What Causes Mesothelioma?
By: Cohen, Placitella & Roth @ Nov 07, 2022
Mesothelioma is a rare and aggressive cancer that affects organ lining, predominantly in the pleura membrane of the lungs and chest or the peritoneum and pericardium membranes in the abdomen or around the heart.
Primary Cause of Mesothelioma
With some limited exceptions the only proven cause of mesothelioma is exposure to asbestos. There are some recent studies that have shown possible causation between certain genetic factors or exposure to ionizing radiation or zeolite fibers. In reality , a genetic predisposition makes you more susceptible to asbestos exposure. Some studies have suggested that people develop mesothelioma without a known cause. After careful examination, however, most of those studies are flawed in that the researchers did not have enough information on exposure to asbestos including exposures to household products that contained asbestos like cosmetic talc.
How Asbestos Exposure Causes Pleural Mesothelioma
Asbestos is a naturally occurring minerals that appears in the form of fibers. These fibers were used for things like construction, plastic development, mining, and insulation because of their environmental resistance and durability. They also appeared in household products such as spackle and talc based products like baby powder.
Until the 1989 ban by the Environmental Protection Agency (EPA) on all new asbestos uses, workers were regularly exposed to asbestos and unknowingly inhaled dislodged fibers, which often became trapped in their lungs. While not every person exposed to asbestos develops mesothelioma, some are particularly susceptible. In fact, family members of workers exposed to asbestos have developed mesothelioma after breathing in secondhand fibers from the workers’ clothes or hair.
Asbestos is the most apparent cause of malignant pleural mesothelioma—mesothelioma of the lung lining—the disease’s most common form. Asbestos has since been declared a known human carcinogen, and the government and labor-related organizations have taken significant strides to eliminate mesothelioma risk factors from work sites and schools.
How Malignant Mesothelioma Affects the Body
Mesothelioma is a fully differentiated cancer with a range of respiratory and non-respiratory symptoms. Not every patient develops the same side effects.
Some broader health issues include a simple cough, hemoptysis, and chest pain or heaviness, often from fluid in the infected area. Mesothelioma is such a dangerous form of cancer because it typically takes years before detection. By the time the individual undergoes tests, they might have additional symptoms like blood clots or cancer migration to lymph nodes and beyond.
Malignant mesothelioma is incurable, and many people with it die within the first year after diagnosis, though some have lived longer. Most pleural mesothelioma deaths are from respiratory complications, but if the cancer has metastasized to other parts of the body, the specific cause of death can vary.
Conditions That Occur Alongside Mesothelioma
Cancer can impact every part of the body, and mesothelioma treatment is typically intended to improve the quality of life, rather than cure the disease. With so much at stake, all employers have a duty to warn workers of possible exposure and take active steps to reduce and prevent asbestos at the work site. Because most cases of mesothelioma are linked to asbestos exposure, afflicted people may have additional conditions such as:
- Asbestosis: A lung disease caused by scar tissue in the lungs after prolonged asbestos inhalation
- Pleural Effusion: a benign buildup of fluid around the lungs caused by asbestos exposure
Treatment for malignant mesothelioma can create additional complications, including those associated with surgery, immunotherapy, radiation, chemotherapy, prescription medication, or clinical trials.
Depending on its location, type, and stage, mesothelioma can trigger a range of conditions. For example, those with metastatic mesothelioma in the brain may develop neurological side effects they wouldn’t have otherwise experienced.
Risk Factors for Mesothelioma
Several mesothelioma risk factors exist, including asbestos exposure, ionizing radiation, and zeolite fiber inhalation.
How Asbestos Exposure Happens
Most asbestos exposure happens incidentally, leading to more than 80 percent of mesothelioma cases, making it the leading mesothelioma cause. Past and current asbestos workers in the following industries may have increased risk factors:
- Mining and milling
- Construction, roofing, and demolition
- The automotive industry
- The military (including active military members and veterans)
- Industrial manufacturing
- Soundproofing, particularly for ceilings in buildings like schools or offices
- Shipbuilding Some studies have also linked asbestos-related mesothelioma to other conditions like heart disease.
Correlations Between Radiation Exposure and Mesothelioma Exposure to some types of radiation—such as pre-1960 radiation contrast dye or radiation therapy for lymphoma treatment—has been linked with mesothelioma cell development. Though more research is needed to confirm direct causation and how it relates to other risk factors like genetic susceptibility and occupational asbestos exposure, ionized radiation is already a recognized human carcinogen in the United States. Studies demonstrate a stronger risk for mesothelioma in those exposed to high doses of ionizing radiation for a short amount of time and those exposed to smaller doses for a prolonged period. There’s a particularly notable link between peritoneal mesothelioma and external beam radiotherapy (EBRT).
