patients was known to have been exposed to asbestos. The researchers suggest that the three cases show that widespread inflammation, characteristic of Crohn’s disease, may also be linked to peritoneal mesothelioma.

The results of advanced research techniques continue to find possible alternative explanations in rare circumstances. However, it is the historical exposure to asbestos materials, which remains the only currently definitive, known cause of mesothelioma and related asbestosis conditions.