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

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.

Dissociative effects of malarial infection on humoral and cell-mediated immunity in mice.

The effect of malarial infection on immune responses was studied in mice. When sheep red blood cells (SRBC) were injected 2 days before or at the same time as infection with Plasmodium berghei, there was a marked increase in the number of splenic plaque forming cells (PFC) induced by SRBC as compared with uninfected controls. When SRBC were injected 2 days or more after the infection, however, the PFC response was significantly reduced. On the other hand, cell-mediated immunity, as exemplified by delayed-type hypersensitivity (DTH) to a number of antigens, was suppressed whether the infection was introduced before or after antigen stimulation. A similar effect could be produced by injecting the host with the supernatant obtained following incubation in vitro of peripheral blood from heavily infected mice. When this supernatant was injected i.v. into normal mice at the same time as SRBC priming, it enhanced the humoral response to SRBC, but suppressed the DTH to SRBC. The coincident induction of this inverse relationship between humoral and cell-mediated immunities was clearly borne out by a dose response study using different dilutions of supernatant. The active component appeared to be of large molecular weight (greater than 150,000), thermostable and not present in the serum of infected mice.