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Year : 2018  |  Volume : 21  |  Issue : 3  |  Page : 375-379

Helicobacter pylori and precancerous lesions of the stomach in a Nigerian Metropolis: A Cohort Study

1 Digestive Disease Unit, Oak Endoscopy Centre Port Harcourt; Departments of Surgery, University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State, Nigeria
2 Department of Anatomical Pathology, University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State, Nigeria

Date of Acceptance03-Dec-2017
Date of Web Publication09-Mar-2018

Correspondence Address:
Dr. E Ray-Offor
Department of Surgery, University of Port Harcourt Teaching Hospital, P.M.B.6173, Port Harcourt, Rivers State
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/njcp.njcp_302_17

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Introduction: Helicobacter pylori (H. pylori)-related atrophic gastritis transits through a sequential pathway of intestinal metaplasia, dysplasia to gastric cancer. Gastroscopy offers early detection, treatment and surveillance of gastric cancer.Aims: This study aims to study the prevalence of H. pylori infection and evaluate precancerous lesions (PCLs) of the stomach. Patients and Methods: This is a case controlled study of patients with dyspepsia undergoing gastroscopy at a referral endoscopy facility in Port Harcourt metropolis of Nigeria. The variables studied included demographics, clinical, endoscopic, and histopathologic findings. Statistical analysis of data was done using IBM SPSS Statistics for Windows, Version 20.0. (Armonk, NY, USA). Results: A total of 104 patients were included in the study. Age ranged from 20 to 80 years (mean 47.1 ± 14.4 years); 56 were males and 48 were females. H. pylori were detected in 40 (38.5%) mucosal biopsies. The prevalence of PCLs was: chronic atrophic gastritis 6.7% (7 cases); intestinal metaplasia 2.9% (3 cases); and dysplasia 5.8% (6 cases). There was no statistical significance in sex distribution of PCLs (P = 0.245). Conclusion: There is a low prevalence of H. pylori in this metropolitan population. Mandatory multiple topographically targeted biopsies, even with normal mucosal appearance, at gastroscopy in addition to surveillance of PCL are recommended for early detection of gastric cancer.

Keywords: Helicobacter pylori, precancerous lesions, stomach, gastroscopy

How to cite this article:
Ray-Offor E, Obiorah C C. Helicobacter pylori and precancerous lesions of the stomach in a Nigerian Metropolis: A Cohort Study. Niger J Clin Pract 2018;21:375-9

How to cite this URL:
Ray-Offor E, Obiorah C C. Helicobacter pylori and precancerous lesions of the stomach in a Nigerian Metropolis: A Cohort Study. Niger J Clin Pract [serial online] 2018 [cited 2022 Nov 29];21:375-9. Available from:

   Introduction Top

Worldwide, cancers affecting the upper digestive tract occur in 1.6 million people annually, representing about 15% of all cancers.[1] Gastric cancer is the fifth-most common cancer and the second leading cause of cancer mortality worldwide. The incidence is highest in East Asia, Eastern Europe, and parts of Central and Southern America, with the lowest in Southern Asia, North and East Africa, Australia, and North America.[2],[3] A cascade sequence is well established in its pathogenesis from chronic gastritis through recognizable precursors. The sequence of progression is atrophic gastritis, metaplasia, dysplasia then intestinal-type gastric cancer.[4]Helicobacter pylori (H. pylori) infection plays a pivotal role in this progression and the pathogenesis of mucosa-associated lymphoid tissue lymphoma. This organism is classified as a grade 1 carcinogen affecting more than 50% of the world population.[5]

There is a strong association between H. pylori and the symptom of dyspepsia. This organism is a curved, motile, microaerobic gram-positive bacillus. A variety of laboratory investigations are available for H. pylori detection. The tests are divided into two classes – noninvasive and invasive. Noninvasive tests include urea breath, antibody detection, and stool antigen tests. The invasive class of tests is based on endoscopic mucosal biopsy evaluation and includes histopathological examination, culture, rapid urease test, and polymerase chain reaction. Endoscopy-based tests have a sensitivity of 85%–95% and specificity of >90%.[6]

