Peritoneal carcinomatosis happens when cancer cells from the ovary spread to the peritoneum. It is often present in advanced or recurrent epithelial ovarian cancers.

Peritoneal cancer is a rare, advanced cancer that develops in the peritoneum. It may begin in the peritoneum, a condition doctors call primary peritoneal cancer, or the spread of malignant cells from tumors in other organs like the ovaries may cause it. Doctors refer to the condition as peritoneal carcinomatosis when it occurs due to the spread of malignant cells.

Whether peritoneal cancer originates from the peritoneum or has spread from somewhere else, doctors consider it an advanced form of cancer. People with this illness have a poor outlook.

This article explores the link between peritoneal carcinomatosis and ovarian cancer. We also discuss who is at risk of the condition, its symptoms, causes, and more.

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The peritoneum is a thin layer of tissue made of epithelial cells. The parietal peritoneum lines the abdominal walls, while the visceral peritoneum wraps around and is continuous with the organs inside the abdominal cavity, including the ovaries.

It acts as a channel for nerves, lymphatics, and blood and supports the organs in the abdominal cavity. A small space filled with fluid between the two layers reduces friction and allows them and the organs they wrap to glide freely.

When peritoneal carcinomatosis develops with epithelial ovarian cancer, the ovarian tumor sheds cancer cells that float in the peritoneal fluid and attach to the peritoneal cells.

Around 75% of people with ovarian cancers already have peritoneal metastasis when a doctor diagnoses their cancer. At this stage, there is often an extensive spread of cancer cells that look like small, white-colored deposits on the inner surface of the parietal and visceral peritoneum.

However, a person may still have peritoneal cancer even if they remove their ovaries.

A person may also develop primary peritoneal cancer, which occurs when cancer originates from the tissue of the peritoneum. However, this is far less common than peritoneal carcinomatosis.

The peritoneum and the surface of the ovaries both consist of epithelial cells. This means cancers in these areas may look and act the same, cause similar symptoms, and require similar treatments.

Cancerous cells that spread from tumors in other organs covered by the peritoneum cause peritoneal carcinomatosis.

According to a 2021 review, the most common primary tumor locations include the ovaries, stomach, colon, and rectum, making people with these cancers the most at risk.

Primary peritoneal cancer is a rare form of cancer that mainly affects females. Its subtype, extraovarian primary peritoneal carcinoma, occurs exclusively in females. People with the condition have a mean age of 56–62 years.

The National Cancer Institute states that females with a family history of ovarian cancer are at risk for primary peritoneal and ovarian cancer. Other risk factors include:

Peritoneal cancers have different presentations depending on the extent of the disease. Doctors typically diagnose them in the late stages of cancers such as ovarian cancer due to vague symptoms.

These include:

The most common symptoms include abdominal distension and pain, while the most common signs include a noticeable abdominal mass and excess abdominal fluid, which doctors call ascites. Ascites and abdominal symptoms are present in 85% of people with peritoneal cancer.

The spread of cancer cells from tumors in other locations causes peritoneal carcinomatosis. The most common primary tumors that lead to the condition are ovarian, gastric, and colorectal.

Other tumors that can spread to the peritoneum include those in the:

The causes of primary peritoneal cancer are unknown. However, research suggests that germline mutations in the BRCA1 gene cause 17.6% of cases.

A doctor will ask about a person’s symptoms and medical and family history to diagnose peritoneal cancer. They will also perform a physical and pelvic examination to look for signs in the abdomen.

They may request several tests to help make a definite diagnosis. Imaging tests can help look for abnormal masses or granulations in the peritoneum. These tests include:

  • Ultrasound: This is typically the preliminary test doctors use to detect cancerous granulations. However, ultrasounds cannot identify those smaller than 2 centimeters in size. As well as granulations, they can detect other features such as ascites, adhesions, and lymphadenopathy, which is swelling of the lymph nodes.
  • CT scans: These can see granulations as small as 5 millimeters.
  • MRI scans: These are more sensitive than CT scans in detecting small peritoneal carcinomatosis. They are the modality of choice for diagnosing and staging the condition.
  • Lower or upper GI series: This involves a person swallowing a liquid called barium to outline the gastrointestinal structures on an X-ray.

