IJC International Journal of Cancer
Helicobacter pylori but not gastrin is associated with the development of colonic neoplasms Michael Selgrad1, Jan Bornschein1, Arne Kandulski1, Carla Hille1, Jochen Weigt1, Albert Roessner2, Thomas Wex1,3 and Peter Malfertheiner1 1
Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany Department of Pathology, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany 3 Medical Laboratory for Clinical Chemistry, Microbiology and Infectious Diseases, Department of Molecular Genetics, Magdeburg, Germany
Recent studies have suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of colonic neoplasia. Hypergastrinemia can be induced by H. pylori infection, and gastrin can act as putative promoter of colorectal carcinogenesis. Aim of our study was to assess whether H. pylori infection and/or increased serum gastrin levels are associated with the occurrence of colonic neoplasms. For this, we reviewed prospectively collected data of 377 patients with a minimum age of 50 years who underwent colonoscopy. H. pylori and CagA status were determined by serology. Serum gastrin levels were measured in fasting state by commercially available assay. In H. pylori infected patients (n 5 138; 36.6%), the overall prevalence of colonic neoplasms was more frequent compared to H. pylori negative patients (n 5 239; 63.4%) (OR 5 2.73, 95% CI: 1.76–4.24). H. pylori infection occurred more frequently in patients with hyperplastic polyps (OR 5 2.66, 95% CI: 1.23–5.74) and adenomas presenting with low grade intraepithelial neoplasia (IEN) (OR 5 1.85, 95% CI: 1.14–2.99). Attributable risk for adenomas with high grade IEN and colorectal adenocarcinoma (n 5 14) was not assessed due to the low number of cases. The expression of CagA was also associated with an increased risk for colonic neoplasms (OR 5 2.25, 95% CI: 1.29–3.94). Hypergastrinemia did not increase the risk for any colonic neoplasms and there was no difference in basal serum gastrin levels between H. pylori positive and negative patients. In conclusion, H. pylori infection, including CagA expression is associated with an increased risk for the development of colonic neoplasm.
Helicobacter pylori (H. pylori) infection affects 20–50% of the adult population in industrialized nations and remains a significant cause of morbidity and mortality in gastro-duodenal diseases.1,2 H. pylori infection is the main risk factor for the development of adenocarcinoma of the stomach3,4 and predisposes to several other complications that include peptic ulcer disease and mucosa-associated lymphoid tissue lymphoma. Among bacterial virulence factors of H. pylori that are responsible for an increase in pathogenicity of the bacteria, CagA plays a prominent role. CagA is not expressed in all H. pylori strains, but CagA positive H. pylori strains show Key words: Helicobacter pylori, gastrin, colonic neoplasms Grant sponsor: BMBF; Grant number: BMBF-0315905D (in the frame of ERA-NET PathoGenoMics) DOI: 10.1002/ijc.28758 History: Received 10 July 2013; Accepted 20 Jan 2014; Online 4 Feb 2014 Correspondence to: Michael Selgrad, Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-vonGuericke-University of Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany, Tel.: 149-391-6713100, Fax: 149-391-6713105, E-mail: [email protected] or Peter Malfertheiner, Department of Gastroenterology, Hepatology and Infectious Diseases, Ottovon-Guericke-University of Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany.
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
an association with higher grades of inflammation of the gastric mucosa and significantly increase the risk of gastric cancer development.5,6 Moreover, H. pylori infection has been suggested to also play a role in extragastric malignancies.7 In this context, previous studies have demonstrated that H. pylori infection is associated with an increased risk for the development of colonic neoplasms.8–13 Most of the studies have used positive serology for anti-H. pylori antibodies as a marker for H. pylori infection. But a recent study has further strengthened the association by showing that various forms of H. pylori-induced gastritis display an attributable risk for the occurrence of colorectal neoplasms.8 The pathophysiological mechanism underlying the association between H. pylori infection and colorectal neoplasms is unclear and certainly not explained by a direct effect of H. pylori, since H. pylori is uniquely adapted to colonize the gastric mucosa.7 A hypothesis is that H. pylori may contribute to the colonic carcinogenesis indirectly via gastrin: H. pylori-induced atrophic changes of the gastric body mucosa lead to increased levels of serum gastrin by negative feedback on the antral G-cells.14 Gastrin is capable of stimulating growth factor dependent signaling pathways and therefore hypergastrinemia may act as a putative promoter of colorectal neoplasia in humans.15 In vitro, high gastrin levels have been shown to be associated with growth and proliferation of colon cancer cells.16,17 Furthermore, patients with elevated gastrin levels (i.e., Zollinger-
Infectious Causes of Cancer
2
1128
H. pylori is associated with colonic neoplasms
What’s new? Though the bacteria H. pylori is best known for its effects on the stomach, evidence has been emerging that it may also contribute to cancer of the colon. In this paper, the authors checked for colonic neoplasms in patients with and without H. pylori infection, paying special attention to strains that express CagA, which are most likely to cause gastric inflammation and cancer. They did indeed find neoplasms more often in the colons of patients who harbored the bacteria, especially those that express CagA. Although the protein gastrin seemed a likely mechanism for spurring these neoplasms, the authors found no increase in serum gastrin levels among the patients with H. pylori infection.
Ellison Syndrome) show an increased proliferation of the colonic and rectal mucosa and consecutively an increased risk for colorectal cancer development.18,19 For this reason, we examined the serological prevalence of H. pylori and serum levels of gastrin in patients undergoing colonoscopy to detect a possible association between H. pylori and colonic neoplasms and the putative mechanisms of gastrin.