A proper biopsy and histopathology at endoscopy is the gold standard for early detection of gastric cancer and related precancerous lesions (PCLs). Currently, there are endoscopic therapeutic modalities which are curative alternatives for dysplastic lesions and early gastric cancer with low risk of lymph node metastasis. Endoscopic mucosal resection is useful for en bloc resection of differentiated gastrointestinal neoplasia ≤2 cm while endoscopic submucosal dissection can achieve a higher en bloc endoscopic resection rate of wider lesions involving superficial submucosal involvement.[7] While gastrectomy is the mainstay for advanced gastric cancer treatment, surveillance for early diagnosis of cases and detection of precursor lesions are preventive measures which potentially improve the prognosis of this otherwise lethal disease.

The objective of this paper is to obtain endoscopic and histological data on the prevalence of H. pylori infection in a Nigerian population. Furthermore, this study evaluates PCLs of the stomach.

   Patients and Methods Top

Study setting

This study was conducted in a referral endoscopy centre in Port Harcourt metropolis of Rivers State Nigeria. The centre also serves patients from neighboring states of the Niger Delta region of Nigeria.

Study design

A case–controlled study of all consecutive patients with dyspepsia referred for gastroscopy at a referral endoscopy centre from February 2014 to January 2017. The diagnosis of dyspepsia was based on clinical findings. Exclusion criteria from the study included age below 18 years (pediatric patients), nonavailability of histopathology report and cases of gastric cancer. The variables studied were demographics, clinical, endoscopic, and histopathological findings.


A written informed consent was obtained from each patient or his/her legal guardian in accordance with the Helsinki Declaration. All endoscopies were performed by the same surgical endoscopist. The equipment used included: Karl Storz (Germany) video processor, 100W Xenon lamp, and forward viewing video gastroscope. After a 6-h fast a systematic examination at gastroscopy was performed in the left lateral position preceded by conscious sedation using intravenous diazepam 2.5–5 mg and a pharyngeal local anesthesia. The endoscopic findings were categorized as normal (Group A), ulcerative with or without concurrent abnormalities (Group B) and abnormal nonulcerative Group C (erythema nodularity, atrophic mucosa, polyps, etc.). A minimum of 4 biopsies were taken; 2 from antrum and 2 from body including targeted lesional biopsy. The specimen was fixed in neutral 10% buffered formalin and transported to the laboratory in appropriate condition accompanied with documentation on clinical information and endoscopic findings.


The samples underwent automated tissue processing in the histopathology laboratory. Proper specimen orientation was ensured during paraffin embedding and thin microtome serial sections were stained with hematoxylin/eosin and Giemsa stains. The tissue slides were examined with light microscope only. H. pylori were sought for specifically on Giemsa-stained sections and were light blue to grayish colored short rods within the luminal mucin or epithelial crypts. The histological examinations were performed by the same pathologist using Sydney classification.

Each tissue section was assessed for suitability of pathologic diagnoses and was adjudged as suitable if it showed well-oriented tissue sections with intact mucosal surface and muscularis mucosae. Chronic gastritis was diagnosed when there are patchy or diffuse infiltrates of the lamina propria by mononuclear cells (plasma cells and lymphocytes). Intraglandular neutrophil was the tool for assessment of the activity of the lesion. The presence of glandular neutrophils and/or lymphoid follicle formation heightens suspicion for H. pylori infection and leads to intensified efforts for the search of the organism in Giemsa-stained sections. Intestinal metaplasia was seen as the replacement of gastric mucinous epithelial cells with small intestinal epithelium containing mucin-producing goblet cells with or without a brush border, while atrophy was diagnosed as gland-depleted mucosa, with or without fibrosis or replacement of native glands by intestinal-type glands. Dysplasia was characterized by cytologic and architectural atypia composed of the presence of crowded tubular glands lined by atypical cells. The atypical features include nuclear pseudostratification and pleomorphism with pencillate, hyperchromatic appearance, mucin depletion, crowding, loss of polarity, increased mitoses, and lack of surface maturation. Depending on the intensity of the features, dysplasia was graded low or high grade.

