Introduction

Oxyntic gland neoplasms (OGNs) are recently described gastric lesions that differ in histological and clinical characteristics when compared with traditional intestinal-type gastric adenocarcinoma. First described in 2007^[1], interest in these tumors has been gradually increasing in the past few years. Given this, most previous studies had involved cases collected by tertiary referral centres, leading to a gap in the knowledge of the true disease frequency in the real-world setting.

Aims & Methods

The goal of this study was to better characterize the disease frequency and clinicopathological characteristics of oxyntic gland neoplasms, by more than doubling the number of lesions discovered since the previous report. All upper gastrointestinal endoscopies performed at a high-volume outpatient clinic between December 2017 and January 2023 were reviewed, and cases of histologically diagnosed OGN were identified. Patient demographics, endoscopic and histopathological details are presented.

Results

During the study period, 8709 patients underwent 19073 procedures, with 51 patients having a total of 64 OGNs, resulting in a point prevalence of 0.59% (51/8709). Eleven patients (22%) had multiple lesions. Most patients (65%) had a history of H. Pylori infection. Twenty nine lesions (45%) underwent endoscopic management, with 8 resected via ESD and 21 via EMR-C. The median tumour diameter was 4mm (range 2-8). Nine of the resected lesions had evidence of submucosal involvement. In this subset, the deepest penetration ranged from 10-950um into the submucosal layer. No patients with submucosal involvement had any other high risk tumor features, nor desmoplastic reaction of the submucosa, and all elected for conservative management after complete endoscopic resection. Median Ki67 index value was 2% (range 1-8). Thus far, there has been no evidence of recurrence on clinical follow up.

Conclusion

Though the most recent WHO classification states the prevalence of OGNs remains unknown^[2], it is clear that these lesions are more common than once thought. Initial reports had suggested rates of <0.01%^[3], and our previous study had found a community point prevalence of 0.36%^[4]. However, in less than two years since the previous study period, the amount of lesions identified have more than doubled, leading us to a more accurate prevalence estimate of 0.59%. It is possible this number may continue to rise in the future, as knowledge about this atypical form of gastric neoplasia is further disseminated amongst gastroenterologists and pathologists.
As more lesions are discovered, we also continue to learn more about the clinical course, and efficacy of treatment. Although submucosal involvement has been noted in almost a third of resected cases in this series, no patients have had local recurrence on follow up, or evidence of metastatic disease. Combined with other atypical histological features, including the lack of desmoplastic reaction near the areas of submucosal penetration, we suggest that this may be due to a ‘prolapse’ effect of the tumour into the submucosal layer, rather than the high risk invasion seen in intestinal type gastric adenocarcinoma. Ongoing surveillance will be essential to support these suspicions.

References

^[1] Tsukamoto, Tetsuya, et al. "Gastric adenocarcinoma with chief cell differentiation." Pathology international 57.8 (2007): 517-522.
^[2] WHO Classification of Tumours Editorial Board : WHO classification of tumours, 5th edn, Vol 1 Digestive system tumours. IARC, Lyon, 2019
^[3] Tohda, Gen, et al. "Gastric adenocarcinoma of fundic gland type: endoscopic and clinicopathological features." World Journal of Gastrointestinal Endoscopy 8.4 (2016): 244.
^[4]Asahara, Hikari, et al. "Clinicopathological Features and the Prevalence of Oxyntic Gland Neoplasm: A Single-center Retrospective Study." Internal Medicine (2023): 0552-22.

Introduction

Oxyntic gland neoplasms (OGNs) are uncommon gastric growths, primarily composed of cells resembling chief cells. The fifth edition of the World Health Organization (WHO) classification includes both oxyntic gland adenoma and gastric adenocarcinoma of fundic gland type in the OGN category. While OGNs are a relatively new disease entity with largely unknown incidence and prognosis, we previously reported an OGN incidence of 0.36% in 7488 patients at an outpatient clinic between 2017 and 2021. However, that study had a limited patient cohort. In Japan, OGNs are classified as a special type of cancer, and endoscopic treatment (endoscopic submucosal dissection [ESD] or endoscopic mucosal resection using a cap-fitted panendoscope [EMRC]) is generally recommended. Nevertheless, given reports of the low malignant potential of OGNs, we have followed patients who opted for observation with upper endoscopy and CT scans instead of pursuing endoscopic treatment.