Infectious Causes of Cancer
Patients and Methods We performed a review of a prospectively collected database that includes 377 patients with a minimum age of 50 years undergoing colonoscopy in the Department of Gastroenterology, Hepatology and Infectious Diseases at the University of Magdeburg, Germany, in the period between August 2008 and January 2013. Patients were enrolled in the course of a different prospectively conducted study that was approved by the local Ethics Committee. Written informed consent was obtained from all patients. Histopathological assessment
Polypectomy samples were processed by routine methods and sections were stained with hematoxylin and eosin. All pathological specimens from the colorectal tract were assessed for the degree of dysplasia and the presence of villous architecture according to criteria established by the WHO.20 Assessment of serum parameters
About 5–7 ml blood sample was taken from patients in fasting state prior to the endoscopic procedure. Serum was prepared by centrifugation at 7000g at 4 C for 15 min, aliquoted in three individual cryotubes (each 1–1.5 ml) within 3 hr after sample retrieval. Samples were stored at 280 C until analysis. Anti-H. pylori IgG and anti-CagA antibodies were analyzed using an H. pylori IgG enzyme-linked immunosorbent assay (Biohit, Rosbach, Germany) and a CagA IgG kit (Genesis Diagnostics, London, United Kingdom), respectively, according to manufacturers’ instructions. The H. pylori IgG enzyme-linked immunosorbent assay provides a sensitivity of 96.5% (95% CI 5 92.6–98.4) and a specificity of 96.0% (95% CI 5 93.4–97.6).21 Based on the presence of H. pylori-specific IgG (30 enzyme immunounits) and/or the presence of antiCagA IgG (>6.25 U/ml), patients were classified as H. pylori
positive, whereas the lack of both antibodies led to the assignment of an H. pylori-negative status. The analyses of serum gastrin (Gastrin EIA Test Kit, Biohit Plc, Finland) were performed in all subjects at the same aliquot and as described by the manufacturer. Statistical analysis
All statistical analyses were performed using SPSS19.0 for windows (SPSS, Chicago, IL). For groupwise comparison of parametrical data (age), Student’s t-test and the Mann–Whitney U test for nonparametrical comparisons (serological parameters) were applied. Categorical data were compared by Fisher’s exact test also applying Pearson’s v2 for risk assessment and odds ratio calculation. For all tests a two-sided significance level of p < 0.05 was considered to be statistically significant.
Results General characteristics of the study population
A total of 377 patients, 188 females and 189 males with a mean age of 66.38 years (69.83 years standard deviation (SD)) were enrolled in the study. The clinical indications for performing colonoscopies are listed in Table 1. H. pylori infection status based on the concentration of anti-H. pylori IgG antibodies and/or CagA status was positive in 138 patients (36.6%). H. pylori infection was detected more Table 1. Clinical indications for performing colonoscopy Indication for colonoscopy
H. pylori positive (n 5 138)
H. pylori negative (n 5 239)
Abdominal pain
22 (16%)
35 (14.6%)
p value 0.997
Diarrhea
14 (10.1%)
19 (7.9%)
0.735
Anemia
13 (9.4%)
25 (10.5%)
0.468
Hematochezia
9 (6.5%)
19 (7.9%)
0.747
Weight loss
10 (7.2%)
14 (5.9%)
0.610
Colon cancer screening
40 (29%)
68 (28.5%)
0.595
Constipation
4 (2.9%)
9 (3.8%)
0.912
Polyp surveillance
16 (11.6%)
31 (13.0%)
0.657
Inflammatory bowel disease
4 (2.9%)
8 (3.3%)
0.697
Other
6 (4.4%)
11 (4.6%)
0.811
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
1129
Selgrad et al.
Total number of patients (n 5 377)
H. pylori infection (n 5 138)
H. pylori negative (n 5 239)
Odds ratio
95% CI
Age
66.38 (69.83 years SD)
66.72 (69.32 years SD)
66.18 (6 10.13 years SD)
–
–
Female
188 (49.9%)
60 (31.9%)
128 (68.1%)
1
–
Male
189 (50.1%)
78 (41.3%)
111 (58.7%)
1.39
(0.96–2.16)
Parameter
Colonic neoplasm overall
133 (35.3%)
69 (50.0%)
64 (26.8%)
2.73
(1.76–4.24)
Hyperplastic polyp
29 (7.7%)
17 (12.3%)
12 (5.0%)
2.66
(1.23–5.74)
Low grade IEN polyp
90 (23.9%)
43 (31.2%)
47 (19.7%)
1.85
(1.14–2.99)
High grade IEN polyp
5 (1.3%)
4 (2.9%)
1 (0.4%)
n.s.
n.a.
Adenocarcinoma
9 (2.4%)
5 (3.6%)
4 (1.7%)
n.s.
n.a.
