What is the management of appendiceal cancer?

Management of Appendiceal Cancer

The management of appendiceal cancer depends primarily on tumor size, histological subtype, and disease extent, with surgical resection being the cornerstone of treatment for localized disease. 1, 2

Initial Assessment and Diagnosis

• Complete evaluation with multiphasic abdominal-pelvic CT or MRI to assess local and distant extension
• Measurement of tumor markers (Chromogranin A for neuroendocrine tumors)
• Histological confirmation if diagnosis is not established

Surgical Management by Tumor Type

Appendiceal Carcinoid (Neuroendocrine) Tumors

Size-based approach:

• ≤2 cm and confined to appendix: Simple appendectomy is sufficient 1
• >2 cm: Right hemicolectomy with regional lymphadenectomy 1
• 1-2 cm with poor prognostic features: Consider more aggressive treatment 1
  • Poor prognostic features include:
    • Lymphovascular invasion
    • Mesoappendiceal invasion
    • Atypical histologic features

Appendiceal Adenocarcinoma

• Right hemicolectomy with regional lymphadenectomy is the standard approach 3
• These tumors have a prognosis similar to other colon adenocarcinomas 3

Mucinous Cystadenocarcinoma

• Right hemicolectomy is recommended 2, 3
• If pseudomyxoma peritonei is present, aggressive surgical debulking is indicated 3

Adenocarcinoid (Goblet Cell Carcinoid)

• Right hemicolectomy is recommended 1, 3
• Consider concomitant oophorectomy in postmenopausal women due to predilection for ovarian metastases 3

Management of Metastatic Disease

Resectable Metastases

• Hepatic metastases: Consider curative surgical resection 2
• Peritoneal metastases: Cytoreductive surgery with heated intraperitoneal chemotherapy (HIPEC) 4, 5

Unresectable Metastases

• Local-regional therapies for hepatic metastases:
  • Transarterial chemoembolization (TACE)
  • Transarterial radioembolization (TARE) 2
• Systemic chemotherapy based on histological subtype:
  • For high-grade tumors: 5-FU-based regimens (similar to colorectal cancer) 1, 4
  • For neuroendocrine differentiation: Somatostatin analogs (Octreotide LAR 20-30 mg IM every 4 weeks) 2

Follow-up and Surveillance

• Clinical examination every 3-6 months for 5 years
• Imaging (CT or MRI) at least annually
• Measurement of appropriate tumor markers (e.g., Chromogranin A for NETs)
• Prolonged surveillance up to 10 years for high-grade tumors 2

Important Considerations

• Frozen section should be performed when appendiceal findings are atypical during surgery 3
• All patients with appendiceal neoplasms should be followed long-term due to 15-20% risk of developing a second malignancy 3, 6
• Prophylactic cholecystectomy should be considered if future treatment with somatostatin analogs is anticipated 1
• Prophylactic octreotide (100-200 μg IV followed by continuous infusion) may prevent carcinoid crises before invasive procedures in patients with carcinoid tumors 2

Common Pitfalls

• Underestimating the risk of metastasis in small (1-2 cm) appendiceal carcinoids with aggressive features 1
• Failing to perform complete staging before definitive surgical intervention 2
• Not recognizing the high incidence of synchronous and metachronous colorectal cancers in patients with appendiceal tumors 6
• Using colorectal cancer treatment protocols for appendiceal cancer without considering the different disease biology 4