Pericardial Mesothelioma

Mesothelioma is a type of cancer that arises in the mesothelium, which is a membrane that surrounds various organs. Pericardial mesothelioma is a very rare type of mesothelioma that arises from the pericardium, which is a membrane that surrounds the heart. This disease carries a poor prognosis overall, although treatment can extend survival.

Pericardial Mesothelioma Causes and Risk Factors

Pericardial mesothelioma is one of the rarest types of mesothelioma. Pleural mesothelioma (found in the membrane around the lungs) accounts for more than 80 percent of cases, while peritoneal mesothelioma (found in the membrane around the digestive system) accounts for 10 to 15 percent of cases. By contrast, pericardial mesothelioma accounts for less than one percent of all mesothelioma cases. There have only ever been a few hundred cases of pericardial mesothelioma reported in scientific literature.

In general, asbestos exposure is the strongest risk factor for the development of mesothelioma. More than 80 percent of all pleural mesothelioma patients and up to half of peritoneal mesothelioma patients have a known history of asbestos exposure. However, for pericardial mesothelioma, the link with asbestos exposure is less clear. Researchers believe that there is a link between asbestos and pericardial mesothelioma, but it doesn’t appear to be as strong as for other types of this cancer. Only 25 percent of peritoneal mesothelioma patients report a known history of asbestos exposure.

Asbestos is known to be extremely carcinogenic. When the fibers of this mineral become embedded into tissues, they provoke a strong immune response as the body attempts to get rid of the foreign material. Because asbestos is very chemically stable, the immune response cannot destroy it. A strong immune response is sustained over many years, which can damage the DNA of cells and cause them to become cancerous.

With pleural and peritoneal mesothelioma, scientists understand how microscopic asbestos fibers are able to get into the mesothelium and lead to cancer. However, it’s more difficult to determine how asbestos fibers make their way into the pericardium. One theory is that they pass through the pleura into the pericardium, since the two membranes are adjacent to each other. Because asbestos fibers are long, thin and sharp, this is a plausible explanation.

Pericardial Mesothelioma Symptoms

Pericardial mesothelioma can cause a variety of symptoms, including:

  • Pain in the chest or shoulder
  • Shortness of breath
  • Trouble swallowing
  • Irregular heartbeat or heart palpitations
  • Heart murmurs (unusual sounds heard when listening to the heart with a stethoscope)
  • Swelling of the legs
  • Fatigue
  • Unexplained weight loss

These symptoms are nonspecific, meaning that they can be caused by a variety of different conditions. Multiple different heart conditions could cause similar symptoms, including more common conditions like congestive heart failure or pericarditis (inflammation of the pericardium, usually caused by a virus). Because the symptoms are so nonspecific and because it’s such a rare cancer, the diagnosis of pericardial mesothelioma is difficult.

Pericardial Mesothelioma Diagnosis

The process of pericardial mesothelioma diagnosis begins when a patient first discusses symptoms with his or her doctor. At first, the doctor will consider many possible causes of these symptoms. The diagnostic process will then slowly narrow in on pericardial mesothelioma. The steps of this process generally include:

  • Imaging studies. A variety of imaging studies may be used during the diagnostic process:
    • A chest X-ray may be used initially to look for problems in the lungs or chest cavity. In pericardial mesothelioma patients, the chest X-ray may show findings such as pericardial thickening or a pericardial effusion (buildup of fluid around the heart).
    • A computerized tomography scan (CT scan) of the chest may be performed next to check on concerning findings on the chest X-ray, or it may be the initial choice of imaging study. This is a more detailed type of scan that uses X-rays to generate a 3D image of a particular part of the body.
    • An echocardiogram is a type of ultrasound imaging that uses sound waves to visualize the heart. This test allows doctors to look at the heart’s function while it’s beating.
    • A PET scan, which uses a tracer to check for cancer cells throughout the body, may be useful in allowing doctors to detect metastasis, or spread of the cancer to more distant organs.
    • An MRI may also be useful. This is a detailed scan created using a magnetic field, which can help doctors to localize the tumor and check for metastases.
  • A biopsy. This is a small sample of tissue that’s examined in a lab to determine whether it contains cancer cells and, if so, what type of cancer the patient has. A biopsy is required to definitively diagnose pericardial mesothelioma.
    • The biopsy is most commonly obtained during a surgical procedure known as thoracoscopy. During this procedure, a thoracic surgeon makes small cuts in the chest wall and inserts a scope. This allows the surgeon to view the inside of the thoracic cavity using a video camera and to take tissue samples using specially designed surgical instruments.
    • In some cases, a more extensive surgical procedure is used to perform the biopsy and determine the diagnosis. Doctors may need to examine the heart directly and take samples of tissue from the pericardium in order to determine the diagnosis.

