Peritoneal Mesothelioma Survival Rates

What Is a Survival Rate?

Survival rate is the percentage of patients diagnosed with a fatal condition who reach a certain survival benchmark. The rate is often measured in increments of years, such as the 1-year, 2-year, or 5-year survival rate. 

A patient’s survival rate is monitored once they are diagnosed or complete a specific treatment and ends once the patient passes away. Survival rates are educated predictions based on past cases and how the disease affected the patient. 

Survival rates may not be applicable to every patient because rates can be broken down into age groups, gender, type of disease, treatment plan and more. By dividing survival rate data into specific groups, doctors can provide a more relevant prediction for each individual case. 

What Are the Rates for Peritoneal Mesothelioma?

Unfortunately, overall survival rates for peritoneal mesothelioma are lower than for most other cancers. The 1-year survival rate for peritoneal mesothelioma is close to 50%, and the 2-year survival rate is 35%.

Peritoneal mesothelioma survival rates mostly depend on the stage of the cancer at diagnosis and a patient’s treatment options. Patients eligible for peritoneal mesothelioma surgery (cytoreduction with HIPEC) can improve their life expectancy significantly. The 5-year survival rate for cytoreduction with HIPEC is 65%.

Staging for Peritoneal Mesothelioma

Peritoneal mesothelioma staging is different from many other types of cancer. Peritoneal mesothelioma forms in the lining of the abdominal cavity. This lining protects the many organs within the abdominal cavity, such as the spleen, stomach and liver.

Peritoneal mesothelioma often does not metastasize (spread) beyond the abdomen, but it can affect many vital organs. Therefore, peritoneal mesothelioma is staged based on how far the cancer has spread in this cavity.

The abdomen is split into 13 regions, and each region receives a score from 0-3. All 13 regions’ scores are added up to calculate the patient’s Peritoneal Cancer Index (PCI) score. The lowest score is 1 and the maximum score is 39. The higher the score, the more the cancer has overtaken the abdominal cavity.

Early Stage Peritoneal Mesothelioma Survival Rates

The survival rate for early stage peritoneal mesothelioma patients is higher than later stages due to low volume of tumors and treatment eligibility. Due to the rarity of peritoneal mesothelioma, exact survival rates for stage 1 (PCI 1-10) peritoneal mesothelioma are unclear.

However, if peritoneal mesothelioma is diagnosed in early stages (PCI 1-20), the patient is more likely to be a proper candidate for surgery or other types of treatment. The lower the PCI score, the more treatment options are available. Undergoing cytoreductive surgery with HIPEC can add years to a patient’s life. 

Late-Stage Peritoneal Mesothelioma 

Survival rates for late-stage (PCI 21 and higher) peritoneal mesothelioma depend on various factors – specifically whether or not the patient is a surgical candidate. Patients with a higher PCI score have a more advanced disease, meaning tumors have spread to other organs and tissue. When the disease has progressed so much, the patient may no longer be a surgical candidate, which means survival rates decrease significantly. 

Patients ineligible for surgery often receive treatments to slow the progression of the disease, shrink tumors, decrease symptoms, and palliative treatments to manage pain. An example of a palliative treatment is paracentesis, which drains excess fluid from the abdomen and relieves abdominal pain, nausea, and abdominal distention. 

Other Factors Affecting Peritoneal Mesothelioma Survival Rates

There are other factors – aside from stage and PCI score – affecting peritoneal mesothelioma survival rates, such as age, gender, health and treatment plan. Additionally, there are medical factors that should be considered when evaluating peritoneal mesothelioma life expectancy. 

Mesothelioma Cell Type 

All peritoneal mesothelioma cases are diagnosed as a specific cell type: epithelioid, sarcomatoid or biphasic. Of the many factors affecting survival rates, mesothelioma cell type plays a key role in determining a patient’s life expectancy.

Epithelioid mesothelioma often has the most positive survival rate. Epithelioid cells have the best response to treatment and spread slower than the other two types. They are easier to identify on imaging scans or during surgery. The sarcomatoid cell type has the lowest survival rate as they spread quickly and are difficult to locate and treat.

Treatments: Surgery & Therapy 

Depending on the patient’s treatment eligibility, survival rates can improve significantly. The most common and beneficial treatment option to improve survival is peritoneal mesothelioma surgery.

Peritoneal mesothelioma surgery offers the patient the best chance to improve survival because surgery can remove a large volume of tumors. Removing the peritoneal mesothelioma tumors and cancer cells requires less work from the body to fight off the disease and can improve the effectiveness of subsequent treatments. This can lead to a smaller chance of the cancer growing or spreading. 

Cytoreductive surgery with HIPEC is the primary surgery method for peritoneal mesothelioma patients. This procedure involves removing all visible tumors and diseased tissue, the affected area(s) of the peritoneum, the spleen, the omentum (a fatty tissue layer covering the abdominal cavity), and potentially a portion of the intestines and other affected organs. After surgically removing tumors and affected organs, doctors will administer hyperthermic intraperitoneal chemotherapy (HIPEC) directly into the abdominal cavity to target and kill any remaining cancer cells not removed during surgery.

Peritoneal mesothelioma chemotherapy is another treatment option proven to increase survival for peritoneal mesothelioma patients, especially compared to patients who receive no treatment at all.

According to one study, 41% of patients receiving the chemotherapy combination of pemetrexed and cisplatin experienced an improvement in survival. Only 17% of participants showed satisfactory results after receiving only cisplatin. On average, the chemotherapy combination treatment extended patients’ lives by at least 12 months. 

Peritoneal mesothelioma immunotherapy is an emerging treatment option. The FDA has approved select immunotherapy drugs for treating pleural mesothelioma, which forms in the lining of the lungs. However, new studies and clinical trials show the drugs have promising effects on peritoneal mesothelioma, too.