Advancements in Mesothelioma Research : Uncovering Causes, Promising Treatments, and Future Cures

Mesothelioma, or malignant mesothelioma, is a rare type of cancer that is caused by exposure to asbestos. This type of cancer develops in the thin layer of tissue that covers the surface of many of your internal organs known as the mesothelium. Mesothelioma is an aggressive form of cancer that is fatal. While there are several treatments available for mesothelioma, but for most people with this type of cancer, there is no cure for the disease.^(1,2,3)

Mesothelioma is segregated into different types depending on what part of the body or the mesothelium is affected. Mesothelioma is most commonly known to affect the lungs or the tissue that covers the lungs, known as pleura. This is the most common form of mesothelioma is known as pleural mesothelioma.^(4,5) Some of the other, rarer forms of mesothelioma are those that affect the tissue that lines the abdomen, known as peritoneal mesothelioma, pericardial mesothelioma which affects the lining around the heart, and testicular mesothelioma that affects the tissue that surrounds the testicles.^(6,7,8,9,10)

Being exposed to asbestos fibers is one of the most common causes of malignant mesothelioma. Most people who are diagnosed with this type of cancer have worked or lived in places where they were exposed to asbestos and they inhaled or swallowed asbestos.

The poisonous fibers of asbestos do not cause mesothelioma to develop overnight. After the initial exposure to asbestos, it generally takes a long time for mesothelioma to develop. It is important to know, though, that living with a person who works near asbestos is also a significant risk factor for the development of malignant mesothelioma.

Asbestos is a type of fibrous mineral that creates powder or dust. If this dust or powder is inhaled or ingested, these fibers can become lodged in your internal organs and go on to cause tumors at a later stage. Those people who have an occupational risk of getting exposed to asbestos have a greater risk of developing mesothelioma and other asbestos-related diseases like lung cancer and asbestosis.^(11,12)

The usual survival rate for mesothelioma patients is usually in the range of 18 to 31 months with treatment. Mesothelioma treatment can only help improve certain factors like the overall quality of life and survival time, but it is not able to actually treat the disease. Treatment plans for mesothelioma include traditional cancer methods like chemotherapy and radiation therapy, along with newer methods like immunotherapy. In most cases, doctors prefer to choose multi-modal plans, meaning a treatment plan with a combination of different treatment options.

The primary risk factor for mesothelioma is being exposed to asbestos. In fact, asbestos exposure is the only definitive cause of mesothelioma as of today. In fact, studies have found that asbestos exposure is the main cause of mesothelioma in 80 percent of all cases.^(13,14) Exposure usually happens at work or in older buildings. When a person inhales or ingests the asbestos fibers, they may become embedded in the lining of the lungs, heart, or abdomen. Over a period of time, these asbestos fibers can cause scarring and inflammation. This irritation, over time, can lead to the development of cancerous tumors of mesothelioma.

Asbestos is a mineral that was earlier used in many materials and products, all the way up until the 1980s. Some of the most common sources of exposure are from older buildings and certain industries. For example, construction workers are more likely to come in contact with and handle many materials that include asbestos such as old asbestos insulation and drywall.
Those who work in high-risk asbestos jobs have a much higher risk of being exposed to this toxic substance. This usually results in the development of asbestos-related diseases such as mesothelioma and asbestosis. It is estimated that eight out of ten people who have mesothelioma have experienced some form of asbestos exposure that could be traced back. According to the World Health Organization (WHO), it is estimated that asbestos is responsible for nearly half of all the cases of occupational cancer deaths.^(15,16,17)

Exposure to asbestos fibers increases the chances of developing mesothelioma over a course of 10 to 50 years. Exposure to asbestos typically occurs in two ways, known as primary and secondary.^(18,19,20) People may also experience primary exposure to asbestos themselves in many places, such as school or at work, while others may experience secondary exposure, which happens when someone unknowingly carries the fibers of asbestos to another location from the primary location. This exposes other people in the secondary location to these asbestos fibers. Secondary exposure usually affects family members who live in the same place as asbestos workers.^(21,22)

Research on mesothelioma is still continuing to determine how exactly asbestos causes mesothelioma. Many medical experts agree that according to the current evidence, the following process seems to occur:^(23,24)

• Step 1: A person inhales or ingests the asbestos fibers.
• Step 2: The asbestos fibers settle into the lining surrounding the organs known as the mesothelium.
• Step 3: Over time, these fibers cause inflammation in these thin tissues.
• Step 4: This inflammation starts causing damage and cancerous changes start occurring in the mesothelial cells.
• Step 5: All these changes combined to cause the development of mesothelioma.

