Relation Between Mesothelioma and Asbestos Exposure and Treatment Breakthroughs
Mesothelioma is a cancer that affects the mesothelium (a thin layer of tissue covering many body organs). The areas most commonly affected are the chest and abdominal linings. While the incidence is rare, they account for 0.17% of cancers, and the incidence rate is much higher in men. This article explores the link between asbestos exposure and the incidence of mesothelioma and new treatment options.
Mesothelioma and Asbestos Exposure
A recent study showed that 80% of patients with mesothelioma reported a history of direct or indirect asbestos exposure. Asbestos is a mineral used in construction, automotive products, and shipbuilding for insulation, fireproofing, and brakes. When agitated, asbestos releases tiny particles in the air that can be inhaled or swallowed; this is called asbestos exposure. While low exposure does not lead to mesothelioma, occupational exposure, such as mining, construction, and military workers, puts the workers at risk.
When asbestos fibers are inhaled or swallowed, they stick to the mesothelial lining covering the organs and cause irritation and inflammation. This inflammation leads to scarring and loss of functional tissue. If the inflammation persists, it can cause DNA damage and lead to cancer.
Mesothelioma has a long latency period (time between exposure and disease), and it can take up to 10 to 50 years from the initial exposure to asbestos to diagnosis. This prolonged latency period leads to diagnosis years after exposure and can be a reason for the poor prognosis of this disease.
Treatment Breakthroughs
Patients diagnosed with mesothelioma have a five-year survival rate of 30%, which means only 30% of the people diagnosed survive for five years after diagnosis. An early diagnosis and discussing recent treatment plans with your mesothelioma doctors can help you improve your quality of life and better prognosis. Here are some of the recent breakthroughs in mesothelioma treatment;
1. ATOMIC-Meso Trial
ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a randomized placebo-controlled study led by Queen Mary University of London. It increased the median survival rate by 1.6 months. The study is in its third phase, during which a drug’s safety is tested compared to standard treatment at multiple centers. This therapy works by including the drug ADI-PEG20 along with chemotherapy.
Like regular body cells, tumors require nutrients, such as amino acids like arginine, to grow. The drug works by depleting the level of arginine in your bloodstream, which the tumor cannot synthesize as it lacks the required enzyme, stopping its growth.
2. Immunotherapy
Immunotherapy improves the immune system’s ability to recognize and kill cancer cells. Cancer cells can deactivate immune system T cells, allowing them to remain undetected by the body’s defense system. Pembrolizumab (Keytruda) blocks this effect and exposes cancer cells to the immune system.
Therapeutic Vaccines, including the Galinpepimut-S (WT1) and listeria-based cancer vaccine CRS-207 , have shown promising results in clinical trials. In one study, CRS-207 had a disease control rate (percentage of advanced cancer patients who showed complete response) of 89% and a reduction in tumor size in 31% of the patients. The Galinpepimut-S study showed a 30% disease control rate at eight weeks.
3. Epigenetic Therapy
It is a form of therapy that modifies gene expression, the process by which information on a gene is used to synthesize proteins. Targeting parts of the DNA, such as UHRF1 and inflammation biomarkers, can reverse the damage caused by asbestos. Decreased levels of UHRF1 and inflammation biomarkers are linked to higher survival rates in patients with mesothelioma.
Endnote
Mesothelioma is a cancer with one of the lowest survival rates and limited treatment options. With recent studies like ATOMIC-Meso trials and advances in immunotherapy and epigenetic therapy, there is hope for improvement in mesothelioma prognosis.