Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer

Figure 1 Lymph node metastasis. A: In each subgroup of undifferentiated-type gastric adenocarcinoma. The figure demonstrates incidence of lymph node metastasis (LNM) with 95%CIs in subgroups classified by gastroscopic findings (size and depth) of undifferentiated-type gastric adenocarcinoma. The dashed lines represent incidence of LNM (%) in cases ≤ 2 cm and > 2 cm. A P value with a significant difference between two groups is shown. LNM was absent in the mucosal ≤ 2 cm group. The LNM rate was significantly higher in the > 2 cm group than in the > 2 cm group and higher in submucosal cancer than in mucosal cancer; B: In each subgroup with and without lymphatic involvement (LI) of undifferentiated-type gastric adenocarcinoma. The figure demonstrates incidence of LNM with its 95%CI in subgroups classified by size, depth, and LI in undifferentiated-type gastric adenocarcinoma. The dashed lines represent incidence of LNM (%) with or without LI. There was no case with LI-positive, ≤ 2 cm, and mucosal, which was referred to as not applicable (NA). A P value with a significant difference between two groups is shown. There was no significant difference in the LNM rate among LI-negative groups. The LNM rate was significantly lower in the LI-negative group than in the LI-positive group. The LNM rate (LI-positive, ≤ 2 cm, and submucosal) was relatively low at 11.4%.

Figure 2 Decision tree analysis. A: Preoperatively evaluable factors. Based on nine factors of age, gender, location, size, form, ulcer, depth, histology, and mixed-type, 567 cases were classified into five subgroups. Boxes indicate the factors used for splitting with cut-off points. Pie charts indicate the rate of lymph node metastasis in each group. Numbers show the rate of lymph node metastasis with 95%CI; B: Postoperatively evaluable factors. Based on 11 factors of age, gender, location, size, form, ulcer, depth, histology, mixed-type, lymphatic involvement, venous involvement, and lymph node metastasis, 567 cases were classified into four subgroups on the decision tree. Boxes indicate the factors used for splitting with cut-off points. Pie charts indicate the rate of lymph node metastasis in each group. Numbers shows the rate of lymph node metastasis with 95%CI. LNM: Lymph node metastasis; M/U: Middle/upper third of the stomach; L: Lower third of the stomach; LI: Lymphatic involvement.