Factors Associated With the Development of Gastric Cancer in FAP: 2017 Fellows-in-Training Award (Stomach Category): 2017 Presidential Poster Award

Abstract

Introduction: Gastric cancer has not been described as a cancer risk in Western patients with FAP. Data demonstrates a recent and rapid increase in the incidence of gastric cancer (GC) in FAP patients. We performed a case control study to determine clinical and endoscopic factors associated with GC in FAP. Methods: FAP patients were identified through the IRB approved David G. Jagelman Inherited Colorectal Cancer Registries CologeneTM database. All FAP patients with GC and randomly selected FAP patients without GC with > 2 EGDs were analyzed. Demographic, clinical, endoscopic and pathologic features were compared. A p < 0.05 was considered statistically significant. Results: Ten (10) patients developed GC. Age at diagnosis of FAP, age at the last EGD or age at diagnosis of GC, race, gender, BMI, tobacco exposure, personal history of cancer (CRC, thyroid, duodenal), family history of CRC, and history of duodenal surgery were not different between cases and controls (Table 1). Patients with GC were more likely than controls to have desmoids (60% vs 16%, p < 0.001), PPI (90% vs 54%, p 0.029) and H2RA exposure (60% vs13%, p < 0.001). Patients with GC had a longer length of EGD surveillance (10.8 vs 6 years, p< 0.002) but similar intervals between EGDs (1.3 vs 2.3 years, p=0.21) as controls (Tables 1 & 2). Endoscopic features significantly associated with GC include a carpeting of proximal polyposis (100% vs 26%, p < 0.001), greater numbers and largest sizes of solitary proximal polyps and presence of a polypoid mound of proximal polyposis (all p < 0.001) (Table 2). The pathology of proximal polyps varied significantly between GC and controls including the presence of intestinal metaplasia (IM) (30% vs 2.9%, p=0.013), fundic gland polyps with low grade (100% vs 54%, p=0.006) and high grade dysplasia (FGPHGD) (40% vs 7%, p=0.002), pyloric gland adenomas with HGD (PGAHGD) (20% vs 0%, p=0.014) and tubular adenomas (TA) (30% vs 5.7%, p=0.011) (Table 3).Table: Demographics and Medical History.Table: EGD Surveillance.Table: EGD Findings.Conclusion: Endoscopic features associated with GC in FAP include a carpeting, large size and polypoid mounds of proximal gastric polyposis. Worrisome histologic features include FGPHGD and PGAHGD. FAP patients with concerning endoscopic features should undergo intensive surveillance, aggressive debulking of polypoid mounds in addition to random sampling of polyps. Prophylactic gastrectomy should be offered to those with endoscopically worrisome stomachs and any lesion with HGD.