Features of duodenal cancer in patients with familial adenomatous polyposis.

Background & Aims: Most patients with familial adenomatous polyposis (FAP) develop duodenal adenomas; duodenal cancer is a major cause of mortality in this patient group. We reviewed cases of duodenal cancer in patients with FAP to identify factors that determine long-term cancer risk.

Methods: Twenty FAP patients (12 male) were identified from a registry database search. Data from registry and medical notes and endoscopic and histopathologic reports were evaluated.

Results: Of the cancers that developed in these patients, 11 were ampullary and 9 were duodenal. The median age at cancer diagnosis was 53 years. Seventeen patients died (median age at death, 57 y; median survival from diagnosis, 11 mo); the cause of death was metastatic or duodenal/ampullary cancer in 14 patients. Fifteen patients presented symptomatically (including 3 interval cancers while on surveillance). Two were diagnosed at surveillance and 3 were diagnosed during surgery performed for endoscopic features of advanced benign disease. Duodenal cancers were associated with a significantly lower mean colonic polyp count than ampullary cancers (496 +/- 282 vs 1322 +/- 735; P = .025); there appeared to be familial clustering of this cancer. When endoscopic data were available (n = 11 of 20), all ampullary cancers arose from ampullas greater than 1 cm. The Spigelman stage did not predict risk of ampullary cancer but did predict duodenal cancer (median stage 2 vs stage 4 for duodenal cancer).

Conclusions: Once cancer arises in patients with FAP, prognosis is poor, so cancer prevention should be the main goal. Surveillance intervals should reflect both Spigelman staging and ampullary disease.