What Is Malignant Peritoneal Mesothelioma?
Peritoneal mesothelioma is a cancer of the lining of the abdomen, called the peritoneum. Common symptoms include abdominal pain and swelling, weight loss and nausea. It is the second most common form of mesothelioma, accounting for 10% – 15% of cases. Pleural mesothelioma is the most common, representing more than 80% of cases.
Research has linked peritoneal mesothelioma to asbestos exposure. Exposure can result in a person inhaling or ingesting asbestos fibers. These fibers may enter the abdomen and become lodged in the peritoneum. There is debate about how asbestos fibers enter the abdomen. Some experts believe the fibers may reach the abdomen via blood vessels.
Over time, asbestos fibers may lead to mesothelioma tumors developing in the peritoneum. The cancer may also spread to organs in the abdominal cavity. The abdomen contains many vital organs, including the stomach, intestines, kidneys and liver.
Median survival for patients diagnosed with peritoneal mesothelioma is about 2.5 years. But life expectancy may vary based on several factors, like cell type, sex and stage of disease. Treatment options are also available that may help improve a mesothelioma patient’s prognosis.
Resources for Peritoneal Mesothelioma Patients
Symptoms of Peritoneal Mesothelioma
Peritoneal mesothelioma may not cause symptoms until it is fairly advanced. Patients commonly report nausea, weight loss, abdominal pain and swelling. Abdominal swelling is also known as peritoneal effusion or ascites. Ascites is a build-up of fluid between the layers of the peritoneum, which lines the abdominal cavity.
Peritoneal mesothelioma symptoms are often nonspecific. This means that the symptoms could be attributed to many different conditions. For example, nausea and fever could be caused by a stomach flu, allergies or mesothelioma. The nonspecific nature of symptoms can make peritoneal mesothelioma difficult to identify.
Symptoms may worsen as the disease progresses. This could include an increase in severity of existing symptoms or brand new symptoms arising. If mesothelioma tumors grow and affect the stomach, this may cause gastrointestinal symptoms, such as weight loss and pain.
Patients can help doctors arrive at the correct diagnosis by sharing any history of asbestos exposure. Any level of asbestos exposure can put a person at risk for mesothelioma. But mesothelioma has a long latency period. Symptoms can take decades to appear after a person encounters asbestos. In that time, patients may forget they were exposed to the dangerous mineral.
People who may have been exposed to asbestos should tell their doctor. A doctor may recommend regular cancer screenings and can watch for mesothelioma symptoms. A mesothelioma doctor can also recommend treatment options to help manage symptoms.
What Causes Peritoneal Mesothelioma?
Asbestos exposure causes peritoneal mesothelioma. Asbestos fibers can be inhaled or ingested. These fibers can end up in the lining of the abdomen, possibly by way of blood vessels. Over time, peritoneal mesothelioma may develop.
Experts do not wholly understand how asbestos causes mesothelioma. Mesothelioma researchers say the following process may lead to peritoneal mesothelioma:
- A person ingests or inhales asbestos fibers.
- The fibers travel to and settle in the lining of the abdomen, also called the peritoneum.
- The fibers irritate the mesothelial cells in the peritoneum, causing inflammation.
- Over time, inflammation damages the mesothelial cells and causes cancerous changes to them.
- The inflammatory changes to the cells allow peritoneal mesothelioma tumors to develop.
This process takes many years from initial exposure to tumor development.
Who Is at Risk for Peritoneal Mesothelioma?
Peritoneal mesothelioma can develop in anyone after asbestos exposure. However, certain mesothelioma risk factors may increase the likelihood of developing this cancer. This includes gender, occupation and duration of asbestos exposure.
Men have a slightly higher risk of developing peritoneal mesothelioma than women. This may be because of the types of jobs that men and women historically had. Men were more likely to work jobs with a higher chance of asbestos exposure, like construction and auto mechanic work. These occupations often led to high levels of dangerous asbestos exposure. The most dangerous type of asbestos exposure is high levels of prolonged exposure to small fibers.
