What Is Primary Peritoneal Cancer?

Medically Reviewed by Poonam Sachdev on April 21, 2022
6 min read

The inside of your abdomen (the part of your body below your chest and above your hips) is lined with a slick, transparent tissue. It also covers the surfaces of all the organs in that area, and it lets them sit next to one another without sticking together. It’s called the peritoneum (pronounced pair-it-oh-NEE-um).

When the cells that form it grow abnormally and turn into cancer cells, it's called primary peritoneal cancer. It’s a relatively rare disease that mainly affects women. This cancer can happen anywhere in the abdomen, and it can affect the outsides of any of the organs there.

The cells that make up the film are the same kind as the ones that form the surface of a woman’s ovaries. Because of that, peritoneal cancer is related to the most common kind of ovarian cancer. The two illnesses cause some of the same symptoms, and doctors often use the same treatments for them. But a woman can have peritoneal cancer even if their ovaries have been removed.

Doctors don’t know why some people get this kind of cancer.

As with many types of cancer, getting older is the main risk. If breast cancer or ovarian cancer runs in a woman’s family, they may be more likely to have peritoneal cancer.

Recognizing peritoneal cancer is a challenge, because the symptoms seem to suggest problems in your digestive tract rather than what’s actually wrong. You might:

Many other things can cause these symptoms. Only a doctor can figure out what the problem is.

And because the signs are vague, doctors usually can’t diagnose peritoneal cancer until its later stages. By that time, it’s often harder to treat.

Doctors generally have to go through more than one step before they can identify the problem. After you tell your doctor what you’re feeling, you’ll probably also get:

A pelvic exam. Your doctor will feel your vagina, uterus, ovaries, and other organs to see if their size or shape is abnormal.

Blood tests. They can identify chemicals that may signal the presence of cancer.

An ultrasound. A small instrument sends sound waves into your abdomen. When they bounce back, the machine turns them into an image that your doctor can see on a screen. That may reveal tissue with cancer.

Surgery. A surgeon will make a small cut in your belly, put in a tiny instrument with a light, look around, and take out tissue that your medical team can examine for cancer.

A fluid sample. If there’s too much fluid in your abdomen, your doctor may take some out with a needle and have it checked for cancer cells.

If your medical team does find peritoneal cancer, they will analyze how far it has developed using categories called stages. That helps them decide what treatment you need. The stages use Roman numerals:

Stage I (stage one): The cancer is in one or both of the ovaries, the almond-shaped organs that produce eggs and female hormones. The fluid in the abdomen may also have cancer cells.

Stage II (stage two): The disease has spread to other tissues or organs in the pelvis, such as the uterus.

Stage III (stage three): Cancer cells have gone father into the abdomen, such as the intestine or the outside of the liver.

Stage IV (stage four): The cancer has spread to even more distant parts of your body, such as to the lungs.

Your doctor will recommend a treatment plan based on how far the cancer has developed, where it’s located, and how healthy you are in general. You may get:

Surgery. This is usually the starting point. The medical team tries to take out all visible signs of the disease. That usually includes removing the ovaries, uterus, and the tubes that connect them -- the fallopian tubes. If necessary, your surgeon may take out part of your intestines or liver.

Chemotherapy. This uses drugs to fight the cancer. You might get them injected into a vein or through a catheter into your abdomen. You’d probably get six doses, and your doctor will spread them out over weeks or months. If you get chemotherapy through an IV, for instance, you would probably get it once every 3 weeks.

You won’t have to check into the hospital. Instead, you’ll get each dose as an outpatient, which means you get the treatment at your doctor’s office or a clinic and then go home.

Radiation. This involves aiming at the cancer with intense X-rays or other radiation. Doctors rarely start someone’s treatment with this. But they may use it on a small area of the abdomen if cancer returns after the first treatment.

Targeted therapy. This  treatment uses drugs or other substances to attack certain molecules such as proteins on cancer cells. It does not kill healthy cells and is typically used in conjunction with chemotherapy, surgery, or radiation.

Cancer treatment usually has effects on your body that you may feel while it’s going on or afterward. These can include:

You and your doctor can also check on another source of help: clinical trials.

When medical researchers come up with potential treatments that look promising, they try them out on patients. These are clinical trials. They help doctor learn how well the treatments work and what the side effects are.

Your medical team can help you find out whether any trials that might help you are going on. You can also check the website of the federal government’s National Cancer Institute. Another federal agency, the National Institutes of Health, keeps an online listing of trials at clinicaltrials.gov.

Because doctors sometimes can’t find peritoneal cancer until it has gotten to a later stage, you might need extra help dealing with the illness itself or the treatment’s side effects. Your medical team may call this palliative care. (That’s pronounced PAL-yah-tiv.)

This support goes alongside your treatment, and it may start as soon as your doctor gives you the diagnosis. You can continue it as long as you have cancer. You may receive it at your doctor’s office, in the hospital, or at home. Your medical team and others will assist with your:

Physical needs.Medications and other therapies can help you manage pain, nausea, or other problems.

Emotional and spiritual concerns. Counselors can coach you about how to handle anxiety and fear. If you have a religious or spiritual faith that’s part of how you handle your illness -- or if your condition shakes your core beliefs -- palliative care specialists can help you with that.

Practical needs. If you need help seeking financial aid for your care, filling out medical or legal paperwork, setting up transportation, or tackling other issues, your team can pitch in.

Experience shows that palliative care improves quality of life not only for the person who has the condition, but for their families, too. It helps everyone find what they need.

You may also want to look into joining a support group. And you can also let your friends and family know how they can help. Chances are, they’ll want to be there for you but may not know the best ways to do that. You can decide what works best for you as your treatment goes forward.