High grade IEN 1 adenocarcinoma
14 (3.7%)
9 (6.5%)
5 (2.1%)
3.26
(1.07–9.95)
No polyps
244 (64.7%)
69 (50.0%)
175 (73.2%)
1
–
frequently in male (41.3%) compared to female patients (31.9%). There was no significant difference in age between H. pylori positive (66.72 years; 69.32 years SD) and H. pylori negative (66.18 years; 610.13 SD) patients (p 5 0.145). A positive CagA status was detectable in 43.5% of the H. pylori positive patients. A complete colonoscopy, defined as reaching the caecum was performed in 95.7% of the H. pylori positive patients (n 5 132) compared to 97.1% of the noninfected patients (n 5 232) (p 5 0.325). Furthermore, there was no significant difference in the performance of a previous colonoscopy between H. pylori positive (n 5 27; 19.6%) and H. pylori negative (n 5 57; 23.8%) patients (p 5 0.203). Association of H. pylori infection and colorectal neoplasm
In H. pylori-infected patients (n 5 138), the occurrence of colonic neoplasms was more frequent compared to H. pylori negative patients (n 5 239) (OR 5 2.73, 95% CI: 1.76–4.24). Hyperplastic polyps (OR 5 2.66, 95% CI: 1.23–5.74), polyps with low grade (OR 5 1.85, 95% CI: 1.14–2.99) and high grade intraepithelial neoplasia (IEN) were all found at a higher percentage among patients with H. pylori infection compared to those without H. pylori infection. Interestingly, H. pylori infection was most frequently detected in patients with low grade IEN adenomas of the colon. H. pylori infection was not detected at a higher rate in patients with colorectal cancer. It has to be noted, that only 14 patients (3.7%) included in our study were diagnosed with high grade IEN in the colorectum or invasive colorectal adenocarcinoma. Due to the low number of patients in this group, risk stratification was not performed for these single entities. However, when combing the patients with high grade IEN and colorectal cancer, H. pylori infection was associated with an increased risk for developing those entities (OR 5 3.26, 95% CI: 1.07–9.95). The presence of the virulence factor CagA was further associated with an increased risk of colonic neoplasms C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
(OR 5 2.25, 95% CI: 1.29–3.94). After adjustment for confounding factors such as sex, age, previous and complete colonoscopy, H. pylori infection represents the only independent risk factor for the development of colonic neoplasms (OR 5 2.71, 95% CI: 1.74–4.23) (p < 0.001). The overall stratification of the patient population by H. pylori infection status and histopathological findings of colonoscopy specimens are displayed in Table 2. Association of serum-Gastrin, H. pylori infection and colorectal neoplasm
Hypergastrinemia was not associated with an increased risk of occurrence of any colonic neoplasms. In total, 52 patients (13.8%) had an increased serum gastrin level (defined as >50 pg/ml). There was no difference in the number of patients with increased gastrin levels with or without H. pylori infection (p 5 0.125). Interestingly, overall gastrin levels were similar between H. pylori positive subjects (mean, 17.17 pg/ml) and H. pylori negative subjects (mean, 20.77 pg/ml).
Discussion In our study, we demonstrate that H. pylori infection is more prevalent among patients with colorectal neoplasia, and the infection is associated with a risk for the development of colonic neoplasms. This risk was significant for adenomas with low grade IEN and hyperplastic polyps. Our results are consistent with results of previous studies including two meta-analyses that reported an increased risk of colorectal neoplasia in patients with H. pylori infection.9,10,22 Even though some studies did not find an association,11,23,24 the positive correlation of H. pylori and colonic neoplasia was strengthened by a recent study including a large number of patients, in which various forms of gastritis related to H. pylori consistently increased the risk for colonic neoplasms.8 Recently, another interesting study demonstrated that
Infectious Causes of Cancer
Table 2. Association of H. pylori infection with colonic neoplasm
Infectious Causes of Cancer
1130
H. pylori is associated with colonic neoplasms
patients with H. pylori-induced atrophic gastritis are at an increased risk for the recurrence of colorectal neoplasia after endoscopic resection.25 The small number of patients with colorectal cancer or adenomas with high grade neoplasia in our study did not permit an interpretation of this group of patients and thus a solid conclusion on the absence of an association between H. pylori infection and colorectal cancer or adenomas with high grade neoplasia cannot be given. A novel aspect of our study is the increased risk for colonic neoplasms in patients infected by a CagA positive H. pylori strain. CagA positive H. pylori strains are well known to induce a stronger inflammatory response in the gastric mucosa and to carry an increased risk for gastric cancer development. Whether CagA-released proinflammatory molecules might promote the proliferation of colonic cells remains speculative. Certainly studies addressing this aspect should be encouraged. One strength of our study is the fact that we determined H. pylori infection status based on serology only and thus not only patients with an active infection were classified as H. pylori-positive but also possibly patients with prior eradication therapy or those with a long-standing infection in which the bacteria have disappeared during the progression of histological alterations (i.e., atrophic gastritis). However, the prevalence of H. pylori infection in our study population is still lower compared to the general population in our region.2 Pathophysiological mechanisms underlying the association between H. pylori infection and the increased risk of colonic neoplasm development are not understood. One explanation is that H. pylori antigens may act directly on the colon
mucosa which has been speculated in two previous studies.26,27 A plausible explanation was proposed for increased serum gastrin levels as a consequence of H. pylori infection. However, in our patient population hypergastrinemia was not associated with an increased risk for colonic neoplasms. A possible explanation for this result might represent the fact that we might have included patients with autoimmune gastritis, prior intake of proton-pump inhibitors, or patients with an atrophic gastritis in whom a spontaneous eradication of H. pylori occurred. In those patients, gastrin levels are lower due to the break of the normal pH-driven feedback on gastrin regulation. Due to the design of our study some further limitations have to be considered. There is a possible chance of an inadvertent inclusion of subjects with a previous gastrectomy, previous H. pylori eradication therapy and current use of proton-pump inhibitors which are generally accepted to increase serum-gastrin levels. Previous studies analyzing the association between serum gastrin levels and risk of colonic neoplasms have shown inconsistent results.28–31 Most of the studies have proven that high serum gastrin level confer an increased risk for colorectal cancer but not for colonic adenomas.11,24,32 One possible explanation for this is that gastrin might promote colorectal carcinogenesis at a later stage in the adenomacarcinoma sequence, and in our study population we mainly analyzed colonic neoplasms of an early stage. In conclusion, our study demonstrates that H. pylori infection and CagA positive strains in particular are associated with an increased risk for colonic neoplasms. Future studies are needed to explore the underlying pathophysiological mechanisms.
References 1.
2.
3.
4.
5.
6.
7.
8.