Statistical analysis

The data were analyzed using IBM SPSS Statistics for Windows, Version 20.0. (Armonk, NY, USA). Categorical data were analyzed using the Chi-square or Fisher's exact test, and continuous data were analyzed using the Student's t-test. The level of significance was set at 0.05.

   Results Top

Baseline data

A total of 104 patients with dyspepsia were evaluated. The age range was from 20 to 80 years; a mean age of 47.1 ± 14.4 years. The age and sex distribution are as shown in [Figure 1]. The fourth decade of life was the most common age group affected closely followed by the third decade. There were 56 males and 48 females; a male to female sex ratio of 1.2:1.
Figure 1: Age and sex of patients with dyspepsia

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Clinical data

Ten patients knew their blood group to be Group A with 2 of these later diagnosed with PCL. There was no case of pernicious anemia, gastric surgery or family history of gastric cancer.

Endoscopic findings:

Group A: Three patients (3.0%) had normal gastric mucosal appearance at endoscopy [Figure 2].
Figure 2: Distribution of endoscopic findings in study population

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Group B: 7 (6.3%) cases of gastric ulcers were recorded-1 cardia, 1 lesser curvature, and 5 antral area (3 prepyloric).

Group C: The features of inflammation (erythema, mucosal hemorrhage, and nodularity) were recorded in 92 cases with 49 (52.7%) in the antrum only and 14 (15.1%) involved the cardia, corpus and antrum. Gastric erosions were observed in 7 cases and polyps in 4 cases (1 fundic and 3 antrum). A case of gastric diverticulum was recorded.

Histopathologic findings

The histopathologic findings are as shown in [Table 1]. Forty cases were positive for H. pylori. Twenty-one were females and nineteen were males. There was no statistical significance in the sex distribution of H. pylori infection (p. 0.305). The age distribution of patients with H. pylori infection and PCLs are as shown in [Figure 3].
Table 1: Histopathologic diagnosis in study population

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Figure 3: Age-adjusted distribution of Helicobacter pylori positivity and precancerous lesion in study population

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A total of 16 PCLs in 14 patients were histologically diagnosed. These included: 7 atrophic changes, 3 intestinal metaplasia, and 6 dysplasia. Nine were females and five were males.

   Discussion Top

The prevalence of H. pylori infection is related to age, sex, and socioeconomic conditions.[8] In this study, conducted in a metropolitan city of a developing country, a prevalence rate of 38.5% was recorded. A similar detection rate of 41% was recorded in Lagos, another metropolitan city in Nigeria, yet 59.4% prevalence from a rural/suburban area in India, 92.2% from urban/suburban/rural areas in Cameroon and 94% in a high-risk population in Venezuela[9],[10],[11],[12] The possible reason for a lower rate of H. pylori detection in our study is the common practice eradication therapy for dyspeptic symptoms prescribed by managing physician before referral for gastroscopy. There was no variation of infection with sex observed. When adjusted for age, 64.1% patients in this study with H. pylori infection were below 50 years. This is unlike the trend in developed countries of a higher prevalence rate later in life.

Gastritis was the most common endoscopic finding. Chronic gastritis has several etiological factors such as smoking, nonsteroidal inflammatory drugs, reflux of bilious fluid into the stomach and H. pylori infection. A normal endoscopic mucosa is often pathologic as was observed in three cases of normal appearing mucosa with tissue diagnosis of chronic gastritis. A similar study in Iran reported a 6.8% prevalence of PCL in normal-appearing mucosa.[13] This underscores the need for routine gastric mucosal biopsies at gastroscopy. Atrophic gastritis and intestinal metaplasia are often unevenly distributed throughout the stomach. The biopsies from antrum and corpus are a useful strategy to guarantee the maximum diagnostic yield.[14] This was adopted in our methodology in addition to target biopsies of lesions. We observed a low peptic ulcer rate. This may be due to the low colonization rate of H. pylori recorded in addition to a global decline of this with eradication therapy. Further studies on a larger population will draw further conclusion. Erythematous nodular mucosa and erosive changes showed a higher rate of positivity for H. pylori. By logic, this is a predictor of PCL.

