Evaluating the detection rate and pathological features of polyps in patients with upper gastrointestinal endoscopy

Abstract

BACKGROUND

The incidence of gastric polyps (GPs) has ranged from 0.30% to 6.8% in various studies. Most GPs include hyperplastic polyps (HPs), fundic gland polyps (FGPs), and adenomatous polyps (APs). Although APs have a high malignant potential, HPs have a low risk of potential harm, whereas sporadic FGPs have no malignant potential. It is not enough to determine the type and displacement of a polyp by biopsy alone; therefore, some polyps may require an extensive biopsy or complete resection.

AIM

To evaluate the detection rate and pathological features of polyps in patients undergoing upper gastrointestinal endoscopy.

METHODS

This retrospective study included patients with GPs or polyphenic lesions with polyps or malignant histology found in polyps or by gastroscopy at the Department of Gastroenterology at the Shaanxi Provincial Hospital of Traditional Chinese Medicine from 2019 to 2023.

RESULTS

In a series of 10000 patients who underwent upper gastrointestinal endoscopy, 384 (3.84%) had GPs. There were 98 males (25.5%) and 286 females (74.5%). The mean age of patients was 62.8 ± 10.4 (36-75) years. The frequencies of HPs, APs, and FGPs were 88.5%, 5.2%, and 2.1%, respectively. The polyp size of 274 patients (71.3%) was ≤ 1 cm. Polyps were found in 262 cases (68.2%). The most common sites for polyps were the lumen and body of the intestine. Endoscopic polypectomy was performed in 128 patients. Bleeding events were observed and endoscopic treatment was required after endoscopic polypectomy.

CONCLUSION

The incidence of GPs was low. HPs were the most common types of GPs. Of note, as GPs have the potential to develop into adenocarcinoma or precancerous lesions, we suggest that appropriate GP resection technology (e.g., biopsy forceps or mesenchymal resection) be applied.

Key Words: Endoscopic polypectomy; Gastric polyps; Histological examination; Adenomatous polyps; Hyperplastic polyps; Fundic gland polyps; Abdominal pain

Core Tip: Gastric polyps (GPs) are a common clinical disease. In recent years, with the change in dietary habits, the incidence of GPs is increasing in China. GPs are usually found by gastroscopy. Some GPs may have malignant potential and are associated with hereditary diseases. Therefore, early detection and biopsy examination are important in clinical practice to better reduce the rate of cancer.

INTRODUCTION

Most gastric polyps (GPs) are found accidentally when an upper gastrointestinal endoscopy is performed for other reasons[1]. Although there are no specific clinical manifestations, these lesions typically cause discomfort such as indigestion, gastric pain, abdominal pain, or gastrointestinal bleeding[2]. Due to the anatomical differences in different regions, polyps in the cardia may cause difficulty in swallowing, whereas polyps (especially pedicled polyps) in the pylorus can lead to outflow tract obstruction[3]. An extremely small proportion of patients may have large polyps, which cause gastrointestinal bleeding when the lesions become eroded and ulcerated[4]. Larger polyps have high malignant potential, and some of them are actually malignant tumors[5]. Although polyps can induce symptoms, few patients seek medical treatment merely for this disease[6]. Clinically, polyps are mostly accompanied by a variety of disorders such as gastritis or peptic ulcer, and some polyps or even the normal mucosa or mucosal lesions around a polyp may develop atypical hyperplasia, intestinal metaplasia, and other conditions[7]. As a result, the symptoms in a patient with polyp may not be caused by the polyp itself. The treatment options for GPs include endoscopic polypectomy, removal with biopsy forceps, endoscopic mucosal resection, endoscopic submucosal stripping, and even partial or total gastrectomy, depending on the location and size of the polyp and the presence or absence of a pedicle[8]. The endoscopic technique is simple and minimally invasive and has been widely used[9].

Polyps are usually asymptomatic and > 88% are detected by esophagogastroduodenoscopy for other reasons. Large polyps can cause bleeding, anemia, abdominal pain, or obstruction due to their position[10]. The diagnosis of polyps must be confirmed by histological examination[11]. The frequency of GPs and other polyps varies depending on the population under study[12]. The prevalence of polyps is 0.6%-6%[13,14]. Hyperplastic polyps (HPs) are most common in people with Helicobacter pylori infection[15]. In countries with low rates of H. pylori infection, fundic gland polyps (FGPs) are more common. The long-term use of proton pump inhibitors (PPIs) increases the frequency of FGPs[16]. The importance of GPs stems from the fact that some GPs have malignant potential or are associated with some genetic syndromes. While GPs are present in many congenital conditions, such as familial adenomatous polyposis (FAP), juvenile polyposis, and Peutz-Jeghers syndrome, they are most often misdiagnosed[17]. In addition to FGPs and polyps such as inflammatory fibrinoid polyps (IFPs), the risk of cancer is increased with polyps. Although the risk of malignant transformation in HPs is low, it is more common in adenomatous polyps (APs). Due to their malignant potential and symptomatic nature, GPs are removed completely with endoscopic resection or surgery[18].