It’s not uncommon for cases to be diagnosed after the patient’s death when the cancer is found on an autopsy. In fact, only 25 percent of cases of pericardial mesothelioma are definitively diagnosed before the patient’s death.

Pericardial Mesothelioma Staging

The stage of a cancer refers to how advanced the disease is. While pleural mesothelioma has a formally defined staging system, other types of mesothelioma, including pericardial mesothelioma, do not have this. There is no official set of criteria used to determine the stage of a particular case of pericardial mesothelioma.

In general, a system called the TNM system is commonly used to describe a cancer’s stage. This uses information about the size and extent of the original tumor (T), spread to lymph nodes (N) and spread to distant parts of the body (metastasis, or M). Doctors will evaluate these factors during the process of diagnosis using the results of imaging studies, the biopsy and the thoracoscopy, and may also use information obtained during surgery.

The three factors of the TNM system are commonly used to determine a numerical stage. The earliest is stage 1, in which the cancer is localized to the tissue where it first developed; the most advanced is stage 4, in which the cancer has spread widely around the body. Although there’s no formal system for turning the TNM system into a numerical stage for pericardial mesothelioma, some doctors may still estimate a numerical stage based on various factors of the cancer. Most commonly, pericardial mesothelioma is diagnosed in an advanced stage.

Pericardial Mesothelioma Life Expectancy

Pericardial mesothelioma is an aggressive cancer and generally carries a poor prognosis. A 2017 study showed that average life expectancy after diagnosis is only 5.6 months. Another study published in 2021 showed a median survival time of only two months. Only 22 percent of pericardial mesothelioma patients survive for one year after diagnosis, and 12.2 percent survive for two years.

Despite these figures, there have been some case reports in the scientific literature of patients who lived for years after their diagnosis. One case report describes a woman who is alive and disease-free 28 years after her treatment for pericardial mesothelioma. Although this disease carries a poor prognosis overall, good patient outcomes are possible.

Pericardial Mesothelioma Treatment

Because pericardial mesothelioma is so rare, it’s difficult for medical researchers to determine the best way to treat this disease. However, based on the treatments that are effective for other types of mesothelioma (such as pleural mesothelioma), doctors have been able to find ways of treating this disease. The treatment plan may include one or more of the following:

  • Surgery to remove as much visible tumor tissue as possible from the chest. Some studies have found a survival benefit for this surgery. A more radical surgery called pericardiectomy, which removes the entire pericardium from around the heart, is sometimes used. Overall, this has not been shown to provide a survival benefit in patients with pericardial mesothelioma, but doctors may recommend it in certain cases.
  • Chemotherapy.2019 study found that systemic chemotherapy (in which the medications are delivered to the whole body through an IV) increased the median survival to 13 months. This is significantly longer than the usual survival for patients with this cancer, so chemotherapy is commonly recommended. Doctors usually use the same combination of medications that are effective for pleural and peritoneal mesothelioma; the regimen includes cisplatin or carboplatin, often combined with pemetrexed.
  • Palliative procedures, such as pericardiocentesis, in which a doctor uses a needle to remove a buildup of fluid from around the heart. This can be helpful to relieve symptoms and improve comfort. Other palliative treatments, such as prescription medication for pain, may also be helpful for many patients.

Radiation therapy is used for pleural and peritoneal mesothelioma patients, but so far it has not been shown to be beneficial in treating pericardial mesothelioma. Immunotherapy is approved for certain pleural mesothelioma patients, but it has not been approved for other types of mesothelioma. Its use in patients with pericardial mesothelioma would be considered experimental.

Your doctor will talk with you about the specific treatment plan recommended in your case. The specifics of your treatment will depend on many factors, including the stage of your cancer, your age and overall medical condition, and your preferences.

Clinical Trials for Pericardial Mesothelioma

Although the current treatment options for pericardial mesothelioma are limited, it’s hoped that further research will help to develop better treatments for this disease.

Some patients choose to take part in a clinical trial. This is a research study to test a new treatment or a new combination of treatments. Although many patients are attracted by the possibility of getting early access to a new treatment option, it’s important to consider the tradeoffs. If you’re interested in this option, you should discuss it with your oncologist, who can help you weigh the pros and cons of participating.

You may want to try checking the National Cancer Institute’s clinical trials database to look for current trials. Because pericardial mesothelioma is so rare, researchers don’t generally conduct studies of only this specific cancer; it would take too long to find enough patients for a statistically significant sample. However, pericardial mesothelioma patients may be eligible for clinical trials that involve multiple different types of cancer. For example, trials testing treatments for “unresectable solid tumors” could potentially include pericardial mesothelioma patients. When you’re searching for trials for which you may be eligible, you may need to search using broader terms like this. Your oncologist can also help you to find appropriate trials to consider.