The annual incidence of PCL observed in this study was low however in the Netherlands a study revealed that premalignant lesions would progress to GC with an annual incidence of 0.2% from AG, 0.25% from IM, 0.6% from mild-to-moderate dysplasia, and 6% from severe dysplasia.[15] Three independent risk factors have been identified in the development of gastric cancer in atrophic gastritis: over the age of 50 years, the presence of atrophic pangastritis and of severe body intestinal metaplasia.[16] In this study, the prevalence of dysplasia was seen more in the 7th and 8th decades of life despite the high incidence of H. pylori infection in the 3rd and 4th decades of life. This portends a long-term progression over the years to gastric cancer. In the UK, a varying progression rate of AG to GC up to 2% per year is documented.[17] It has been reported that the eradication of H. pylori can reverse atrophic gastritis and intestinal metaplasia.[18] There is a paucity of data on progression rate in Sub-Saharan Africa.

Therapeutic endoscopy has reduced the need for surgery in the treatment of benign and malignant conditions of the digestive tract. No case met the criteria for advanced endoscopic resection techniques. However, endoscopic mucosal resection was performed for sessile colonic adenoma during the study. It has been canvassed that the identification and surveillance of patients with precursor conditions and lesions may lead to early diagnosis of gastric cancer and improved survival.[19],[20] A recent International multisociety guideline on the management of patients with precancerous conditions and lesions proposed a 6 monthly endoscopic follow-up for high-grade dysplasia and 12 monthly for low-grade dysplasia (evidence level 2+); patients with extensive atrophy and/or extensive IM should be offered endoscopic surveillance (evidence level 2++, recommendation grade B) every 3 years; patients with mild-to-moderate atrophy and or IM only in antrum do not need follow-up (evidence level 4).[21]

There were some limitations to this study. It was a single-center study evaluating only symptomatic patients and H. pylori infection which was confirmed using only one method-histologic, despite this test having a high sensitivity and specificity. Another limitation was the use of white light endoscopy which is known to have a significant miss rate in gastrointestinal pathology. At present, new advanced high-resolution endoscopic technologies are showing promising results with respect to visual diagnosis of precancerous mucosal lesions and targeted biopsy. These include magnification endoscopy, chromoendoscopy, narrow band imaging, autofluorescence, and confocal endomicroscopy lesions.[22],[23],[24]

As recommendations based on our results, further study on the prevalence of H. pylori and PCL should include asymptomatic population. For gastric cancer screening, people younger than 30 years should be tested for H. pylori infection, and infected patients should receive eradication therapy. H. pylori-infected patients older than 30 years should receive endoscopic examination in addition to eradication therapy. In the absence of expertise and nonavailability of advanced imaging techniques in developing countries, surgeon endoscopists and gastroenterologists practicing in these parts are to acquire expertise in using conventional endoscopy to uncover subtle mucosal changes. Furthermore, mandatory topographic biopsy at gastroscopy is recommended even in the presence of normal-appearing mucosa. Finally, with paucity of data on the natural history of gastric cancer in Sub-Saharan Africa, an annual endoscopic/histopathologic surveillance plan for atrophy/intestinal metaplasia and a 6-monthly plan in all grades of dysplasia, will aid the study of any geographic variation of this disease.

   Conclusion Top

There is a low prevalence of H. pylori in this metropolitan population. Mandatory multiple topographically targeted biopsies, even with normal mucosal appearance, at gastroscopy in addition to surveillance of PCL are necessary for early detection of gastric cancer.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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