The purpose of this study was to evaluate the demographic, clinical, endoscopic, and histologic data in patients with polyps or polypoid lesions. In addition, we evaluated diagnostic procedures, treatments and their complications, and the relationship between age and size and number of polyps.

MATERIALS AND METHODS

At the Department of Gastroenterology, Shaanxi Hospital of Traditional Chinese Medicine (Shaanxi, China) and People’s Hospital of Jishan County (Jianshi County, China), we retrospectively reviewed the results of 10000 consecutive esophagogastroduodenoscopy (EGD) procedures performed for various reasons between September 2019 and July 2023. We evaluated age and sex; endoscopic indications and findings; GP count, size and location; histological diagnostic methods; and endoscopic treatment complications. The relationship between age and size and number of polyps was also assessed. The endoscope used was the Olympus EG 290 WR video endoscope (Olympus, Tokyo, Japan). The size of the polyps was estimated by comparing it with the opening size of the biopsy forceps. In patients with multiple polyps, polyp diameter was calculated by measuring the largest polyp diameter. Inclusion criteria were: (1) No contraindications for gastroscopy; (2) Adequate gastric preparation before the examination; and (3) Detailed and complete examinations of esophagus, cardia, gastric fundus, gastric body, pylorus, and other areas. Exclusion criteria were: (1) Previous gastric surgery for other reasons; (2) History of gastric cancer, Peutz-Jeghers syndrome, FAP, and/or juvenile polyposis; (3) Difficulty observing the gastric mucosa due to poor gastric preparation and/or incomplete exploration of the gastric cavity due to interrupted examination; (4) Presence of inflammatory bowel disease; and (5) Lack of pathological results.

Histopathological examination

An appropriate treatment strategy was adopted in patients who had no contraindications for surgery and agreed to receive endoscopic resection. Single GPs with a diameter < 3 mm were directly removed by electrocoagulation after biopsy, and those with a diameter > 3 mm were partially sampled for pathology. For multiple polyps, only the polyp with the largest diameter was partially sampled for pathological examination. All of the above specimens were examined in the Department of Pathology in our hospital.

Statistical analyses

Data were analyzed using the SPSS software package program for Windows 23.0 (IBM SPSS, Armonk, NY, United States). Descriptive statistics were used to describe the continuous variables. The χ² (Fisher’s exact) test was used to classify variables and expressed as the number of observations (and percentages). Statistical significance was obtained when P < 0.05. The Kolmogorov-Smirnov test was used to analyze the category data corresponding to the normal distribution, and Spearman’s correlation was used if the distribution of variables was abnormal.

RESULTS

We included 10000 patients receiving EGD in the Shaanxi Hospital of Traditional Chinese Medicine and People’s Hospital of Jishan County. GPs were found in 384 patients. The incidence of polyps was 3.84%. Patient characteristics are shown in Table 1. Among these patients, 34 (8.9%) were aged 40 years, 72 (18.7%) 41-50 years, 84 (21.9%) 51-60 years, 34 (33.8%) 61-70 years, and 64 (16.7%) > 70 years. The average polyp diameter was 10.6 ± 4.1 (range: 3-21) mm: 98 (25.5%) were £ 5 mm, 176 (45.8%) 6-10 mm, 90 (23.4%) 11-20 mm, and 20 (5.2%) > 20 mm. There were no significant correlations between age and polyp size (P > 0.05). Endoscopy revealed that 262 (68.2%) patients had one polyp, and 122 (31.8%) patients had more than one. Age was not significantly associated with polyp count (P > 0.05). A total of 204 (53.1%) patients underwent histopathological diagnosis of polyposis, 150 (39.1%) underwent polypectomy with forceps biopsy, and 30 (7.8%) underwent polypectomy and surgical resection. Ten patients could not be diagnosed by endoscopic biopsy. Histologically, the denucleated polyp was defined as IFP. Twenty (5.2%) patients had foveolar hyperplasia. Table 2 summarizes the histological distribution of polyps. Only 1 (0.3%) patient with GPs was diagnosed with adenocarcinoma. The most common localization of GPs was the antrum (150/384; 39.1%), followed by the corpus (112/384, 29.2%) and cardia (70/384, 18.2%). Polypectomy was performed in 150 (39.1%) patients using forceps biopsy. There were no complications in 74 patients who underwent polyp resection with forceps biopsy, and only 1 patient had bleeding in the form of leakage during polyp resection, and the bleeding was controlled by sclerotherapy.

