Peritoneal Mesothelioma

Malignant mesothelioma is a relatively rare type of cancer that develops in people who have experienced long-term or repeated exposure to asbestos. In America, peritoneal mesothelioma cases account for approximately 10 to 20 percent of the two to three thousand reported cases of mesothelioma each year.

Peritoneal mesothelioma develops in the abdomen, in the mesothelial cells that form the peritoneum. The peritoneum is a membranous layer that is made up of two 'sub-layers' called the parietal and visceral layers. The parietal layer covers the abdominal cavity, while the visceral layer surrounds abdominal organs. Together these two layers provide support and protection for abdominal organs and the abdominal cavity as a whole.

How Does Asbestos Cause Peritoneal Mesothelioma?

Once asbestos is inhaled it can effect many of the bodys different organs including the throat, lungs, stomach, heart and testicles.

There are two main theories regarding the method by which asbestos exposure leads to the development of peritoneal mesothelioma:

• Asbestos fibers are ingested, and these fibers work their way from digestive organs into the peritoneal membrane.
• Asbestos fibers are inhaled, and travel to the peritoneal membrane via the lymphatic system.

Regardless of how asbestos fibers actually enter the peritoneal layers, once they do enter the membrane, the body is unable to expel them. The fibers become trapped in the peritoneal membrane, and over a period of two or more decades, they cause certain changes in the mesothelial cells of the peritoneum.

The exact way in which asbestos fibers cause changes in these mesothelial cells is uncertain. One theory is that asbestos fibers cause long-term inflammation and irritation that eventually causes mesothelial cells to become cancerous. When cells become cancerous, they lose the ability to regulate their own division and growth. Cancerous mesothelial cells divide and grow without restraint, and this uncontrolled cell growth causes thickening of the peritoneum, and the build-up of fluid in the peritoneal layers. Over time, as cancerous cells continue to divide, tumors form.

Peritoneal Mesothelioma Symptoms

Most peritoneal mesothelioma symptoms are caused by membrane thickening, fluid build-up, and eventual tumor development, all of which put pressure on internal organs.

Peritoneal mesothelioma symptoms include:

• Abdominal pain or swelling
• Changes in bowel habits (such as diarrhea or constipation)
• Development of lumps under the skin on the abdomen
• Night sweats or fever
• Unexplained weight loss
• Nausea or vomiting
• Fatigue
• Anemia

Peritoneal Mesothelioma Diagnosis

A peritoneal mesothelioma diagnosis cannot be made on the basis of symptoms alone. The diagnostic process begins with a thorough medical history and physical examination, followed by sophisticated diagnostic testing, such as a CT scan, PET scan, or MRI.

X-Rays are the most common scans used to help diagnose peritoneal mesothelioma.

These tests can not only confirm a diagnosis of peritoneal mesothelioma, but also provide important information that will help determine the patient's best mesothelioma treatment options.

Following these imaging tests, a biopsy is usually performed to confirm that the cancer involved is indeed mesothelioma. A biopsy is a minor surgical procedure that involves the removal of fluid or tissue from the peritoneum.

After the biopsy, the fluid and tissue is tested in a laboratory for the presence of mesothelioma cells.

Treatment for Peritoneal Mesothelioma

One of the biggest stumbling blocks in treating peritoneal mesothelioma effectively stems from the fact that the disease is very difficult to diagnose in its early stages, therefore providing few treatment options.

Intraperitoneal chemotherapy is just one effective form of peritoneal mesothelioma treatment.

Some peritoneal mesothelioma patients can opt for intraperitoneal chemotherapy, in which drugs are injected directly into the peritoneum, immediately following surgery. In some cases, patients may undergo radiation therapy first - to shrink tumors - before undergoing surgery.

Most patients, however, are not good candidates for surgery; either because their cancer has spread too extensively or because their general health is not good enough to cope with the stress of surgery. These patients are usually limited to palliative treatment options. Palliative treatments do not attempt to cure a patient - instead they are designed to relieve symptoms and improve the quality of life for peritoneal mesothelioma patients.