Mesothelioma: Symptoms, Causes, Diagnosis & Treatment

What Is Mesothelioma?

Mesothelioma is a cancer caused in the thin layer of the mesothelium. Mesothelial cells form a monolayer of specialised pavement-like cells that lines the body’s internal organs and serous cavities. The main function of the mesothelium is to protect the body and give the body a slippery and non-adhesive surface.

The other roles of mesothelium cells include fluid transportation, antigen presentation, coagulation, inflammation and tissue repair and tumour cell adhesion.

Mesothelioma is linked to asbestos exposure. Cancer mainly affects

• The lining of the lungs (pleural mesothelioma)
• The lining of the tummy (peritoneal mesothelioma)
• Heart
• Testicles.

According to research, men are most affected by mesothelioma compared to women. Men aged above 75 years are commonly affected by this type of cancer.

Types of Mesothelioma

The types of mesothelioma depend on the location of the tumour. The common type of mesothelioma is malignant pleural mesothelioma. Other three types of mesothelioma include

• Epithelioid mesothelioma
• Sarcomatoid mesothelioma
• Biphasic mesothelioma

Pleural mesothelioma

Pleural mesothelioma occurs in the lining of the lungs, called the pleural. Cancer occurs when a person inhales asbestos fibres. After the inhalation of the fibres, they get attached to the pleura, which causes scarring and inflammation. Over time, it can develop as a mesothelioma tumour.

According to research, malignant mesothelioma accounts for about 80-90% of all mesothelioma diagnoses. Some of the common symptoms of mesothelioma include

• Dry cough
• Chest pain
• Shortness of breath
• Coughing blood
• Fever
• Fluid in the lungs
• Weight loss

There is no cure for pleural mesothelioma, and the treatment will aim to reduce the severity of the symptoms and increase the survival rate of the person.

Epithelioid mesothelioma

Epithelioid mesothelioma is a cancer of epithelial cells. The epithelial cells are present in one of the four tissues in the body. These cells are predominantly found in the skin’s surface, the lining of hollow organs and internal cavities and blood vessels.

Epithelial mesothelioma is caused when a person is exposed to asbestos. The epithelial cells tend to mutate and become cancerous. According to research, epithelial mesothelioma accounts for about 50-70 per cent of mesothelioma cancer patients.

These cells are found in various shapes like

• Columnar
• Squamous
• Cubed

The epithelioid mesothelioma cells can be recognised compared to other mesothelioma cell types. They can be identified by the way they adhere to each other, visible nuclei and the formation of cells that usually occurs in oval or round.

The symptoms of epithelioid mesothelioma depend on where cancer develops. The severity of the symptoms also depends on the patient’s age, health and stage of cancer.

The common symptoms of epithelioid mesothelioma include fluid build-up around the lungs or abdomen and fever. Other symptoms include

• Chest pain
• Unexplained weight loss
• Hoarseness
• Abdominal pain
• Coughing
• Constipation
• Loss of appetite

The treatment for epithelioid mesothelioma includes surgery, radiation therapy and chemotherapy. In severe cases, a patient may undergo a multimodal treatment plan, combining two treatments. These treatments will help reduce the symptoms of the patients.

Sarcomatoid mesothelioma

Sarcomatoid mesothelioma contains epithelial cells resembling epithelioid cells in the skin and other tissues. This rare type of cancer accounts for about 10-20 per cent of all diagnoses. These cells are recognised by their oval spindle shape, also called spindle cell mesothelioma.

Sarcomatoid mesothelioma develops in nodes and lesions and can spread easily to other organs. This type of cancer is very difficult to treat, with a prognosis of about six months.

The characteristics of sarcomatoid mesothelioma include

• Multiple nuclei in cells
• Oval, elongated shape with a large nucleus
• Distant cell formation
• Unstructured formation in lesions and fibrous nodes

Sarcomatoid mesothelioma is also caused due to exposure to asbestos. The mineral fibres can get embedded in the lungs or tissues and can irritate internal issues, which can cause inflammation.

As cancer progresses, it can cause genetic mutation, which develops as mesothelioma cancer.

Symptoms of sarcomatoid mesothelioma include

The symptoms of sarcomatoid mesothelioma can take about 10-50 years to develop. Individuals can experience different symptoms depending on the severity of the disease.