Malfertheiner P, Megraud F, O’Morain CA, et al. Management of Helicobacter pylori infection—the Maastricht IV/Florence Consensus Report. Gut 2012;61:646–64. Wex T, Venerito M, Kreutzer J, et al. Serological prevalence of Helicobacter pylori infection in Saxony-Anhalt, Germany, in 2010. Clin Vaccine Immunol 2011;18:2109–12. Malfertheiner P, Selgrad M, Bornschein J. Helicobacter pylori: clinical management. Curr Opin Gastroenterol 2012;28:608–14. Selgrad M, Malfertheiner P. Treatment of Helicobacter pylori. Curr Opin Gastroenterol 2011;27: 565–70. Parsonnet J, Friedman GD, Orentreich N, et al. Risk for gastric cancer in people with CagA positive or CagA negative Helicobacter pylori infection. Gut 1997;40:297–301. Selgrad M, Malfertheiner P, Fini L, et al. The role of viral and bacterial pathogens in gastrointestinal cancer. J Cell Physiol 2008;216:378–88. Selgrad M, Bornschein J, Rokkas T, et al. Helicobacter pylori: gastric cancer and extragastric intestinal malignancies. Helicobacter 2012;17 (Suppl 1):30–5. Sonnenberg A, Genta RM. Helicobacter pylori is a risk factor for colonic neoplasms. Am J Gastroenterol 2013;108:208–15.
9.
10.
11.
12.
13.
14.
15.
16.
Zhao YS, Wang F, Chang D, et al. Meta-analysis of different test indicators: Helicobacter pylori infection and the risk of colorectal cancer. Int J Colorectal Dis 2008;23:875–82. Zumkeller N, Brenner H, Zwahlen M, et al. Helicobacter pylori infection and colorectal cancer risk: a meta-analysis. Helicobacter 2006;11:75–80. Robertson DJ, Sandler RS, Ahnen DJ, et al. Gastrin, Helicobacter pylori, and colorectal adenomas. Clin Gastroenterol Hepatol 2009;7:163–7. Inoue I, Mukoubayashi C, Yoshimura N, et al. Elevated risk of colorectal adenoma with Helicobacter pylori-related chronic gastritis: a population-based case-control study. Int J Cancer 2011;129:2704–11. Zhang Y, Hoffmeister M, Weck MN, et al. Helicobacter pylori infection and colorectal cancer risk: evidence from a large population-based casecontrol study in Germany. Am J Epidemiol 2012; 175:441–50. Watson S, Grabowska AM, El-Zaatari M, et al. Gastrin—active participant or bystander in gastric carcinogenesis? Nat Rev Cancer 2006;6:936–46. Thorburn CM, Friedman GD, Dickinson CJ, et al. Gastrin and colorectal cancer: a prospective study. Gastroenterology 1998;115:275–80. Watson SA, Durrant LG, Crosbie JD, et al. The in vitro growth response of primary human colo-
17.
18.
19.
20.
21.
22.
23.
rectal and gastric cancer cells to gastrin. Int J Cancer 1989;43:692–6. Smith JP, Solomon TE. Effects of gastrin, proglumide, and somatostatin on growth of human colon cancer. Gastroenterology 1988;95:1541–8. Sobhani I, Lehy T, Laurent-Puig P, et al. Chronic endogenous hypergastrinemia in humans: evidence for a mitogenic effect on the colonic mucosa. Gastroenterology 1993;105:22–30. Renga M, Brandi G, Paganelli GM, et al. Rectal cell proliferation and colon cancer risk in patients with hypergastrinaemia. Gut 1997;41:330–2. Hamilton SR, Vogelstein B, Kudo S. World Health Organization classification of tumours: pathology and genetics of tumours of the digestive system. Lyon: IARC, 2000. http://www.biohithealthcare.com/resource/files/ media/manuals/hp-igg-ifu-multilanguage.pdf.; 2013. Zhang Y, Hoffmeister M, Weck MN, et al. Helicobacter pylori infection and colorectal cancer risk: evidence from a large population-based casecontrol study in Germany. Am J Epidemiol 2012; 175:441-50. Abbass K, Gul W, Beck G, et al. Association of Helicobacter pylori infection with the development of colorectal polyps and colorectal carcinoma. South Med J 2011;104:473–6.
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
1131
Selgrad et al.
in neoplasms of the colon. BMC Gastroenterol 2008;8:35. 27. Jones M, Helliwell P, Pritchard C, et al. Helicobacter pylori in colorectal neoplasms: is there an aetiological relationship? World J Surg Oncol 2007;5:51. 28. Georgopoulos SD, Polymeros D, Triantafyllou K, et al. Hypergastrinemia is associated with increased risk of distal colon adenomas. Digestion 2006;74:42–6. 29. Kikendall JW, Glass AR, Sobin LH, et al. Serum gastrin is not higher in subjects with colonic neo-
plasia. Am J Gastroenterol 1992;87: 1394–7. 30. Imdahl A, Michalski Y, Eggstein S, et al. [Serum gastrin level in patients with colorectal adenoma or carcinoma]. Zentralbl Chir 1992;117:439–43. 31. Suzuki H, Matsumoto K, Terashima H. Serum levels of gastrin in patients with colorectal neoplasia. Dis Colon Rectum 1988;31:716–7. 32. Seitz JF, Giovannini M, Gouvernet J, et al. Elevated serum gastrin levels in patients with colorectal neoplasia. J Clin Gastroenterol 1991;13: 541–5.