Aims & Methods

This study aims to determine the true frequency of OGNs in a larger patient cohort and to investigate size changes or metastasis in OGNs managed with observation. We retrospectively reviewed all upper gastrointestinal endoscopies performed at a high-volume outpatient clinic from December 2017 to November 2024, identifying newly diagnosed OGN cases based on histological examination. Patient demographics, endoscopic and histopathological findings, and clinical courses are presented.

Results

During the study period, 10,110 patients underwent 25,480 procedures, with 118 patients diagnosed with a total of 153 OGNs, resulting in a point prevalence of 1.2% (118/10,110). Among the 153 OGN lesions, 3 were classified as gastric adenocarcinoma of fundic gland type (GA-FG-M). The prevalence of GA-FG-M was 0.03% (3/10,110). Thirty-five patients (30%) had multiple lesions (simultaneously or metachronously). Sixty-five patients (55%) had a history of H. pylori infection. Endoscopic treatment was performed in 65 lesions (12 via ESD, 53 via EMR-C), with 19 of these 65 lesions (29%) showing submucosal invasion (depth range: 10-950 µm). Of the 88 lesions, the tumor was endoscopically unidentifiable after biopsy in 37 cases, while 51 lesions remained identifiable but were observed. Throughout a median follow-up of 347 days (range: 26-2555 days), none of these 51 cases showed changes in size or morphology, and no metastasis was detected on CT.

Conclusion

Although the WHO classification indicates that the prevalence of OGNs is unknown, this large cohort study demonstrated an OGN incidence of 1.2% and a GA-FG-M prevalence of 0.03%. Furthermore, observation of biopsy-diagnosed OGNs revealed no changes in size or metastasis on CT, suggesting that OGNs may be slow-growing tumors that do not always require immediate treatment.

References

[1]Tsukamoto, Tetsuya, et al. "Gastric adenocarcinoma with chief cell differentiation." Pathology international. 2007, 57(8): 517-522.
[2] Ueyama H, Yao T, Nakashima Y, et al. Gastric adenocarcinoma of fundic gland type (chief cell predominant type): proposal for a new entity of gastric adenocarcinoma. Am J Surg Pathol. 2010, 34(5):609-619.
[3] Yao T, Vieth, M. Oxyntic gland adenoma. Digestive system tumours. In World Health Organization Classification of Tumours 5th edition (ed. WHO Classification of Tumours Editorial Board) 83–84, (International Agency for Research on Cancer, World Health Organization, 2019.
[4] Asahara, Hikari, et al. "Clinicopathological Features and the Prevalence of Oxyntic Gland
Neoplasm: A Single-center Retrospective Study." Internal Medicine (2023): 0552-22.
[5] Japanese Classification of Gastric Carcinoma (October 2017 [The 15th Edition]),
Japanese Gastric Cancer Association, p30, 36, Tokyo, Kanehara Shuppan.

Disclosure

No COI

Introduction

Oxyntic gland neoplasms (OGNs) are rare gastric lesions that mainly show differentiation to chief cells [1, 2]. In the fifth edition of the WHO classification, the OGN entity includes oxyntic gland adenoma and gastric adenocarcinoma of fundic gland type [3]. Though these subtypes are classically considered more benign, interest has been developing in a third group, gastric adenocarcinoma of fundic-gland mucosa type (GA-FG-M). GA-FG-M are distinct among OGN in that they more commonly show lymphovascular invasion on histology and are thus considered more aggressive lesions with higher malignant potential. Although interest in OGNs has been gradually increasing in the past few years, most studies had involved cases collected by tertiary referral centers, leading to a gap in the knowledge of the true disease frequency in the real-world setting. To address this issue, we previously reported the incidence of OGNs in 7488 patients in a large outpatient clinic in Japan between 2017 and 2021. However, the absolute number of OGNs was limited and the incidence of GA-FG-M was unknown [5].

