Is the eCura system useful for selecting patients who require radical surgery after noncurative endoscopic submucosal dissection for early gastric cancer? A comparative study

Background We have established a risk-scoring system, termed the "eCura system," for the risk stratification of lymph node metastasis in patients who have received noncurative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to clarify whether this system contributes to the selection of patients requiring radical surgery after ESD. Methods Between 2000 and 2011, 1,969 patients with noncurative ESD for EGC were included in this multicenter study. Depending on the treatment strategy after ESD, we had patients with no additional treatment (n = 905) and those with radical surgery after ESD (n = 1,064). After the application of the eCura system to these patients, cancer recurrence and cancer-specific mortality in each risk category of the system were compared between the two patient groups. Results Multivariate Cox analysis revealed that in the high-risk category, cancer recurrence was significantly higher (hazard ratio = 3.13, p = 0.024) and cancer-specific mortality tended to be higher (hazard ratio = 2.66, p = 0.063) in patients with no additional treatment than in those with radical surgery after ESD, whereas no significant differences were observed in the intermediate-risk and low-risk categories. In addition, cancer-specific survival in the low-risk category was high in both patient groups (99.6 and 99.7%). A limitation of this study is that it included a small number of cases with undifferentiated-type EGC (292 cases). Conclusions The eCura system is a useful aid for selecting the appropriate treatment strategy after noncurative ESD for EGC. However, caution is needed when applying this system to patients with undifferentiated-type EGC.