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For a long time, peritoneal cancer was thought to be a very rare disease. This perception may still be true for specific subtypes of peritoneal cancer, such as malignant mesothelioma and pseudomyxoma peritonei (PMP). However, every year hundreds of thousands of patients around the world are diagnosed with peritoneal cancer originating from a primary tumor located elsewhere in the body, such as colon cancer, gastric cancer or ovarian cancer.


Rare subtypes

Malignant mesothelioma and pseudomyxoma peritonei are rare subtypes of peritoneal cancer, which affect approximately one to two people per one million people each year.

10 - 30%

Common causes of peritoneal cancer

Peritoneal cancer from colon cancer is much more common: At least 10% of patients with colon cancer will develop peritoneal cancer at some point in their disease. For gastric cancer, this percentage is even higher, with estimates as high as 30% of the patients. Worldwide, hundreds of thousands of patients will develop peritoneal cancer each year as a result of a tumor elsewhere in the body.

6 weeks

6 weeks – 6 months Life expectancy

If left untreated, the median survival time for peritoneal cancer patients may be as short as six weeks for patients who have pancreatic cancer or six months for patients who have colon cancer. Survival time may be considerably longer when adequate treatment is provided.

What is peritoneal cancer?

All of the organs in the abdominal cavity – such as the stomach and the intestine – and the abdominal wall are covered with a thin layer of cells. This layer is called ‘the peritoneal lining’ or ‘the peritoneum’. Unfortunately, the peritoneum can be invaded by cancer cells. This condition is most commonly referred to as “peritoneal cancer,” but it has also been called peritoneal surface malignancy (“PSM”), peritoneal carcinomatosis, peritoneal metastases or pseudomyxoma peritonei (“PMP”).

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Peritoneal cancer is difficult to diagnose, especially because it often cannot be detected by radiological imaging. As a result, the incidence of peritoneal cancer has long been underestimated, and it was considered to be a very rare disease. Even today, the reported incidence rates of peritoneal cancer vary widely, but increasing awareness has led to increases in the reported incidence of peritoneal cancer in more recent studies. However, the “true” incidence is potentially higher because autopsy studies have found undetected peritoneal metastases in many cancer patients.

Learn more on incidence of peritoneal cancer


In early stages, peritoneal cancer may not cause symptoms at all. Frequently, peritoneal cancer is even discovered by complete surprise during surgery for the primary tumor. Even during the asymptomatic stage, the disease may already be widespread and advanced, which supports the reputation of peritoneal cancer as a “silent killer”.

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Peritoneal cancer is usually very difficult to diagnose, but it may be discovered during the examination or the surgical treatment of the primary tumor or when a patient develops symptoms related to peritoneal cancer. There is no specific examination that is ideal for diagnosing peritoneal cancer. Most often, a combination of examinations is required.

Learn more on diagnosing peritoneal cancer

Treatment options

Not so long ago, treating patients with peritoneal cancer was thought to be a futile endeavor. At that time, these patients typically lived for only a few weeks to a few months after diagnosis depending on the severity of the disease, condition of the patient and the origin of the peritoneal cancer.

Over the last two decades, this outlook has changed and many hospitals around the world now offer treatment for select patients with peritoneal cancer. The treatment is challenging and requires medical professionals with specific expertise in peritoneal cancer.

Learn more on treatment options for peritoneal cancer