Colon Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Colon Cancer, including details on causes, treatment, symptoms.

Genotype-phenotype correlations as a guide in the management of familial adenomatous polyposis.

Nieuwenhuis MH, Mathus-Vliegen LM, Slors FJ, Griffioen G, Nagengast FM, Schouten WR, Kleibeuker JH, Vasen HF

The Netherlands Foundation for the Detection of Hereditary Tumours, Leiden University Medical Centre, Leiden, The Netherlands.

BACKGROUND & AIMS: The options for prevention of colorectal cancer in familial adenomatous polyposis are either a colectomy with ileorectal anastomosis (IRA) or a total proctocolectomy with ileal pouch-anal anastomosis (IPAA). Rectal cancer risk is eliminated by IPAA, but complication rate is higher than in IRA. Mutation analysis might predict severity of polyposis and be helpful in the surgical decision. METHODS: Patients from the Dutch Polyposis Registry with an IRA were subdivided according to the site of adenomatous polyposis coli gene mutation into the attenuated (1), intermediate (2), and severe (3) genotype groups. Cumulative risks of secondary rectal excision and rectal cancer were calculated for each group. RESULTS: A total of 174 patients underwent an IRA: 26 patients from group 1, 121 from group 2, and 27 from group 3. Cumulative risks of rectal cancer 15 years after surgery were 6%, 3%, and 8% in groups 1, 2, and 3, respectively. Cumulative risks of rectal excision 20 years after IRA were 10%, 43%, and 74%, respectively. The risk of rectal excision was significantly higher in group 3 than in the other groups (P < .05). CONCLUSIONS: The risk of secondary rectal excision after IRA can be predicted on the basis of the adenomatous polyposis coli mutation site. An IRA appears to be the appropriate treatment in patients with the attenuated genotype. Patients with a severe genotype are good candidates for an IPAA.

Published 19 March 2007 in Clin Gastroenterol Hepatol, 5(3): 374-8.
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