Mesothelioma

21.03.2024

MESOTHELIOMA DIAGNOSIS AND TREATMENT

Mesothelioma is a rare type of cancer that often develops as a result of exposure to asbestos. When asbestos fibers reach the lungs through inhalation, these fibers can accumulate in various parts of the body, such as the pleura and peritoneum, and cause mesothelioma cancer years later. Mesothelioma is often diagnosed in the late stages and effective treatment options are limited. Early diagnosis of this type of cancer and preventing exposure to asbestos are critical in reducing the risk of mesothelioma. It is also of great importance to raise awareness and improve occupational health and safety standards in the fight against this disease.

WHAT ARE THE RISK FACTORS?

Mesothelioma cancer has been associated with several risk factors. Although the most important risk factor is exposure to asbestos, other factors may also play a role:

Exposure to Asbestos: It is the most common and known risk factor. Asbestos is a natural mineral found especially in old building materials and some industrial products. Inhaling asbestos fibers increases the risk of developing mesothelioma.

Occupational Exposure: Workers who work with asbestos (e.g., construction workers, shipbuilders, asbestos miners) are at risk of developing mesothelioma.

Environmental Exposure: There is an increased risk for people living in areas close to asbestos mines or in areas where natural materials containing asbestos are present.

Family History: Family members with a history of mesothelioma may increase the risk of developing this disease.

SV40 Virus: Some studies have suggested a link between Simian virus 40 (SV40) and mesothelioma, but this relationship is not definitive.

Radiation Exposure: Exposure to treatments that involve radiation, such as Thorotrast (a radioactive substance), may also increase the risk.

Chronic Inflammation: Chronic inflammatory processes can also increase the risk of developing mesothelioma.

Because exposure to asbestos is the most important risk factor, reducing this exposure can significantly lower the risk of mesothelioma. It is recommended that people working with asbestos use appropriate protective equipment and be careful when working with asbestos-containing materials.

Image 1: Mesothelioma can occur in different organs in the body.

HOW DOES IT OCCUR?

Although the mechanisms of development of mesothelioma cancer are complex and not fully understood, several key processes have been identified. Basically, it starts when asbestos fibers reach the lungs and pleural membrane through inhalation. These fibers can attach to tissues such as the pleura and remain there for a long time. The constant irritation and inflammation caused by asbestos fibers leads to DNA damage in cells and disrupts the normal processes of cell growth and death. This causes cells to divide uncontrollably and form cancerous tumors. Additionally, asbestos may have immunosuppressive effects, weakening the body's defenses against cancer cells. The chronic inflammatory response can promote the formation of free radicals and further increase cellular damage. Mesothelioma is characterized by the uncontrolled growth of these damaged cells in the lung lining or abdominal lining (peritoneum). A full understanding of these processes is important in developing more effective treatment and prevention methods of the disease.

WHAT ARE THE SYMPTOMS?

Mesothelioma cancer is a difficult disease to diagnose because its symptoms usually take a long time to develop and progress insidiously. But some common signs and symptoms may include:

Shortness of breath: Due to the lung membrane being affected, difficulty in breathing may occur.

Chest or Abdominal Pain: As the tumor grows, pain may occur in the chest wall or abdominal area.

Cough: Cough, especially dry and persistent, may occur.

Weight Loss: Unexplained and unintentional weight loss may occur.

Tiredness: There may be a general weakness and lack of energy.

Anorexia:There may be a desire to eat less than normal.

Swelling or Mass Under the Rib: Swelling or palpable masses may be detected in the abdominal area.

Hoarseness: Hoarseness may occur due to tumors that can put pressure on the respiratory tract.

Difficulty in Swallowing: Difficulty in swallowing may occur due to tumors pressing on the esophageal (esophagus) region.

Because the symptoms of mesothelioma often resemble those of more common diseases, this disease is difficult to diagnose in its early stages. If you have a history of asbestos exposure and are experiencing any of the symptoms listed above, it is important to contact a healthcare professional.

HOW IS IT DIAGNOSED?

Diagnosis of mesothelioma cancer usually involves a combination of the patient's medical history, symptoms, and various medical tests. When symptoms occur in people with a history of asbestos exposure, doctors first perform a physical exam and may order imaging tests, such as a chest X-ray or computed tomography (CT) scan. These tests indicate the presence of abnormalities in the lungs and pleura. However, the definitive diagnosis of mesothelioma is usually made by taking a tissue sample. Tissue samples taken through biopsy are examined under a microscope and the presence of cancerous cells is investigated. Sometimes further tests may be required to make a diagnosis, including magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. During the diagnostic process, oncologists and other specialists evaluate these findings to determine the stage of the disease and create the appropriate treatment plan. Diagnosis of mesothelioma can also be supported by the detection of specific biomarkers and cellular features. This comprehensive diagnostic process ensures accurate identification of the disease and implementation of an effective treatment plan.

Image 2: Lung mesothelioma is often associated with asbestos. It may cause complaints such as cough, phlegm and shortness of breath.

WHAT ARE THE PATHOLOGICAL TYPES?

Mesothelioma cancer is mainly divided into three main pathological types depending on the cell type. Each of these types looks different under the microscope and can have impacts on disease prognosis and treatment options:

Epiteloid Mezotelyoma: It is the most common type of mesothelioma and generally has a better prognosis than other types. This type is characterized by regular, oval or cubic shaped cells.

Sarcomatoid (Fibrous) Mesothelioma: This type accounts for a smaller percentage of mesothelioma cases and is the most aggressive type. Sarcomatoid mesothelioma consists of elongated, spindle-shaped cells and is generally associated with a worse prognosis.

