No abstract

Background and study aims: Hereditary diffuse gastric cancer (HGGC), an autosomal dominant tumor-syndrome, accounts for 1 % to 3 % of gastric cancers worldwide. Presumably 30 % to 40 % of all patients fulfilling the clinical guidelines for HDGC are carriers of a pathogenic mutation in the CDH1 gene. Patients often show multiple foci of signet ring cell carcinoma at early age and are advised to undergo prophylactic total gastrectomy (PTG). Our aim was to improve the endoscopic detection of HDGC by using an enhanced endoscopic protocol. Patient and methods: Patients with a proven CDH1 germline mutation identified in our institute were prospectively included. Patients were advised to undergo PTG and offered a baseline endoscopic examination prior surgery. Examination was performed by using high-resolution white-light endoscopy and pan-gastric chromoendoscopy with indigo carmine as dye combined with targeted and multiple random biopsies assessed by an expert histopathologist. Postoperative histopathology was compared with results from endoscopic biopsies. Results: Between September 2012 and November 2014 8 patients with a proven CDH1 germline mutation were included. We conducted 44 targeted (6.3/patient) and 225 random (32.1/patient) biopsies in 7 patients. We detected 1 gastric cancer by random biopsy (14 %). All other examinations showed no signs of cancer. Histopathology of gastrectomy specimen revealed multiple foci of gastric carcinoma in 6 patients (86 %) with a total number of 27 cancer foci. Conclusions: Examination with targeted and random biopsies combined with chromoendoscopy is not able to detect small foci of gastric cancer in CDH1 mutation carriers. Therefore PTG is advocated in these patients.

Backround and study aims Duodenal cancer is the cancer most often seen in patients with familial adenomatous polyposis (FAP) who have undergone risk-reducing colonic surgery. Almost all patients with FAP eventually develop duodenal adenomas and risk for duodenal cancer is up to 12 % with poor prognosis. In addition, there is a rising concern regarding increased gastric cancer risk in patients with FAP. Our aim was to enhance polyp detection by using CE (CE) with the application of indigo carmine dye. Patient and methods We conducted a prospective, blinded study of patients with FAP undergoing endoscopic examination of the upper gastrointestinal tract. First, a standard white-light examination (WLE) was done followed by an examination performed by an endoscopist who was blinded to the previous examination, using chromoendoscopy (CE) (0.4 % indigo carmine dye). Results Fifty patients were included in the study. Using WLE, a median number of 13 adenomas (range 0–90) was detected compared to 23 adenomas/patient (range 0–150; P < 0.0001) detected after staining, leading to a higher Spigelman stage in 16 patients (32 %; P = 0.0003). CE detected significantly more larger adenomas (> 10 mm) than WLE (12 vs. 19; P = 0.0391). In the gastric antral region, a median number of 0 adenomas (range 0–6) before and 0.5 adenomas (range 0–7) after staining (P = 0.0025) were detected. Conclusion This prospective endoscopic trial, to our knowledge the largest in patients with FAP, showed a significant impact of CE on adenoma detection and therapeutic management in the upper gastrointestinal tract. This leads to more intensive surveillance intervals.