From the Guidelines
Metastatic adenocarcinoma from a mullerian primary (endometrial cancer) can cause ascites through several mechanisms, including cancer cells irritating the peritoneal lining, blocking lymphatic drainage, and increasing vascular permeability, as noted in a recent study 1.
Mechanisms of Ascites Formation
The cancer cells that have spread to the peritoneal cavity can irritate the peritoneal lining, leading to increased production of peritoneal fluid. Additionally, these malignant cells can block lymphatic drainage, preventing normal reabsorption of peritoneal fluid. The cancer may also cause hypoalbuminemia due to malnutrition or liver dysfunction, reducing oncotic pressure and contributing to fluid accumulation.
- Tumor-induced inflammation can increase vascular permeability, allowing more fluid to leak into the peritoneal space.
- In some cases, direct tumor invasion of blood vessels or lymphatics can cause leakage of fluid.
- Metastatic lesions on the liver surface or portal hypertension from liver metastases may further exacerbate ascites formation, as discussed in the context of gastric cancer peritoneal metastasis 1.
Clinical Implications
This malignant ascites is a poor prognostic sign in endometrial cancer patients, indicating advanced disease with peritoneal spread.
- Management typically focuses on treating the underlying cancer with systemic therapy, such as paclitaxel-based combination regimens, which have shown a response rate >60% in first-line chemotherapy of advanced and recurrent endometrial cancer 1.
- Providing symptomatic relief through paracentesis for significant accumulations is also crucial in improving the patient's quality of life.
- The interaction between the niche peritoneal microenvironment and malignant ascites with tumor cells is an area of great interest from a cancer biology point of view, as perturbation of these interactions may form potential therapeutic targets 1.
From the Research
Causes of Ascites in Metastatic Adenocarcinoma
- Malignant ascites (MA) is a common complication in patients with advanced cancer, including those with metastatic adenocarcinoma from a known history of mullerian primary 2, 3.
- The pathophysiological mechanism of ascites formation involves increased vascular permeability and impaired fluid drainage through the lymphatic system, which can be caused by peritoneal carcinomatosis, portal hypertension, liver cirrhosis, and Budd-Chiari syndrome 4.
- In patients with metastatic adenocarcinoma, the accumulation of malignant cells in the peritoneal cavity can lead to the production of excess fluid, resulting in ascites 3, 5.
Symptoms and Treatment of Malignant Ascites
- Malignant ascites can cause significant symptoms, including abdominal distension, discomfort, and shortness of breath, which can impair the patient's quality of life 2, 5.
- Treatment options for malignant ascites include paracentesis, diuretics, peritoneovenous shunting, permanent catheters, and intraperitoneal chemotherapy, although none of these options have proven curative or free from side effects and complications 2, 3, 6.
- The management of malignant ascites should be individualized, taking into account the patient's symptoms, performance status, and life expectancy, as well as the potential risks and benefits of each treatment option 3, 5.
Prognosis and Future Directions
- Malignant ascites is a poor prognostic factor, with a median survival time of approximately 20 weeks from the time of diagnosis 3.
- Despite the availability of various treatment options, there is a need for further research into novel therapies for the management of malignant ascites, including experimental therapies such as intraperitoneal drug administration and cell-free and concentrated ascites reinfusion therapy 6, 4.