Peritoneal cancer is a rare cancer. It develops in a thin layer of tissue that lines the abdomen. It also covers the uterus, bladder, and rectum. Made of epithelial cells, this structure is called the peritoneum. It produces a fluid that helps organs move smoothly inside the abdomen.
Sometimes people confuse peritoneal cancer with intestinal or stomach cancer. And it's not the same thing as cancers that spread (metastasize) to the peritoneum. Peritoneal cancer starts in the peritoneum. So it is called primary peritoneal cancer.
Peritoneal cancer acts and looks like ovarian cancer. This is mainly because the surface of the ovaries is made of epithelial cells, as is the peritoneum. Therefore, peritoneal cancer and a type of ovarian cancer cause similar symptoms. Doctors also treat them in much the same way.
Despite its similarities with ovarian cancer, you can have peritoneal cancer even if your ovaries have been removed. Peritoneal cancer can occur anywhere in the abdominal space. It affects the surface of organs contained inside the peritoneum.
The causes of peritoneal cancer are unknown. However, there are different theories about how it begins. Some believe it comes from ovarian tissue implants left in the abdomen during fetal development. Others think the peritoneum undergoes changes that make it more like the ovaries.
Risks of Peritoneal Cancer
Primary peritoneal cancer is more common in women than in men. Women at risk for ovarian cancer are also at increased risk for peritoneal cancer. This is even more likely if you have the BRCA1 and BRCA2 genetic mutations. Older age is another risk factor for peritoneal cancer.
Peritoneal Cancer Symptoms
Just as with ovarian cancer, peritoneal cancer can be hard to detect in the early stages. That's because its symptoms are vague and hard to pinpoint. When clear symptoms do occur, the disease has often progressed. Then, symptoms resemble those of ovarian cancer. Many of these symptoms are due to buildup of fluid (ascites) in the abdomen. Peritoneal cancer symptoms may include:
Abdominal discomfort or pain from gas, indigestion, pressure, swelling, bloating, or cramps
In addition to asking about symptoms, your doctor will review your medical history and conduct a physical exam, which involves examining for abnormalities in these areas:
Colon and rectum
Tests you may have include:
Ultrasound. High-frequency sound waves produce a picture called a sonogram.
CA-125 blood test. This test measures levels of a chemical in the blood called CA-125. If levels are high, peritoneal or ovarian cancer is more likely present. But CA-125 can be high for other reasons. So this test cannot confirm a diagnosis of these cancers.