Tumor budding and size as risk factors of lymph node metastasis in early colorectal cancer

This study was designed to investigate risk factors for lymph node metastasis of the Chinese people with early stage colorectal cancer, which was confirmed to a carcinoma that invaded the submucosa after radical resection. In total, 68 patients revealing submucosal invasive colorectal carcinoma on pathology who underwent curative radical resection from October 2007 to September 2011 were evaluated retrospectively. Tumor size, depth of submucosal invasion, histological grade, lymph-vascular invasion, tumor budding, and microacinar structure were reviewed independently by two pathologists. Student t-test for continuous variables and Chi-square test for categorical variables were used for comparing the clinic-pathological features between two groups (whether lymph node involvement existed or not). Continuous variables are expressed as the mean +/- standard error while statistical significance is accepted at P < 0.05. As results, the mean age of the patients was 65.7 +/- 9.6 years (range from 47 to 84). The mean tumor size (the largest diameter) was 21.5 +/- 1.2 mm (range from 5 to 84 mm). Histologically, 11 patients (16.2%) had metastatic lymph node. The lymph node metastasis was significantly associated with the tumor budding (P = 0.038) and the tumor size (P = 0.031) while other factors were not statistically significant. Tumor budding seems to have a high sensitivity (80.0%) for lymph node metastasis, acceptable specificity (55.6%). Therefore, tumor budding should be performed in order to clarify early colorectal cancer with lymph node metastasis through pathologic analysis.