Diagnosing Peritoneal Mesothelioma
A biopsy is the only way to definitively diagnose peritoneal mesothelioma. Doctors may initially perform other types of tests, to rule out other conditions. These may include general tests like blood tests and a physical exam. If these tests suggest a serious condition, an oncologist may perform more specific tests, like biopsies. Biopsies can help differentiate mesothelioma from other cancers.
Initial diagnostic tests for mesothelioma may consist of:
- Basic imaging tests: Types of imaging tests performed in the initial diagnostic phase often include X-rays to look for signs of illness.
- Blood tests: Basic blood tests can help doctors learn more about a patient’s overall health, organ function and potential illness.
- Medical history review: A medical history review can help discover related symptoms and risk factors for mesothelioma. This review may include an examination of potential occupational asbestos exposures.
- Physical examination: Doctors generally perform this type of examination to check for lumps and other signs of illness.
If initial tests suggest a serious condition, the doctor can order more specific tests. These tests can help them determine if a patient has mesothelioma.
For example, a CT scan is an imaging test that offers a higher level of detail than an X-ray. It helps doctors find tumors and other signs of cancer that did not appear on an X-ray.
A doctor may also collect and test suspicious cells and tissue for analysis. This type of medical procedure is called a biopsy. Testing a biopsy sample is the only way to confirm a mesothelioma diagnosis.
Several types of mesothelioma biopsy procedures are available. A doctor can determine the appropriate procedure to perform. Some biopsy procedures may also serve palliative purposes, meaning they may increase patient comfort. For example, a paracentesis procedure collects peritoneal fluid from the abdomen. This can help relieve pressure and stomach pain.
Misdiagnosing Peritoneal Mesothelioma
According to some experts, peritoneal mesothelioma is misdiagnosed at a high rate. This means that some cases are mistaken for other illnesses. For example, doctors may mistake it for ovarian cancer in women, colon cancer or tuberculous peritonitis. But peritoneal mesothelioma is a rare disease, and information about misdiagnosis is limited.
Patients can help doctors arrive at the correct diagnosis by sharing any history of asbestos exposure. A person may have experienced asbestos exposure in several ways. Occupational exposure, secondary exposure and talc exposure are among the potential exposure sources.
Staging Peritoneal Mesothelioma
Staging is a representation of how extensive a patient’s cancer is. Early-stage peritoneal mesothelioma patients may have more treatment options available to them. Late-stage patients may have fewer options, but this may change if they respond well to the treatment they do receive.
Doctors commonly determine the stage of peritoneal mesothelioma as part of the diagnostic process. They may be able to assess the stage of cancer using a CT scan. Staging helps oncologists determine disease progression and treatment options. It also helps patients know what to expect. However, cancer stage alone does not define patient outcomes. Prognosis depends upon many factors like treatment, age and overall health.
There is no official staging system for peritoneal mesothelioma. Doctors may refer to the Tumor Node Metastasis (TNM) System to categorize disease progression. They may also use the Peritoneal Cancer Index (PCI) to assess stage. These systems have either 3 or 4 stages of peritoneal mesothelioma.
Stage 1 peritoneal mesothelioma is considered early-stage, with cancer limited to the abdominal lining. Stage 2 is mid-stage and has more cancer spread. Stages 3 and 4 are late-stage and involve spread to more distant tissues and organs.
Earlier-stage peritoneal mesothelioma has been associated with better survival outcomes. One study reported survival rates for patients diagnosed with stages 1 – 3 peritoneal mesothelioma as follows:
- Stage 1: 5-year survival rate of 87%
- Stage 2: 5-year survival rate of 53%
- Stage 3: 5-year survival rate of 29%
All the patients in this study received surgery and chemotherapy as part of their treatment plan.
Peritoneal Mesothelioma Survival Rate and Prognosis
Prognosis for peritoneal mesothelioma may be better than for pleural mesothelioma. Life expectancy for peritoneal mesothelioma patients is about 31 months but can range from 6 months to more than 6.5 years.
