Ascites (uh-SIGH-tees) refers to excess fluid in the abdomen. This fluid collects in the space within the walls of the abdomen, between the abdominal organs. It is common in patients with liver disease and cirrhosis, though patients with cancer can also develop ascites.
What Causes Ascites in Patients With Cancer?
Two main reasons cause ascites in patients with cancer. First, cancer can spread to the lining of the organs—the peritoneum—and make it leaky, causing malignant ascites. Second, cancer can spread to the liver and cause increased pressure in the liver. Certain cancers, such as ovarian, pancreatic, liver, and colon cancers, are more likely to cause ascites.
What Are the Symptoms and Complications of Ascites?
Patients can experience swelling and tightness of the abdomen, feeling full when eating, nausea, or shortness of breath. The fluid can become infected, which can cause fever and pain.
How Do We Diagnose Ascites?
Ascites may be suspected because of symptoms and examination findings. Ultrasonography is often the first step. A computed tomography or magnetic resonance imaging scan can provide more information about the underlying cancer. A needle and syringe may be used to remove some of the fluid in a procedure called a paracentesis. Checking this fluid for white blood cells, blood, cancer cells, and bacteria can help determine the cause and diagnose an infection, if present. Finding cancer cells in the fluid confirms a diagnosis of malignant ascites as opposed to liver damage or other causes.
How Do We Treat Ascites in Patients With Cancer?
Treatment depends on the cause (cancer spread or liver damage); the severity of symptoms; the cancer type, extent of spread, and suitability of anticancer treatments; and patient preferences.
If patients have few symptoms, specific treatment may not be needed. If liver damage is the cause, patients may be prescribed a diuretic (water pill) to increase water in the urine or asked to cut down the amount of salt in their food.
If patients have severe tightness in the abdomen or shortness of breath, a paracentesis can remove several liters of fluid in minutes. A hollow needle is inserted into the fluid and connected to a bottle via tubing. This can provide immediate relief, though fluid can return, often in days to weeks. The procedure can be repeated if needed.
If fluid keeps recurring, an alternative may be to place an indwelling flexible catheter into the fluid cavity that can open to the outside through the skin and be drained using a valve. Patients or caregivers can typically be trained to do this at home.
For most patients, development of malignant ascites signals advanced, incurable cancer. Often, there may be no suitable cure for the underlying cancer. However, for some cancers (eg, ovarian cancer, lymphoma), treating the underlying cancer with chemotherapy and/or surgery may control ascites as well.
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Published Online: December 19, 2019. doi:10.1001/jamaoncol.2019.5409
Conflict of Interest Disclosures: Dr Beg reported receiving personal fees from Array BioPharma, Boston Biomedical, Bristol-Myers Squibb, Genentech, and Ipsen, and grants from Merck outside the submitted work. No other disclosures were reported.