What are the primary recommendations for pseudomyxoma peritonei (PMP) palliative care?

Palliative Care for Pseudomyxoma Peritonei

For patients with pseudomyxoma peritonei (PMP) requiring palliative care, aggressive surgical debulking remains the primary intervention even in advanced disease, as it provides immediate symptom control with acceptable morbidity and can achieve prolonged survival despite incomplete tumor removal. 1, 2

Primary Palliative Intervention: Surgical Debulking

Palliative debulking surgery should be offered as first-line treatment for symptomatic PMP patients who are not candidates for curative cytoreductive surgery (CRS) with HIPEC. 1, 3

Surgical Approach and Safety Profile

• Omentectomy is the primary palliative procedure (performed in 93% of cases), with additional procedures added based on symptom burden and disease distribution. 1
• Median operative time is approximately 88 minutes, with median hospital stay of 8 days and 30-day mortality of 0%. 1
• Complication rates are acceptable at 15%, with most being mild (Clavien-Dindo grade II), making this a safe palliative option. 1
• Median survival after palliative debulking is 3.0 years, demonstrating meaningful disease control despite non-curative intent. 1

Rationale for Aggressive Palliative Surgery

The unique natural history of PMP justifies aggressive surgical palliation even when complete cytoreduction is impossible. PMP progresses slowly with tumor accumulation at specific anatomic sites (greater omentum, diaphragmatic surfaces, pelvis) due to the "redistribution phenomenon," while relatively sparing the small bowel. 2 This predictable pattern allows targeted debulking to relieve symptoms effectively.

Even extensive disease with high peritoneal carcinomatosis index (PCI) can benefit from maximum tumor debulking, resulting in long-term survival unique to PMP compared to other peritoneal malignancies. 2

Symptom Management Priorities

Cardinal Symptoms Requiring Intervention

The primary symptoms requiring palliative intervention in PMP are abdominal distension (most common), abdominal pain, and weight loss. 4, 5

• Abdominal distension results from mucinous ascites and peritoneal tumor accumulation, best managed by surgical debulking rather than repeated paracentesis. 2, 5
• Pain control should follow standard cancer pain management principles, with consideration of the complex nociceptive and inflammatory components specific to peritoneal disease. 6
• Weight loss and anorexia reflect advanced disease burden and warrant nutritional support alongside tumor debulking. 4

Adjuvant Palliative Therapies

Intraperitoneal Chemotherapy and Radioisotopes

Following palliative debulking, intraperitoneal chemotherapy (p=0.009) and radioisotopes (p=0.0043) are both effective in prolonging the time to symptomatic recurrence. 3

• These regional therapies should be considered after surgical debulking to extend the symptom-free interval, even when complete cytoreduction is not achieved. 3
• Systemic chemotherapy has not demonstrated benefit in PMP and is associated with worse survival outcomes (p=0.005), likely reflecting selection of patients with more aggressive disease. 3

Prognostic Factors Guiding Palliative Decisions

Adverse Predictors of Survival

Key clinical factors predicting worse outcomes include weight loss (p=0.001), abdominal distention (p=0.004), diffuse disease (p=0.038), and invasion of other organs (p=0.04). 3

• Patients presenting with these features still benefit from palliative debulking but require realistic prognostic discussions. 3
• Despite tumor progression occurring in 76% of patients, 5-year survival reaches 53% and 10-year survival 32%, reflecting the indolent nature of PMP. 3

Critical Pitfalls to Avoid

• Do not rely on repeated paracentesis for mucinous ascites management—this provides only temporary relief and should be replaced by early surgical debulking before disease becomes loculated or the bowel becomes fixed. 6, 2
• Do not delay palliative surgery in symptomatic patients based on extent of disease alone—PMP's unique biology allows meaningful palliation even with very extensive peritoneal involvement. 2
• Do not confuse PMP with other peritoneal malignancies when counseling patients—the natural history is distinctly more favorable, with slow progression allowing multiple palliative interventions over years. 3, 2
• Ensure appendectomy is performed even if the appendix appears grossly normal, as appendiceal mucinous neoplasms are the source in the vast majority of cases and pathologic examination is essential. 5

When Palliative Surgery Is Not Feasible

For very frail patients unable to tolerate surgery, repeated aspiration or indwelling pleural/peritoneal drainage may be the most practical approach, though this is suboptimal. 6

• Early involvement of palliative care specialists is recommended for symptom management following standard cancer care guidelines. 6
• Low-dose oral morphine may reduce dyspnea and associated anxiety in patients with respiratory compromise from diaphragmatic disease. 6