Some of the common symptoms include

• Chest pain
• Shortness of breath
• Decreased appetite
• Difficulty breathing
• Persistent cough
• Weight loss
• Nausea
• Vomiting
• Excess fluid in lungs and abdomen

The life expectancy of sarcomatoid mesothelioma ranges from about three months to eighteen months with proper treatment. If people are not treated properly, the symptoms can be severe. However, life expectancy depends on the stage of cancer and the age of the person.

Biphasic mesothelioma

Biphasic mesothelioma is a combination of sarcomatoid and epithelioid cells. This type of mesothelioma commonly occurs in the lung lining (pleura) and abdominal lining (peritoneum).

Biphasic mesothelioma accounts for about 10-20 per cent of overall mesothelioma cancers. Like the other type, biphasic mesothelioma is caused due to asbestos exposure.

Symptoms may not develop immediately, and it can take decades for the symptoms to set in. The symptoms will depend on the location of the mesothelioma.

Some of the common symptoms include

• Chest pain
• Pleural thickening
• Difficulty breathing
• Pleural effusion
• Pleural plaques

Biphasic mesothelioma can be treated with surgery, radiation therapy and chemotherapy. A combination of treatments can also be used to treat mesothelioma.

Mesothelioma Stages

Mesothelioma stages are crucial to determine the treatment of a person. After confirming that it is mesothelioma, the doctor will determine the stage, and the most common staging method is the tumour node metastasis (TNM) staging system.

The four stages include

• Stage 1
• Stage 2
• Stage 3
• Stage 4  

Stage 1 and 2 are considered early stages and stage 3 and 4 are later stages of the cancer. Various treatment options will be available in the early stages, whereas, in the later stages, it is difficult to treat.

The earliest stage of mesothelioma is Stage 1. Stage 1 of mesothelioma will not show any symptoms, and the cancer has not spread to other organs. Treatments will be effective and respond well in this stage. Stage 1 of mesothelioma has worked well with a combination of treatments. People also have a long-term survival rate when treated early.

Stage 2 mesothelioma indicates that cancer has spread to other organs and tissues. Stage 2 mesothelioma is a localised cancer, and a person can experience mild symptoms.

In stage 2 mesothelioma, many treatment options are available, like therapeutic surgeries. The survival rate of stage 2 mesothelioma is about 19-67 months.

Stage 3 mesothelioma is an advanced stage of cancer. Cancer would have spread to nearby organs, lymph nodes and tissues at this stage. During stage 3, the treatment options will be wide, and life expectancy will depend on certain factors like age, health and the type of cancer. The treatment will mainly aim to reduce the severity of the symptoms and improve the quality of life. The life expectancy of stage 3 cancer ranges from 16-56 months.

Stage 4 mesothelioma is the advanced stage of cancer, and cancer would have spread to other distant organs, tissues and lymph nodes. There are only limited treatment options available for stage 4. However, surgery and chemotherapy are used in this stage of cancer.

A new treatment called immunotherapy has increased the potential option for people in the last stage of cancer. Immune checkpoint inhibitors have been effective and improved the survival rate and quality of life.

Symptoms of Mesothelioma

Mesothelioma symptoms can cause different symptoms depending on the individual’s age, gender, health conditions and the type and stage of cancer. Some of the common symptoms include

• Chest pain
• Unexplained weight loss
• Fatigue
• Dry cough
• Weight loss
• Difficulty breathing
• Fever
• Night sweats
• Abdominal pain
• Pleural effusion
• Ascites or peritoneal effusion
• Coughing
• Right shoulder pain
• Fluid build-up
• Wheezing

The symptoms can vary depending on the origin of cancer. Early stages of cancer will not show any symptoms and may go unnoticed. So, it is advised to consult your doctor when you have symptoms.

Causes of Mesothelioma

Asbestos exposure is the primary cause of mesothelioma. When asbestos fibres are inhaled or ingested, they can get embedded in the lining of the lungs, heart or abdomen. As time progresses, this can lead to inflammation or scarring that leads to the development of mesothelioma.

People who are continuously exposed to asbestos fibres have an increased risk of getting affected with mesothelioma. People who work in asbestos industries have a higher exposure and risk rate. This is called primary exposure.

Workers who work in the asbestos industry can carry these fibres home unintentionally. These fibres can get attached to the skin, clothes and hair through which their family members can be exposed to the asbestos fibres. This is called secondary exposure or second-hand exposure. People who live with asbestos industry workers are at risk of getting affected with mesothelioma.

