The Changing Trends of T Stage and Size of Early Gastric Cancer

We would like to express our sincere appreciation to Prof. Takahashi for the constructive suggestions. As mentioned, intramucosal gastric cancer (GC) diagnosed according to the Japanese criteria may be regarded as dysplasia based on the WHO criteria [1, 2]. Diagnosing dysplasia as cancer will inevitably increase the rate of early gastric cancer (EGC), which is attributed to the impact of the change in diagnostic criteria rather than the widespread application of endoscopic screening. Stage T1b GC is an invasive cancer that penetrates the submucosa, and its diagnostic criteria are consistent across different diagnostic systems. However, the changing trend of these cases over time to some extent reflects the actual effect of endoscopic screening. Here we conducted a trend analysis of the T stage for all cases using a non-parametric trend test. The results showed that the rates of EGC at both T1a and T1b stages were on the rise over time (p < 0.05); the rate of stage T1a GC increased from 7.82% in 2007 to 25.23% in 2022, and that of stage T1b GC increased from 6.85% in 2007 to 11.46% in 2022 (Figure 1). In addition, we analyzed the changes in the lesion size of EGC using the Poisson regression, and found that the rates of minute (≤ 5 mm) and small (> 5 and ≤ 10 mm) GC presented an upward trend over time (p < 0.001; Figure 2). This further confirms the significant achievements of endoscopic screening for EGC, and indicates that Chinese endoscopists are increasingly emphasizing EGC and improving their ability to identify such lesions. This study was supported by the National Natural Science Foundation of China (82203224). This work was supported by National Natural Science Foundation of China (82203224). The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.