Background: Prognostic factors for superficial esophageal cancer cannot be limited to such factors as lymph node metastasis (N factor), depth of tumor invasion (T factor), and genetic alterations. The purpose of this study was to examine whether invasive growth patterns of tumors, such as infiltrative growth pattern c (INFc) and budding, represent new useful prognostic factors for superficial esophageal cancer.
Methods: We investigated 87 cases of superficial esophageal cancer in patients treated with radical surgery. First, the invasive growth pattern of the tumor was pathologically evaluated based on the traditional infiltrative growth pattern (INF) classification. Next, new INF criteria were proposed, and the invasive pattern was re-evaluated. We also investigated budding (Bud) in the stroma of the invasive frontal lesion.
Results: When the patients were divided into two groups, with and without an INFc component, the group with an INFc component had a poorer outcome than the group without an INFc component. When the group with an INFc component was defined as "new INFc", new INFc was correlated with the T factor (p = 0.006) and the ly factor (lymphatic invasion) (p = 0.041). Bud was correlated with the T factor (p = 0.001), the N factor (p = 0.030), and new INFc (p < 0.001). An analysis of survival revealed new INFc (p = 0.002) and Bud (p = 0.006) to be prognostic factors. The survival of the group with new INFc(+)/Bud(+) was poorer than that with new INFc(-)/Bud(-) (p = 0.007).
Conclusions: New INFc and Bud, which represent new invasive patterns, were prognostic factors for superficial esophageal cancer.