Twenty years of familial adenomatosis polyposis syndromes in the Singapore Polyposis Registry: an analysis of outcomes

Chew MH, Quah HM, Teh KL, Loi TTC, Eu KW, Tang CL
Correspondence: Dr Hak-Mien Quah, quah.hak.mien@sgh.com.sg

ABSTRACT
Introduction The Singapore Polyposis Registry (SPR) was established in 1989 at the Singapore General Hospital. This initiative was aimed at providing a central registry service to facilitate identification, surveillance and management of families and individuals at high risk of colorectal cancer. The aim of the present study was to provide a comprehensive review of all patients with familial adenomatous polyposis (FAP) syndrome in the SPR.
Methods All patients diagnosed with FAP in 1989–2009 were analysed. Data was extracted from a prospectively collected database.
Results 122 patients from 88 families were analysed. The median age of this cohort was 29 (range 10–68) years. 97 percent of the cases were FAP and 3 percent were attenuated FAP. 92 patients tested positive for adenomatous polyposis coli gene. 42 percent of patients were diagnosed with colorectal cancer, of which 78 percent were diagnosed at an advanced stage. 73 percent of patients underwent restorative proctocolectomy and 21 percent had total colectomy. The median age at operation was 30 years. At median follow-up of 98 months, ten-year overall survival was 75.6 percent (95 percent confidence interval 67.0–84.2) and the median age at death was 40 years. For cancer cases, the overall recurrence was 13.5 percent. Recurrence and disease-free survival were not significant for the type of surgery performed (p-value is 0.486).
Conclusion The SPR plays an important and integral part in counselling patients and families with FAP. Improved surveillance programmes may be required to detect the development of cancers in these patients at an earlier stage.

Keywords: colorectal cancer, familial adenomatous polyposis, outcomes
Singapore Med J 2011; 52(4): 246-251