If the patient has recent labs including a hepatic function panel, the serum-ascites albumin gradient (SAAG) can be calculated.
The SAAG is calculated by subtracting the ascitic albumin from the serum albumin value. If the SAAG is 1.1 g/dL or more, it is indicative of portal hypertension, which is seen in extensive hepatic metastases and portal vein thrombosis. A SAAG value of less than 1.1 g/dL does not indicate portal hypertension and is typically associated with peritoneal carcinomatosis.
Therefore, the SAAG value does not definitively rule cancer in or out, but may help guide future workup and management.
Patients with malignant ascites may require repeat paracentesis for symptomatic relief. After removing fluid, intravenous albumin is sometimes given in order to prevent paracentesis-induced circulatory dysfunction (PICD). PICD occurs when the renin-angiotensin system is activated after removal of ascitic fluid, resulting in relative hypoperfusion of the kidneys.
Most of the data evaluating the need for post-paracentesis albumin administration is within cirrhotic patients (who have resulting portal hypertension) and not in patients with malignant ascites.
Patients with malignant ascites can sometimes have portal hypertension and “functional” cirrhosis based on tumor burden, which can make the decision on whether or not to administer albumin challenging.
There is currently a lack of quality data examining the role of albumin administration in this subtype of patients with malignant ascites and may represent an interesting topic to research in the future.
- Runyon BA, Montano AA, Akriviadis EA, et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites. Ann Intern Med. 1992;117(3):215-220.
- Runyon BA, Hoefs JC, Morgan TR. Ascitic fluid analysis in malignancy-related ascites. Hepatology. 1988;8(5):1104-1109.
- Becker G, Galandi D, Blum HE. Malignant ascites: systematic review and guideline for treatment. Eur J Cancer. 2006;42(5):589-597.
- Ayantunde AA, Parsons SL. Pattern and prognostic factors in patients with malignant ascites: a retrospective study. Ann Oncol. 2007;18(5):945-949.