Aims & Methods

The goal of this study was to more accurately characterize the disease frequency and clinicopathological characteristics of OGNs by including more than three times the number of lesions discovered since the previous report. We also aim to include an estimate for the GA-FG-M subtype. All upper gastrointestinal endoscopies performed at a high-volume outpatient clinic between December 2017 and December 2023 were retrospectively reviewed, and new cases of histologically diagnosed OGN were identified. Patient demographics, endoscopic and histopathological details are presented.

Results

During the study period, 9431 patients underwent 22322 procedures, with 85 patients having a total of 106 OGNs, resulting in a point prevalence of 0.9% (85/9431). GA-FG-M was identified in 3 patients, leading to a prevalence of 0.03% (3/9431). Fifteen patients (18%) had multiple lesions simultaneously or metachronically. Forty-six patients (54%) had a history of H. Pylori infection. Forty-nine lesions underwent endoscopic management, with 11 resected via ESD and 38 via EMR-C. The median tumor diameter was 3mm (range 2-9). Fourteen of the resected lesions had evidence of submucosal involvement. In this subset, the deepest penetration ranged from 10-950um into the submucosal layer. Median Ki67 index value was 2% (range 1-15). Thus far, there has been no evidence of recurrence on clinical follow up.

Conclusion

Though the most recent WHO classification states the prevalence of OGNs remains unknown [3], our data supports that these lesions are more common than once thought. Initial reports had suggested rates of <0.01% [6], and our previous study had found a community point prevalence of 0.36% [5]. However, in two years since that study period, the amount of lesions identified has more than tripled, leading us to a more accurate prevalence estimate of 0.9%. In addition, we clarified the prevalence of GA-FG-M to be 0.03%. It is possible this number may continue to rise in the future, as knowledge about this atypical form of gastric neoplasia is further disseminated amongst gastroenterologists and pathologists.

References

[1]Tsukamoto, Tetsuya, et al. "Gastric adenocarcinoma with chief cell differentiation." Pathology international. 2007, 57(8): 517-522.
[2] Ueyama H, Yao T, Nakashima Y, et al. Gastric adenocarcinoma of fundic gland type (chief cell predominant type): proposal for a new entity of gastric adenocarcinoma. Am J Surg Pathol. 2010, 34(5):609-619.
[3] Yao T, Vieth, M. Oxyntic gland adenoma. Digestive system tumours. In World Health Organization Classification of Tumours 5th edition (ed. WHO Classification of Tumours Editorial Board) 83–84, (International Agency for Research on Cancer, World Health Organization, 2019.
[4] Ueyama H, Yao T, Akazawa Y et al. Gastric epithelial neoplasm of fundic-gland mucosa lineage: proposal for a new classification in association with gastric adenocarcinoma of fundic-gland type. J Gastroenterol. 2021, 56(9):814-828.
[5] Asahara, Hikari, et al. "Clinicopathological Features and the Prevalence of Oxyntic Gland
Neoplasm: A Single-center Retrospective Study." Internal Medicine (2023): 0552-22.
[6] Tohda G, Osawa T, Asada Y, et al. Gastric adenocarcinoma of fundic gland type: Endoscopic and clinicopathological features. World J Gastrointest Endosc. 2016, 25(4):244-251.

Disclosure

There are no COIs to disclose in relation to this presentation.

Introduction

Gastric cancer ranks as the fifth most common cancer and the second leading cause of cancer-related deaths. Multifocal atrophic gastritis and gastric intestinal metaplasia (GIM) often coexist and are both associated with the risk of developing gastric cancer, with GIM being the first irreversible mucosal transformation to cancer. Endoscopic surveillance was associated with earlier cancer detection and improved survival. This study aims to evaluate the prevalence, epidemiological characteristics, and clinical features of patients with GIM.

Aims & Methods

This is a single-center, retrospective study from January 1, 2022 to December 31, 2023. Including patients aged ≥18 years who underwent esophagogastroduodenoscopy (EGD) with gastric biopsies confirming GIM, All identified cases of GIM were reviewed by gastrointestinal pathologists to confirm the diagnosis. Th primary outcome was to assess the prevalence, epidemiological characteristic, and clinical features of GIM. The secondary outcome was to evaluate adherence to recommended surveillance protocols for GIM.

