Objective Early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2G-NBI) can improve early detection, is unknown.
Design This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (WLI) followed by secondary 2G-NBI (WLI group: n=2258) and primary 2G-NBI followed by secondary WLI (2G-NBI group: n=2265) performed by the same examiner. Suspected early gastric cancer (EGC) lesions in both groups were biopsied. Primary endpoint was the rate of EGC patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for EGC in suspicious lesions detected (primary examination).
Results EGCs were found in 44 (1.9%) and 53 (2.3%; p=0.412) patients in the WLI and 2G-NBI groups, respectively, during primary EGD. In a post hoc analysis, the overall rate of lesions detected at the second examination was 25% (n=36/145), with no significant differences between groups. PPV for EGC in suspicious lesions was 13.5% and 20.9% in the WLI (50/371 target lesions) and 2G-NBI groups (59/282 target lesions), respectively (p=0.015).
Conclusion The overall sensitivity of primary endoscopy for the detection of EGC in high-risk patients was only 75% and should be improved. 2G-NBI did not increase EGC detection rate over conventional WLI. The impact of a slightly better PPV of 2G-NBI has to be evaluated further.
Trial registration number UMIN000014503.
- gastric cancer
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Contributors NY: study concept and design; acquisition of data; analysis and interpretation of data; drafting of the manuscript; critical revision of the manuscript for important intellectual content; final approval of the article; and study supervision. MM: study concept and design; acquisition of data; analysis and interpretation of data; drafting of the manuscript; critical revision of the manuscript for important intellectual content; final approval of the article; study supervision and obtaining of funding. HD and NU: study concept and design; acquisition of data; analysis and interpretation of data; drafting of the manuscript; critical revision of the manuscript for important intellectual content; and final approval of the article. TY, TH, YY, NK, HK, SH, KensY, IO, CK, CY, and KO: study concept and design; acquisition of data; analysis and interpretation of data; and final approval of the article. KeniY and HI: study concept and design; analysis and interpretation of data; statistical analysis; and final approval of the article.
Funding The Olympus Corporation provided partial funding for this study. This study was funded by joint research funds supplied by Kyoto University and the Olympus Corporation. Conflicts of interest exist between Kyoto University, but not the other participating institutions, and the Olympus Corporation.
Disclaimer The funding source had no role in the conduct of the study; the collection, management, analysis or interpretation of the data; or in the preparation, review or approval of the manuscript.
Competing interests MM received grants from Olympus during the study period. TY received personal fees and non-financial support from Olympus, outside this study.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available on reasonable request. The data that support the findings of this study have been deposited in UMIN (https://www.umin.ac.jp/icdr/index.html), and the data are available from the corresponding author, MM, on reasonable request.
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