Multimodal treatment plans often achieve the best survival results. Multimodal plans combine two or more forms of treatment. In recent years, eligible peritoneal mesothelioma patients often received both of the following:
- Cytoreductive surgery (CRS): This is a procedure to remove visible tumor tissue from the abdomen.
- Heated intraperitoneal chemotherapy (HIPEC): This is a heated chemotherapy wash that circulates throughout the abdominal cavity. Doctors use it to target cancer cells left behind after surgery.
Studies have shown improved survival rates in peritoneal mesothelioma patients treated with CRS and HIPEC.
| 1-year survival rate | 83% |
| 3-year survival rate | 62% |
| 5-year survival rate | 52% |
Other factors that can affect a patient’s peritoneal mesothelioma prognosis include:
- Cell type: Mesothelioma survival may be affected by the cancer’s cell type. In one study, patients with epithelioid cell mesothelioma had a median survival of 79 months. Biphasic and sarcomatoid mesothelioma had a significantly shorter median survival.
- Disease progression at diagnosis: Early mesothelioma diagnoses and treatment may help improve outcomes for mesothelioma patients.
- Gender: Median survival for female peritoneal mesothelioma patients is generally higher than for male patients.
A doctor can consider all factors when determining a patient’s treatment plan to help achieve the best survival results.
What Is the Treatment for Peritoneal Mesothelioma?
Doctors often combine different therapies to treat peritoneal mesothelioma. This multimodal approach may include chemotherapy, surgery and immunotherapy. Multimodal therapy may be the most effective way of improving mesothelioma survival. Radiation is not commonly used to treat peritoneal mesothelioma. It has not been tied to improved survival results for this disease.
Doctors often consider several factors when making treatment recommendations. Patient health, disease stage and tumor cell type may all affect treatment options. Patients with certain characteristics may benefit from less aggressive treatments, like peritonectomy.
For example, patients over a certain age or who have a condition where the body makes too many platelets may be ineligible for certain treatments. Tumor growth on important organs and biphasic and sarcomatoid tumor cell types may also affect treatment options.
Researchers continue to explore innovative ways to treat peritoneal mesothelioma. Doctors can help patients understand their options, including experimental treatments and clinical trials. They can also help manage any treatment side effects patients may experience.
“Peritoneal mesothelioma is a rare type of an already rare cancer which doesn’t seem to spread as aggressively as pleural mesothelioma. Intraperitoneal chemotherapy, where chemotherapy is infused directly into the abdominal cavity, and cytoreductive surgery are both effective treatment options for peritoneal mesothelioma.”
Medical Doctor
Peritoneal Mesothelioma Chemotherapy
Peritoneal mesothelioma patients may receive chemotherapy as part of their cancer treatment plan. Chemotherapy may be systemic, meaning it circulates throughout the body’s bloodstream. It may also be regional, meaning it is applied only to the abdomen.
Patients with inoperable peritoneal mesothelioma may receive systemic chemotherapy. The most common regimen for peritoneal mesothelioma is a combination of chemotherapy drugs pemetrexed and cisplatin. Reported survival for patients who received pemetrexed with or without cisplatin ranges from 12 to 23 months.
Doctors may combine systemic chemotherapy with other therapies to try to improve results. For example, systemic and local chemotherapy may both be part of a multimodal treatment plan.
Hyperthermic Intraperitoneal Chemotherapy (HIPEC)
Eligible peritoneal mesothelioma patients may receive cytoreductive surgery (CRS) and HIPEC. CRS and HIPEC are associated with long-term peritoneal mesothelioma survival.
HIPEC is usually administered after surgery. It is a heated chemotherapy wash circulated within a patient’s abdomen. It helps kill cancer cells left behind after surgery removes larger, visible masses.
Studies show survival for patients receiving CRS and HIPEC ranging from 33 to 79 months. Survival for patients who receive this treatment combination may vary based on different factors. Cell type, disease progression and other factors may impact treatment effectiveness.
