Peritoneal Cancer

Peritoneal cancer refers to cancer that develops within or, more commonly, has spread to the peritoneum from other organs within the abdomen (known as peritoneal metastases).

Last modified: December 20, 2021

Quick facts about peritoneal cancerQuick facts

  • Primary peritoneal cancer is a rare cancer which develops in the cells of the peritoneum. This condition is more common in women than men, and most people are over the age of 60 when they are diagnosed 
  • The peritoneum is made of epithelial cells, which is the same type of tissue that lines the ovaries 
  • Peritoneal cancer often acts and looks like ovarian cancer, causing similar symptoms and typically requiring the same types of treatments
  • Peritoneal metastases occur when other abdominal cancers such as appendix, stomach, bowel and ovarian cancers spread to the peritoneum. Peritoneal metastases are more common than primary peritoneal cancer

Types of peritoneal cancerTypes of peritoneal cancer

The peritoneum is the tissue that lines and protects the organs in the abdomen such as the stomach, bowel and ovaries. Cancers affecting the peritoneum include:  

Primary peritoneal cancer

This develops in the cells of the peritoneum (the tissue that lines and protects the organs in the abdomen such as the stomach, bowel and ovaries).

Peritoneal metastases

This refers to cancer that has spread to the peritoneum from other organs within the abdomen such as the appendix, bowel, stomach or ovaries. Peritoneal metastases are classified by their primary cancer. For example, ovarian cancer which has spread to the peritoneum is known as metastatic ovarian cancer.

Signs and symptoms of peritoneal cancerSigns and symptoms

As signs and symptoms for primary peritoneal cancer and peritoneal metastases can be similar to other common conditions, it’s important to see your GP or healthcare professional if you experience any of the symptoms below. Discussing anything concerning with your doctor as soon as possible can help give you peace of mind and offer the best chance of successful treatment if you receive a peritoneal cancer diagnosis.

Symptoms may include:

  • Bloating or an extended abdomen

  • Reduced appetite or a feeling of being full after small meals 

  • Pain in the abdomen or pelvic area 

  • Changes in urinating, more frequent or urgent need to pass urine 

  • Bleeding between periods or after menopause 

  • Changes in bowel habits such as constipation or diarrhoea 

  • Unexplained weight loss or loss of appetite

  • Tiredness 

  • Nausea and vomiting

Stages of peritoneal cancerStages

Primary peritoneal cancer is typically staged using the FIGO (International Federation of Gynaecology and Obstetrics) system, which helps doctors understand what your cancer looks like. Primary peritoneal cancer is often diagnosed at a more advanced stage – Stage III or Stage IV, because the symptoms in the early stages are often missed. 

Peritoneal metastases, or cancers that have spread from other areas of the body to the peritoneum, are considered advanced cancers and are typically classified as Stage IV based on the staging of their primary cancer type. 

The FIGO system, along with other tests, helps determine the stage of your primary peritoneal cancer using the guidelines below:

Stage IIIA

The cancer has spread to the lymph nodes outside of the peritoneum, or to the surface of the peritoneum outside of the pelvis.

Stage IIIB 

The cancer has grown into the peritoneum outside the pelvis and the cancer in the peritoneum is 2cm or smaller. The cancer may also have spread to lymph nodes outside the peritoneum.

Stage IIIC 

The cancer has spread to the peritoneum outside the pelvis and the cancer in the peritoneum is larger than 2cm. The cancer may also have spread to lymph nodes outside the peritoneum or to the surface of the liver or spleen.

Stage IVA

The cancer has caused a build-up of fluid in the lungs (pleural effusion).

Stage IVB

The cancer has spread to areas outside of the abdomen, such as the lungs or inside of the liver or spleen.

Treatment for peritoneal cancer

There are many different types of treatment for peritoneal cancer. Your treatment will depend on you and your cancer.

Frequently asked questions about peritoneal cancerFAQs

Is peritoneal cancer hereditary?

Some women are at increased risk of peritoneal cancer because they have a strong family history of ovarian cancer. They may also be at increased risk when a family member is known to have inherited a fault in a gene associated with breast or ovarian cancer.

