Effect of Helicobacter pylori infection on malignancy of undifferentiated-type gastric cancer

Background Although almost all cases of gastric cancer are caused by Helicobacter pylori (HP) infection, there are some rare exceptions. Furthermore, the clinicopathological characteristics of gastric cancer may differ depending on HP infection status. This study aimed to determine the clinicopathological characteristics of undifferentiated-type gastric cancer (UD-GC) according to HP status. Methods The study involved 83 patients with UD-GC who were selected from 1559 patients with gastric cancer who underwent endoscopic resection at our hospital and whose HP infection status was confirmed. Clinicopathological characteristics were evaluated according to HP status (eradicated, n = 28; infected, n = 32; not infected, n = 23). Results In patients without HP infection, UD-GCs were < 20 mm and intramucosal with no vascular invasion. In patients with eradicated HP, there was no correlation between development of UD-GC and time since eradication. Nine of twelve patients with a tumor detected ≥ 5 years after eradication had undergone yearly endoscopy. Submucosal invasion was observed in two of four patients and lymphovascular invasion in three of four patients whose UD-GC was detected ≥ 10 years after eradication. There was no significant between-group difference in the frequency of lesions with invasion into the submucosal layer or deeper (14.3%, 10.5%, and 0% in the UD-E, UD-I, and UD-U groups, respectively). Conclusion The clinicopathological characteristics of UD-GC were similar between HP-infected patients and HP-eradicated patients. Three of four patients with eradicated HP whose UD-GC developed ≥ 10 years after eradication were not eligible for endoscopic treatment and required additional surgery resection. In contrast, UD-GC was curable by endoscopic resection in all patients without HP infection.

Prevalence and risk factors of irritable bowel syndrome in Irkutsk

Introduction. The study of the problem of irritable bowel syndrome (IBS) in recent years has been very dynamic. In the Rome IV criteria, new criteria for the diagnosis of this pathology were proposed. Along with the existence of ethnic and geographic differ­ences, this has led to an increase in the activity of studies on the prevalence of IBS.Aim. To study the prevalence and risk factors of irritable bowel syndrome in Irkutsk.Materials and methods. A single-stage observational non-randomized study was performed on the basis of three medical institu­tions in Irkutsk. Interviewing and clinical examination were performed in 1 529 people: 724 men and 805 women, average age 51.0 years. The questionnaire contained questions to determine the presence of alarm symptoms. The diagnosis of IBS was based on the Rome IV criteria. IBS with a predominance of diarrhea, IBS with a predominance of constipation and mixed and undiffer­entiated IBS were distinguished. Taking into account the position of the Rome IV criteria and the recommendations of the American College of Gastroenterology (2021), we used a positive diagnosis of IBS in our study and did not perform an instrumental examination of patients.Results. The prevalence of IBS was 12.3%. Among the subtypes of IBS, IBS prevailed with a predominance of constipation (preva­lence 5.7%) and IBS of mixed and undifferentiated type (prevalence 4.6%). Risk factors for IBS were female sex (OR = 0.73; CI 0.53-0.99; p = 0.05), age over 50 years (OR = 0.66; CI 0.48-0.90; p = 0.01) and obesity (OR = 0.46; CI 0.31-0.69; p < 0.001). Risk factors for IBS with a predominance of constipation were female sex (OR = 0.46; CI 0.29-0.73; p = 0.001), age over 50 years (OR = 0.46; CI 0.29-0.73; p = 0.001) and obesity (OR = 0.41; CI 0.23-0.72; p = 0.002).Conclusions. In general, our results are consistent with data from other regions of the world. It should be emphasized that the prevalence of IBS in Irkutsk is quite high, which requires careful attention to this problem.

The effect of Helicobacter pylori eradication on prognosis of postoperative early gastric cancer: a multicenter study

Objective To investigate the effect of Helicobacter pylori (H. pylori) eradication on the prognosis of postoperative early gastric cancer (EGC). Methods This is a retrospective study based on data from 6 hospitals. We identified 429 patients with EGC who underwent curative gastrectomy from January 2010 to December 2016. All of the patients were tested for H. pylori. Patients were divided into two groups, the successful H. pylori eradication group (group A, 268 patients) and the non-H. pylori eradication group (group B, 161 patients), for calculating the disease-free survival (DFS) and overall survival (OS) of each group. Result Positive node metastasis (hazard ratio (HR), 3.13; 95% confidence interval (CI), 1.84–5.32; P < 0.001), undifferentiated type (HR, 2.54; 95% CI, 1.51–4.28; P < 0.001), and non-H. pylori eradication (HR, 1.73; 95% CI, 1.08–2.77; P = 0.023) were statistically significantly independent risk factors of recurrence. Patient’s age ≥60 years old (HR, 3.32; 95% CI, 2.00–5.53; P < 0.001), positive node metastasis (HR, 3.71; 95% CI, 2.25–6.12; P < 0.001), undifferentiated type (HR, 3.06; 95% CI, 1.79–5.23; P < 0.001), and non-H. pylori eradication (HR, 1.83; 95% CI, 1.11–3.02; P = 0.018) were statistically significantly independent risk factors of overall survival. Conclusion H. pylori eradication treatment could prevent the recurrence of postoperative EGC to prolong the overall survival of patients with EGC.