Invasive procedures are essential to help determine the histological subtype of the tumor. These may include biopsies, in which a doctor performs a laparotomy or a laparoscopy and takes a tissue sample of one or more organs to check if it is cancerous.

A doctor may also perform a paracentesis, which involves removing fluid from the abdomen for examination under a microscope.

They may request a blood test to check for a CA-125 tumor marker. Peritoneal cancers often produce this protein, and a raised CA-125 can signify cancer. However, it is not limited to peritoneal cancers.

Learn more about tumor marker tests for ovarian cancer here.


Doctors consider primary peritoneal cancers and peritoneal carcinomatosis terminal illnesses, and people with these conditions have a poor outlook.

Peritoneal carcinomatosis has a median survival rate of 6 months, but this varies according to the stage. For people with stage 0, 1, and 2 peritoneal carcinomatoses, it is 5–10 months. For people with stage 3 and 4 cancers, it is 2 to 3.9 months.

Survival rates may also differ depending on the origin of the primary tumor:

  • pancreas: 2.9 months
  • gastric: 6.5 months
  • colorectal: 6.9 months

Learn more about the different stages of cancer here.

A multimodal treatment approach is the best option for peritoneal cancers. A person’s treatment may vary depending on the stage, grade, size, and location of the tumor, as well as the person’s age and overall health.

Treatments include:

  • Chemotherapy: This treatment uses anticancer drugs to stop the growth of cancer cells. As peritoneal cancers are usually at an advanced stage, doctors can use chemotherapy systemically to target cancer cells that have spread to other parts of the body. They can administer these intravenously into the bloodstream, or people can take them orally.
  • Cytoreductive surgery: This surgical procedure involves removing tumors in parts of the peritoneum, removing part or all of the peritoneum through a peritonectomy, and the total removal of affected organs or tissues.
  • Laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC): This involves pumping chemotherapy drugs heated higher than the average body temperature directly into the peritoneum for 2 hours after surgery. This occurs for 30–120 minutes and aims to enhance the effect of the drugs.
  • Early postoperative intraperitoneal chemotherapy: This is similar to HIPEC in that it involves delivering chemotherapy drugs into the peritoneum. Doctors perform the procedure on the first day after surgery.
  • Palliative surgery: This involves using surgery to relieve a person’s symptoms and improve their quality of life. Doctors use this when cancer has spread and is inoperable.

Doctors often treat primary peritoneal cancer the same way as advanced epithelial ovarian cancer, with the same type of chemotherapy drugs.

According to the National Institutes of Health (NIH), treatment may include:

  • Surgery followed by other treatment: A surgeon will try to remove all or as much cancer as possible, and they may remove the womb, ovaries, and fallopian tubes. Intravenous chemotherapy, intraperitoneal chemotherapy, or chemotherapy with targeted therapy usually follows surgery.
  • Chemotherapy and targeted therapy followed by surgery: Intraperitoneal chemotherapy may also follow this.
  • Chemotherapy as the sole treatment: Doctors may use this for people who cannot have surgery.
  • Targeted therapy with a PARP inhibitor: PARP inhibitors are a type of drug that prevents cancer cells from repairing and replicating.
  • Clinical trials of targeted therapy with a PARP inhibitor: Doctors may recommend a person tries a new cancer drug under clinical trial.

Peritoneal carcinomatosis can be challenging to diagnose early, especially when someone is already experiencing nonspecific symptoms from ovarian cancer. A person should talk with their doctor if they experience any new symptoms, including:

  • abdominal pain
  • feeling full after light meals
  • loss of appetite
  • rectal or vaginal bleeding

Learn more about commonly missed symptoms of ovarian cancer here.

Peritoneal carcinomatosis is a secondary form of peritoneal cancer that occurs when cancer cells spread from distant tumor sites, including the ovaries. It happens when the cancer cells travel through the peritoneum, a lining that covers the organs in the abdomen.

Like ovarian cancer, its symptoms are vague and nonspecific, meaning doctors often diagnose this type of cancer at a late stage. Most people who receive a diagnosis of advanced ovarian cancer already present with peritoneal carcinomatosis. Doctors associate it with advanced cancer, and people with the condition have a poor outlook.