Background: The clinical relevance and general applicability of the 8th American Joint Committee on Cancer TNM gastric cancer staging system vs the 7th version have not been examined using datasets from both the East and West. Methods: Patients (n = 29 984) treated for gastric adenocarcinoma at two high-volume centers (Severance Hospital [SH] and Gangnam Severance Hospital [GSH]) in Korea and data from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. Survival curves, the performance of tumor staging, and the homogeneity of modified subgroups were compared. Results: Minute changes were noted in the stage IIB subgroup; most changes were noted in stage III. Applying the 8th staging system facilitated better prediction of survival than applying the 7th version for SH data according to the log-rank test, C-index, and AIC (8444.5 vs 9263.8, 0.796 vs 0.798, and 104152 vs 103909, respectively). Its performance was also superior for GSH and SEER data. In a subgroup analysis of stages IIB to IIIC in SH, GSH, and SEER data, the 8th staging system showed similar or more homogeneous survival for each sub-classification than the 7th version. Conclusion: Compared with the 7th gastric cancer staging system, the newer version more accurately predicted prognosis and stratified subgroups more homogeneously.
Bibliographical noteFunding Information:
We would like to thank Anthony Thomas Milliken, ELS (Editing Synthase, Seoul, Korea) for his assistance with editing the manuscript. We also acknowledge the assistance of BioScience Writers, LLC (Houston, TX) with copyediting and correction of English language usage. This study was supported by a grant from the Investigator Sponsored Research Program (ISR‐2017‐10924, Covidien Private Limited [Medtronic]). This funding source had no role in the design of this study nor any role during its execution, data analyses and interpretation, or decision to submit results for presentation or publication.
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