Table 1 Demographic data and clinical characteristics of patients, n (%).

Patients		Patients
Sex		Distribution of polyp size (mm)
Male	98 (25.5)	< 5	98 (25.5)
Female	286 (74.5)	6-10	176 (45.8)
Age (year)		11-20	90 (23.4)
< 40	34 (8.9)	> 20 mm	200 (5.2)
41-50	72 (18.7)	Symptom
51-60	84 (21.9)	Dyspepsia	126 (32.8)
61-70	34 (33.8)	Anemia	82 (21.3)
> 70	640 (16.7)	Abdominal pain	70 (18.2)
Polyp size (mm), mean ± SD	10.6 ± 4.1 (3-21)	Other	106 (27.6)

SD: Standard deviation.

Table 2 Distribution of histopathological types of gastric polyps, n (%).

Characteristic	n = 384
Hyperplastic polyp	340 (88.5)
Foveolar hyperplasia	20 (5.2)
Fundic gland polyp	8 (2.1)
Adenomatous polyp	8 (2.1)
Adenomatous and hyperplastic polyp	2 (0.5)
Inflammatory fibroid polyp	2 (0.5)
Fibrotic polyp	2 (0.5)
Adenocarcinoma	1 (0.3)
Carcinoid tumor	1 (0.3)

The clinical manifestations of the patients in this group mainly included retrosternal discomfort, acid reflux, heartburn, weight loss, loss of appetite, nausea, vomiting, abdominal pain, and abdominal discomfort were not statistically significance (P > 0.05). These clinical manifestations of GPs were not specific, and these symptoms are common. It is not just one symptom, but rather two or more symptoms. As shown in Table 3, since two or more symptoms can be present at the same time, the total number of cases is more than 384.

Table 3 Distribution of clinical symptoms in different pathological types.

Symptoms	Hyperplastic polyp	Foveolar hyperplasia	Fundic gland polyp	Adenomatous polyp	Adenomatous and hyperplastic polyp	Inflammatory fibroid polyp	Fibrotic polyp	Adenocarcinoma	Carcinoid tumor
Regurgitation	104	12	3	2	1	1	1	1	1
Heartburn	92	6	2	2	1	0	0	0	0
Belching	70	6	1	1	0	1	1	0	0
Poststernal discomfort	15	0	0	0	0	0	0	0	0
Weight loss	8	1	0	0	0	0	0	0	0
Nausea/vomiting	16	1	0	0	0	0	0	0	0
Abdominal pain	31	1	0	1	0	0	0	0	0
Bloating	8	4	2	2	0	0	0	0	0

Snare polypectomy was performed in 128 patients (33.3%) who were treated alone or in combination with sclerotherapy, inner canthus, or inner canthus. The distribution of different snare polypectomy methods is shown in Table 4. In patients who underwent polypectomy, polyps were 10.6 ± 4.1 (3-21) mm in diameter. No complications associated with polypectomy were observed in 118 patients (92%). Bleeding occurred in 8 patients during polypectomy. Spontaneous bleeding occurred in 2 patients during endoscopic polypectomy, and sclerotherapy was used in 2 patients. The bottom of the polyp was bleeding, and hematemesis occurred 4 hours after polypectomy. Sclerotherapy controls bleeding without the need for blood transfusions.

Table 4 Distribution of types of snare polypectomy, n (%).

Characteristic	Patients
PS	75 (58.6)
PS + sclerotherapy	41 (32.0)
PS + endoloop	7 (5.5)
PS + sclerotherapy + endoloop	3 (2.3)
PS + sclerotherapy + endoclip	2 (1.6)
Total	128 (100)

PS: Polypectomy with snare.

DISCUSSION

In this study, we found that the most common symptoms of GPs were abdominal pain, anemia, and nausea. The increasing incidence of GPs in recent years may be attributed to the following reasons: (1) An increasing number of people undergo endoscopy for health check-ups[19]; (2) Environment and diet components have changed with socioeconomic development; and (3) Advances in endoscopic technology and its wide application have increased the positivity rate. The detection rate of GPs is reportedly 6.35% in the United States[20,21]; in China, it ranges from 1% to 4.3%. The literature suggests that GPs tend to be more common in females[22-25].