High-risk of mesothelioma includes these occupations and their families.

• Construction workers
• Auto mechanics
• Firefighters
• Machine operators
• Industrial workers
• Textile Mill Workers
• Aircraft mechanics
• HVAC workers
• Machinists
• Mineworkers
• Shipyard workers
• Oil refinery workers
• Teachers
• Insulators
• Boiler workers

Diagnosis of Mesothelioma

Diagnosis is a crucial step in mesothelioma, as the treatment will depend on the diagnosis. Additionally, early diagnosis will help improve the quality of life and provides wide treatment options.

Common Tests for Diagnosing Mesothelioma

Some of the common tests used to diagnose mesothelioma are listed below.

Imaging Scans

The initial stage of diagnosis will use imaging techniques. The commonly used imaging techniques are CT scans, X-rays and MRI scans. Scans and X-rays will help the doctor determine the extent and the location to which cancer has spread.

The tests are also used to determine how the disease has progressed. Depending on these tests further, the test will be recommended by the doctor if the test results are not convincing and to determine the stage of the disease, fluid build and the spreading rate of cancer.

Biopsies

Biopsies are crucial for diagnosing and treating mesothelioma. A small part of the tissue or fluid will be removed and sent to the laboratory. Imaging tests will help identify the presence of cancer, but biopsies can give a conclusive result.

The fluid or the tissue will be removed with the help of the needle. Some biopsies are less invasive and help determine the cell type.

Blood Tests

Blood tests are used as indicators of mesothelioma called biomarkers. The collected blood sample will be incorporated with biomarkers which can indicate the presence of mesothelioma. The blood test will be a combined diagnosis with a biopsy, as blood tests alone cannot diagnose mesothelioma.

Prognosis of Mesothelioma

A prognosis is a description of how cancer progresses over time. It also estimates the quality of life and life expectancy. According to research, mesothelioma patients have an average life expectancy of about 18-31 minutes.

Treatment for Mesothelioma

Mesothelioma treatment usually requires a combination of chemotherapy, immunotherapy, and surgery. Patients will also receive supportive care called palliative care. The treatment will aim to reduce the symptoms’ severity and extend life expectancy.

Chemotherapy

Chemotherapy will aim to shrink cancer and control its growth with the help of medication. The therapy will be used for fast-growing cancer and slows the growth.

Immunotherapy

Immunotherapy is an effective treatment to fight cancer. Research stated that people treated with immunotherapy had a better quality of life, longer life expectancy and less or manageable side effects.

Immunotherapy is a treatment that uses the patient’s immune system to fight cancer cells. Effective immunotherapy for mesothelioma includes immune checkpoint inhibitors.

These drugs have shown improved quality of life and an extended survival rate. Immune checkpoint inhibitors also tend to be less toxic when compared to chemotherapy drugs.

Radiation

Radiation therapy uses energy to kill cancer cells. The cancer cells will be killed with the help of radiation therapy using ionising radiation. The radiation occurs in two forms—photon radiation and particle radiation.

Surgery

Surgery is used to remove the cancer cells from the body. Surgery may also be used with other therapies to control the spread and growth of cancer cells. This method is called multimodal treatment.

Surgery can also help improve the quality of life and reduce the severity of the disease. Therapeutic surgeries may help to extend life expectancy.

Risk Factors for Mesothelioma

People who are often exposed to asbestos fibres are at an increased risk of developing mesothelioma. Their families are also at an increased risk of developing mesothelioma. People working in asbestos industries can carry the fibres home, affecting their families.

Living with Mesothelioma

Mesothelioma can cause severe symptoms, and treatment can also lead to certain side effects. There is also a chance of cancer coming back.

However, for many people, mesothelioma treatment will be required for a lifetime. Living with cancer can be stressful, and the treatment will aim to reduce the severity of the disease.

Even if you have completed the treatment, make sure you regularly visit the doctor. If cancer reoccurs, it can be treated at an earlier stage. Additionally, be watchful about your symptoms and never ignore them.

Conclusion

Mesothelioma is caused due to exposure to asbestos fibre. If you work in the asbestos industry, follow safety measures to reduce the risk. You can also tend to put your loved ones at risk.

Make sure you wear proper safety equipment and protect yourself from getting exposed. Early diagnosis can also help with treatment and can reduce the severity of the symptoms.

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