Usefulness of Magnifying Endoscopy with Narrow-Band Imaging for Diagnosing Mixed Poorly Differentiated Gastric Cancers

<b><i>Introduction:</i></b> Curative rates of endoscopic treatment for undifferentiated-type early gastric cancer (EGC), particularly mixed poorly differentiated adenocarcinoma (MIXED-POR), are lower than those of endoscopic treatment for the differentiated type. Magnifying endoscopy with narrow-band imaging (ME-NBI) is useful for diagnoses of the histological type. This study aimed to investigate the detection rates of MIXED-POR among undifferentiated-type EGCs using biopsy and ME-NBI in order to improve curative rates through endoscopic treatment. <b><i>Methods:</i></b> We analyzed 267 lesions initially subjected to endoscopic submucosal resection (ESD) and histologically diagnosed as undifferentiated-type EGCs between July 2005 and December 2016 at our hospital. We obtained written informed consent from all participants. Biopsy and ME-NBI findings were compared to distinguish pure signet ring cell carcinoma (PURE-SIG) and MIXED-POR. ME-NBI findings were divided into 2 categories depending on the presence of irregular vessels. Results of biopsy and ME-NBI (combination method) were also analyzed, and detection rates of MIXED-POR and PURE-SIG were evaluated in terms of sensitivity, specificity, and accuracy. <b><i>Results:</i></b> Overall, 114 lesions were analyzed. Fifty-eight lesions (50.9%) were identified as MIXED-POR. With biopsy, the detection rate of MIXED-POR was significantly lower than that of PURE-SIG (<i>p</i> &#x3c; 0.0001). ME-NBI detected significantly more MIXED-POR with irregular vessels than PURE-SIG (<i>p</i> &#x3c; 0.0001). The combination method could detect significantly more MIXED-POR than PURE-SIG (<i>p</i> &#x3c; 0.0001). The sensitivity and accuracy for MIXED-POR diagnosis were significantly higher with the combination method than with biopsy alone (<i>p</i> &#x3c; 0.0001). <b><i>Discussion/Conclusion:</i></b> Combining biopsy and ME-NBI improved the accuracy of pretreatment diagnosis before ESD in undifferentiated-type cancer.

Effect of Helicobacter Pylori Infection on Malignancy of Undifferentiated-type Gastric Cancer

Background: Although almost all cases of gastric cancer are caused by Helicobacter pylori (HP) infection, there are some rare exceptions. Furthermore, the clinicopathological characteristics of gastric cancer may differ depending on HP infection status. This study aimed to determine the clinicopathological characteristics of undifferentiated-type gastric cancer (UD-GC) according to HP status.Methods: The study involved 83 patients with UD-GC who were selected from 1559 patients with gastric cancer who underwent endoscopic resection at our hospital and whose HP infection status was confirmed. Clinicopathological characteristics were evaluated according to HP status (eradicated, n=28; infected, n=32; not infected, n=23).Results: In patients without HP infection, UD-GCs were <20 mm and intramucosal with no vascular invasion. In patients with eradicated HP, there was no correlation between development of UD-GC and time since eradication. Furthermore, 75% of patients with a tumor detected ≥5 years after eradication had undergone yearly endoscopy. Submucosal or deeper invasion was observed in 50% of patients and vascular invasion in 75% of patients whose UD-GC was detected ≥10 years after eradication. The proportion of patients with UD-GC and submucosal or deeper invasion was zero in the group without HP infection, 14.3% in the group with eradicated HP, and 10.5% in the HP-infected group.Conclusion: The clinicopathological characteristics of UD-GC were similar between HP-infected patients and HP-eradicated patients. Patients with eradicated HP whose UD-GC developed long after eradication had high rates of vascular and submucosal invasion. In contrast, UD-GC was curable by endoscopic resection in all patients without HP infection.