Helicobacter pylori Treatment: Potential for Gastric Cancer Prevention

article information

International Journal of Infection: Vol.5, issue 2; e14138
published online: June 6, 2017
article type: Letter
received: January 7, 2017
accepted: January 14, 2017
DOI: https://doi.org/10.5812/iji.14138
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Helicobacter pylori Treatment: Potential for Gastric Cancer Prevention

authors:

avatar Mostafa Ibrahimi 1 , avatar Maryam Alaei 1 , avatar Mohammad-Ali Gholampour 2 , avatar Milad Mohammdoo-Khorasani 1 , *

Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Department of Hematology and Blood Banking, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

how to cite: Ibrahimi M, Alaei M, Gholampour M, Mohammdoo-Khorasani M. Helicobacter pylori Treatment: Potential for Gastric Cancer Prevention. Int J Infect. 2018;5(2):e14138. https://doi.org/10.5812/iji.14138.

Dear Editor,

Helicobacter pylori (H. pylori), a Gram-negative bacterium, which colonizes in the gastric mucosa, was discovered in 1984 and was found to be associated with peptic ulcer disease (1). Almost half of the world’s population has been infected with H. pylori, particularly in developing countries where people are more susceptible to the infection, mostly due to the large populations and poor sanitation (2, 3).

H. pylori infection occurs during childhood mostly before 5 years of age. Despite severe immune responses and acidic environment of gastric mucosa, bacteria survive in most occasions. Furthermore, without proper combination antibiotic treatment, these bacteria can live in the host for a lifetime. Survival of bacteria inside the host is mainly related to the local change in acidity through inhibition of acid secretion in the host. In addition, the urease activity of H. pylori neutralizes gastric acidity by generating ammonium.

H. pylori infection leads to complications, ranging from gastritis to different types of gastric cancer (4). Gastric cancer, as the fourth most common cancer, accounts for one-third of cancer-related deaths. Moreover, it has remained one of the public health issues worldwide. In view of the insidious progression of gastric cancer, most cases are diagnosed in advanced stages; therefore, only less than 30% of the patients survive more than 5 years, which indicates the significance of screening programs.

Gastric cancer was the leading cause of more than 700 000 deaths in 2012 (5). According to the histological classification, gastric cancer is categorized into diffused and intestinal or cardia and noncardia types, based on its location (6). Different risk factors, including genetic factors, have been associated with gastric cancer. Moreover, polymorphisms in interleukin-1β and tumor necrosis factor-α are considered significant. However, it should be mentioned that environmental factors such as high salt intake and low level of iron could be also effective.

H. pylori is known as a class I carcinogen and is recognized as the most important risk factor for gastric cancer, responsible for more than 75% of gastric cancer cases (4, 7). The mechanism through which H. pylori infection leads to gastric cancer remains to be clarified; however, the inflammation caused by H. pylori infection predisposes patients to atrophic gastritis, which can progress to precancerous lesion (8).

Cytotoxic antigen (CagA, which forms a secretion system) and vacuolisation protein (VacA) are 2 pathogenic proteins of H. pylori, which have been identified to increase the risk of gastric cancer (9, 10). Epigenetic changes in epithelial cells, for instance, DNA methylation and histone modification induced by H. pylori infection, also lead to gastric cancer progression (11).

H. pylori is the most important risk factor for gastric cancer; therefore, there are promising assumptions for cancer prevention by means of H. pylori treatment. Different studies on many populations have demonstrated the remarkable association between the decreased rate of H. pylori infection and reduced incidence of gastric cancer (5). Therefore, based on international guidelines, high-risk populations are suggested to be screened and treated for H. pylori infection (3), although recent investigations have shown that H. pylori screening and eradication could be costly, even in low-risk populations (12, 13).

The prevalence of H. pylori infection has been reported to be exceedingly high among Iranians (94% and 83% for noncardia and cardia gastric cancer, respectively) (14). On the other hand, gastrointestinal cancer accounts for almost half of cancer cases, and gastric cancer has the second highest incidence rate among all types of cancer in Iran (15).

In conclusion, according to recent studies, H. pylori screening and treatment in highly susceptible populations could be an effective effort to prevent the incidence and mortality of gastric cancer.

References

  • 1.