Results

Among 3,663 patients who underwent EGD, GIM was identified in (4.17%, n=153). The mean age of patients with GIM was 60 years, Males represented more than half of patients (54.2%), the majority were classified as overweight (Body mass index (BMI) 25–29.9; 64%, n=97) or obese (BMI ≥30; 24.3%, n=37).Smoking was reported in (17.6%, n=27), while (5.2%, n=8) reported alcohol consumption. Moreover, (7.2%, n=11) had a history of prior gastric surgeries. Dyspepsia (33.3%) was the most common indication for EGD. Gastritis was the predominant endoscopic finding and the primary reason for performing gastric biopsies (73%, n=112 ).The most common GIM subtype was complete (52%), followed by incomplete (37%) and mixed (11%). In terms of GIM location, extensive GIM was observed in (28.7%), localized GIM in (17.6%), while the location remained unknown in (53.6%) due to the lack of a follow-up EGD for mapping. Coexisting autoimmune atrophic gastritis was observed in (12.4%, n=19), Helicobacter pylori infection was detected in (16.3%, n=25). Furthermore, Dysplasia was identified in (2.6%, n=4), with low-grade dysplasia and high-grade dysplasia each accounting for (1.3%, n=2) (Table 1). Three patients developed.gastric cancer (2%) , while (4.6%, n=7) were found to have neuroendocrine tumors (NET). First degree family history of gastric cancer was reported in (12.4%, n=19).

Conclusion

This study highlights a 4.17% prevalence of GIM among patients who underwent EGD. High BMI and male sex were observed in more than half of the patients. Dysplasia was detected in 2.6%, gastric cancer in 2%, and NET in 4.6% of cases. Many patients lacked follow-up EGD surveillance, limiting effective monitoring. Larger studies with extended follow-up are required to further investigate these associations and their clinical implications.

Introduction

Endoscopic submucosal dissection (ESD) is a common treatment for low-risk gastric cancers, but postoperative bleeding, affecting 0%-15.6% of patients, remains a concern. With aging populations and increased antithrombotic agent use, post-ESD bleeding may soon become even more frequent. Fibrin glue with polyglycolic acid (PGA) sheets has shown promise in preventing post-ESD bleeding, but challenges exist, especially when applying sheets against gravity in gastrointestinal ulcers. Moreover, the PGA sheets themselves can be difficult to manipulate and place onto the ulcer bed. The envelope method, developed in 2017, involves storing PGA sheets in a protective envelope that is carried alongside the endoscope, preventing exposure to saliva or mucus which commonly occurs when PGA sheets are individually passed down the endoscope channel. The envelope then adheres to the gastric wall, and clean PGA sheets can be drawn easily using forceps. This method has demonstrated efficient PGA sheet delivery and fixation but was only found to be effective for gravitational ulcers.

Aims & Methods

The study aims to evaluate the envelope method's efficacy in treating both gravitational and anti-gravitational post-ESD ulcers in living porcine stomachs.Gravitational and anti-gravitational artificial ulcers were created via ESD in living porcine stomachs, using a standardized template as a sizing guide. PGA sheets were then applied to each ulcer, employing the conventional and envelope methods six times each. To standardize the ulcer location and characteristics, the sheets were removed after application, and reapplied over the same ulcer bed. To account for minute changes in ulcer environment over time, the method of re-application was alternated between the conventional and envelope methods. The delivery time of PGA sheets and the endoscopic and histological observations of the treated ulcer surfaces were comparatively analyzed. The ulcers were measured with an endoscopic scale, and the delivery time was presented in min/cm² to allow for subtle differences in ulcer size.

Results

The envelope method showed significantly shorter application times compared to the conventional method for both gravitational (1.0 min/cm² vs 0.32 min/cm², p=0.002) and anti-gravitational ulcers (1.2 min/cm² vs 0.50 min/ cm² p=0.002). In endoscopic examinations, the envelope group demonstrated appropriately applied PGA sheets in anti-gravitational ulcers, with flat sheets and minimal overlapping, while the conventional group showed uneven sheets and clumping. Histologically, the envelope method provided uniform coverage of the ulcer floor with a mixture of PGA sheets and fibrin glue, while the conventional method left gaps between sheets.

