Ascites and Cancer

What is ascites?

Ascites is the abnormal buildup of fluid in your belly (abdomen) that may cause swelling. It occurs when fluid builds up between the two layers of tissue, called the peritoneum, that cover the organs in your abdomen.

Causes of ascites in people with cancer

Certain types of cancer may cause ascites, especially advanced cancer that has spread to the peritoneal cavity. When the fluid in the abdomen has cancer cells, it’s called malignant ascites.

Cancer-related causes 

Ascites is most common in people with bladder, breast, colon, liver, lung, ovarian, pancreatic, stomach, or uterine cancers. Cancer cells can cause the peritoneum to leak too much fluid. 

Other causes of ascites

Ascites may also be caused by conditions that are not related to cancer. The most common cause of ascites is a liver disease called cirrhosis, kidney failure, chronic hepatitis, congestive heart failure, and infection. Ascites may develop slowly or rapidly, depending on what is causing it.

Signs and symptoms of ascites

Ascites may cause the following signs and symptoms: 

• abdominal swelling 
• bloating that causes an enlarged and painful belly
• weight gain and/or clothes that become tight
• shortness of breath and coughing, as more fluid collects

Additional symptoms of ascites may include appetite loss, constipation, fatigue, fever, nausea, vomiting, and swelling in your ankles or legs.

How is ascites diagnosed?

Your doctor will perform a physical exam. These procedures and tests may also be used to diagnose and determine what is causing ascites:  

• Scans: Often an imaging test such as ultrasound or a CT scan is used to see if the tissues and organs in your abdomen are surrounded by excess fluid. Sometimes an MRI may be advised.
• Paracentesis: This medical procedure uses a needle and catheter to remove ascitic fluid from your abdomen or belly area (the peritoneal cavity). The ascitic fluid is then analyzed. Paracentesis may be used to both diagnose the cause of the ascites and to provide relief from symptoms caused by ascites.
• Ascitic fluid analysis: After the fluid is collected using paracentesis, it is analyzed for cancer cells as well as infectious agents, proteins, and other substances to determine what is causing the buildup of fluid. If cancer cells are found in the fluid, it means that you have malignant ascites.

Treatment and management of ascites

Treatment for malignant ascites is based on the severity of your symptoms, as well as the type and extent of the cancer. Treatments include: 

• Cancer treatment: Sometimes cancer treatments, such as chemo, hormone therapy, or surgery, may be used to help lower symptoms caused by ascites. Cancer treatments work by shrinking the tumor so it does not produce the fluid that causes ascites.
• Diet: You may be advised to avoid foods high in sodium (salt), which can cause the body to retain fluid. Avoiding alcohol can also help minimize fluid retention. Your doctor or nurse will talk with you about food and drink choices that are best for you.
• Diuretics (sometimes called water pills): Medicines called diuretics are sometimes prescribed to help your body get rid of fluid in your abdomen and other areas of your body. These medicines cause the kidneys to make more urine, but they also come with side effects that your doctor will discuss with you. 
• Paracentesis: Paracentesis may be used to both diagnose and treat ascites, as explained in the section above. This procedure may provide temporary relief of symptoms, although it may need to be repeated if fluid builds up again. 
• Surgery: A shunt or catheter is inserted into your abdomen, where it remains in place to help drain the fluid, as needed. If a shunt or catheter is advised, your doctor will help you or your caregivers learn how to drain it at home.

Talking with your doctor about ascites

Tell your doctor or nurse if you notice abdominal swelling or other symptoms of ascites. They will work to determine the cause of swelling and talk with you about treatment options.

Questions to ask your provider about ascites:

• Is the cancer I have or the treatment I’m receiving likely to cause ascites? 
• What urgent problems should I call you about? 
• What treatment options do you recommend based on my symptoms?
• What are the advantages and disadvantages of the ascites treatment that you recommend for me?
• Will treating the cancer help the ascites to go away? 
• What are the chances that ascites may come back after treatment?

Ascites research and clinical trials

Research studies called clinical trials help find better ways to prevent and treat side effects such as ascites. Your doctor may have information about open clinical trials. You can also search for clinical trials supported by the National Cancer Institute at NCI-supported clinical trials and clinical trials supported by other organizations at ClinicalTrials.gov. For help finding a clinical trial, contact NCI’s Cancer Information Service.

Getting support if you have ascites

Side effects like ascites can be hard to deal with, both physically and emotionally. It’s important to ask for support from your health care team. They can help you prepare for and make it through difficult times. Learn more about ways to cope with cancer, including ways to adjust to daily life during cancer treatment. 
 
For family members and friends who are caring for someone with cancer, you may find these suggestions for caregivers to be helpful.