EFFICACY OF RADIOFREQUENCY ABLATION AS A TREATMENT FOR GASTRIC INTESTINAL METAPLASIA: A RANDOMIZED, SELF-CONTROL STUDY

INTRODUCTION:
Countries with a high prevalence of gastric cancers have well developed programs aimed at identifying and monitoring gastric cancer precursors. However, there is limited information about the performance of such programs in the United States. In 2015, we initiated a surveillance program to follow patients with gastric intestinal metaplasia (GIM) by upper endoscopy every three years. We aim to gauge the implementation and compliance of surveillance at 7-10 years of follow-up.

METHODS:
Between March 2010 to March 2014, 366 patients had GIM on index upper endoscopy at our large metropolitan safety-net hospital. These patients were followed as part of a prospective cohort study. In our gastroenterology and primary care clinics we implemented a practice to recommend surveillance endoscopy every three years beginning in January 2015, given demographic risk factors of our population. The primary outcome was the proportion of GIM patients who returned for follow-up endoscopy with gastric biopsies. Additional outcomes were predictors of compliance, progression and regression of lesions, and length of time between surveillance.

RESULTS:
Patients identified with GIM on index upper endoscopy were predominantly Hispanic (77%) and female (62.8%), with a mean age of 57.8 years. Of this group, 90 (24.6%) patients underwent surveillance endoscopy. The average time interval was 31.8 months following the index assessment and the number of follow-up endoscopies per patient ranged from 1 to 8.

Of the 34 patients with focal intestinal metaplasia on index endoscopy, 4 (12%) progressed to multifocal metaplasia while the remainder either maintained focal metaplasia or regressed to lower risk lesions. Of the 55 patients with non-focal metaplasia initially, 5 (9%) patients progressed to neoplasia (including neuroendocrine lesions), 20 (36%) maintained multifocal metaplasia, and the remainder (55%) regressed to focal metaplasia or less worrisome lesions. One patient with dysplasia on index endoscopy developed carcinoma and underwent gastrectomy.

Multivariable logistic regression analysis showed that patients with a high-risk indication for index endoscopy based on clinical outcomes research initiative (CORI) terms (weight loss, iron deficiency anemia, abnormal imaging, gastric ulcer, and epigastric abdominal pain) were more likely to undergo surveillance (OR 2.03, CI 1.20 – 3.45) (Table 1). Those found to be H. pylori positive during the index endoscopy were less likely to follow-up for surveillance (OR = 0.47, CI 0.26 – 0.87).

CONCLUSION:
Surveillance of GIM in a high-risk American population has a significant yield, particularly among those with multifocal involvement. However, in the underserved setting, surveillance compliance is suboptimal. Our findings underscore the need to develop strategies to improve participation and compliance in these important programs.

Background: The guidelines recommend gastric cancer surveillance with esophagogastroduodenoscopy (EGD) every 3 years in both extensive and incomplete type gastric intestinal metaplasia (GIM). To date, there has been no promising endoscopic tool to prevent gastric cancer development in these patients. Radiofrequency ablation (RFA) has been used to eradicate intestinal metaplasia in Barrett’s esophagus. This study aimed to evaluate the efficacy of RFA in diminishing and downgrading GIM in those patients with high risk GIM.
Methods: This randomized, self-control trial was conducted in a tertiary hospital in Thailand between June 2020 and October 2022. Patients with histology proven of extensive or incomplete GIM were enrolled in the study. All patients underwent surveillance EGD with white-light and narrow band imaging gastroscopy. The performing endoscopists took biopsy from either suspected GIM area or randomly (negative GIM read by NBI) to complete 5 areas as per the Sydney protocol at both left and right side of stomach (total 10 biopsies). Then, the included patients were randomized with 1:1 concealed allocation to receive either right or left side RFA (Barrx™ 90 RFA Focal Catheter, Medtronic, Thailand). The RFA procedures were repeated at the assigned right or left side of stomach every 2-3 months for 3 times by the same endoscopist. The primary outcome was the complete resolution of GIM (disappearance of GIM epithelium confirmed by histology after RFA at the previous complete or incomplete GIM) at 1 year after RFA. The gold standard for GIM diagnosis was the pathology read by two gastrointestinal pathologists.
Results: Forty-six patients with either extensive or incomplete GIM lesion were enrolled. Male and female was 1:1 with mean age of 66± 8 years. Majority of them (65%) had neither history of smoking nor alcohol drinking. One-third had a history previous H.pylori infection with successful eradication. Half had dyspeptic symptom. The incomplete and complete GIM lesions were not different in RFA vs. observation group (73 vs. 77, p=0.76 and 53 vs. 49, p=0.73, respectively). The complete resolution rate of incomplete GIM lesions after RFA was higher (22/73; 30%) than that of in the observation group (10/77; 13%) (p=0.05). In contrast, the complete resolution rate of complete GIM lesions was not different between RFA and observation groups (27/53; 51% vs. 24/49; 49%, respectively, p=1.00).When compare the downgrading (complete resolution or de-staging) of incomplete GIM lesions, there was no different between RFA and observational group (34/73 (46%) vs. 30/77 (39%), p=0.65) (Table)
Conclusion: This study showed that RFA could facilitate complete resolution of incomplete GIM lesions but not complete GIM. Instead of only diagnostic EGD during surveillance, RFA may be a viable therapy to diminish incomplete GIM.