Tumor Budding as an Additional Factor in Determining the Need for Surgery after Endoscopic Resection in Mucosal Invasive Gastric Cancer: A Retrospective Study from a Korean Tertiary Hospital.

[BACKGROUND/AIMS] The presence of individual cancer cells at the invasive tumor front is referred to as tumor budding (TB). The purpose of this study was to assess the clinicopathological significance of TB in patients with early gastric cancer (EGC).

[METHODS] A total of 939 patients who received radical surgery for EGC were included in this retrospective study. We assessed clinicopathological features in relation to TB including the grade of histologic differentiation, the extent of invasion depth, the width of submucosal (SM) invasion, and the presence of lymphovascular invasion (LVI), lymph node metastasis (LNM) and perineural invasion (PNI).

[RESULTS] TB was identified in 59.5% of the patients with EGC, 38.7% of the patients with mucosal invasive cancer, and 80.4% of the patients with SM invasive cancers. TB showed significant association with male sex, undifferentiated tumor types, SM invasion, LVI, PNI, and LNM. The presence of SM invasion (odds ratio [OR], 8.750; p<0.001), TB (OR, 5.586; p<0.001), and an undifferentiated-type histology (OR, 2.648; p=0.0005) were found to be significantly associated with LNM/LVI. TB was the sole significant risk factor for LNM/LVI (OR, 7.181; p=0.0016) among the mucosal invasive cancers. In SM invasive cancers, three independent risk factors for LNM/LVI were identified: a tumor located in the lower third of the stomach (OR, 3.425; p=0.0061), an undifferentiated-type histology (OR, 2.320; p=0.0177), and an SM invasion width greater than 4,000 μm (OR, 2.849; p=0.0041).

[CONCLUSIONS] TB may be an important factor associated with LNM, particularly in mucosal gastric cancer.