Incidence of gastric cancer among patients with gastric precancerous lesions: observational cohort study in a low risk Western populationBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h3867 (Published 27 July 2015) Cite this as: BMJ 2015;351:h3867
- Huan Song, PhD candidate1,
- Isabella Guncha Ekheden, PhD candidate1,
- Zongli Zheng, postdoctoral scientist1,
- Jan Ericsson, professor2,
- Olof Nyrén, professor1,
- Weimin Ye, professor1
- 1Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 171 77 Stockholm, Sweden
- 2Department of Pathology, Karolinska Hospital, Sweden
- Correspondence to: W Ye
- Accepted 3 July 2015
Objective To accurately measure the incidence of gastric cancer among patients with gastric precancerous lesions, and to quantify the excess incidence in comparison with people with normal mucosa on endoscopy and a general population.
Design Population based cohort study.
Setting Population of Sweden using data from its national disease registers.
Participants 405 172 patients who had gastric biopsy samples taken for non-malignant indications between 1979 and 2011.
Main outcome measures Incidence of gastric cancer, reported separately for patients with different mucosal changes in biopsy samples. Standardised incidence ratios provided estimation of the relative risk, using the general Swedish population as reference; and hazard ratios were derived from Cox regression modelling for internal comparisons with patients with normal gastric mucosa.
Results After excluding the first two years of follow-up, 1599 cases of gastric cancer were identified. The annual crude incidence of gastric cancer was 20×10−5 for those in the normal mucosa group (standardised incidence ratio 1.0), 42×10−5 for those with minor changes (1.5), 59×10−5 for the gastritis group (1.8), 100×10−5 for the atrophic gastritis group (2.8), 129×10−5 for the intestinal metaplasia group (3.4), and 263×10−5 for the dysplasia group (6.5). Cox regression modelling confirmed that excess risks increased monotonically with progressive severity of gastric lesions, with the highest hazard ratio of 10.9 (dysplasia versus normal mucosa, 95% confidence interval 7.7 to 15.4). The increased incidence was stable throughout the follow-up period, and the gaps between cumulative incidence curves grew continuously.
Conclusions Among patients who undergo gastroscopy with biopsy for clinical indications, approximately 1 in 256 with normal mucosa, 1 in 85 with gastritis, 1 in 50 with atrophic gastritis, 1 in 39 with intestinal metaplasia, and 1 in 19 with dysplasia will develop gastric cancer within 20 years. These numbers, along with cost-benefit analyses, should guide future surveillance policies for these particular patient groups.
Contributors: HS was involved in the study design, data collection, analysis and interpretation of the data, and writing the manuscript. IGE was involved in data collection and writing the manuscript. ZZ was involved in conception of the study, data analysis, interpretation of the data, and revision of the manuscript. JE was involved in interpretation of the data and revision of the manuscript. ON and WY were involved in conception of the study, study design, interpretation of the data, and writing the manuscript. All authors revised the article critically for important intellectual content and gave final approval of the version to be published. WY is the guarantor.
Funding: This study was supported by the Swedish Research Council (grant No 2011-3182) and Cancerfonden (grant No 2013-798). HS was partly supported by a scholarship from the China Scholarship Council, and IGE is partly supported by a scholarship from the Karolinska Institutet MD/PhD programme. The funders had no role in the conduct of this research.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the regional ethical review board in Stockholm (2010-819-31-3; 2013-1244-32).
Data sharing: No additional data available.
Transparency: The lead author (WY) affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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