A Rare Abdominal Cancer

The Peritoneum Lines the Abdominal Cavity

The peritoneum is a two-layered membrane composed of epithelial cells. It lines the abdominal and pelvic cavity organs, covering the digestive tract, liver, and reproductive organs. The peritoneal membranes and the fluid between the membranes protect the organs, allowing them to move freely against each other without sticking or rubbing.

Symptoms of Peritoneal Cancer

People with peritoneal cancer often have few symptoms until the disease is fairly advanced. When symptoms occur, they are often vague and nonspecific, including fatigue, abdominal swelling, diffuse abdominal pain, urinary frequency, and a sense of fullness when eating. Other symptoms may include constipation, bowel changes, abnormal vaginal bleeding, an abdominal mass, or unintentional weight loss.

Causes and Risk Factors for Peritoneal Cancer

It’s not known precisely what causes peritoneal cancer, though the process begins when a series of mutations in peritoneal cells results in out-of-control growth. Peritoneal cancer is much more common in females than males and has risk factors similar to the risk factors for ovarian cancer. Risk factors include age, with most people being diagnosed being over the age of 60, a history of breast cancer, the use of hormone replacement therapy, a history of endometriosis, obesity, and using talc below the waist. In contrast, some factors are associated with a decreased risk of developing the disease, including using oral contraceptives, having a tubal ligation, giving birth (especially before age 35), and breastfeeding.

Treatment Options for Peritoneal Cancer

Treatment for peritoneal cancer typically involves a combination of surgery, chemotherapy, and radiation therapy. Surgery is often the primary treatment, with the goal of removing as much of the cancer as possible. Chemotherapy is commonly used for treating peritoneal cancer, and it can be started during or after surgery, or used alone for tumors that are widespread. Radiation therapy is used infrequently for peritoneal cancer but may be useful for treating isolated areas of cancer.

Chemotherapy

Chemotherapy is commonly used for treating peritoneal cancer. It can be started during or after surgery, or used alone for tumors that are widespread. Chemotherapy can be given intravenously or injected directly into the abdominal cavity (intraperitoneal chemotherapy). Hyperthermic intraperitoneal chemotherapy is a fairly unique treatment that has proven beneficial for peritoneal cancer. During this procedure, chemotherapy drugs are heated to 107.6 degrees F prior to being injected into the abdomen. Immunotherapy may also be used in some cases.

Targeted Therapies

Targeted drugs are medications that target specific pathways involved in the growth of a specific type of cancer cell. Avastin (bevacizumab) is approved for use along with chemotherapy (followed by Avastin alone). A class of drugs called PARP inhibitors, which inhibit the poly ADP ribose polymerase enzyme, may be used for women who carry BRCA gene mutations. The PARP inhibitors Lynparza (olaparib), Rubraca (rucaparib), and Zejula (niraparib) are approved for treating this type of cancer.

Supportive/Palliative Care

Most people are diagnosed with peritoneal cancer only after it is in the advanced stages, when a cure is not possible. Yet, there are many things that can be done to improve quality of life. Paracentesis may improve breathing by draining fluid. Nutritional consultation may help with the loss of appetite associated with cancer, and reduce the risk of cancer cachexia (unintentional weight loss and muscle wasting). Management of nausea can improve quality of life. Pain management is also important and controlling pain is an essential part of treatment.

Prognosis

While the prognosis of peritoneal cancer is generally poor, there have been documented cases of complete remission from the disease. Factors associated with better survival rates include the absence of cancer in the lymph nodes and complete cytoreduction surgery.

Coping

Coping with cancer is challenging, and the fact that many people have never heard of peritoneal cancer can add to the stress and anxiety of having this diagnosis. While you are unlikely to find a support group for peritoneal cancer in your community due to the relative rarity of the disease, it is possible to connect with peritoneal cancer communities online. In addition to these resources, some of the cancer organizations that represent ovarian cancer, as well as organizations that support people with many forms of cancer, may also be a source of support. Some, like CancerCare, even provide support groups and communities for friends and family members of people living with cancer.

Summary

Peritoneal cancer is a rare cancer that forms in the lining of the abdominal cavity, known as the peritoneum. Symptoms of peritoneal cancer are often vague and include fatigue, abdominal pain and swelling, urinary frequency, and a sense of fullness when eating. A diagnosis of peritoneal cancer is made through bloodwork, imaging studies, and a biopsy. It is treated by surgically removing as much of the cancer as possible, followed by chemotherapy, radiation, or other targeted therapies.