A case-control study comparing methylene blue directed biopsies and random biopsies for detecting pre-cancerous lesions in the follow-up of gastric cancer patients

Objectives: To compare the accuracy of Methylene Blue (MB) targeted biopsies with random biopsies in detecting intestinal metaplasia and dysplasia in the follow-up of patients after gastrectomy for gastric cancer. Methods. Thirty patients (21 Billroth 11, 9 Billroth 1) for cancer, referred to the Gastroenterology Unit for an elective esophagogastroduodenoscopy (EGD), were enrolled. All endoscopies were performed with a high-resolution videoendoscope with an adjustable image magnification: EG-485ZH (Fujinon, Omiya, Japan). During EGD three random biopsies were taken in the stomach and, after staining with MB, three targeted biopsies were taken from every stained area. Results: In 28 patients traditional endoscopy showed hyperemia of the anastomosis, in 2 patients a lesion. After MB in 6/30 there were stained area (2 lesions seen with traditional endoscopy and 4 blue areas in other patients). As regards hystology: 24 patients showed inflammation, while 2 patients with alterations in traditional endoscopy and with MIS showed metaplasia and high grade dysplasia. In 4/30 (13.3%) patients MB guided biopsies showed significant lesions (3 intestinal metaplasia, 1 low grade dysplasia) while random biopsies showed only inflammation. Conclusions: After partial gastrectomy, the mucosa of the residual stomach usually undergoes severe changes, and these lesions are known to be pre-cancerous. The diagnostic accuracy of the MB technique seems to be superior to random biopsies for identification of intestinal metaplasia, dysplasia, and may be helpful in targeting biopsies and early endoscopic treatment.