Primary peritoneal cancer (PPC) is a rare cancer that starts in the layer of tissue called the peritoneum. The peritoneum lines the inside of the abdomen.

This information is about primary peritoneal cancer (PPC) in women. It’s best to read it alongside our information about ovarian cancer. PPC and ovarian cancer are very similar and doctors treat them in the same way.

If you’re a man with PPC, please contact our cancer support specialists. They can provide you with more specific information.

Another rare cancer that can affect the peritoneum is peritoneal mesothelioma, which is linked with exposure to asbestos. We have more information about mesothelioma.

If you have any further questions, you can ask your doctor or nurse at the hospital where you are having your treatment.

The peritoneum covers and helps protect all the organs in the abdomen (tummy area) – for example, the stomach, liver and bowel, as well as the womb, ovaries and fallopian tubes. It also produces a lubricating fluid which helps these organs move around smoothly inside the abdomen.

A PPC can start anywhere in this area and can affect the surface of any of the organs in the peritoneum. Ovarian cancers often spread from the ovaries to the peritoneum so doctors always rule out ovarian cancer before PPC is diagnosed.

The causes of PPC are unknown. Like most cancers, it’s more common in older people. PPC rarely happens in men.

A small number of PPCs are thought to be caused by an inherited faulty gene linked to ovarian and breast cancer in the family. People who are worried about cancer because of their family history can be referred to specialist clinics where their risk will be carefully assessed.

Most women don't have obvious symptoms for a long time. Symptoms can include any of the following:

• loss of appetite
• indigestion
• feeling sick (nausea) and bloated
• unexplained weight gain
• swelling in the abdomen due to a build-up of fluid
• pain in the lower abdomen
• constipation or diarrhoea
• needing to pass urine more often
• shortness of breath, if there is a build-up of fluid in the lungs as well as the abdomen.

These symptoms may be caused by a number of conditions other than PPC. But, if you have any symptoms that get worse or last for a few weeks, it's important to have them checked by your GP.

Usually you begin by seeing your GP, who will examine you and may arrange for you to have an ultrasound scan and blood tests. Your GP will refer you to a specialist doctor, usually a gynaecologist (a specialist in women’s health), for advice and treatment.

At the hospital, the gynaecologist will ask you about your general health and any previous medical problems. They will then examine you. This will include an internal (vaginal) examination to check for any lumps or swellings. Sometimes, you may also have an examination of your back passage (rectum). You can ask for a female doctor to do the internal examination if you prefer.

You may also have a chest x-ray to check your general health. You will have a blood test to check the levels of a protein called CA125. CA125 levels may be higher than normal in women with PPC or ovarian cancer.

The following tests are commonly used. You can read about these in more detail in our information about ovarian cancer.

Ultrasound scan

This test uses sound waves to build up a picture of the organs inside the tummy (abdomen) and pelvis. A computer converts the sound waves into pictures that you can see on a screen. There are two types of ultrasound that can be used:

Pelvic ultrasound

You will be asked to drink plenty of fluids before this ultrasound so that your bladder is full. This helps to give a clearer picture. The person doing the scan spreads a gel on to your tummy (abdomen). They then gently go over the area with a small handheld device, which produces the sound waves.

Vaginal ultrasound

The tip of an ultrasound probe (the size of a tampon) is gently inserted into your vagina. The probe produces sound waves. Although this may sound uncomfortable, you may find it easier than a pelvic ultrasound, as you don’t need a full bladder.

CT (computerised tomography) scan

A CT scan takes a series of x-rays that build up a three-dimensional (3D) picture of the inside of the body. It is painless and takes 10 to 30 minutes. It uses a small amount of radiation, which is very unlikely to harm you or anyone you come into contact with.

You will be asked not to eat or drink for at least four hours before the scan.

You may be given a drink or injection of a dye that allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. It is important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection.

MRI (magnetic resonance imaging) scan

This test uses magnetism to build up a detailed picture of areas of your body. Before the scan you may be asked to complete and sign a checklist. This is to make sure it is safe for you to have the MRI scan. Before the scan, you will be asked to remove metal belongings including jewellery. Some people are given an injection of dye into a vein in the arm. This is called a contrast medium and can help the images from the scan to show up more clearly. During the test, you will be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It is painless but can be slightly uncomfortable, and some people feel a bit claustrophobic. It is also noisy, but you will be given earplugs or headphones.

Removing fluid from the tummy

If you have a build-up of fluid in the tummy (called ascites) your doctor may take a sample to check for cancer cells. They numb the skin over the area first with a local anaesthetic. The doctor then passes a needle through the skin into the fluid and draws some into a syringe.