How Zeolites Can Cause Mesothelioma
Zeolites are crystalline mineral structures found in nature, though they’ve also been developed synthetically using other crystals. Some zeolites, like erionite, have similar physical properties to asbestos fiber and have been linked with an increased risk of pleural mesothelioma and other lung cancers and conditions. Zeolites have been found in places like Nevada, Utah, Arizona, Oregon, Montana, and South Dakota, and they are particularly hazardous for road construction and surfacing workers or anyone working with erionite gravel.
Because there are currently no occupational standards or regulations for erionite exposure, workers exposed to the mineral should pay close attention to each symptom and tell their doctor. The more aware of the risks you and your doctor are, the faster you can catch and treat signs of malignant mesothelioma.
Early Signs of Mesothelioma
Specific mesothelioma symptoms vary, but some early signs including shortness of breath, chest pain, night sweats or unexpected weight loss could warrant a discussion with your doctor.
When Mesothelioma Can Be Detected Some mesothelioma symptoms don’t appear until decades after initial exposure, so by the time the patient seeks testing and pursues a treatment option, their condition may be in its late stages with rapidly progressing side effects. Pleural mesothelioma tumors and asbestos fibers don’t generally appear on chest X-ray exams, but many people receive a mesothelioma diagnosis after their doctor finds abnormal lung scarring or fluid buildup.
Some pericardial and peritoneal mesothelioma cases aren’t discovered until the patient seeks treatment for an unrelated personal injury.
Respiratory Symptoms of Mesothelioma Respiratory symptoms are the most common signs of mesothelioma cells in the lungs and may cause:
- A cough with or without blood
- Chest pain and pressure
- Shortness of breath
Less Common Early Symptoms of Mesothelioma
Additional symptoms in someone with mesothelioma in their lungs, heart, or abdominal lining may include:
- Weakness and fatigue
- Unexplained weight loss
- Pain and swelling in the abdomen in cases of peritoneal mesothelioma
- Nausea and loss of appetite
- Vomiting and diarrhea
- Fever and/or night sweats
- General malaise
- Bowel obstruction
- Abnormal heart rhythm and low blood pressure in cases of pericardial mesothelioma
Different symptoms may appear at separate stages of the cancer type and progression. Specific causes, like asbestos exposure, may produce secondary side effects or related conditions.
What to Do If You Think You Have Mesothelioma
If you think you have symptoms of mesothelioma or have known asbestos exposure, schedule an appointment with your doctor right away to initiate testing.
People at Risk of Developing Mesothelioma
In addition to workers exposed to asbestos fiber, other risk factors may increase the chance of developing mesothelioma, such as:
- Living with someone who’s been exposed to asbestos
- Living near an asbestos work site or mine
- Having certain gene mutations, like BAP1
- Being a cigarette smoker with asbestos exposure
Statistics show mesothelioma diagnosis is most common in adults fifty or older, and men are historically the most at risk. About three thousand people in the United States are diagnosed annually, though many cases of mesothelial cells remain undetected or misdiagnosed.
The Process of Diagnosing Mesothelioma
Receiving a mesothelioma diagnosis might look like this:
- Your doctor notes your symptoms and performs basic examinations and tests to rule out other conditions. These may include an electrocardiogram (ECG) and X-rays.
- A computed tomography (CT) scan and magnetic resonance imaging (MRI) scan can help doctors locate any tumors or fluid buildup.
- Doctors remove a sample of fluid or tumor tissue for more tests, including a biopsy. They may also drain some fluid buildup to alleviate discomfort, if necessary.
- Inconclusive results may require more-invasive tests to confirm a diagnosis, such as thoracic surgery.
- If mesothelioma is present, your doctor will guide you through the appropriate steps to identify the cancer’s stage and spread, then develop a cancer care plan.
Who Can Diagnose Mesothelioma?
Though your primary care provider will oversee much of your testing, you could receive an official diagnosis from oncologists or lung cancer specialists. Because misdiagnosis is common, consider consulting a mesothelioma specialist for further confirmation or a second opinion.
Next Steps after Mesothelioma Diagnosis
Anyone with more than one mesothelioma symptom or risk factor should talk to their doctor, especially if they’ve been exposed to asbestos at some point in their life.
As scientists conduct more studies and new research emerges, tomorrow’s healthcare providers could gain a better understanding of what causes mesothelioma to possibly develop new ways to treat the condition.