Infectious Causes of Cancer
24. Strofilas A, Lagoudianakis EE, Seretis C, et al. Association of Helicobacter pylori infection and colon cancer. J Clin Med Res 2012;4: 172–6. 25. Inoue I, Yoshimura N, Maeda Y, et al. Elevated risk of recurrent colorectal neoplasia with Helicobacter pylori-associated chronic atrophic gastritis: a follow-up study of patients with endoscopically resected colorectal neoplasia. Mol Clin Oncol 2013;75–82. 26. Soylu A, Ozkara S, Alis H, et al. Immunohistochemical testing for Helicobacter pylori existence
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
Helicobacter pylori but not gastrin is associated with the development of colonic neoplasms Michael Selgrad1, Jan Bornschein1, Arne Kandulski1, Carla Hille1, Jochen Weigt1, Albert Roessner2, Thomas Wex1,3 and Peter Malfertheiner1 1
Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany Department of Pathology, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany 3 Medical Laboratory for Clinical Chemistry, Microbiology and Infectious Diseases, Department of Molecular Genetics, Magdeburg, Germany
Recent studies have suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of colonic neoplasia. Hypergastrinemia can be induced by H. pylori infection, and gastrin can act as putative promoter of colorectal carcinogenesis. Aim of our study was to assess whether H. pylori infection and/or increased serum gastrin levels are associated with the occurrence of colonic neoplasms. For this, we reviewed prospectively collected data of 377 patients with a minimum age of 50 years who underwent colonoscopy. H. pylori and CagA status were determined by serology. Serum gastrin levels were measured in fasting state by commercially available assay. In H. pylori infected patients (n 5 138; 36.6%), the overall prevalence of colonic neoplasms was more frequent compared to H. pylori negative patients (n 5 239; 63.4%) (OR 5 2.73, 95% CI: 1.76–4.24). H. pylori infection occurred more frequently in patients with hyperplastic polyps (OR 5 2.66, 95% CI: 1.23–5.74) and adenomas presenting with low grade intraepithelial neoplasia (IEN) (OR 5 1.85, 95% CI: 1.14–2.99). Attributable risk for adenomas with high grade IEN and colorectal adenocarcinoma (n 5 14) was not assessed due to the low number of cases. The expression of CagA was also associated with an increased risk for colonic neoplasms (OR 5 2.25, 95% CI: 1.29–3.94). Hypergastrinemia did not increase the risk for any colonic neoplasms and there was no difference in basal serum gastrin levels between H. pylori positive and negative patients. In conclusion, H. pylori infection, including CagA expression is associated with an increased risk for the development of colonic neoplasm.
Helicobacter pylori (H. pylori) infection affects 20–50% of the adult population in industrialized nations and remains a significant cause of morbidity and mortality in gastro-duodenal diseases.1,2 H. pylori infection is the main risk factor for the development of adenocarcinoma of the stomach3,4 and predisposes to several other complications that include peptic ulcer disease and mucosa-associated lymphoid tissue lymphoma. Among bacterial virulence factors of H. pylori that are responsible for an increase in pathogenicity of the bacteria, CagA plays a prominent role. CagA is not expressed in all H. pylori strains, but CagA positive H. pylori strains show Key words: Helicobacter pylori, gastrin, colonic neoplasms Grant sponsor: BMBF; Grant number: BMBF-0315905D (in the frame of ERA-NET PathoGenoMics) DOI: 10.1002/ijc.28758 History: Received 10 July 2013; Accepted 20 Jan 2014; Online 4 Feb 2014 Correspondence to: Michael Selgrad, Department of Gastroenterology, Hepatology and Infectious Diseases, Otto-vonGuericke-University of Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany, Tel.: 149-391-6713100, Fax: 149-391-6713105, E-mail: [email protected] or Peter Malfertheiner, Department of Gastroenterology, Hepatology and Infectious Diseases, Ottovon-Guericke-University of Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany.
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
an association with higher grades of inflammation of the gastric mucosa and significantly increase the risk of gastric cancer development.5,6 Moreover, H. pylori infection has been suggested to also play a role in extragastric malignancies.7 In this context, previous studies have demonstrated that H. pylori infection is associated with an increased risk for the development of colonic neoplasms.8–13 Most of the studies have used positive serology for anti-H. pylori antibodies as a marker for H. pylori infection. But a recent study has further strengthened the association by showing that various forms of H. pylori-induced gastritis display an attributable risk for the occurrence of colorectal neoplasms.8 The pathophysiological mechanism underlying the association between H. pylori infection and colorectal neoplasms is unclear and certainly not explained by a direct effect of H. pylori, since H. pylori is uniquely adapted to colonize the gastric mucosa.7 A hypothesis is that H. pylori may contribute to the colonic carcinogenesis indirectly via gastrin: H. pylori-induced atrophic changes of the gastric body mucosa lead to increased levels of serum gastrin by negative feedback on the antral G-cells.14 Gastrin is capable of stimulating growth factor dependent signaling pathways and therefore hypergastrinemia may act as a putative promoter of colorectal neoplasia in humans.15 In vitro, high gastrin levels have been shown to be associated with growth and proliferation of colon cancer cells.16,17 Furthermore, patients with elevated gastrin levels (i.e., Zollinger-
Infectious Causes of Cancer
2
1128
H. pylori is associated with colonic neoplasms
What’s new? Though the bacteria H. pylori is best known for its effects on the stomach, evidence has been emerging that it may also contribute to cancer of the colon. In this paper, the authors checked for colonic neoplasms in patients with and without H. pylori infection, paying special attention to strains that express CagA, which are most likely to cause gastric inflammation and cancer. They did indeed find neoplasms more often in the colons of patients who harbored the bacteria, especially those that express CagA. Although the protein gastrin seemed a likely mechanism for spurring these neoplasms, the authors found no increase in serum gastrin levels among the patients with H. pylori infection.
Ellison Syndrome) show an increased proliferation of the colonic and rectal mucosa and consecutively an increased risk for colorectal cancer development.18,19 For this reason, we examined the serological prevalence of H. pylori and serum levels of gastrin in patients undergoing colonoscopy to detect a possible association between H. pylori and colonic neoplasms and the putative mechanisms of gastrin.