If you have a lot of fluid it can be uncomfortable so your doctor may remove it by putting a short tube (a cannula) into the tummy (abdomen). The tube attaches to a bag that collects the fluid as it drains.

We have more information about ascites.

Genetic testing

Your doctor may talk with you about having a blood test to look for genetic changes that are linked to cancer. This is only done if you have certain types of cancer, such as high-grade serous or endometrioid cancer.

Knowing about any genetic changes helps your doctor plan your treatment.

We have more information about cancer and genetic changes.

Laparotomy

Sometimes the surgeon needs to do an operation called a laparotomy to make a definite diagnosis of primary peritoneal cancer. A larger cut is made in the skin and muscle of the abdomen. This allows the surgeon to look at all the organs in the abdomen. This will involve an overnight stay in hospital.

The stage of a cancer describes its size, position and if it has spread from where it started.

Knowing the stage helps the doctors decide on the most appropriate treatment for you.

Because ovarian and primary peritoneal cancers are alike, doctors use the same staging system. In PCC the cancer is either stage 3 or stage 4 but has not started in the ovaries or the fallopian tubes.

Stage 3

The cancer may have spread outside the pelvis and/or to the lymph nodes at the back of the tummy.

Stage 4

This is when the cancer has spread to organs inside the abdomen, for example the liver, or organs further away such as the lungs.

There’s more detailed information on staging in our information on ovarian cancer.

A team of specialists will meet to discuss and decide on the best treatment for you. This multidisciplinary team (MDT) will include:

• a surgeon who specialises in gynaecological cancers (a gynaecological oncologist)
• a cancer doctor (oncologist) who specialises in cancer treatments for gynaecological cancers
• a gynae-oncology nurse specialist
• a radiologist (a doctor who analyses x-rays and scans)
• pathologists (who advise on the type and extent of the cancer).

Your cancer doctor and nurse specialist will advise you about the best treatment for your particular situation and answer any questions you have.

The main treatments for PPC are surgery and chemotherapy. You may have a combination of both. The aim of treatment is to keep the cancer under control for as long as possible. If surgery isn’t possible or suitable for you, you will usually be offered chemotherapy on its own.

Occasionally some people have treatment with radiotherapy.

Your cancer doctor and specialist nurse will talk to you about your treatment options. You and your doctor can then decide on the best treatment plan for you. We have more information on ovarian cancer.

Some women may not be well enough to have treatment or may decide not to have it. But they can still have treatment to relieve symptoms.

Surgery

You may have surgery to remove as much of the cancer as possible. This usually involves removing the:

• womb
• ovaries and fallopian tubes
• sheet of fatty tissue inside the abdomen (omentum).

Doctors sometimes call this debulking surgery.

Most women can go home 3–7 days after the operation. How long you spend in hospital depends on the operation you have and how quickly you recover. 

Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. You may have chemotherapy:

• on its own as the main treatment
• before surgery to make the tumour smaller and easier to remove
• after surgery to treat any cancer cells that may be left behind
• after surgery to treat any areas of cancer that couldn’t be removed.

Your doctor and nurse will tell you more about the chemotherapy drugs and their side effects. They’ll explain how long the course is likely to be. You usually have a session of treatment followed by a rest period of a few weeks.

A nurse will usually give you the chemotherapy drugs into a vein (intravenously). You usually have this in a chemotherapy day ward. They give you anti-sickness drugs to take at home before you go. Some of the common side effects of chemotherapy are being more likely to get an infection, feeling sick, and tiredness. We have more information about chemotherapy.

Radiotherapy

Radiotherapy treats cancer by using high-energy rays to destroy cancer cells, while doing as little harm as possible to normal cells. Doctors occasionally use radiotherapy to treat individual areas of PPC that come back after surgery and chemotherapy.

Research into new ways of treating cancer is ongoing. Doctors are always looking for improved ways of treating cancer and they do this by using clinical trials. Many hospitals now take part in these trials. Before any trial is allowed to take place it must have been approved by an ethics committee, which checks that the trial is in the interest of patients.

You may be asked to take part in a clinical trial. Your doctor will discuss the treatment with you so you have a full understanding of the trial. You may decide not to take part, or withdraw from a trial, at any stage. You'll then receive the best standard treatment.

After treatment, you will have regular follow-up appointments with your specialist to monitor how you’re recovering. They can also pick up any new symptoms or difficulties. Follow-up usually includes a physical examination and you may have blood samples taken.

You may have many different emotions, including anger, resentment, guilt, anxiety and fear. These are all normal reactions and are part of the process many people go through in trying to come to terms with their condition.

Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. Our cancer support specialists can give you information about counselling in your area.