Apart from the inflammation and scarring, the asbestos fibers can also sometimes cause damage to your DNA. Damaged DNA is also a potential cause of many types of cancers, including mesothelioma. Asbestos fibers disrupt the process of cell division, which can damage the DNA. At the same time, asbestos can physically interact with your DNA and even change its functioning. Inflammation caused by asbestos can also damage DNA, which in turn can cause cancer in the long run.^(25,26)

It is the exact location in the body where the asbestos fibers get stuck and causes damage to the tissues and the DNA that has an impact on which type of mesothelioma develops.

As mentioned earlier, there is no cure for mesothelioma, but there are many treatment options that can help improve the overall quality of life and help you manage the symptoms of the disease. Let us take a look at some of the potential treatments for mesothelioma and the ongoing research to discover a potential cure for this fatal disease.

The treatment for mesothelioma usually involves a combination of surgery, chemotherapy, and/or immunotherapy. Along with these, patients may also need to undergo radiation therapy or need supportive care, also known as palliative care. Treatment for mesothelioma provides relief from your symptoms, while also somewhat increasing the life expectancy for patients.

Your doctor will determine your treatment plan based on the exact type of mesothelioma you have, the cancer stage, how far it has spread, and your overall health. The four main treatment options that are recommended by the American Society of Clinical Oncology for mesothelioma are:^(27,28)

• Surgery: Surgical intervention is used to partially or fully remove the cancerous tumors and diseased lymph nodes.
• Chemotherapy: Chemotherapy drugs are used to attack the rapidly growing mesothelioma cancer cells.
• Radiation Therapy: Radiation therapy is used to kill the mesothelioma cells and also to prevent the cancer from spreading further.
• Multimodal Therapy Approach: Multimodal therapy makes use of a combination of two or more of the above cancer treatments.

These conventional treatments have helped mesothelioma patients live a better quality of life, though there is still a lot of room left for improvement. This is why there is a lot of research being done in this field and many new and emerging treatments have come up for mesothelioma.^(29,30,31)

For patients who do not respond to these traditional therapies, the experimental new treatment options can be the source of hope they need. However, it is important to note that there is still no cure or any scope of a potential cure for mesothelioma at present. Nevertheless, doctors and researchers all over the world are developing many new and promising treatments for mesothelioma cancer that can help extend the lives of patients.

Some of the emerging mesothelioma treatments include:

• Immunotherapy
• Vaccine therapy
• Gene therapy
• Cryotherapy
• Photodynamic Therapy
• Tumor Treating Fields

These emerging treatments have determined new targets against mesothelioma, and these options also work well when paired with the conventional treatments as well.

Let us take a closer look at these emerging treatments and how they work.

1. Immunotherapy

   Immunotherapy helps boost the patient’s immune system in order to allow the body to better fight against mesothelioma. In 2020, the US Food and Drug Administration (FDA) gave approval for two immunotherapy drugs for the treatment of pleural mesothelioma after the trials showed that they helped extend the lives of patients. The two drugs were nivolumab (brand name Opdivo) and ipilimumab (brand name Yervoy). In 16 years, this was the first drug regimen that was approved for mesothelioma. There are studies going on many other mesothelioma immunotherapy drugs currently.^(32,33)

2. Vaccine Therapy

   Cancer vaccines are also a form of immunotherapy and they work by teaching the patient’s immune system to fight against the cancer. Mesothelioma vaccines are in development for both the prevention and treatment of mesothelioma. The FDA has to date approved only one therapeutic cancer vaccine – Provenge (Sipuleucel-T) received approval in 2010 for the treatment of advanced-stage prostate cancer. However, therapeutic cancer vaccines for mesothelioma are still only available through clinical trials. There is a lot of research going on to study potential mesothelioma vaccines though they are mostly in the preliminary phases of animal testing.