Infectious Causes of Cancer
Patients and Methods We performed a review of a prospectively collected database that includes 377 patients with a minimum age of 50 years undergoing colonoscopy in the Department of Gastroenterology, Hepatology and Infectious Diseases at the University of Magdeburg, Germany, in the period between August 2008 and January 2013. Patients were enrolled in the course of a different prospectively conducted study that was approved by the local Ethics Committee. Written informed consent was obtained from all patients. Histopathological assessment
Polypectomy samples were processed by routine methods and sections were stained with hematoxylin and eosin. All pathological specimens from the colorectal tract were assessed for the degree of dysplasia and the presence of villous architecture according to criteria established by the WHO.20 Assessment of serum parameters
About 5–7 ml blood sample was taken from patients in fasting state prior to the endoscopic procedure. Serum was prepared by centrifugation at 7000g at 4 C for 15 min, aliquoted in three individual cryotubes (each 1–1.5 ml) within 3 hr after sample retrieval. Samples were stored at 280 C until analysis. Anti-H. pylori IgG and anti-CagA antibodies were analyzed using an H. pylori IgG enzyme-linked immunosorbent assay (Biohit, Rosbach, Germany) and a CagA IgG kit (Genesis Diagnostics, London, United Kingdom), respectively, according to manufacturers’ instructions. The H. pylori IgG enzyme-linked immunosorbent assay provides a sensitivity of 96.5% (95% CI 5 92.6–98.4) and a specificity of 96.0% (95% CI 5 93.4–97.6).21 Based on the presence of H. pylori-specific IgG (30 enzyme immunounits) and/or the presence of antiCagA IgG (>6.25 U/ml), patients were classified as H. pylori
positive, whereas the lack of both antibodies led to the assignment of an H. pylori-negative status. The analyses of serum gastrin (Gastrin EIA Test Kit, Biohit Plc, Finland) were performed in all subjects at the same aliquot and as described by the manufacturer. Statistical analysis
All statistical analyses were performed using SPSS19.0 for windows (SPSS, Chicago, IL). For groupwise comparison of parametrical data (age), Student’s t-test and the Mann–Whitney U test for nonparametrical comparisons (serological parameters) were applied. Categorical data were compared by Fisher’s exact test also applying Pearson’s v2 for risk assessment and odds ratio calculation. For all tests a two-sided significance level of p < 0.05 was considered to be statistically significant.
Results General characteristics of the study population
A total of 377 patients, 188 females and 189 males with a mean age of 66.38 years (69.83 years standard deviation (SD)) were enrolled in the study. The clinical indications for performing colonoscopies are listed in Table 1. H. pylori infection status based on the concentration of anti-H. pylori IgG antibodies and/or CagA status was positive in 138 patients (36.6%). H. pylori infection was detected more Table 1. Clinical indications for performing colonoscopy Indication for colonoscopy
H. pylori positive (n 5 138)
H. pylori negative (n 5 239)
Abdominal pain
22 (16%)
35 (14.6%)
p value 0.997
Diarrhea
14 (10.1%)
19 (7.9%)
0.735
Anemia
13 (9.4%)
25 (10.5%)
0.468
Hematochezia
9 (6.5%)
19 (7.9%)
0.747
Weight loss
10 (7.2%)
14 (5.9%)
0.610
Colon cancer screening
40 (29%)
68 (28.5%)
0.595
Constipation
4 (2.9%)
9 (3.8%)
0.912
Polyp surveillance
16 (11.6%)
31 (13.0%)
0.657
Inflammatory bowel disease
4 (2.9%)
8 (3.3%)
0.697
Other
6 (4.4%)
11 (4.6%)
0.811
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
1129
Selgrad et al.
Total number of patients (n 5 377)
H. pylori infection (n 5 138)
H. pylori negative (n 5 239)
Odds ratio
95% CI
Age
66.38 (69.83 years SD)
66.72 (69.32 years SD)
66.18 (6 10.13 years SD)
–
–
Female
188 (49.9%)
60 (31.9%)
128 (68.1%)
1
–
Male
189 (50.1%)
78 (41.3%)
111 (58.7%)
1.39
(0.96–2.16)
Parameter
Colonic neoplasm overall
133 (35.3%)
69 (50.0%)
64 (26.8%)
2.73
(1.76–4.24)
Hyperplastic polyp
29 (7.7%)
17 (12.3%)
12 (5.0%)
2.66
(1.23–5.74)
Low grade IEN polyp
90 (23.9%)
43 (31.2%)
47 (19.7%)
1.85
(1.14–2.99)
High grade IEN polyp
5 (1.3%)
4 (2.9%)
1 (0.4%)
n.s.
n.a.
Adenocarcinoma
9 (2.4%)
5 (3.6%)
4 (1.7%)
n.s.
n.a.
