Facts about Pleural Mesothelioma
Mesothelioma is a cancer that attacks the mesothelium. The mesothelium is a double layer of tissue surrounding most of the body’s organs.
- The pleura is the part of the mesothelium around the lungs.
- The main risk factor for pleural mesothelioma is exposure to asbestos, which typically occurs at work.
- It can take 20 to 60 years from initial exposure to asbestos for mesothelioma to develop.
- Symptoms include chest pains, a dry cough, shortness of breath, and fatigue.
- Pleural mesothelioma is rare. Only about 3,000 people are diagnosed each year.
- The pleural type accounts for nearly 75 percent of mesothelioma diagnoses.
- Most of these cases are seen in older men because of workplace exposure to asbestos.
- Pleural mesothelioma can be treated with a combination of chemotherapy, radiation, surgery, and/ or experimental therapies, with participation in clinical trial research.
- The prognosis is poor with 40 percent of patients surviving just a year after diagnosis.
How Asbestos Causes Pleural Mesothelioma
Asbestos is made up of of very small, needle-like fibers. These come loose from the material when disturbed. The fibers become part of the dust in air and on surfaces. Anyone in the vicinity is likely to inhale those fibers, which then can lodge in the pleura, lungs, and other tissue. They may also accidentally ingest the fibers.
The lodged fibers cause damage to tissue, including irritation and inflammation. Eventually this can trigger serious illnesses in some people. Mesothelioma, lung cancer, or asbestosis can all be caused by asbestos fibers. When pleural mesothelioma develops, it spreads rapidly, often from one layer of the pleura to the next and then to the lung and other tissues.
The symptoms of mesothelioma make it difficult to diagnose. They don’t always develop right away and often mimic more common illnesses:
- Chronic bronchitis
- Lung Cancer
Symptoms of pleural mesothelioma may include:
- Shortness of breath
- Difficulty swallowing
- A persistent dry cough
- Coughing up blood
- Chest pains
- Painful breathing
- Lumps under the skin of the chest
As the cancer gets more advanced, patients may complain about unintentional weight loss and fatigue.
Diagnosing mesothelioma is difficult for many reasons. The early symptoms of pleural mesothelioma often mimic other illnesses and lead to a misdiagnosis. It may not be until after the symptoms persist and treatments don’t provide relief that a patient will get a cancer diagnosis. The diagnostic process usually follows these steps:
- A thorough physical examination to rule out other illnesses
- Imaging scans including X-rays to rule out pneumonia and other respiratory conditions, or a CT or MRI scan to search for soft tissue abnormalities
- A biopsy, the removal of a small amount of tissue from any abnormal areas indicated on scans
- Investigation of cells from the biopsy under a microscope to identify malignancy
Once a diagnosis of pleural mesothelioma has been made, doctors assign a stage. This describes how far the cancer has progressed:
- Stage 1: Tumors are localized to pleural tissue around one lung.
- Stage 2: The tumor cells have migrated to nearby lymph nodes.
- Stage 3: The cells have spread to other tissue near the pleura and to more distant lymph nodes.
- Stage 4: The cancer has metastasized, spread to distant organs.
Once the medical team understands the stage of pleural mesothelioma, cell subtype, and other medical conditions, they can develop an appropriate treatment plan. This should consider the patient’s input and preferences. Treatment for pleural mesothelioma is typically aggressive, so it is important the patient and medical care team have open communication about the expected outcomes of treatment and the risks and benefits of each treatment.
Treatment for pleural mesothelioma typically includes a combination of two or more of the standard chemotherapies. These are drugs are used to kill cancer cells, but they can also kill healthy cells causing side effects. Most chemotherapy is administered intravenously (IV) into a vein in your arm or chest.
Early-stage patients may benefit from cytoreductive surgeries, procedures to remove as much cancerous tissue as possible. Radical procedures, such as a pleurectomy and decortication or extrapleural pneumonectomy, aim to remove as much as visible disease as possible. In some cases, this is done to possibly cure the cancer. In other cases, the goal is to remove as much tumor as possible so the cancer will take longer to grow back and spread to other areas.
Radiation therapy uses high-energy beams to target and kill cancer cells. It is usually used after surgery to reduce tumor size or eliminate any remaining cells. It can also be used in conjunction with chemotherapy.
Clinical Trials and Experimental Therapies
Mesothelioma is a rare and aggressive cancer with less treatment options than many other cancer types. In order to gain access to treatment not yet approved by the Food and Drug Administration (FDA) yet, patients are encouraged to participate in clinical trial research.
Some of the emerging therapies patients may access in clinical trials include immunotherapy, vaccines, surgical therapies, or new radiation techniques. Immunotherapy treatment targets the patient’s immune system to turn it against the cancer cells. Photodynamic therapy is being tested as a way to use light energy to focus toxic drugs directly on tumor cells. Gene therapies use genetically-modified viral or bacterial cells to deliver treatments or alter cancer cells to self-destruct.
The prognosis for pleural mesothelioma is usually negative, but it depends on individual factors. Survival rates for this type of cancer are comparatively low. Diagnosis typically comes after the cancer has reached a later stage and this means it is difficult to treat and nearly impossible to cure.
Some studies indicate that the median survival time for patients with pleural mesothelioma is just nine months, but this includes those who did not receive treatment. Any kind of treatment, but especially a combination of therapies, extends survival times. Patients with pleural mesothelioma who undergo surgical procedures as part of treatment live an average of three years after diagnosis.
Individual factors that can affect prognosis include:
- Cancer stage
- Smoking status or history
- Extent and duration of exposure to asbestos
- Overall health and fitness
Prognosis can be improved with early diagnosis and aggressive treatments, but patients often have limited options. Some may choose to fight the cancer and extend survival time, while others choose treatments that improve symptoms and quality of life.
A diagnosis of pleural mesothelioma can be a shock, and many people who develop this disease are victims. They experienced asbestos exposure without their knowledge or without being warned of the risks of being around asbestos. If you have been impacted by pleural mesothelioma because of workplace asbestos exposure, you have legal rights to seek compensation from your former employer or the manufacturer of asbestos-containing materials.
Page Medically Reviewed and Edited byLuis Argote-Greene, M.D.
Luis Argote-Greene is an internationally recognized thoracic surgeon. He has trained and worked with some of the most prominently known thoracic surgeons in the United States and Mexico, including pioneering mesothelioma surgeon Dr. David Sugarbaker. He is professionally affiliated with University Hospitals (UH). His areas of interest and expertise are mesothelioma, mediastinal tumors, thoracic malignancies, lung cancer, lung transplantation, esophageal cancer, experimental surgery, and lung volume reduction. Dr. Argote-Greene has also done pioneering work with video-assisted thoracoscopic surgery (VATS), as well as robotic assisted minimally invasive surgery. He has taught the procedures to other surgeons both nationally and internationally.