   In 2021, a clinical research trial called NIPU was launched and is currently in its phase II. The trial is testing second-line ipilimumab and nivolumab with UV1, which is a telomerase vaccine on patients who have malignant pleural mesothelioma that cannot be operated on. In total 118 patients will receive this vaccine therapy until the disease progresses, there is any type of unacceptable toxicity, or for a maximum period of two years.⁽³⁴⁾

3. Gene Therapy

   Gene therapy for mesothelioma alters the DNA of the existing cells in order to fight against the cancer. With the use of this novel therapy, new genes are inserted into the mesothelioma cancer cells to allow the body to destroy these cancerous cells.

   In 2022, doctors in Japan created versions of two gene therapy drugs that are inhalable and can be used in the treatment of non-small cell lung cancer and pleural mesothelioma. The study found that by inhaling the drugs, it was possible to deliver them straight to the lung, and that too in a less invasive manner than the other conventional treatments. The process is very similar to how you use an asthma inhaler.^(35,36)

4. Cryotherapy

   Also known as cryosurgery, this emerging treatment option for mesothelioma focuses on the use of liquid nitrogen to freeze and then destroy the cancer cells. This is a minimally invasive surgical technique that has been successfully used for treating many other types of cancer for several decades now and has also shown some amount of success in the treatment of mesothelioma.⁽³⁷⁾

   The UCLA Medical Center has been at the forefront of testing cryotherapy as an emerging treatment option for mesothelioma.⁽³⁸⁾

5. Photodynamic Therapy

   In this type of therapy, high-intensity light is used to activate the immune response of the body. This boosts the immune system to destroy cancer cells. Photodynamic therapy has been found to be more effective in the treatment of localized mesothelioma cases instead of widespread cancer.

   This treatment is usually administered in an outpatient setting and patients can go home after being treated, with no need for hospitalization.⁽³⁹⁾

6. Tumor Treating Fields (TTFields)

   Tumor treating fields or TTFields makes use of harmless electrical pads to prevent the mesothelioma cancer from spreading. The electrical field that is generated by the pads helps interrupt the ability of the cancer cells to divide. This form of treatment was only approved by the FDA for the treatment of pleural mesothelioma in 2019, though it is necessary to be aware that patients who are receiving TTFields for mesothelioma need to also be taking chemotherapy side by side.^(40,41)

   Apart from these treatments, many mesothelioma patients sometimes also decide to supplement their treatment with alternative therapies like chiropractic cancer treatment, medical marijuana, healing touch and touch therapy for cancer, mind-body therapies, as well as nutritional and herbal supplements.

   However, it is important to remember that you should never begin having any other supplementary medication without consulting your doctor first as there can be many side effects and these supplements may also interact with your primary cancer medications.

While the potential for a cure for mesothelioma seems to be farfetched at present, there is a lot of research going on to search for more promising and effective mesothelioma treatments. If you or someone you know has been diagnosed with mesothelioma, you should do some research to find out about doctors who have extensive knowledge and experience in treating this type of cancer. It is only trained and experienced doctors who truly understand the many intricacies involved with mesothelioma and are also well-versed with the latest trends in mesothelioma research and treatments. It is a great idea to visit a specialized cancer center first to find the right specialist for mesothelioma.

References:

Also Read:

• Mesothelioma: Causes, Who Is At Risk, Types, Symptoms, Diagnosis, Present Treatment, Emerging Treatment
• What Is Mesothelioma: Causes, Symptoms, Treatment, Diagnosis
• The Different Types of Mesothelioma and their Symptoms
• The Impact of Genetics on Mesothelioma Development and Treatment
• Treatment Options for Mesothelioma : An Overview
• Mesothelioma Claims | What You Need to Know About Filing a Claim for Compensation