High grade IEN 1 adenocarcinoma
14 (3.7%)
9 (6.5%)
5 (2.1%)
3.26
(1.07–9.95)
No polyps
244 (64.7%)
69 (50.0%)
175 (73.2%)
1
–
frequently in male (41.3%) compared to female patients (31.9%). There was no significant difference in age between H. pylori positive (66.72 years; 69.32 years SD) and H. pylori negative (66.18 years; 610.13 SD) patients (p 5 0.145). A positive CagA status was detectable in 43.5% of the H. pylori positive patients. A complete colonoscopy, defined as reaching the caecum was performed in 95.7% of the H. pylori positive patients (n 5 132) compared to 97.1% of the noninfected patients (n 5 232) (p 5 0.325). Furthermore, there was no significant difference in the performance of a previous colonoscopy between H. pylori positive (n 5 27; 19.6%) and H. pylori negative (n 5 57; 23.8%) patients (p 5 0.203). Association of H. pylori infection and colorectal neoplasm
In H. pylori-infected patients (n 5 138), the occurrence of colonic neoplasms was more frequent compared to H. pylori negative patients (n 5 239) (OR 5 2.73, 95% CI: 1.76–4.24). Hyperplastic polyps (OR 5 2.66, 95% CI: 1.23–5.74), polyps with low grade (OR 5 1.85, 95% CI: 1.14–2.99) and high grade intraepithelial neoplasia (IEN) were all found at a higher percentage among patients with H. pylori infection compared to those without H. pylori infection. Interestingly, H. pylori infection was most frequently detected in patients with low grade IEN adenomas of the colon. H. pylori infection was not detected at a higher rate in patients with colorectal cancer. It has to be noted, that only 14 patients (3.7%) included in our study were diagnosed with high grade IEN in the colorectum or invasive colorectal adenocarcinoma. Due to the low number of patients in this group, risk stratification was not performed for these single entities. However, when combing the patients with high grade IEN and colorectal cancer, H. pylori infection was associated with an increased risk for developing those entities (OR 5 3.26, 95% CI: 1.07–9.95). The presence of the virulence factor CagA was further associated with an increased risk of colonic neoplasms C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
(OR 5 2.25, 95% CI: 1.29–3.94). After adjustment for confounding factors such as sex, age, previous and complete colonoscopy, H. pylori infection represents the only independent risk factor for the development of colonic neoplasms (OR 5 2.71, 95% CI: 1.74–4.23) (p < 0.001). The overall stratification of the patient population by H. pylori infection status and histopathological findings of colonoscopy specimens are displayed in Table 2. Association of serum-Gastrin, H. pylori infection and colorectal neoplasm
Hypergastrinemia was not associated with an increased risk of occurrence of any colonic neoplasms. In total, 52 patients (13.8%) had an increased serum gastrin level (defined as >50 pg/ml). There was no difference in the number of patients with increased gastrin levels with or without H. pylori infection (p 5 0.125). Interestingly, overall gastrin levels were similar between H. pylori positive subjects (mean, 17.17 pg/ml) and H. pylori negative subjects (mean, 20.77 pg/ml).
Discussion In our study, we demonstrate that H. pylori infection is more prevalent among patients with colorectal neoplasia, and the infection is associated with a risk for the development of colonic neoplasms. This risk was significant for adenomas with low grade IEN and hyperplastic polyps. Our results are consistent with results of previous studies including two meta-analyses that reported an increased risk of colorectal neoplasia in patients with H. pylori infection.9,10,22 Even though some studies did not find an association,11,23,24 the positive correlation of H. pylori and colonic neoplasia was strengthened by a recent study including a large number of patients, in which various forms of gastritis related to H. pylori consistently increased the risk for colonic neoplasms.8 Recently, another interesting study demonstrated that
Infectious Causes of Cancer
Table 2. Association of H. pylori infection with colonic neoplasm
Infectious Causes of Cancer
1130
H. pylori is associated with colonic neoplasms
patients with H. pylori-induced atrophic gastritis are at an increased risk for the recurrence of colorectal neoplasia after endoscopic resection.25 The small number of patients with colorectal cancer or adenomas with high grade neoplasia in our study did not permit an interpretation of this group of patients and thus a solid conclusion on the absence of an association between H. pylori infection and colorectal cancer or adenomas with high grade neoplasia cannot be given. A novel aspect of our study is the increased risk for colonic neoplasms in patients infected by a CagA positive H. pylori strain. CagA positive H. pylori strains are well known to induce a stronger inflammatory response in the gastric mucosa and to carry an increased risk for gastric cancer development. Whether CagA-released proinflammatory molecules might promote the proliferation of colonic cells remains speculative. Certainly studies addressing this aspect should be encouraged. One strength of our study is the fact that we determined H. pylori infection status based on serology only and thus not only patients with an active infection were classified as H. pylori-positive but also possibly patients with prior eradication therapy or those with a long-standing infection in which the bacteria have disappeared during the progression of histological alterations (i.e., atrophic gastritis). However, the prevalence of H. pylori infection in our study population is still lower compared to the general population in our region.2 Pathophysiological mechanisms underlying the association between H. pylori infection and the increased risk of colonic neoplasm development are not understood. One explanation is that H. pylori antigens may act directly on the colon
mucosa which has been speculated in two previous studies.26,27 A plausible explanation was proposed for increased serum gastrin levels as a consequence of H. pylori infection. However, in our patient population hypergastrinemia was not associated with an increased risk for colonic neoplasms. A possible explanation for this result might represent the fact that we might have included patients with autoimmune gastritis, prior intake of proton-pump inhibitors, or patients with an atrophic gastritis in whom a spontaneous eradication of H. pylori occurred. In those patients, gastrin levels are lower due to the break of the normal pH-driven feedback on gastrin regulation. Due to the design of our study some further limitations have to be considered. There is a possible chance of an inadvertent inclusion of subjects with a previous gastrectomy, previous H. pylori eradication therapy and current use of proton-pump inhibitors which are generally accepted to increase serum-gastrin levels. Previous studies analyzing the association between serum gastrin levels and risk of colonic neoplasms have shown inconsistent results.28–31 Most of the studies have proven that high serum gastrin level confer an increased risk for colorectal cancer but not for colonic adenomas.11,24,32 One possible explanation for this is that gastrin might promote colorectal carcinogenesis at a later stage in the adenomacarcinoma sequence, and in our study population we mainly analyzed colonic neoplasms of an early stage. In conclusion, our study demonstrates that H. pylori infection and CagA positive strains in particular are associated with an increased risk for colonic neoplasms. Future studies are needed to explore the underlying pathophysiological mechanisms.
References 1.
2.
3.
4.
5.
6.
7.
8.
