What is carcinomatosis?

Carcinomatosis: Definition and Management

Carcinomatosis is defined as the widespread dissemination of cancer cells throughout a body cavity, most commonly the peritoneum, characterized by multiple metastatic implants on serosal surfaces with potential for significant morbidity and mortality.

Types and Pathophysiology

Carcinomatosis most frequently refers to peritoneal carcinomatosis (PC), which involves the spread of malignant cells throughout the peritoneal cavity. The process occurs through several well-defined steps:

1. Detachment: Cancer cells detach from the primary tumor
2. Access: Cells gain access to the peritoneal cavity
3. Transport: Cells are transported via peritoneal fluid circulation
4. Attachment: Cells adhere to distant peritoneal surfaces
5. Invasion: Cells invade the subperitoneal space
6. Angiogenesis: New blood vessel formation supports tumor growth 1

Common Primary Sources

Carcinomatosis can originate from various primary tumors:

• Gastrointestinal tract: Colorectal, gastric, and pancreatic cancers
• Gynecologic organs: Ovarian, endometrial, and fallopian tube cancers
• Other sources: Appendiceal tumors, mesothelioma, and rarely other solid tumors

Clinical Presentation

Patients with carcinomatosis may present with:

• Abdominal distention and ascites
• Abdominal pain or discomfort
• Bowel obstruction
• Nausea and vomiting
• Weight loss and cachexia
• Fatigue and general malaise
• Paraneoplastic syndromes (in some cases)

Diagnosis

Diagnosis of carcinomatosis involves:

• Imaging: CT scan with contrast enhancement of the chest, abdomen, and pelvis is the primary imaging modality 2
• Paracentesis: Cytological examination of ascitic fluid when present
• Laparoscopy/Laparotomy: Direct visualization and biopsy of peritoneal implants
• Tumor markers: CA-125, CEA, and other markers depending on suspected primary 3

Prognostic Factors

Key factors affecting prognosis include:

• Primary tumor histology and grade
• Extent of peritoneal disease (measured by Peritoneal Cancer Index)
• Completeness of cytoreduction
• Patient's performance status
• Response to systemic therapy

Treatment Approaches

1. Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

For selected patients with limited peritoneal disease:

• Patient selection criteria: Good performance status, limited intraperitoneal tumor dissemination (PCI < 20), limited small bowel disease, and no extra-abdominal metastasis 2
• Procedure: Complete surgical removal of all visible tumor implants followed by heated chemotherapy perfusion of the peritoneal cavity
• Benefits: May improve progression-free and overall survival in carefully selected patients 2, 4

2. Systemic Chemotherapy

• Standard first-line treatment for most patients with carcinomatosis
• Regimens depend on primary tumor histology
• Limited efficacy for peritoneal disease compared to other metastatic sites

3. Palliative Care

• Focus on symptom management and quality of life
• Paracentesis for symptomatic ascites
• Pain management
• Nutritional support

Special Considerations

Colorectal Cancer Peritoneal Carcinomatosis

• Occurs in approximately 10-15% of colorectal cancer patients
• CRS-HIPEC may improve survival in selected patients with limited disease 2, 5
• Peritoneal Cancer Index (PCI) < 20 is associated with better outcomes

Gastric Cancer with Bone Marrow Carcinomatosis

• Rare but aggressive presentation with poor prognosis (less than one year)
• Characterized by widespread bone metastasis with hematological disorders
• Limited treatment options and poor response to standard therapies 6

Monitoring Response

• Regular clinical assessment
• Imaging (CT or MRI) every 3-6 months
• Tumor markers (CEA for colorectal cancer, CA-125 for ovarian cancer) 3
• Quality of life assessments

Conclusion

Carcinomatosis represents an advanced stage of cancer with significant impact on morbidity and mortality. While traditionally considered a terminal condition, modern approaches including CRS-HIPEC offer improved outcomes for carefully selected patients. Treatment decisions should be made by multidisciplinary teams with expertise in managing peritoneal surface malignancies.