Peritoneal Carcinomatosis
Cancer that has spread to the lining of the abdomen
Quick Facts
- Type: Advanced (metastatic) cancer
- Affected area: Peritoneum (lining of the abdomen)
- Common sources: Ovary, colon, stomach, appendix cancers
- Common sign: Abdominal swelling from fluid (ascites)
Overview
The peritoneum is the thin membrane that lines the inside of the abdomen and drapes over the organs within it. Peritoneal carcinomatosis means that cancer has spread to and grown on this membrane, usually as small deposits scattered across its surface. It is a form of metastatic (advanced) cancer.
In most cases, the cancer started in another abdominal or pelvic organ, such as the ovary, colon, stomach, or appendix, and then seeded onto the peritoneum. It often causes a buildup of fluid in the abdomen, called ascites, leading to swelling and discomfort. Treatment depends heavily on the original cancer, the extent of spread, and the person's overall health, and is part of a broader cancer care plan guided by a specialist team.
Symptoms
Symptoms often develop gradually and can be vague at first, which is one reason peritoneal spread is sometimes found at a later stage.
- A swollen or distended abdomen, frequently from fluid buildup (ascites)
- Abdominal discomfort, bloating, or a feeling of fullness
- Loss of appetite and unintended weight loss
- Nausea, vomiting, or changes in bowel habits
- Fatigue and a general decline in well-being
- Signs of bowel obstruction if deposits press on the intestines
New or worsening abdominal swelling, severe pain, or symptoms of bowel obstruction should be evaluated promptly.
Causes
Peritoneal carcinomatosis develops when cancer cells reach and grow on the peritoneum. The most common originating cancers include:
- Ovarian cancer: Frequently spreads within the abdomen to the peritoneum.
- Colorectal cancer: Can seed the peritoneal surface.
- Stomach (gastric) cancer: A recognized source of peritoneal spread.
- Appendix and pancreatic cancers: Including some rare appendix tumors.
- Other cancers: Less commonly, cancers from outside the abdomen.
Cancer cells can reach the peritoneum by shedding directly from a nearby tumor, through the lymph system, or via the bloodstream.
Risk Factors
- An existing cancer of the ovary, colon, stomach, appendix, or pancreas
- Advanced-stage abdominal or pelvic cancer
- Tumors that have grown through the wall of an organ
- Previously treated abdominal cancer that has recurred
Diagnosis
Diagnosis involves confirming peritoneal involvement and identifying the source cancer:
- Imaging: CT, MRI, or PET scans can show peritoneal deposits and fluid.
- Fluid sampling: Removing and testing abdominal fluid (ascites) can reveal cancer cells.
- Biopsy: A tissue sample, sometimes taken during a minimally invasive procedure (laparoscopy), confirms the diagnosis and the cancer type.
- Tumor markers and other tests: Blood tests and further imaging help find the primary cancer if it is not already known.
Treatment
Treatment is highly individual and depends on the original cancer, how widespread the deposits are, and the person's overall health. It is always guided by a cancer specialist team.
- Chemotherapy: Often the mainstay, tailored to the type of cancer.
- Surgery with heated chemotherapy (in selected cases): For some cancers, removing visible deposits and bathing the abdomen in warmed chemotherapy may be considered at specialist centers.
- Targeted and other therapies: Depending on the cancer type and its features.
- Managing fluid (ascites): Draining fluid can relieve abdominal swelling and discomfort.
- Supportive and palliative care: Controlling symptoms and maintaining quality of life is an important part of treatment.
Prevention
- Peritoneal carcinomatosis is a complication of cancer rather than a preventable condition on its own
- Cancer screening and early detection can help find and treat tumors before they spread
- Following recommended treatment and surveillance for a known cancer helps detect spread early
- Reporting new abdominal symptoms during cancer follow-up allows prompt evaluation
When to See a Doctor
If you have or have had cancer, contact your care team for new or worsening abdominal swelling, persistent bloating, abdominal pain, loss of appetite, or unexplained weight loss. Seek urgent care for symptoms of bowel obstruction, such as severe abdominal pain, persistent vomiting, and an inability to pass stool or gas, or for any sudden, severe abdominal pain, as these need prompt assessment.
Frequently Asked Questions
What does peritoneal carcinomatosis mean?
It means cancer has spread to the peritoneum, the membrane lining the abdomen, usually as scattered deposits on its surface. It is a form of metastatic cancer, most often arising from a tumor that began in an abdominal or pelvic organ such as the ovary, colon, or stomach.
What are the common symptoms?
Common symptoms include a swollen abdomen from fluid buildup (ascites), bloating, abdominal discomfort, loss of appetite, weight loss, and nausea. If deposits press on the bowel, they can cause symptoms of obstruction. Symptoms often develop gradually.
How is peritoneal carcinomatosis treated?
Treatment depends on the original cancer and how widespread the deposits are, and is guided by a specialist team. It may include chemotherapy, in selected cases surgery combined with heated chemotherapy at specialist centers, targeted therapies, draining fluid for comfort, and supportive care.
Why does it cause fluid in the abdomen?
Cancer deposits on the peritoneum can interfere with the normal balance of fluid in the abdominal cavity, leading to a buildup called ascites. Draining this fluid can relieve the swelling and discomfort, and the underlying cancer is treated to help control it.
References
- National Cancer Institute (NCI). Metastatic Cancer.
- MedlinePlus, U.S. National Library of Medicine. Ascites.
- Mayo Clinic. Ovarian cancer - Symptoms and causes.
- American Cancer Society. Understanding advanced and metastatic cancer.