Peritoneal mesothelioma is a cancer that develops in the membrane that lines the abdomen and its organs, known as the peritoneum. Asbestos exposure is its most common risk factor.

Peritoneal mesothelioma is a type of cancer that currently has no cure. Still, a combination of treatments, including surgery and palliative care, can help manage the condition, improve a person’s outlook, and enhance a person’s quality of life.

This article will discuss peritoneal mesothelioma, including its symptoms, risk factors, causes, diagnosis, and treatment.

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Peritoneal mesothelioma is the second most common type of mesothelioma, and it involves the peritoneum. The peritoneum is a membrane that surrounds the organs in the abdomen, such as the intestines and the liver.

Generally, though, it is a rare type of cancer.

Getting an early diagnosis of peritoneal mesothelioma can be difficult. This is because it is an aggressive type of cancer that spreads to surrounding organs quickly.

According to a 2023 review, the incidence of peritoneal mesothelioma in the United States is 19.4 million cases among males and 4.1 million cases among females. The same review also estimates about 15,000 new confirmed cases of peritoneal mesothelioma each year.

Learn more about mesothelioma.

Peritoneal mesothelioma does not usually cause symptoms until it spreads to other organs in the abdomen. When symptoms occur, they may include:

Asbestos exposure is one of the most common causes of peritoneal mesothelioma and is responsible for about a third of cases. However, people can develop this cancer even without being exposed to asbestos.

Individuals who have occupational exposure to asbestos are at a higher risk of peritoneal mesothelioma. These may include those who work in construction, electrical work, roofing, plumbing, or the automotive industry.

Exposure to radiation or certain minerals may cause peritoneal mesothelioma. A person may be exposed to radiation due to undergoing radiation treatment.

A 2022 study also reports that people with certain gene variations, especially those associated with the BAP1 gene, may have a higher risk of developing mesothelioma, including peritoneal mesothelioma. The BAP1 gene plays an important role in preventing tumor growth.

While anyone can develop peritoneal mesothelioma, it is more common in advanced adulthood.

Doctors often find it challenging to diagnose peritoneal mesothelioma, especially in its early stages, since it does not usually produce any symptoms. They may sometimes misdiagnose peritoneal mesothelioma since its symptoms are similar to many other types of cancer.

Typically, to diagnose peritoneal mesothelioma, doctors perform a combination of tests, such as:

The median age at the time of diagnosis is 63.3 years of age. Generally, though, it usually occurs in people around the ages of 40 to 50 years who have had exposure to asbestos.

Staging

Doctors use a cancer staging system called the peritoneal cancer index (PCI) to determine how advanced peritoneal mesothelioma is.

The PCI has 4 stages:

  • PCI stage 1: score from 1 to 10
  • PCI stage 2: score from 11 to 20
  • PCI stage 3: score from 21 to 30
  • PCI stage 4: score from 31 to 39

The PCI divides the belly into 13 sections and assigns each area a score from 0 to 3. Zero means no cancer, and 3 means the cancer is prevalent in that area. The doctor adds up all the scores to determine the cancer stage.

Stage 1 is the least advanced stage of cancer, while stage 4 is the most advanced.

Currently, there is no cure for peritoneal mesothelioma. Treatment depends on the stage of the cancer and the symptoms a person experiences. It aims to improve a person’s outlook and quality of life.

Options may include:

Cytoreduction with hyperthermic intraperitoneal chemotherapy (HIPEC)

The first-line treatment for peritoneal mesothelioma is cytoreduction with HIPEC. This consists of undergoing surgery, where a doctor removes all tumors from the abdomen and the organs where cancer has spread, and then receiving HIPEC.

HIPEC is a type of chemotherapy that uses a safe temperature of 43°C and is applied directly to the abdomen. The heat makes chemotherapy stronger than a regular dose of the same drug, and it helps kill any remaining cancer cells that the doctor may have missed during cytoreduction surgery.

Surgery

Doctors may perform a peritonectomy (removal of the peritoneum) to treat peritoneal mesothelioma. If cancer has spread to other organs, such as the spleen, the gallbladder, or sections of the bowel, doctors may also remove them during the same procedure.

Immunotherapy

This approach uses drugs to activate the immune system to find and kill cancerous cells. However, this is not a first-line treatment for peritoneal mesothelioma. Still, doctors may sometimes recommend it depending on a person’s cancer stage and symptoms.

Chemotherapy

Doctors may prescribe systemic chemotherapy if a person with peritoneal mesothelioma cannot undergo cytoreduction with HIPEC. The medication travels around the body through the bloodstream.

Chemotherapy may consist of a combination of drugs that can help kill cancer cells and slow down their growth. It aims to improve symptoms and a person’s life expectancy.

Medications include:

  • carboplatin
  • cisplatin
  • gemcitabine (Gemzar)
  • pemetrexed (Alimta)
  • vinorelbine

Targeted therapy

Targeted therapy may help people who develop peritoneal mesothelioma due to a genetic mutation.

This therapy type targets genetic changes that cause the growth of healthy cells into cancer cells.

Radiation therapy

Radiation therapy may help kill cancer cells in small areas of the body following surgery. Radiation therapy may also be given as part of palliative care to ease symptoms linked to peritoneal mesothelioma, such as abdominal pain.

However, it is not a first-line treatment, since peritoneal mesothelioma does not usually grow as a single distinct tumor.

There is no cure for peritoneal mesothelioma, but receiving appropriate treatment can improve life expectancy. This, however, also depends on the stage of cancer at diagnosis.

Generally, the 5-year survival rate for people with peritoneal mesothelioma after receiving the diagnosis is about 30%. This statistic does not take into account the following factors:

  • age at diagnosis
  • general health conditions
  • advancements in cancer treatments

People who receive a diagnosis today may be more likely to have a better outlook than the people considered for this statistic.

Peritoneal mesothelioma is a type of cancer that develops in the peritoneum, the membrane that lines the abdomen and its organs. The most common cause of peritoneal mesothelioma is asbestos exposure, causing about one-third of cases.

There is no cure for peritoneal mesothelioma, and doctors find it difficult to diagnose since it displays symptoms that are similar to many other types of cancer. However, several treatment options are available to manage peritoneal mesothelioma symptoms and improve life expectancy.