Appendix cancer is a cancer arising in the appendix that resembles but is not the same as, colorectal cancer. Appendix cancer can be difficult to diagnose and can appear like pseudomyxoma peritonei or colorectal cancer.
What are the reasons for recommending Peritonectomy?
In our unit and other units performing peritonectomy and HIPEC the chances of living 5 years after surgery are 50%. The chemotherapy we use is HIPEC with oxaliplatin and an intravenous injection of 5-fluorouracil.
What are the alternatives?
The main alternative to peritonectomy and HIPEC is chemotherapy. Most oncologists would use similar chemotherapy to that used for colon cancer. There is little published data on the results of this chemotherapy, but the limited data suggests that results of chemotherapy in appendix cancer are similar to those in colon cancer. We would expect that the chances of living 5 years with chemotherapy alone (and no peritonectomy surgery) would be 5% or less.
Epithelial appendiceal neoplasms account for 1% of CRC. Appendix tumour perforation and seeding of tumour cells within the peritoneal cavity leading to the clinical syndrome of pseudomyxoma peritonei (PMP) or Jelly Belly. Psudomyxoma peritonei is accumulation of mucin in the peritoneal cavity due to a secreting mucinous primary neoplasm.
PMP is a rare malignant disease, with an estimated annual incidence of 1-2 cases per million population. Psudomyxoma peritonei is classified according to the following classification:
- A cellular mucin PMP
- Low-grade mucinous carcinoma peritonei OR (DPAM)
- High-grade mucinous carcinoma peritonei OR (PMCA)
- Peritoneal mucinous carcinomatosis with signet ring cells (PMCA-S)
Debulking surgery only results in 30 % of patients alive in 5 years. However, complete Cytoreduction surgery and HIPEC of patients with PMP and low-grade appendix tumours result in 85 % of patient alive in 5 years and 68% alive in 10 year time. In Patients with pmp and high-grade appendix tumour, our results showed 52% and 30% of our patient will be alive in 5 years and 10 years post CRS and HIPEC respectively.
Tumour burden (PCI) is not a prognostic factor if complete cytoreduction is achieved which is 95 % in our centre.
Other Factors affecting the long-term survival in patients with PMP post-CRS and HIPEC are the following:
- Complete cytoreduction, use of HIPEC, use of EPIC, blood transfusion, high tumor markers, Histopathology
- There is a steep learning curve in peritonectomy and Center experience is important prognostic factors in patients with PMP as the rate of completion of cytoreduction and complication will be improved in experienced centres.
Our indication for CRS and HIPEC for PMP
- History of or current Perforated Appendix tumour with evidence of peritoneal metastases or local-regional recurrence.
- Perforated appendix tumour with mucinous ascites
- PMP with Limited extra-abdominal disease e.g. limited Lung metastases amenable for lung ablation or resection.
- Positive margin of resection on caecum and other anatomic sites
- Positive biopsy of a peritoneal nodule
- Recurrent PMP
- Positive biopsy or pathologic enlargement of an Ovary
- Positive peritoneal cytology
- Perforated through the appendix