Primary peritoneal cancer

Primary peritoneal cancer (PPC) is a rare cancer that starts in the peritoneum. This is the membrane which lines the inside of the abdomen (tummy), clinging to and covering all the organs in the abdomen (for example the intestines, the liver, and the stomach). This membrane helps to protect the contents of the abdomen. It also produces a lubricating fluid, which helps the organs to move smoothly inside the abdomen as we move around. A PPC can start in any part of this membrane, usually in the lower part of the abdomen (pelvis).
The peritoneum is made up of cells called epithelial cells. These cells also line the ovaries. Although the lining tissue in the ovaries forms only a small part of the ovaries themselves, this is where most ovarian cancers start. Ovarian cancers commonly spread from the ovaries to the peritoneum. For this reason, primary peritoneal cancer can only be diagnosed in women once ovarian cancer has been excluded.
Primary peritoneal cancer and epithelial ovarian cancer (the commonest type of ovarian cancer) behave very similarly, and are treated in the same way.