H. pylori infection can cause an inflammatory reaction of the mucosa, and a polyp may form due to overgrowth of cells during the recovery period[26,27]. In fact, HPs are byproducts of the damaged mucosa during its healing[28]. According to the literature, the vast majority of FGPs occur in patients who are not infected with H. pylori[29,30]. In addition, long-term duodenal reflux can cause chronic inflammation, gastric pit cell hyperplasia, atypical hyperplasia, polyps, and other lesions[31,32]. Large amounts of gastric reflux can cause inflammatory changes in the mucosa[33]. Also, it can alter the acid-base balance in the stomach, leading to excessive secretion of gastrin, which, to a certain extent, promotes cell proliferation and thus triggers the forming of HPs[34,35].

Use of PPIs can affect the course of FGP[36]. Prolonged PPI administration results in the increased number and volume of FGP[37], whereas PPI reduction and withdrawal are associated with gradually decreased number and volume of FGP[38]. It has been found patients taking PPI for less than 1 year will not develop FGP[39]; however, long-term PPI therapy increases the risk of polyps (in particular, it is associated with a 4-fold increased risk for FGP)[40]. This phenomenon is considered to be a cystic change caused by the chronic stimulation of gastric mucosa by a high level of gastrin[41]. Animal experiments have revealed that gastrin can promote the growth of parietal cells by increasing their height and size[42]. When the parietal cells in the neck of gland are enlarged, they may block the opening of the gland and increase the pressure inside the gland, leading to the development of cystic changes and eventually the forming of polyps[43].

In recent years, the incidence of FGP has markedly increased in Western countries, accounting for more than 70% of GP[44]. It has been reported that FGP is not associated with H. pylori but with PPI therapy[45]. FGP may be resolved with the withdrawal of PPI[46]; therefore it is speculated that the pathogenesis of FGP may be related to the inhibition of gastric acid secretion[47]. Long-term PPI use can lead to hypergastrinemia, which promotes the cystic dilatation of gastric glands to form polyps[48].

However, the development of HP has been associated with H. pylori infection and hypergastrinemia[49]. In this study, FGPs were found in 8 patients. H. pylori infection is known to reduce the formation of FGP, and these polyps are common in H. pylori-negative patients. This low incidence may be related to the high rate of H. pylori infection in China. However, the incidence of FGP may be high even in countries with high rates of H. pylori infection, but these polyps have not been observed in several studies[50]. The frequency of FGPs is associated with long-term PPI use. No increased risk was observed for short-term use. The most common reason for EGD surgery is indigestion. The frequency of FGPs in our patients is low, probably because they were treated with PPIs for a short period of time. In addition, because these polyps are small, they may be missed during EGD surgery or overlooked due to their unclear endoscopic appearance.

In our study, 200 (5.2%) patients had FHPs. These lesions are considered to be precursors of HPs, although it is unclear how long FHPs take to change to HPs. The lesions may be stable, or they may enlarge or shrink. However, whether they are precursors of HPs remains controversial. Studies have shown that biopsy material obtained with endoscopic forceps easily differentiates FHPs from HPs by basic structural and cytologic criteria. These lesions were not caused by HP precursors[51]. FHPs were common lesions in the study. Among 8 patients in our research, APs were detected in 8 patients. APs accounts for 2.1% of GPs. These polyps are more common in patients with stomach cancer, with a malignant potential of 6.8% to 55.3%[52]. The size of the lesion, the height of atypical hyperplasia, and the presence of intestinal epithelium are risk factors for the development of malignant tumors. During long-term follow-up, even low-displacement adenomas have the potential for malignancy. Thus, resection of these lesions is recommended. In addition, our study identified 1 patient with IFP. These polyps are not always diagnosed by endoscopic biopsy as they are localized[53]. Since our case was not confirmed by endoscopic biopsy, the diagnosis was made after surgical excision[54].

In our study, 128 patients (33.3%) had undergone snare polypectomy. One patient required endoscopic bleeding control. Bleeding rates due to endoscopic polypectomy are low and can be treated with sclerotherapy, endoclip, or endoloop procedures. No patient died or perforated. Snare polypectomy is a safe and effective way to diagnose and treat polyps. In conclusion, the GP frequency in this research was low (3.84%). HP polyps were the most common types of GPs. Of note, as GPs may have a risk of developing adenocarcinoma or precancerous lesions, we suggest that appropriate GP resection technology (such as biopsy forceps or mesenchymal resection) should be applied.

CONCLUSION

GP is a common clinical disease. In recent years, with the change in dietary habits, the incidence of GP is increasing in China. GP is usually found by gastroscopy. Some GPs may have malignant potential and are associated with hereditary diseases. Therefore, early detection and biopsy examination are important in clinical practice. In the current study, the frequency of GPs was low (0.38%) and the frequency of HP was likely high due to the high frequency of H. pylori infection in China. Due to the high frequency of H. pylori infection and the short-term use of PPs, the frequency of FGPs may be low.