Peritoneal Mesothelioma

Peritoneal mesothelioma is a rare, aggressive cancer in your peritoneum. This is a membrane that lines the inside of your abdomen. The disease affects between 400 and 1,000 people in the U.S. each year. Experts believe exposure to asbestos fibers increases the chance you’ll have it. There’s no cure for peritoneal mesothelioma. But surgery and chemotherapy are helping people live longer with this disease.

Symptoms of peritoneal mesothelioma

This disease develops over many years. Most people are in their 50s before their diagnosis. It may not cause symptoms until it spreads within your peritoneum and forms cancerous tumors in your abdominal cavity and pelvis. Symptoms include:

• Fluid buildup in your abdomen (ascites)
• Pain that feels spread out in your abdomen (most common) or local to one spot (less common)
• Swelling or bulging in your abdomen
• A painful mass in your pelvis
• Constipation or bowel obstruction (blockage)
• Nausea and vomiting
• Fever and night sweats
• Loss of appetite
• Unexplained weight loss

Peritoneal mesothelioma causes

Experts link this disease to exposure to asbestos fibers in the air. Asbestos is a fiber used in professions like construction, plumbing, electrical work, roofing, manufacturing and the automotive industry. If you inhale the fibers, they may travel from your mouth and nose and land in the mesothelial cells in your peritoneum. Your body can’t break these fibers down, so they stay in your body. Over time, asbestos causes the cells to change (mutate) into cancerous cells. The cells then multiply to form cancerous tumors.

That being said, many people with the disease don’t do work that would expose them to asbestos. Researchers aren’t sure why this is the case.

Risk factors

Asbestos exposure is a known risk factor. But there are other issues that may increase the chance you’ll develop this disease. Those include:

• Age: Most people are 50 to 65 when they receive a diagnosis.
• Sex: The disease affects slightly more males than females. Women make up 45% of peritoneal mesothelioma cases.
• Silica and erionite exposure: Silica and erionite are common minerals in the earth. Exposure has been linked to peritoneal mesothelioma and pleural mesothelioma.
• Genetic changes (mutations): Changes in the BAP1 gene may increase your risk if you’re exposed to asbestos. This gene manages cell growth and how your DNA repairs damaged cells. Some people inherit the changed gene. But sometimes, the change happens after you’re born and for no known reason.
• Radiation exposure: Researchers are studying connections between radiation therapy for abdominal cancer and peritoneal mesothelioma. More research is needed to understand the connection between radiation and mesothelioma risk.

How to lower your risk

The only known way to reduce your risk of developing this disease is to avoid asbestos exposure. You may be exposed to asbestos if you work in construction, plumbing or electrical repair. Asbestos exposure can happen if you live or work in places built before the 1970s. That’s when the U.S. Environmental Protection Agency started regulating how industries use asbestos. You can reduce your exposure risk by:

• Following safety guidelines set by the U.S. Occupational Safety and Health Administration (for example, always use protective gear if your work involves asbestos)
• Working with experts if a home remodeling project involves removing asbestos

How doctors diagnose this condition

A healthcare provider will ask about your symptoms and your medical history. They may ask if you know of any past exposure to asbestos. Peritoneal mesothelioma symptoms can be similar to symptoms of other conditions. Providers may do tests to rule out other conditions, like:

• CT or MRI scan: These tests may detect tumors in your abdomen or pelvis.
• Blood tests: Your provider can check for markers in your blood, like specific proteins, that may be signs of a tumor.
• Paracentesis: Your provider may collect a fluid sample from your abdominal cavity. A medical pathologist will check the sample for signs of cancer.
• Biopsy: This procedure is the only way to confirm a peritoneal mesothelioma diagnosis. Your provider may do a CT-guided core needle biopsy or laparoscopic biopsy. A pathologist will examine tissue samples for signs of cancer.

How is peritoneal mesothelioma treated?

The most common treatment is cytoreduction surgery with hyperthermic intraperitoneal chemotherapy (HIPEC):

• Cytoreduction: This surgery removes tumors in your abdominal cavity and pelvis. Your surgeon will remove parts of your peritoneum and abdominal organs where the cancer has visibly spread.
• HIPEC: Your provider places heated chemotherapy medication directly into your abdominal cavity to remove any remaining cancer cells.

Other treatments are:

• Chemotherapy: You may have this treatment before or after surgery. It’s also treatment if surgery isn’t an option.
• Immunotherapy: This treatment helps your immune system find and kill cancer cells. Your provider may combine this treatment with chemotherapy.
• Targeted therapy: This is possible treatment if you have a changed gene that causes this disease.

Your provider may recommend palliative care to help you manage cancer symptoms and treatment side effects. They can also help you with mental health support.

They may recommend that you participate in a clinical trial, where researchers are testing new ways to treat this rare disease.

When should I seek care?

Talk to a healthcare provider if you have symptoms like belly pain, swollen belly or you lose weight without trying. Many things may cause these symptoms. Having them doesn’t mean you have peritoneal mesothelioma.

What can I expect if I have this disease?

There’s no cure for peritoneal mesothelioma. But people are living longer with it. In some cases, treatment may put the disease into remission. This means you don’t have symptoms, and tests don’t find signs of cancer. But everyone’s situation is a bit different. Your provider is your best resource for information about what you can expect.

What is the difference between peritoneal mesothelioma and pleural mesothelioma?

Both diseases form in the mesothelial cells in membranes lining different parts of your body. The difference is that peritoneal mesothelioma develops in the membrane lining your abdominal cavity. Pleural mesothelioma forms in the membrane that lines your chest cavity and protects your lungs (pleura). Pleural mesothelioma is more common than peritoneal mesothelioma.