Duodenal adenomatosis in familial adenomatous polyposis.

BACKGROUND

The prevalence of duodenal carcinoma is much higher in familial adenomatous polyposis (FAP) than in the background population, and duodenal adenomatosis is found in most polyposis patients.

AIMS

To describe the long term natural history of duodenal adenomatosis in FAP and evaluate if cancer prophylactic surveillance of the duodenum is indicated.

METHODS

A prospective five nation study was carried out in the Nordic countries and the Netherlands.

PATIENTS

A total of 368 patients were examined by gastroduodenoscopy at two year intervals during the period 1990-2001.

RESULTS

At the first endoscopy, 238 (65%) patients had duodenal adenomas at a median age of 38 years. Median follow up was 7.6 years. The cumulative incidence of adenomatosis at age 70 years was 90% (95% confidence interval (CI) 79-100%), and of Spigelman stage IV 52% (95% CI 28-76%). The probability of an advanced Spigelman score increased during the study period (p<0.0001) due to an increasing number and size of adenomas. Two patients had asymptomatic duodenal carcinoma at their first endoscopy while four developed carcinoma during the study at a median age of 52 years (range 26-58). The cumulative incidence rate of cancer was 4.5% at age 57 years (95% CI 0.1-8.9%) and the risk was higher in patients with Spigelman stage IV at their first endoscopy than in those with stages 0-III (p<0.01).

CONCLUSIONS

The natural course of duodenal adenomatosis has now been described in detail. The high incidence and increasing severity of duodenal adenomatosis with age justifies prophylactic examination, and a programme is presented for upper gastrointestinal endoscopic surveillance.