Gastric tumours in FAP

Gastric cancer is not a recognised extra-colonic manifestation of FAP, except in countries with a high prevalence of gastric cancer. Data regarding gastric adenomas in FAP are sparse. The aim of this study was to review the clinical characteristics of gastric tumours occurring within an FAP population from the largest European polyposis registry. All patients that developed a gastric adenoma or carcinoma were identified from a prospectively maintained registry database. The primary outcome measure was the occurrence of gastric adenoma or adenocarcinoma. Secondary outcomes included APC mutation, tumour stage, management and survival. Eight patients developed gastric cancer and 21 an adenoma (median age 52 and 44 years, respectively). Regular oesophagogastroduodenoscopy surveillance was performed in 6/8 patients who developed cancer. Half were advanced T3/4 tumours and 6/8 had nodal or metastatic spread at diagnosis. All cancer cases died within a median of 13.5 months from diagnosis. Gastric adenomas were evenly distributed: 11/21 (52%) in the distal and 10/21 (48%) proximal stomach, whereas 5/8 (63%) cancers were located proximally. An association between gastric tumour and desmoid development was observed; 7/8 (88%) cancer and 11/21 (52%) adenoma cases had a personal or family history of desmoid. It would appear from this small, retrospective study that gastric cancer is not a prominent extra-colonic feature of FAP in the Western world. It seems to present at an advanced stage with a poor prognosis. There may be an association between gastric tumour and desmoid occurrence but a large multicentre cohort is necessary to investigate this further.