Peritoneal Mesothelioma

Peritoneal mesothelioma is a type of cancer that affects the tissue that surrounds abdominal organs, called the peritoneal membrane or the mesothelial layer. It is the second most common type of mesothelioma and affects 300 to 400 Americans each year.

Experts are still not certain why peritoneal mesothelioma develops. Some people with this cancer have been exposed to asbestos or radiation, and some have a history of chronic inflammation of the peritoneum. But for most people, it’s not clear why the disease occurs.

Memorial Sloan Kettering has one of the country’s largest and most experienced programs in treating peritoneal-based tumors. Among the variety of such tumors that we treat are those associated with the appendix, colon, and ovaries, as well as teratomas (an encapsulated tumor) and gastrointestinal neuroendocrine tumors.

Our many experts in surgery and medical oncology collaborate in the treatment of these difficult cases.

We are actively searching for new therapies to treat peritoneal disease, and are collaborating with Memorial Sloan Kettering experts in pleural mesothelioma and other areas to identify genetic mutations in these diseases that might help us find new treatments for them.

Peritoneal mesothelioma may cause symptoms such as pain or bloating in the abdominal area, or unexplained weight loss. But many people have no symptoms at all and do not realize that there is something wrong until they have undergone surgery or a radiology test for another issue.

The first step in receiving the appropriate treatment for peritoneal mesothelioma is to confirm the diagnosis. Only then will your doctors be able to determine whether surgery or chemotherapy is the best approach for you.

The three major types of peritoneal mesothelioma are epithelial, sarcomatoid, and mixed (also known as biphasic). Because all are rare and occasionally misdiagnosed, it’s best to have a specialist in mesothelioma examine you, and with the help of an experienced pathologist determine which subtype you may have. On occasion, a person has inflammation in the abdomen that leads to noncancerous changes in the lining of the peritoneum, for example, that are mistaken for mesothelioma.

Knowing which type you have is very important for determining your best course of treatment. Within the epithelial subtype alone there are varying grades of disease, and one of them – well-differentiated papillary mesothelioma – may not require monitoring with anything other than a radiology test such as a CT scan.

By the time a doctor diagnoses peritoneal mesothelioma, most people have developed a buildup of fluid in the abdomen called ascites. The doctor may drain the fluid if it is causing discomfort or other problems in a procedure called paracentesis. This is done under local anesthetic.

The doctor can also use a sample of this fluid to look for cancer cells and diagnose peritoneal mesothelioma (and the type involved). Sometimes the doctor has to take more tissue from the area (a biopsy) to make a diagnosis because not enough cancer cells are in the fluid.

At Memorial Sloan Kettering, an interventional radiologist would likely do this as an outpatient procedure that involves sedating you and using a needle passed through the skin to take sample tissue from the abdominal area.

If your treatment team decides it is unsafe to do this biopsy through the skin or if the biopsy is performed but is inconclusive, we may recommend a minimally invasive procedure known as laparoscopy to make a definitive diagnosis. When you are under general anesthesia, surgeons insert a tiny video camera through a small incision in your abdomen, and with instruments inserted through other small incisions, remove a small amount of tissue for the pathologist to examine. Most people recover from this procedure in one to three days, and some do not even need to stay in the hospital overnight.

If you are diagnosed with peritoneal mesothelioma, our doctors may recommend a procedure called a cytoreductive surgery (debulking) to remove the tumors and the parts of the membrane that line the abdomen and the abdominal organs. This mesothelial lining surrounds most of the abdominal organs, including the liver, gallbladder, spleen, stomach, small intestine, colon, ovaries, and uterus.

If the tumors are not coming through the surface of this lining, surgeons may be able to peel them off in a procedure called a peritonectomy. Some organs, such as the spleen and small intestine, might be too fragile for this procedure and surgeons will have to remove part, or all, of the organ. Organs such as the uterus and liver are sturdier and will heal well after the surface layer is removed.

These operations can be very lengthy and may take more than ten hours in people with extensive disease. In many cases, our surgeons are able to look at a CT image and predict ahead of time which organs will need to be removed and how long the surgery is likely to take.

Chemotherapy is a drug or combination of drugs that kills cancer cells wherever they are in the body. For most people, surgery alone is not enough to eliminate peritoneal mesothelioma, and one of our medical oncologists will discuss chemotherapy as an additional treatment option for you.

For example, chemotherapy drugs can be administered directly into the abdominal area after your operation. Or if your disease is advanced, our doctors may recommend that you undergo chemotherapy in systemic form that you receive through an IV (intravenously).

Our physicians understand the subtleties of chemotherapy regimens and personalize your treatment, optimizing its strength while minimizing side effects as much as possible.