Peritoneal Mesothelioma Surgery
Multimodal treatment with CRS and HIPEC is the preferred form of peritoneal mesothelioma treatment in eligible patients. CRS is an operation to remove as much visible tumor mass as possible.
CRS is usually followed by one or more regional chemotherapy types. HIPEC is a common regional chemotherapy used to treat peritoneal mesothelioma. Other regional chemotherapies include early postoperative intracavitary chemotherapy (EPIC) and normothermic intracavitary chemotherapy (NIPEC).
In one study, patients who received CRS and HIPEC and/or EPIC had the following survival rates:
- 1-year survival rate: 83%
- 3-year survival rate: 62%
- 5-year survival rate: 52%
Peritoneal Mesothelioma Immunotherapy
Researchers are currently looking into using immunotherapy to treat peritoneal mesothelioma. The FDA has already approved a combination of the immunotherapy drugs Opdivo® (nivolumab) and Yervoy® (ipilimumab) to treat pleural mesothelioma.
Opdivo and Yervoy are both immune checkpoint inhibitors (ICIs). This type of immunotherapy drug allows a patient’s body to attack cancer cells. These drugs can stop cancer cells from evading the immune system.
At least one clinical trial plans to treat peritoneal mesothelioma patients with Opdivo and Yervoy. Patients in the study will receive the drugs after surgery and chemotherapy.
In an earlier study, peritoneal and pleural mesothelioma patients received Imjudo® (tremelimumab) and Imfinzi® (durvalumab). These are two other ICIs. The overall study group had a median survival of about 17 months.
Peritoneal Mesothelioma Multimodal Treatment
Doctors may combine therapies like chemotherapy, surgery and immunotherapy to treat peritoneal mesothelioma. The specific combination of treatments may vary depending on each case. This multimodal approach to treatment is often associated with encouraging results in patients.
Multimodal treatment has helped improve life expectancy for peritoneal mesothelioma. With multimodal treatment, some patients may survive for years. For example, one study found patients with epithelial cell type who received CRS and HIPEC have a median survival of more than 6.5 years.
Patients can discuss potential treatment combinations with their doctors.
After a 26-year career in the HVAC industry, Jim Dykstra was diagnosed with peritoneal mesothelioma. Jim underwent cytoreductive surgery followed by HIPEC. After he recovered, he underwent multiple rounds of chemotherapy and radiation therapy to control the growth of his tumors. Though he is still battling malignant peritoneal mesothelioma, he is a survivor of more than 6 years.
Peritoneal Mesothelioma Doctors
It is important for peritoneal mesothelioma patients to receive care from qualified specialists. Peritoneal mesothelioma specialists know specific therapies to treat the disease. For example, CRS and HIPEC is a common treatment for eligible peritoneal mesothelioma patients. Peritoneal mesothelioma doctors have experience with these specific treatment types.
Peritoneal mesothelioma specialists can be found at cancer centers throughout the country. Clinical trials may also be available for patients who meet the eligibility requirements. These trials give patients access to experimental therapies.
Top Peritoneal Mesothelioma Doctors in the Country
Common Questions About Peritoneal Mesothelioma
- Can peritoneal mesothelioma spread to the lungs?
Yes, it is possible for peritoneal mesothelioma to spread to the lungs. However, it is rare for this disease to spread beyond the abdomen. A mesothelioma doctor can determine how far the cancer has spread when diagnosing a patient.
- Can peritoneal mesothelioma be caused by something other than asbestos?
Asbestos is the only known cause of peritoneal mesothelioma. Asbestos fibers can be inhaled or swallowed. If these fibers end up in the abdomen, they may later cause peritoneal mesothelioma to develop. Certain factors like older age may increase the risk of developing mesothelioma. But these risk factors alone do not cause mesothelioma to develop.
- How quickly does peritoneal mesothelioma spread?
Mesothelioma has a reputation for spreading quickly, but it is unclear how fast this rare form spreads. Peritoneal mesothelioma may not cause symptoms, which can delay diagnosis. It may spread throughout the belly before it is caught. But this cancer rarely progresses beyond the abdomen.
