The challenge of preventing gastric cancer in patients under surveillance for familial adenomatous polyposis.

Several extra-colonic manifestations, including duodenal polyposis and desmoid tumors, are well-described manifestations in familial adenomatous polyposis (FAP). More recently, an increase in gastric cancer diagnoses has been observed in FAP. This case series presents nine patients with FAP who were diagnosed with gastric cancer at our FAP expertise center, of whom eight were diagnosed between 2017 and 2023, while before 2017 the only diagnosis of gastric cancer was in 2001. Among the nine cases of gastric cancer, seven were located in the proximal stomach amidst carpeting fundic gland polyposis and two were located in the distal stomach. Despite ongoing advances in endoscopic technology, all patients were diagnosed during regular endoscopic surveillance, and six of the nine patients died within two years. We aim to raise awareness on gastric cancer risk in FAP patients and stress the urgent need of improved gastric surveillance strategies with timely detection of gastric cancer precursors.