    Malfertheiner P, Megraud F, O'Morain CA, Atherton J, Axon AT, Bazzoli F, et al. Management of Helicobacter pylori infection--the Maastricht IV/ Florence Consensus Report. Gut. 2012;61(5):646-64. [PubMed ID: 22491499]. https://doi.org/10.1136/gutjnl-2012-302084.

  • 2.

    Mentis A, Lehours P, Megraud F. Epidemiology and Diagnosis of Helicobacter pylori infection. Helicobacter. 2015;20 Suppl 1:1-7. [PubMed ID: 26372818]. https://doi.org/10.1111/hel.12250.

  • 3.

    Laird-Fick HS, Saini S, Hillard JR. Gastric adenocarcinoma: the role of Helicobacter pylori in pathogenesis and prevention efforts. Postgraduate Med J. 2016.

  • 4.

    Wroblewski LE, Peek RM, Coburn LA. The Role of the Microbiome in Gastrointestinal Cancer. Gastroenterol Clin North Am. 2016;45(3):543-56. [PubMed ID: 27546848]. https://doi.org/10.1016/j.gtc.2016.04.010.

  • 5.

    Hoed CM, Kuipers EJ. Gastric Cancer: How Can We Reduce the Incidence of this Disease? Current gastroenterology reports. 2016;18(7):1-8.

  • 6.

    Lauren P. The Two Histological Main Types of Gastric Carcinoma: Diffuse and So-Called Intestinal-Type Carcinoma. An Attempt at a Histo-Clinical Classification. Acta Pathol Microbiol Scand. 1965;64:31-49. [PubMed ID: 14320675].

  • 7.

    Plummer M, Franceschi S, Vignat J, Forman D, de Martel C. Global burden of gastric cancer attributable to Helicobacter pylori. Int J Cancer. 2015;136(2):487-90. [PubMed ID: 24889903]. https://doi.org/10.1002/ijc.28999.

  • 8.

    Venerito M, Selgrad M, Malfertheiner P. Helicobacter pylori: gastric cancer and extragastric malignancies - clinical aspects. Helicobacter. 2013;18 Suppl 1:39-43. [PubMed ID: 24011244]. https://doi.org/10.1111/hel.12078.

  • 9.

    Amieva M, Peek RM. Pathobiology of Helicobacter pylori-Induced Gastric Cancer. Gastroenterology. 2016;150(1):64-78. [PubMed ID: 26385073]. https://doi.org/10.1053/j.gastro.2015.09.004.

  • 10.

    Cover TL, Blanke SR. Helicobacter pylori VacA, a paradigm for toxin multifunctionality. Nat Rev Microbiol. 2005;3(4):320-32. [PubMed ID: 15759043]. https://doi.org/10.1038/nrmicro1095.

  • 11.

    Ding SZ, Zheng PY. Helicobacter pylori infection induced gastric cancer; advance in gastric stem cell research and the remaining challenges. Gut Pathog. 2012;4(1):18. [PubMed ID: 23217022]. https://doi.org/10.1186/1757-4749-4-18.

  • 12.

    Ford AC, Forman D, Hunt RH, Yuan Y, Moayyedi P. Helicobacter pylori eradication therapy to prevent gastric cancer in healthy asymptomatic infected individuals: systematic review and meta-analysis of randomised controlled trials. BMJ. 2014;348:g3174. [PubMed ID: 24846275]. https://doi.org/10.1136/bmj.g3174.

  • 13.

    Ford AC, Forman D, Hunt R, Yuan Y, Moayyedi P. Helicobacter pylori eradication for the prevention of gastric neoplasia. Cochrane Database Syst Rev. 2015;(7). CD005583. [PubMed ID: 26198377]. https://doi.org/10.1002/14651858.CD005583.pub2.

  • 14.

    Malekzadeh R, Derakhshan MH, Malekzadeh Z. Gastric cancer in Iran: epidemiology and risk factors. Arch Iran Med. 2009;12(6):576-83. [PubMed ID: 19877751].

  • 15.

    Naeimehossadat A, Tohid J, Seyyed MT. Area-to-area poisson kriging and spatial bayesian analysis in mapping of gastric cancer incidence in Iran. APJCP. 2016;17(10):4587.