Upper gastrointestinal tumours in Japanese familial adenomatous polyposis patients

The upper gastrointestinal characteristics in Japanese familial adenomatous polyposis patients have not yet been clarified. The aim of the present study was to elucidate these characteristics in Japanese familial adenomatous polyposis patients.

This study was conducted by the study group for familial adenomatous polyposis in the Japanese Society for Cancer of the Colon and Rectum. Familial adenomatous polyposis patients who underwent surgical resection from 2000 to 2012 were included in the study.

In total, 303 familial adenomatous polyposis patients were enrolled, with 265 cases of classical familial adenomatous polyposis (≥100 adenomas) and 38 cases of attenuated familial adenomatous polyposis (<100 adenomas). Fundic gland polyps were significantly more common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis; however, gastric cancer was significantly less common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis. Gastric cancer and duodenal adenoma were significantly more common in familial adenomatous polyposis patients with gastric adenoma than in those without gastric adenoma. Duodenal cancer was detected in 7 of 72 familial adenomatous polyposis patients with duodenal adenoma. The median tumour risk in 50-year-old familial adenomatous polyposis patients was 55.3, 21.8, 3.8, 39.2 and 7.7% for fundic gland polyp, gastric adenoma, gastric cancer, duodenal adenoma and duodenal cancer, respectively.

Upper gastrointestinal tumours/polyps were frequently found in familial adenomatous polyposis patients, and their incidences were correlated; however, the frequency of gastric cancer in Japanese familial adenomatous polyposis patients was similar to that in the general population.