What Is Ascites and When Does It Happen in Cancer?

Ascites is a build up of fluid inside the abdominal cavity. When it’s linked to cancer, it’s called malignant ascites. It happens most often in ovarian, liver, colorectal, stomach, pancreatic and breast cancer, usually when the disease has spread to the abdominal lining. The fluid builds up because the tumour irritates the peritoneum, blocks lymphatic drainage or damages the liver’s protein balance. Treatment focuses on draining the fluid, controlling the underlying cancer and managing symptoms.

According to Prof. Dr. Sandeep Nayak, Surgical Oncologist in India, “Ascites is one of the clearest signs that cancer has reached the peritoneal cavity, and it changes how we think about treatment. Draining the fluid relieves symptoms quickly, but the real focus has to be on treating the cancer driving it, otherwise the fluid keeps coming back.”

Several mechanisms can trigger it, and most are tied to cancer behaviour.

• Peritoneal spread: When cancer cells reach the abdominal lining, they cause inflammation and leaky blood vessels. Fluid and protein pour into the cavity instead of staying in circulation.
• Liver involvement: Cancer in or around the liver pushes up portal pressure. The liver also makes less albumin, which is what normally holds fluid in the bloodstream.
• Lymph blockage: Tumours can block lymphatic drainage channels in the abdomen. Without proper drainage, fluid that would normally be reabsorbed builds up instead.
• Tumour signals: Some tumours release chemicals that increase blood vessel leakiness. The result is more fluid escaping into the peritoneal space.

For patients whose cancer can be surgically controlled, robotic cancer surgery brings precise tumour removal that often reduces the fluid burden meaningfully.

Diagnosis is straightforward. Treatment is layered, depending on cause and stage.

• Paracentesis: A small needle drains fluid from the abdomen. It relieves symptoms in around 90 percent of patients. The fluid is also tested for cancer cells under cytology.
• Diuretics added: Tablets like spironolactone or furosemide help the kidneys clear extra fluid. Works better when liver involvement is part of the cause.
• Cancer directed: Chemotherapy, targeted therapy or HIPEC can shrink the underlying cancer. When the cancer responds, ascites often slows or stops returning.
• Long term drains: When fluid keeps coming back quickly, a tunnelled catheter lets the family drain at home. Reduces hospital visits significantly.

For patients whose peritoneal cancer is being managed with cytoreductive surgery, our blog on HIPEC surgery walks through outcomes and what survival actually depends on.

Dr. Sandeep Nayak has spent 24 years in surgical oncology. He holds DNB qualifications in Surgical Oncology and General Surgery and trained further with a fellowship in Laparoscopic and Robotic Onco Surgery. He approaches ascites as a sign that needs both immediate relief and root cause treatment, combining paracentesis, diuretics and cancer directed therapy including HIPEC and PIPAC where appropriate.

That dual focus on comfort and underlying disease is what separates real ascites management from symptomatic drainage alone. Every case at MACS Clinic goes through tumour board review, where the treatment plan is set together. Call +91 8104310753 to book your consultation.

Disclaimer: This blog is for informational purposes only and is not a substitute for professional medical advice.