Key Takeaways
- Peritoneal mesothelioma is the second most common type of mesothelioma, accounting for about 20% of all cases. It develops in the lining of the abdominal cavity (the peritoneum).
- There are approximately 500 to 700 new cases per year in the United States, with an average age of diagnosis of 64 years. Unlike pleural mesothelioma, peritoneal mesothelioma affects men and women equally.
- Symptoms include abdominal pain, nausea, vomiting, abdominal swelling or fluid buildup, constipation, weight loss, chest pain, and difficulty breathing. It typically takes 4 to 6 months from first symptoms to diagnosis.
- The primary treatment is cytoreductive surgery (removing visible tumors from the abdomen) combined with HIPEC (heated intraperitoneal chemotherapy) — a procedure that delivers heated chemotherapy drugs directly into the abdominal cavity.
- The disease has three cell subtypes — epithelioid (best prognosis), sarcomatoid, and biphasic — which affect how aggressively the cancer behaves and how well it responds to treatment.
- Peritoneal mesothelioma is typically diagnosed about 20 years after asbestos exposure. Early detection is critical for the best possible treatment outcomes.
There are four types of mesothelioma, the most common being pleural mesothelioma, which begins in the lining of the lung. The second most common type of mesothelioma is peritoneal mesothelioma, which begins in the abdominal cavity. Peritoneal mesothelioma affects about 20% of all mesothelioma patients. The other two types of mesothelioma are pericardial mesothelioma and mesothelioma of the tunica vaginalis, which are both extremely rare.
There are about 500 to 700 new cases of peritoneal mesothelioma each year in the United States, and the average age of diagnosis is 64 years. Based on data, peritoneal mesothelioma affects men and women equally. This differs from pleural mesothelioma, which is usually seen in men, as men typically occupied the jobs in which asbestos was heavily used. Most people diagnosed with peritoneal mesothelioma are non-Hispanic white individuals. This type of mesothelioma is usually treated through cytoreductive surgery to remove the tumors in the abdomen. This treatment is usually coupled with hyperthermic intraperitoneal chemotherapy (HIPEC). This cancer is usually diagnosed around 20 years after asbestos exposure.
Subtypes of Peritoneal Mesothelioma
There are three histologic subtypes of peritoneal mesothelioma that tend to present different outcomes and aggressiveness. For instance, epithelioid mesothelioma tends to result in the best prognosis compared to the other two subtypes. The other two subtypes are sarcomatoid and biphasic, biphasic encompassing both epithelioid and sarcomatoid cells.
Symptoms of Peritoneal Mesothelioma
Symptoms may include abdominal pain, nausea, vomiting, swelling or fluid in the abdomen, and constipation. Patients may also experience weight loss, chest pain, and dyspnea. From the time a victim of peritoneal mesothelioma first experiences symptoms to the time that they are diagnosed, there is usually about a 4–6-month passage of time.
A CT scan is usually used as the imaging test for diagnosis.
Staging
The peritoneal carcinoma index (PCI) can be used to find out the burden and distribution of the cancer. The PCI may be gathered before surgery through a CT scan, however, the best way to determine the PCI is through an intraoperative assessment. This assessment is done by separating the peritoneal cavity into 13 different regions. The sizes of the legions in the regions are then graded from no disease to extensive disease. These scores are then added up on a scale of 0-39, 0 meaning that there has been a complete cytoreduction, and 39 meaning that the disease is very burdensome.
It is necessary to detect peritoneal mesothelioma early for the best possible outcome to be possible when it comes to treatment.
Other Types of Treatment
Except in a select number of cases, systemic therapy is not used as much to treat peritoneal mesothelioma as it is to treat pleural mesothelioma. However, systemic chemotherapy may be administered to patients who have unresectable mesothelioma, meaning that the tumor cannot be removed through surgery. It may also be used in cases where patients refuse surgery, and in those who are not physically able to undergo a surgical procedure.
If you or a loved one has been diagnosed with mesothelioma, or another asbestos-related disease, please contact us at (800) 505-6000 for legal help. To find out more information, fill out the form on our Homepage.
Frequently Asked Questions
What is peritoneal mesothelioma?
Peritoneal mesothelioma is a cancer that develops in the peritoneum — the thin membrane lining the abdominal cavity. It is the second most common type of mesothelioma after pleural mesothelioma (which affects the lungs), accounting for approximately 20% of all mesothelioma cases. Like all forms of mesothelioma, it is caused by exposure to asbestos.
What are the symptoms of peritoneal mesothelioma?
Common symptoms include:
- Abdominal pain
- Nausea and vomiting
- Abdominal swelling or fluid buildup (ascites)
- Constipation
- Unexplained weight loss
- Chest pain
- Difficulty breathing (dyspnea)
Because these symptoms overlap with many other gastrointestinal conditions, peritoneal mesothelioma can be difficult to diagnose. On average, there is a 4- to 6-month gap between when a patient first experiences symptoms and when they receive a diagnosis.
How is peritoneal mesothelioma treated?
The primary treatment is cytoreductive surgery (CRS) combined with HIPEC (hyperthermic intraperitoneal chemotherapy). Cytoreductive surgery is an extensive procedure that removes as much visible cancer as possible from the abdominal cavity. HIPEC is then administered directly into the abdomen — heated chemotherapy drugs that target remaining cancer cells. For patients who cannot undergo surgery — whether due to unresectable tumors, physical condition, or personal choice — systemic chemotherapy may be used as an alternative.
Does peritoneal mesothelioma affect men and women differently?
Unlike pleural mesothelioma — which disproportionately affects men because of historically male-dominated occupational asbestos exposure — peritoneal mesothelioma affects men and women at roughly equal rates. This may reflect the role of secondary and environmental exposure pathways, which affect both sexes equally, as well as differences in how ingested versus inhaled asbestos fibers travel through the body.
What is the peritoneal carcinoma index (PCI)?
The PCI is a scoring system used to measure the burden and distribution of cancer within the abdominal cavity. The peritoneal cavity is divided into 13 regions, and each region is scored based on the size of the lesions — from no visible disease to extensive disease. The scores are totaled on a scale of 0 to 39, with 0 indicating a complete cytoreduction (all visible cancer removed) and 39 indicating very advanced disease. While a CT scan can estimate the PCI before surgery, the most accurate assessment is done during the surgical procedure itself.
What are the subtypes of peritoneal mesothelioma?
There are three histologic subtypes:
- Epithelioid — the most common subtype and generally associated with the best prognosis and response to treatment
- Sarcomatoid — a more aggressive subtype that is typically harder to treat
- Biphasic — contains both epithelioid and sarcomatoid cells. Prognosis depends on which cell type is more dominant in the tumor.
Correctly identifying the subtype through biopsy is important because it directly influences treatment decisions and expected outcomes.
How long after asbestos exposure does peritoneal mesothelioma develop?
Peritoneal mesothelioma is typically diagnosed approximately 20 years after asbestos exposure — somewhat shorter than the 30- to 50-year latency period commonly seen with pleural mesothelioma. However, latency periods can vary widely depending on the duration and intensity of exposure. Because of this delay, many patients do not immediately connect their diagnosis to asbestos exposure from decades earlier.
What should I do if I’ve been diagnosed with peritoneal mesothelioma?
If you or a loved one has been diagnosed with peritoneal mesothelioma or another asbestos-related disease, understanding your treatment options and legal rights is an important first step. Your asbestos exposure history — where you worked, what materials you were around, and for how long — may be critical to pursuing compensation. Call (800) 505-6000 or fill out our contact form for a free consultation.
