Peritoneal cancer is treated by a combination of surgery and chemotherapy. Surgery comprises of cytoreductive surgery (complete removal of the tumor from the peritoneal cavity). Hyperthermic intraperitoneal chemotherapy (HIPEC) may be performed along with cytoreductive surgery for some patients. A large proportion of patients will require systemic chemotherapy (the routine chemotherapy that is injected in the veins- intravenous chemotherapy). Some patients that are treated in this manner experience a prolonged survival or even get cured. For prolonged survival and/or cure, cytoreductive surgery with or without HIPEC is essential. Patients are rarely cured with chemotherapy alone. Contrary to this some patients with peritoneal cancer (like low grade PMP) can be cured with surgery alone.
Cyto means cells and reduction means removal. Cytoreductive surgery or CRS refers to removal of all the tumor from the peritoneal cavity. The aim of the surgery is to remove all the tumors from different regions of the abdominal cavity.
The surgery comprises removal of the areas of peritoneum that are involved by the tumor as well as some organs that are involved by tumor as shown in the adjacent figure. The extent of surgery depends on the extent of cancer spread- if the cancer is confined to few areas, only those areas will be removed whereas when the cancer is widespread, more extensive surgery is required.
HIPEC stands for Hyperthermic Intraperitoneal Chemotherapy. It is a surgical procedure that is performed in the operating room after all the tumor has been removed with the help of cytoreductive surgery.
HIPEC is performed only once, unlike the intravenous chemotherapy. The chemotherapy drugs that are used for HIPEC may be the same or different from those used for intravenous therapy. The choice of drug also depends on the site of the primary tumor (the tumor from which the peritoneal cancer has arisen).
PIPAC is a new method of giving chemotherapy to patients with advanced abdominal cancer, in which chemotherapy is given directly into the abdominal cavity.
Usually, the cancer directed therapy is administered intravenously (through the veins) as a drip. But this method of intraperitoneal chemotherapy is given directly into the abdominal cavity in patients who have cancer spread to the peritoneum, the lining of the abdominal cavity and its organs.
Cancer of the gastrointestinal tract are a common cause of peritoneal cancer. The highest incidence of peritoneal cancer is seen in patients with stomach cancer, followed by colorectal cancer, appendiceal cancer and cancer of the small intestine. Tumors of the liver, the pancreas and the gall bladder are other causes of peritoneal cancer arising from tumors of the digestive system.
There are some cancers that arise primarily from the peritoneum. The peritoenum is a thin membrane that is composed of a layer of cells called mesothelial cells and these cells can give rise to cancer. Cancers that arise from the peritoneum itself are called primary peritoneal cancers.