Biphasic (Mikst) Mezotelyoma: This type includes both epithelioid and sarcomatoid cell types. The prognosis of biphasic mesothelioma varies depending on the ratio and distribution of the two cell types.

Pathological diagnosis is made by examining tissue samples taken during biopsy under a microscope. The pathological type of mesothelioma is an important factor in determining the treatment management and prognosis of the disease. In some cases, making a clear distinction between these types may be difficult and may require advanced pathological techniques. Each type of mesothelioma varies in clinical features and response to treatment, so determining the correct pathological diagnosis is critical to the patient's treatment plan.

HOW IS TUMOR STAGING DONE?

Staging of mesothelioma cancer is used to evaluate how far the disease has progressed and how far it has spread throughout the body. This staging process helps determine the patient's treatment options and predict prognosis. Staging of mesothelioma cancer is usually done as follows:

Stage I (Local): In its initial stage, mesothelioma cancer is usually limited to just one lung lining. In this case, the cancer is limited locally and has not spread to other organs or lymph nodes.

Stage II (Locally Advanced): At this stage the cancer may have spread beyond the lung lining, but is still limited to a single area. It has spread to the lymph nodes.

Stage III (Locally Advanced): Cancer has spread beyond the lining of a lung or to other organs. It has also spread to nearby lymph nodes.

Stage IV (Distant Spread):This is the stage when cancer spreads to distant parts of the body, especially distant organs. This stage of cancer may have a worse prognosis.

Staging of mesothelioma cancer is usually done based on imaging tests (for example, CT scans, MRI, or PET scans), biopsy results, and surgical findings. Combining this information helps determine the stage of the cancer. Treatment options may vary depending on the stage of the disease, the patient's general health and other factors. If you have been diagnosed with mesothelioma cancer, it is important to meet with an oncologist to determine the most appropriate treatment plan and staging.

HOW IS TREATMENT DONE ACCORDING TO STAGES?

Treatment of mesothelioma cancer may vary depending on the stage of the disease, the patient's general health, and other factors. Here is an overview of treatment approaches based on mesothelioma cancer stages:

Stage I Mesothelioma: At this stage, the cancer is usually confined to just one serous membrane. Treatment options may include surgical intervention (surgical resection). Surgery attempts to remove the tumor. After surgery, radiotherapy or chemotherapy may be additional treatment options.

Stage II Mesothelioma: At this stage the cancer may have spread beyond a serous membrane but is still confined to a single area. Surgical resection is often considered as a treatment option. Post-surgical radiotherapy or chemotherapy treatment may be used following complete removal of the tumor or before surgery to reduce the size of the tumor.

Stage III Mesothelioma: At this stage the cancer may have spread beyond a serous membrane or to other organs and has also spread to nearby lymph nodes. Treatment may often include a combination of surgical resection, radiotherapy and chemotherapy. Surgery may be performed to reduce the tumor or control symptoms. At this stage, palliative care (symptom relief) can also play an important role.

Stage IV Mesothelioma: This is the stage when cancer spreads to distant parts of the body, especially distant organs. Treatment options are generally aimed at relieving symptoms and improving the patient's quality of life. Palliative care plays an important role at this stage. Chemotherapy may be used to control symptoms and slow the growth of the tumor.

Mesothelioma treatment requires a multidisciplinary approach and should be determined individually for each patient. The treatment plan is developed collaboratively between oncologists, surgeons, radiation oncologists, and other specialists. Treatment options may vary depending on the patient's overall health, the stage of the tumor, and personal preferences.

Image 3: Mesothelioma treatment varies depending on the stage of the disease. The chance of full recovery increases in the early stages.

WHAT ARE THE DRUGS USED IN TREATMENT?

Chemotherapy, hormonal drugs, targeted therapies (smart drugs), and immunotherapies used in the treatment of mesothelioma cancer are listed below. However, it is important to note that each patient may be different and treatment options should be determined based on the patient's specific situation. Therefore, the treatment plan should be created under the supervision of a healthcare professional and according to the needs of the patient.

Chemotherapy drugs:

Pemetrexed: It is a chemotherapy drug frequently used in the treatment of mesothelioma. It may help prevent the growth of cancer cells.

Platinums (carboplatin and cisplatin): This is another chemotherapy drug frequently used in the treatment of mesothelioma. It damages cancer cells and prevents them from multiplying.

Targeted Therapies (Smart Drugs):

Bevacizumab: Sometimes used to treat mesothelioma. It works to prevent the growth of blood vessels by blocking the activity of a protein called VEGF.

Immunotherapies:

Pembrolizumab: It can be used as immunotherapy in the treatment of mesothelioma. It works to activate the immune system against cancer cells by blocking an immune response regulator called PD-1.

Nivolumab: Likewise, it works to increase the immune response by blocking PD-1 and can be used in the treatment of mesothelioma.

The drugs mentioned above are among the drugs commonly used in the treatment of mesothelioma cancer. However, because every patient is different, the treatment plan should be tailored to the patient's specific situation by a healthcare professional. Treatment options and medications may vary depending on the patient's general health, the stage of the tumor, and other factors.

HOW SHOULD FOLLOW-UP BE DONE AFTER RECOVERY?

Follow-up after mesothelioma cancer treatment is important to monitor the patient's health and detect possible recurrences or side effects early. Follow-up is done through methods such as regular doctor's exams, imaging tests (for example, CT scans or MRI), blood tests, and symptom monitoring. The patient's follow-up program is determined depending on the stage before treatment, the treatment methods used and the patient's general health condition. It is important for mesothelioma patients to be followed throughout their lives because this type of cancer can recur. Regular follow-up after treatment allows patients to monitor their health status and respond quickly to treatment when necessary.