Colon and rectum cancers are the commonest reason for cancer to involve the peritoneal cavity. Patients with colon cancer involving the peritoneum have lower long term survival rates than patients whose cancer spreads in other areas of the body such as the liver or lung. Without treatment for peritoneal carcinomatosis from colon cancer very few people live longer than a year.
What are the reasons for recommending Peritonectomy?
A randomised trial that included patients with peritoneal disease from colon cancer and a small number of appendix cancer compared receiving peritonectomy and HIPEC followed by conventional chemotherapy to chemotherapy alone. In this study, the patients receiving the combination treatment lived longer than patients receiving chemotherapy alone. This trial has been criticised because the type of chemotherapy, whilst standard at the time of the study, is now considered old-fashioned.
Based on current publications, current intravenous or tablet chemotherapy is associated with a 5-10% chance of living 5 years. Based on current case studies, peritonectomy and HIPEC for selected patients with colon cancer achieves survivals of 30 to 40% after 5 years. 10% will live 10 years but half to two-thirds of these patients will have relapsed disease. Redo peritonectomy in selected patients from colorectal cancer may be considered. The chemotherapy we use is HIPEC with is mitomycin C or oxaliplatin and an intravenous injection of 5-fluorouracil. If you are unable to have oxaliplatin then we use mitomycin C for the HIPEC and 5-fluorouracil for the EPIC. It is important to note that the peritonectomy and HIPEC is in addition to regular chemotherapy.
Which patients with colon cancer might benefit from peritonectomy?
Not every patient with colon cancer and peritoneal disease benefits from peritonectomy and HIPEC. We know that patients with a peritoneal cancer index (PCI) of more than 15 who undergo Peritonectomy do not appear to have improved survival. The best reported results are for patients with very low PCI (<5). The average 5 year survival for this group in our unit is 58%.
There are many uncertainties about who is the optimal candidate for this treatment and different units have different selection criteria. Some of the uncertainties include whether prior chemotherapy impacts outcomes, whether the involvement of different parts of the abdomen impacts survival and whether different subtypes of colon cancer respond differently. These issues in relation to your particular situation are discussed at our multidisciplinary team meeting that includes your surgeon and oncologist.
What are the alternatives?
The alternative treatment is systemic chemotherapy and other drug treatments. Current publications report 5 year survival of 5-10% for systemic chemotherapy alone. A further alternative, depending on your personal preferences is to receive palliative care.