Comparison between Peritumoral and Intratumoral Budding in Colorectal Cancer

Tumor budding (TB) is classified, based on location, into peritumoral budding (PTB) or intratumoral budding (ITB). This study aimed to evaluate the relationship between PTB and ITB in colorectal cancers (CRCs). PTB and ITB were investigated and subsequently divided into high and low groups. CRCs were divided into three groups: (1) high PTB/ITB, (2) high PTB or ITB, and (3) low PTB/ITB. The clinicopathological and prognostic significances were evaluated according to the three tumor budding (TB) groups. High PTB/ITB and low PTB/ITB were identified in 32 (12.0%) and 135 (50.8%) patients, respectively. A total of 99 patients (37.2%) were found to have high PTB or ITB. TB was significantly correlated with lymphatic and perineural invasion, lymph node metastasis, metastatic lymph node ratio, distant metastasis, and a higher pTNM stage. A significant correlation was found between high PTB and high ITB (p = 0.010). The amount of PTB was found to increase significantly with the amount of ITB (p < 0.001) in a linear regression test. Patients with high PTB/ITB had worse overall and recurrence-free survival than those with high PTB or ITB. Conversely, patients with low PTB/ITB had better overall and recurrence-free survival rates than those with high PTB or ITB. However, there was no significant difference in overall and recurrence-free survival between patients with high PTB/low ITB and high ITB/low PTB (p = 0.336 and p = 0.623, respectively). In summary, the presence of TB, regardless of PTB or ITB, was significantly correlated with aggressive tumor behavior and a worse prognosis than the absence of TB. Additionally, the present study demonstrated that it is feasible to stratify the prognosis of patients based on whether they have both PTB and ITB or only one of the two.