In some cases, peritoneal cancer is caused mutations in the genes BRCA 1 (Breast Cancer 1) and BRCA 2 (Breast Cancer 2). Mutations in these genes also increase your risk of developing breast cancer and ovarian cancer.

Learn more about the role of BRCA1 and BRCA2 in developing breast and ovarian cancer.

What causes peritoneal cancer?

While similar to ovarian cancer, primary peritoneal cancer can occur even when the ovaries have been removed. The cause of primary peritoneal cancer is not fully known, however there are some factors which contribute to the risk of peritoneal cancer developing, including: 

  • Age – The risk for peritoneal cancer increases for people over 60 years
  • Certain lifestyle related factors – Such as being overweight, drinking alcohol and using Hormone Replacement Therapy (HRT)
  • Endometriosis – A condition where tissue that lines your uterus grows abnormally outside of the uterus
  • Family history – Including ovarian and peritoneal cancers, or a known BRCA gene mutation
How common are peritoneal metastases?

Peritoneal metastases are common for a number of different primary cancer types, including: 

  • Ovarian cancer – 46% of ovarian cancer patients develop peritoneal metastasis
  • Colorectal cancer – 7% of cases develop synchronous peritoneal metastasis
  • Gastric carcinoma – Peritoneal metastasis accounts for 14% of advanced gastric carcinoma diagnoses
  • Cancers located outside of the abdomen – Peritoneal metastasis in cancers located outside of the abdomen account for only 10% of cases, primarily metastatic breast cancer (41%), lung cancer (21%) and malignant melanoma (9%)


How is peritoneal cancer diagnosed?

There are many different tests that are used to diagnose peritoneal cancer. These may include an internal examination, ultrasound or CA125 blood test, followed by further tests such as a CT guided biopsy, peritoneal fluid analysis or tissue obtained from a surgical procedure such a laparoscopy or laparotomy. Genetic testing can be used to identify genetic mutations that are linked to cancer. 

What can I do to decrease my risk of peritoneal cancer?

Although the exact cause of peritoneal cancer is not known, there are some factors that can reduce your risk of developing cancer in general. These include:

  • Getting regular exercise – Cancer Australia recommends at least 30 minutes of moderate-intensity exercise each day
  • Reducing your alcohol intake – If you choose to drink, try to limit your alcohol intake to no more than two standard drinks a day
  • Eating a healthy, balanced diet – Eat a fibre-rich diet from grain and legume sources, as well as enjoy a variety of fruit (2 serves) and vegetables (5 serves) per day, limit your intake of salt, saturated fats, and avoid all processed meat
  • Quitting smoking – Cigarette smoking carries a higher risk of developing peritoneal cancer 
Where can I find out more about peritoneal cancer screening?

There is currently no national screening program for peritoneal cancer available in Australia.

Are there clinical trials available for peritoneal cancer that I can participate in?

Icon offers clinical trials across a wide range of cancer types and treatments. If you would like more information on participating in a clinical trial, please speak with your doctor who will be able to find a trial that might be right for you and your cancer. 

See current clinical trials delivered by Icon Cancer Centre.  


For a full list of references, click here.
  1. Cancer Research UK (2019). Primary peritoneal cancer. Retrieved 13 December 2021 from 
  2. WebMD Cancer Center (2021). Peritoneal cancer. Retrieved 13 December 2021 from 
  3.  Cancer Council Victoria (2021). Rare and less common cancers. Retrieved 13 December 2021 from 
  4. MacMillan Cancer Support (2018). Primary peritoneal cancer. Retrieved 13 December 2021 from 
  5. MacMillan Cancer Support (2018). Staging and Grading of Ovarian, Fallopian Tube or Peritoneal Cancer. Retrieved 13 December 2021 from
  6. Cancer.Net (2020). Ovarian, Fallopian Tube, and Peritoneal Cancer: Stages and Grades. Retrieved 13 December 2021 from
  7. 7. Desai JP, Moustarah F. Peritoneal Metastasis. [Updated 2021 Jun 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from:
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