Malfertheiner P, Megraud F, O’Morain CA, et al. Management of Helicobacter pylori infection—the Maastricht IV/Florence Consensus Report. Gut 2012;61:646–64. Wex T, Venerito M, Kreutzer J, et al. Serological prevalence of Helicobacter pylori infection in Saxony-Anhalt, Germany, in 2010. Clin Vaccine Immunol 2011;18:2109–12. Malfertheiner P, Selgrad M, Bornschein J. Helicobacter pylori: clinical management. Curr Opin Gastroenterol 2012;28:608–14. Selgrad M, Malfertheiner P. Treatment of Helicobacter pylori. Curr Opin Gastroenterol 2011;27: 565–70. Parsonnet J, Friedman GD, Orentreich N, et al. Risk for gastric cancer in people with CagA positive or CagA negative Helicobacter pylori infection. Gut 1997;40:297–301. Selgrad M, Malfertheiner P, Fini L, et al. The role of viral and bacterial pathogens in gastrointestinal cancer. J Cell Physiol 2008;216:378–88. Selgrad M, Bornschein J, Rokkas T, et al. Helicobacter pylori: gastric cancer and extragastric intestinal malignancies. Helicobacter 2012;17 (Suppl 1):30–5. Sonnenberg A, Genta RM. Helicobacter pylori is a risk factor for colonic neoplasms. Am J Gastroenterol 2013;108:208–15.
9.
10.
11.
12.
13.
14.
15.
16.
Zhao YS, Wang F, Chang D, et al. Meta-analysis of different test indicators: Helicobacter pylori infection and the risk of colorectal cancer. Int J Colorectal Dis 2008;23:875–82. Zumkeller N, Brenner H, Zwahlen M, et al. Helicobacter pylori infection and colorectal cancer risk: a meta-analysis. Helicobacter 2006;11:75–80. Robertson DJ, Sandler RS, Ahnen DJ, et al. Gastrin, Helicobacter pylori, and colorectal adenomas. Clin Gastroenterol Hepatol 2009;7:163–7. Inoue I, Mukoubayashi C, Yoshimura N, et al. Elevated risk of colorectal adenoma with Helicobacter pylori-related chronic gastritis: a population-based case-control study. Int J Cancer 2011;129:2704–11. Zhang Y, Hoffmeister M, Weck MN, et al. Helicobacter pylori infection and colorectal cancer risk: evidence from a large population-based casecontrol study in Germany. Am J Epidemiol 2012; 175:441–50. Watson S, Grabowska AM, El-Zaatari M, et al. Gastrin—active participant or bystander in gastric carcinogenesis? Nat Rev Cancer 2006;6:936–46. Thorburn CM, Friedman GD, Dickinson CJ, et al. Gastrin and colorectal cancer: a prospective study. Gastroenterology 1998;115:275–80. Watson SA, Durrant LG, Crosbie JD, et al. The in vitro growth response of primary human colo-
17.
18.
19.
20.
21.
22.
23.
rectal and gastric cancer cells to gastrin. Int J Cancer 1989;43:692–6. Smith JP, Solomon TE. Effects of gastrin, proglumide, and somatostatin on growth of human colon cancer. Gastroenterology 1988;95:1541–8. Sobhani I, Lehy T, Laurent-Puig P, et al. Chronic endogenous hypergastrinemia in humans: evidence for a mitogenic effect on the colonic mucosa. Gastroenterology 1993;105:22–30. Renga M, Brandi G, Paganelli GM, et al. Rectal cell proliferation and colon cancer risk in patients with hypergastrinaemia. Gut 1997;41:330–2. Hamilton SR, Vogelstein B, Kudo S. World Health Organization classification of tumours: pathology and genetics of tumours of the digestive system. Lyon: IARC, 2000. http://www.biohithealthcare.com/resource/files/ media/manuals/hp-igg-ifu-multilanguage.pdf.; 2013. Zhang Y, Hoffmeister M, Weck MN, et al. Helicobacter pylori infection and colorectal cancer risk: evidence from a large population-based casecontrol study in Germany. Am J Epidemiol 2012; 175:441-50. Abbass K, Gul W, Beck G, et al. Association of Helicobacter pylori infection with the development of colorectal polyps and colorectal carcinoma. South Med J 2011;104:473–6.
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
1131
Selgrad et al.
in neoplasms of the colon. BMC Gastroenterol 2008;8:35. 27. Jones M, Helliwell P, Pritchard C, et al. Helicobacter pylori in colorectal neoplasms: is there an aetiological relationship? World J Surg Oncol 2007;5:51. 28. Georgopoulos SD, Polymeros D, Triantafyllou K, et al. Hypergastrinemia is associated with increased risk of distal colon adenomas. Digestion 2006;74:42–6. 29. Kikendall JW, Glass AR, Sobin LH, et al. Serum gastrin is not higher in subjects with colonic neo-
plasia. Am J Gastroenterol 1992;87: 1394–7. 30. Imdahl A, Michalski Y, Eggstein S, et al. [Serum gastrin level in patients with colorectal adenoma or carcinoma]. Zentralbl Chir 1992;117:439–43. 31. Suzuki H, Matsumoto K, Terashima H. Serum levels of gastrin in patients with colorectal neoplasia. Dis Colon Rectum 1988;31:716–7. 32. Seitz JF, Giovannini M, Gouvernet J, et al. Elevated serum gastrin levels in patients with colorectal neoplasia. J Clin Gastroenterol 1991;13: 541–5.
Infectious Causes of Cancer
24. Strofilas A, Lagoudianakis EE, Seretis C, et al. Association of Helicobacter pylori infection and colon cancer. J Clin Med Res 2012;4: 172–6. 25. Inoue I, Yoshimura N, Maeda Y, et al. Elevated risk of recurrent colorectal neoplasia with Helicobacter pylori-associated chronic atrophic gastritis: a follow-up study of patients with endoscopically resected colorectal neoplasia. Mol Clin Oncol 2013;75–82. 26. Soylu A, Ozkara S, Alis H, et al. Immunohistochemical testing for Helicobacter pylori existence
C 2014 UICC Int. J. Cancer: 135, 1127–1131 (2014) V