Conclusion

The envelope method enables swift transportation and accurate fixation of PGA sheets within living porcine stomachs. This approach is applicable for addressing both gravitational and anti-gravitational ulcers, and may have utility in the prevention of post gastric ESD bleeding.

Introduction

Gastric adenoma is recognized as a premalignant lesion.¹Much of the literature lumps all adenomas together with different classifications. These are few western reports regarding the prevalence, associated risk factors and outcomes of endoscopic management of different subtypes of gastric adenoma.

Aims & Methods

Aims: The aim of this study is to determine the prevalence, potential predictors, and outcomes of endoscopic management of the different subtypes of gastric adenoma.
Methods: Of 162 consecutive patients who underwent endoscopic resection for gastric lesions between 2017 and 2022 at our center, 79 patients were enrolled. All the hyperplastic polyps (n=37) and subepithelial lesions (n=46) were excluded. The patient clinical characteristics, endoscopic and histopathological features of gastric lesions were retrospectively collected. Patients were divided according to the histological types of gastric adenoma into 4 groups: intestinal group (n= 49), foveolar group (n= 23),pyloric group (n= 6) and oxyntic group (n=1). We statistically compared the clinical and endoscopic features of the three groups. In addition to the analysis of the outcomes of endoscopic resection of gastric adenomas.

Results

Of the 79 patients with a mean follow-up of 2622 months, 51 patients were males (65 %) and 28 patients were females (35%). Forty-nine patients (49/79,62%) had intestinal adenoma, 23 patients (29%) showed foveolar adenoma, 6 patients (8%) developed pyloric adenoma and only 1 patient (1%) had oxyntic adenoma. The mean age was significantly older in the intestinal group (71 ± 13 years vs. 64 ± 16 years vs. 58 ± 18 years, p = 0.03). Intestinal adenomas were significantly associated with family history of gastric adenocarcinoma (14% vs. 4% vs. 0%, p = 0.01) and history of statin intake (39% vs. 26% vs. 0%, p = 0.04).Foveolar adenomas were significantly associated with multiple lesions (≥3 lesions) (p < 0.001) and 0-IIa+IIc Paris classification (6/23, 26%). the size of largest polyp was significantly higher among pyloric group (28 ±15, p= 0.00). Among intestinal group, 33/49 patients (67%) had atrophic gastritis. 82% of the adenomas were resected by ESD with histologically complete resection (R0) in 72/79 patients (91%). Although the difference was not statistically significant (p = 0.4), adenocarcinoma was most frequently encountered among the intestinal adenoma group (17/49, 35%). The post endoscopic resection outcome was comparable among 3 groups with overall recurrence rate (group1:8% vs. group 2:17% vs group 3:17%, P = 0.07) with a comparable mean time to recurrence among three groups (21 ± 17 months vs. 20±17months vs. 14 months, p=0.8). Family history of gastric adenocarcinoma (HR=1.33, p< 0.001) and active helicobacter pylori infection (HR=1.14, p < 0.001) were identified as independent predictors of recurrence after endoscopic resection of different gastric adenoma. Among baseline endoscopic characteristics, polyp size ³ 30mm(HR= 2.04, p< 0.001), more than 3 polyps (HR=1.51, p<0.001), lesser curvature as lesion location (HR=1.72, p< 0.001) and morphology as Paris classification IIc are potential predictors of post resection recurrence. In addition to specimen size ³ 15mm (HR=2.19, p< 0.001) and T1b as lesion histology (HR=2.07, p< 0.001), in the histopathological examination.

Conclusion

The present study clarifies the endoscopic and histopathological characteristics of different gastric adenomas, in addition to the potential predictive factors for each subtype. Potential predictors of recurrence after endoscopic resection emphazie the importance of endoscopic follow up.

References

1. Fujiwara, Y. et al. Diagnosis of borderline adenomas of the stomach by endoscopic mucosal resection. Endoscopy 28, 425–430 (1996).