Peritoneal carcinomatosis is not technically a type of cancer but a serious condition that affects fewer than 1% of patients with metastatic cancer. It’s often incurable, inoperable and resistant to chemotherapy.
Peritoneal carcinomatosis may cause inflammation, malignant adhesions and enlargement of the abdomen, all of which may be painful.
Peritoneal carcinomatosis is just one form of this type of condition — specific to the abdominal cavity. Other types of carcinomatosis impact the thin tissues lining the brain, spinal cord and lungs. Although it is very difficult to treat, new therapies, pioneered and under study at City of Hope®, have had promising results for some patients.
This article covers the basics of peritoneal carcinomatosis, including:
If you or a loved one is concerned about possible signs or symptoms of cancer and would like an initial appointment or a second opinion, call us 24/7 at 877-460-4673.
What Is Peritoneal Carcinomatosis?
Peritoneal carcinomatosis develops when cancer cells from one part of the body or organ system spread to the thin layer of tissue (called the peritoneum) that lines the abdominal organs.
In most cases, carcinomatosis is a sign that the cancer is getting worse and may not be curable. The most common types of cancer that lead to peritoneal carcinomatosis include colorectal, gastrointestinal and gynecological malignancies.
“The way I explain it to the patients is, the peritoneum is like a cellophane wrap — a very thin layer that covers the surface of your organs and also the lining,” says Hatem Halabi, M.D., F.A.C.S., a surgical oncologist at City of Hope Cancer Center Chicago.
Why Is It Hard to Treat?
Peritoneal carcinomatosis is often difficult to treat because it may involve multiple cancer cells — and not a single solid tumor — throughout the abdominal cavity lining.
That’s why surgery is rarely effective. Also, the peritoneum itself does not have many blood vessels to deliver drugs that reach and kill these cells, so intravenous (IV) chemotherapy and other medications aren’t usually effective treatment approaches.
Dr. Halabi adds that the peritoneum covers “a wide surface” in the abdominal cavity.
“Usually when cancer spreads to the peritoneum, that means patients have a worse prognosis, and these patients don’t fare as well as when cancer metastasis spreads, for example, to the liver or to the lung,” he says. “That's what makes it hard to treat and eradicate.”
Peritoneal Carcinomatosis Treatment
Systemic chemotherapy and other systemic treatments are still the first-line therapy for peritoneal carcinomatosis. But three therapeutic approaches are offered to a select group of patients as detailed below.
Cytoreductive surgery: This procedure, also known as debulking, involves the surgical removal of visible cancerous tumors and nearby tissues from the abdomen, where the cancer has spread.
It is frequently combined with hyperthermic (or heated) intraperitoneal chemotherapy (HIPEC), which bathes the area with heated chemotherapy, to increase its effectiveness.
HIPEC: This technique involves the immediate delivery of a heated, sterilized chemotherapy solution to the peritoneum, immediately after aggressive surgery, in a single procedure. Performed by a board-certified surgical oncologist, HIPEC enhances the effects of the drugs and improves absorption by tumor cells.
After surgery, chemotherapy heated to about 108 degrees Fahrenheit is circulated in the abdomen for 60 to 90 minutes. Afterward, the chemotherapy is drained as part of the operation, which may take more than six hours to complete.
HIPEC allows for higher doses of treatment than standard chemotherapy administered through a vein and is designed to reduce systemic exposure to chemotherapy and reduce side effects. It targets smaller or even microscopic tumors surgeons may not remove because they are not visible or may not be accessible.
Malignant cells subjected to high heat also don’t repair themselves the way healthy cells can. Combining heat with chemotherapy creates an especially lethal environment for cancer cells.
In combination, cytoreductive surgery and HIPEC has been found to be an effective treatment for some patients with advanced peritoneal carcinomatosis.
PIPAC: This newer therapeutic method delivers chemotherapy directly into the abdominal cavity. PIPAC allows for more precise treatment of tumors in the peritoneum than systemic chemotherapy, which is ineffective because there are not enough blood vessels in this area to deliver traditional anti-cancer drugs.
PIPAC also offers several advantages over other treatments:
- It is a short, minimally invasive procedure, so patients are monitored overnight and discharged within a day or two.
- The aerosolization and pressurization result in better distribution to the abdominal cavity.
- It requires lower levels of chemotherapy — only 10-20% of the typical chemotherapy dose — which makes it easier for patients to tolerate.
- Treatment can be delivered more than once, providing multiple opportunities for tumor staging and assessment of the patient’s response.
For all these reasons, it’s a strong option for patients with advanced disease, including colorectal and gastric cancers, who are unable to undergo surgical debulking or HIPEC.
PIPAC is still undergoing study in clinical trials, with City of Hope conducting the first PIPAC trial in the United States.
Dr. Halabi explains that determining which treatment is best depends on the origin of the patient’s primary tumor and other factors.
“Cytoreductive surgery will play a role in certain select groups of patients to basically remove all visible disease, if feasible,” he says. “HIPEC is usually combined with cytoreductive surgery, performed usually only after the tumors have been removed, and to a certain extent, is still investigational. PIPAC is still mainly an investigational treatment being studied that should be done only in a clinical trial setting.”
Dr. Halabi adds that City of Hope takes a “precision medicine” approach to treating peritoneal carcinomatosis — “tailor-making the kind of treatment to a patient's particular needs, goals and situation.”
“City of Hope is at the forefront of research when it comes to patients with peritoneal carcinomatosis and for trials like the PIPAC study,” Dr. Halabi says.
He adds that City of Hope’s doctors have deep expertise and experience in treating the condition.
“In Chicago, we have done more than 500 HIPECs, so we have done a lot of those,” he says. “And I know, from a research perspective, City of Hope has done lots of PIPACs.”
If you or a loved one is concerned about possible signs or symptoms of cancer and would like an initial appointment or a second opinion, call us 24/7 at 877-460-4673.