What are the diagnostic approaches and treatment options for appendix cancer?

From the Guidelines

Appendix cancer diagnosis typically begins with imaging studies such as CT scans, which have become the most useful diagnostic imaging modality for the evaluation of patients with suspected appendicitis, with a summary sensitivity of 0.95 (95% CI: 0.93-0.96) and a summary specificity of 0.94 (95% CI: 0.92-0.95) 1. Imaging studies like CT scans can detect abnormalities in the appendix, and blood tests may show elevated white blood cell counts or tumor markers like CEA. Definitive diagnosis requires histopathological examination of tissue samples obtained through biopsy or surgical resection. Treatment primarily involves surgical intervention, with the extent depending on cancer stage and type. For localized disease, an appendectomy may suffice, while advanced cases often require right hemicolectomy (removal of the right portion of the colon). Some key points to consider in the diagnosis and treatment of appendix cancer include:

• The use of CT scans for diagnosis, with a sensitivity of 0.95 (95% CI: 0.93-0.96) and a specificity of 0.94 (95% CI: 0.92-0.95) 1
• The importance of histopathological examination for definitive diagnosis
• The role of surgical intervention, including appendectomy and right hemicolectomy, in the treatment of appendix cancer
• The use of cytoreductive surgery combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for peritoneal spread, involving surgical removal of visible tumors followed by heated chemotherapy drugs (typically mitomycin C or oxaliplatin) directly into the abdominal cavity
• The use of systemic chemotherapy regimens, such as FOLFOX (leucovorin, 5-fluorouracil, oxaliplatin) or CAPOX (capecitabine plus oxaliplatin), typically administered in 2-week cycles for 3-6 months
• The importance of individualizing treatment decisions based on the specific cancer subtype (mucinous, goblet cell, neuroendocrine, etc.), stage, and patient factors
• The need for regular follow-up with imaging and blood tests to monitor for recurrence, with surveillance typically continuing for at least 5 years after treatment. In terms of specific cancer subtypes, for appendiceal carcinoid tumors 2 cm or smaller and confined to the appendix, simple appendectomy is sufficient, because metastases are uncommon 1. However, some controversy exists regarding the management of appendiceal carcinoids measuring less than 2 cm with more aggressive histologic features. Patients with an incomplete resection or tumors smaller than 2 cm are at risk for locoregional or distant metastases, and should be staged with abdominal/pelvic CT or MRI scans. If no distant disease is identified, they should undergo reexploration with a right hemicolectomy. Additionally, a small proportion of appendiceal carcinoids may also contain evidence of adenocarcinoma (i.e., “adenocarcinoid” or “goblet cell carcinoid”), and these tumors should be managed according to the NCCN Guidelines for Colon Cancer. Follow-up recommendations for patients with resected carcinoid tumors differ from the above general recommendations, and may include follow-up examinations, imaging studies, and surveillance, as clinically indicated 1.

From the Research

Diagnostic Approaches for Appendix Cancer

• The diagnosis of appendix cancer is often made after surgery for appendicitis or other indications 2
• Colonoscopy is not an effective method for detecting appendiceal lesions, with only 11% of patients showing abnormal findings and 3.1% having a diagnostic biopsy 3
• Imaging studies such as ultrasound, computerized tomography, and octreotide scanning may be used to evaluate the extent of disease 4

Treatment Options for Appendix Cancer

• The treatment of appendix cancer depends on the histologic subtype and extent of disease 2
• For carcinoid tumors of the appendix, appendectomy may be sufficient for small tumors (<1 cm), while larger tumors (>2 cm) may require right hemicolectomy 4
• For appendiceal adenocarcinoma, the appropriate surgical procedure is still debated, with some studies suggesting that right hemicolectomy may not always be necessary 5
• Adequate lymphadenectomy is recommended, regardless of the surgical procedure used 5

Histologic Subtypes of Appendix Cancer

• Appendix cancer can be classified into several histologic subtypes, including colonic-type or mucinous adenocarcinoma, goblet cell adenocarcinoma, and neuroendocrine carcinoma 2
• Each subtype has its own unique characteristics and management strategies 6
• The presence of signet ring cells is a histologic feature that may be present in some subtypes, but is not considered a separate entity 2

Prognosis and Survival

• The prognosis and survival of patients with appendix cancer vary depending on the histologic subtype and extent of disease 5
• The 5-year overall survival rate for patients with appendiceal adenocarcinoma is around 58-69% 5
• Early detection and treatment are crucial for improving survival outcomes 3