Epithelial appendiceal neoplasms.

Area of Science:

• Surgical Oncology
• Gastrointestinal Oncology
• Abdominal Malignancies

Background:

• Appendiceal malignancies often originate within mucoceles.
• Tumors can range from minimally aggressive to invasive.
• Mucocele rupture can lead to peritoneal dissemination of cancer cells.

Purpose of the Study:

• To determine prognostic indicators for appendiceal cancer with peritoneal dissemination.
• To evaluate the efficacy of cytoreductive surgery and perioperative intraperitoneal chemotherapy.
• To assess the impact of tumor grade, completeness of cytoreduction, and peritoneal cancer index on survival.

Main Methods:

• Analysis of approximately 900 patients treated at the Washington Cancer Institute.
• Evaluation of quantitative prognostic indicators.
• Assessment of survival rates based on tumor grade, cytoreduction completeness, and peritoneal cancer index.

Main Results:

• Complete cytoreduction with low-grade appendiceal malignancy yields 80% 20-year survival; high-grade disease survival is ~45%.
• Completeness of cytoreduction is the most critical prognostic factor; incomplete resection leads to 10-year mortality.
• Peritoneal cancer index significantly impacts survival for both low- and high-grade disease.

Conclusions:

• Cytoreductive surgery combined with perioperative intraperitoneal chemotherapy is a viable curative treatment for appendiceal cancer with peritoneal dissemination.
• Tumor grade and completeness of surgical resection are paramount for long-term survival.
• While lymph node metastasis has minimal significance, the extent of disease (peritoneal cancer index) strongly influences outcomes.