Hereditary diffuse gastric cancer is defined by germline mutations in the E-cadherin gene, CDH-1.
The first family in which CDH-1 mutations were identified was a large Maori kindred, where lifetime penetrance is 70%.
Prophylactic gastrectomy is an unacceptable option for many mutation carriers.
Dr Shaw and colleagues from New Zealand considered the results of annual chromoendoscopic surveillance using the methylene blue/congo red technique in 33 mutation carriers over a 5 year period.
The researchers enrolled 33 confirmed CDH-1 mutation carriers (18 males and 15 females) with a median age 32 years (range 14–69) from 1999–2003.
|69 chromoendoscopies were noted to be normal, whilst in 24 procedures, 1–6 pale areas/stomach were detected|
Medical records, endoscopy, and pathology were reviewed retrospectively by the research team.
The investigators reported that over 5 years, 99 surveillance endoscopies were performed, of which 93 were chromo-dye enhanced.
69 chromoendoscopies were noted to be normal, whilst in 24 procedures, 1–6 pale areas/stomach (size 2–10 mm) were detected post chromo-dye application (totalling 56 pale lesions).
The research team took 1 biopsy from each pale lesion and showed that 23 lesions (41%) had signet ring cell carcinoma (10 patients), 10 lesions (18%) gastritis (4 patients), and 23 (41%) normal mucosa (10 patients).
The researchers used no chromo-dyes in 6 procedures with macroscopic lesions, where 2 had hereditary diffuse gastric cancer and 4 had ulceration.
In addition, the investigators observed that total gastrectomies from patients with carcinoma were macroscopically normal but pathological mapping showed multiple microscopic foci of early signet ring cell carcinoma.
Correlation of chromoendoscopic and gastrectomy findings showed that congo red/methylene blue detected carcinoma foci 4–10 mm in size but not foci less than 4 mm.
Dr Shaw concludes, “The use of chromoendoscopy following normal white light gastroscopy facilitated detection of early gastric carcinoma foci not visible with white light gastroscopy.”
“If these findings are validated in other hereditary diffuse gastric cancer kindred, chromogastroscopy represents an improved surveillance technique that can be safely considered alongside prophylactic gastrectomy.”