Helicobacter pylori infection and risk of gastric cancer – Authors' reply
Authors: Ling Yang, Christiana Kartsonaki, Iona Y Millwood, Zhengming Chen
Journal: The Lancet Public Health (2022)

We thank Yung-Shuo Kao and colleagues for their interest in our study of the association between Helicobacter pylori infection and risk of gastric cancer in Chinese populations.1Yang L Kartsonaki C Yao P et al.The relative and attributable risks of cardia and non-cardia gastric cancer associated with Helicobacter pylori infection in China: a case-cohort study.Lancet Public Health. 2021; 6: e888-e896Summary Full Text Full Text PDF PubMed Scopus (5) Google Scholar Our study was nested within the prospective China Kadoorie Biobank (CKB) study of over half a million adults recruited from ten geographically defined areas across China. We agree that the criteria and quality of gastric cancer diagnosis, including clinical manifestations and endoscopic, histopathological, or imaging examinations,2National Health Commission of the People's Republic of ChinaChinese guidelines for diagnosis and treatment of gastric cancer 2018.Chin J Cancer Res. 2019; 31: 707-737Crossref PubMed Google Scholar vary between hospitals or institutions. However, our data showed that, overall, the quality of cancer diagnoses in China is of high quality. In the CKB study, around 85% of patients with gastric cancer had their diagnoses confirmed through histopathological examinations, and over 90% of patients had further diagnosis tests—eg, endoscopy and CT or MRI. Furthermore, our analyses were stratified by individual study areas. Therefore, any small regional variation that might exist in making a diagnosis should not have biased our findings. The choice of detection test for H pylori infection depends on the study design, types of sample collected, prevalence and strains of H pylori, accessibility, and clinical circumstances.3Wang YK Kuo FC Liu CJ et al.Diagnosis of Helicobacter pylori infection: current options and developments.World J Gastroenterol. 2015; 21: 11221-11235Crossref PubMed Scopus (165) Google Scholar At baseline, we were not able to undertake urea breath tests for H pylori infection among study participants. Serology of stored plasma samples is useful in screening and epidemiological studies, and has been widely used in previous studies of a similar nature. With both high sensitivity and specificity, the HelicoBlot 2·1 immunoblot assay is accurate for the diagnosis of H pylori infection,4Monteiro L de Mascarel A Sarrasqueta AM et al.Diagnosis of Helicobacter pylori infection: noninvasive methods compared to invasive methods and evaluation of two new tests.Am J Gastroenterol. 2001; 96: 353-358Crossref PubMed Google Scholar and has performed much better than ELISA tests in predicting risk of gastric cancer in several epidemiological studies.5Plummer M Franceschi S Vignat J Forman D de Martel C Global burden of gastric cancer attributable to Helicobacter pylori.Int J Cancer. 2015; 136: 487-490Crossref PubMed Scopus (480) Google Scholar In the CKB study, in addition to excluding the first 2 years of follow-up, we applied a modified criteria to define seropositivity by removing the requirement of the current infection marker band. These approaches made it more relevant to investigate the role of previous H pylori infection in patients progressing towards cancer. We appreciate the suggestion of considering other ethnic groups and interference factors, such as systemic lupus erythematosus. Collaborations with other large prospective studies (eg, the EPIC study and UK Biobank) will be sought in future to further explore the relevance of such factors. We declare no competing interests. The relative and attributable risks of cardia and non-cardia gastric cancer associated with Helicobacter pylori infection in China: a case-cohort studyAmong Chinese adults, H pylori infection is common and is the cause of large numbers of gastric cancer cases. Population-based mass screening and the eradication of H pylori should be considered to reduce the burden of gastric cancer in high-risk settings. Full-Text PDF Open AccessHelicobacter pylori infection and risk of gastric cancerWe read with great interest the study by Ling Yang and colleagues,1 which uniquely showed the association between risk of cardia gastric cancer and Helicobacter pylori infection. However, we would like to raise some concerns. Full-Text PDF Open Access