Predicting lymph node metastasis in pT1 colorectal cancer: a systematic review of risk factors providing rationale for therapy decisions

Abstract

The absence of lymphatic invasion, budding, submucosal invasion ≥ 1 mm, and poor histological differentiation were each associated with low risk of LNM. Risk stratification models integrating these factors need to be investigated further.

A three-tier classification system based on the depth of submucosal invasion and budding/sprouting can improve the treatment strategy for T1 colorectal cancer: a retrospective multicenter study

“…Although the implication of budding/sprouting in deeply invasive colorectal cancer was first reported in 1989, 25 many studies have also focused on budding/sprouting as a risk factor of lymph node metastasis in T1 colorectal cancer. [12][13][14][15][26][27][28][29][30][31][32] Some investigators refer to findings similar to budding/sprouting as 'unfavorable histology at the invasive front,' 33 'focal dedifferentiation,' 34 or 'tumor cell dissociation,' 35 although the definition is not always consistent. 13,25,32,36 In the evaluation of budding/sprouting, we adopted the definition of Ueno et al 13 because it is widely used and has good reproducibility.…”

Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016

“…field" and "10 high power field" methods) [11][12][13][14][15][16]18 . Counting across multiple fields has the advantage of being more representative of the entire invasive front, and there is also some evidence of improved inter-observer agreement using this approach [11][12][13][14][15][16]18,45 . On the other hand, counting multiple fields may "dilute" the final (mean) tumor bud count in cases with focally many tumor buds The "hotspot" method therefore better reflects the maximal extent of tumor budding at the invasive front.…”

“…On the other hand, counting multiple fields may "dilute" the final (mean) tumor bud count in cases with focally many tumor buds The "hotspot" method therefore better reflects the maximal extent of tumor budding at the invasive front. The ITBCC group recommends the use of the "hotspot" method, since this is the method used in the vast majority of outcome based studies, and inter-observer agreement using this method is quite acceptable [11][12][13][14][15][16]18,41,48 .…”

“…, whereas tumor grade is defined by the proportion of tumor demonstrating gland formation. In multivariate analyses, the prognostic effect of tumor budding is independent of tumor grade and growth pattern 1,[11][12][13][14][15][16]18 . Therefore, the ITBCC group considers tumor budding to be different from tumor grade, and to have prognostic value that is independent of tumor grade.…”

“…First, in endoscopically resected pT1 colorectal cancer, tumor budding is associated with an increased risk of lymph node metastases. Therefore, patients with budding may benefit from surgical resection [16][17][18] . Second, in stage II colorectal cancer, the presence of tumor budding is an indicator of shorter disease-free survival compared to stage II colorectal cancer with low grade budding, or no budding.…”