• adjuvant chemotherapy
• colorectal cancer
• early colon cancer
• early rectal cancer
• lymph node dissection
• lymph node metastasis
• pt1
• recurrence risk
• t1
• tumor budding

• Endoscopic resection
• Lymph node metastasis
• Surgical resection
• T1 colorectal cancer
• Treatment strategy

• Colorectal Neoplasms/pathology
• Humans
• Lymph Nodes/pathology
• Lymph Nodes/surgery
• Lymphatic Metastasis
• Neoplasm Staging
• Retrospective Studies
• Risk Assessment
• Risk Factors

Tumour budding in colorectal cancer has become an important prognostic factor. Represented by single cells or small tumour cell clusters at the invasion front of the tumour mass, these tumour buds seem to reflect cells in a ‘hybrid’ state of epithelial–mesenchymal transition, and evidence indicates that the presence of these entities is associated with lymph node metastasis, local recurrence and distant metastatic disease. The International Tumour Budding Consensus Conference (ITBCC) has highlighted a scoring system for the reporting of tumour budding in colorectal cancer, as well as different clinical scenarios that could affect patient management. Other organs are not spared: tumour budding has been described in numerous gastrointestinal and non-gastrointestinal cancers. Here, we give an update on ITBCC validation studies in the context of colorectal cancer and the clinical implications of tumour budding throughout the upper gastrointestinal and pancreatico-biliary tract.

In this study, we aimed to identify independent predictive factors for lymph node metastasis (LNM) in T1 colon cancer.

Data of 8056 eligible patients were retrospectively collected from the Surveillance, Epidemiology, and End Results (SEER) database during 2004–2012. We performed logistic regression analysis to identify predictive factors for LNM. Both unadjusted and adjusted Cox regression analyses were used to determine the association between LNM and patient survival. Finally, we used competing risks analysis and the cumulative incidence function (CIF) to further confirm the prognostic role of LNM in cancer-specific survival (CSS).

The overall risk of LNM in patients with T1 colon cancer was 12.0% (N = 967). Adjusted logistic regression models revealed that mucinous carcinoma [odds ratio (OR) = 2.26, P < 0.001], moderately differentiated (OR 1.74, P < 0.001), poorly differentiated (OR 5.16, P < 0.001), and undifferentiated carcinoma (OR 3.01, P = 0.003); older age (OR 0.66, P < 0.001 for age 65–79 years, OR 0.44, P < 0.001 for age over 80 years); and carcinoma located in the ascending colon (OR 0.77, P = 0.018) and sigmoid colon (OR 1.24, P = 0.014) were independent predictive factors for LNM. Adjusted Cox regression analysis showed that positive lymph node involvement was significantly associated with CSS [hazard ratio (HR) = 3.02, P < 0.001], which was further robustly confirmed using a competing risks model and the CIF.

This population-based study showed that mucinous carcinoma, tumor grade, age, and primary tumor location were independent predictive factors for LNM in T1 colon cancer. The risk of LNM should be carefully evaluated in patients with T1 colon cancer, before clinical management.

• Colon cancer
• Independent predictive factors
• Lymph node metastasis
• SEER database

• Early colon cancer
• Endosocpic mucosal resection
• Margins of excision

• Chemoradiotherapy
• Mismatch repair
• Pathological complete response
• Rectal cancer
• Tumor budding

• colorectal cancer
• lymph node metastasis
• lymphatic vessel invasion
• tumour budding

• Colorectal cancer
• Epithelial-to-mesenchymal transition
• Human chorionic gonadotropin
• Prognostic factor
• Tumor budding

As with other malignancies, lymph node metastasis is an important staging element and prognostic factor in colorectal carcinomas. The number of involved lymph nodes is directly related to decreased 5-year overall survival for all pT stages according to United States Surveillance, Epidemiology, and End Results (SEER) cancer registry database. The National Quality Forum specifies that the presence of at least 12 lymph nodes in a surgical resection is one of the key quality measures for the evaluation of colorectal cancer. Therefore, the harvesting of a minimum of twelve lymph nodes is the most widely accepted standard for evaluating colorectal cancer. Since this is an accepted quality standard, a second attempt at lymph node dissection in the gross specimen is often performed when the initial lymph node count is less than 12, incurring a delay in reporting and additional expense. However, this is an arbitrary number and not based on any hard scientific evidence. We decided to investigate whether the additional effort and expense of submitting additional lymph nodes had any effect on pathologic lymph node staging (pN). We identified a total of 99 colectomies for colorectal cancer in which the prosector subsequently submitted additional lymph nodes following initial review. The mean lymph node count increased from 8.3 ± 7.5 on initial search to 14.6 ± 8.0 following submission of additional sections. The number of cases meeting the target of 12 lymph nodes increased from 14 to 69. Examination of the additional lymph nodes resulted in pathologic upstaging (pN) of five cases. Gross reexamination and submission of additional lymph nodes may provide more accurate staging in a limited number of cases. Whether exhaustive submission of mesenteric fat or fat-clearing methods is justified will need to be further investigated.

• clinicopathological features
• colorectal T1 carcinoma
• colorectal surgery
• endoscopic resection
• lymph node metastasis

• Early rectal cancer
• T1 rectal cancer
• lymph node metastasis
• submucosal invasion
• surgery

Tumour budding, described as the presence of single cells or small clusters of up to five tumour cells at the invasive margin, is established as a prognostic marker in colorectal carcinoma. In the present study, we aimed to investigate the molecular signature of tumour budding cells and the corresponding tumour bulk.

Tumour bulk and budding areas were microdissected and processed for RNA-sequencing. As little RNA was obtained from budding cells, a special low-input mRNA library preparation protocol was used. Gene expression profiles of budding as compared with tumour bulk were investigated for established EMT signatures, consensus molecular subtype (CMS), gene set enrichment and pathway analysis.

A total of 296 genes were differentially expressed with an FDR <0.05 and a twofold change between tumour bulk and budding regions. Genes that were upregulated in the budding signature were mainly involved in cell migration and survival while downregulated genes were important for cell proliferation. Supervised clustering according to an established EMT gene signature categorised budding regions as EMT-positive, whereas tumour bulk was considered EMT-negative. Furthermore, a shift from CMS2 (epithelial) to CMS4 (mesenchymal) was observed as tumour cells transit from the tumour bulk to the budding regions.

Tumour budding regions are characterised by a phenotype switch compared with the tumour bulk, involving the acquisition of migratory characteristics and a decrease in cell proliferation. In particular, most tumour budding signatures were EMT-positive and switched from an epithelial subtype (CMS2) in the tumour bulk to a mesenchymal subtype (CMS4) in budding cells.

• colorectal cancer
• reproducibility
• tumour budding
• virtual microscopy

• Lymph node metastasis
• T1 colorectal cancer
• Tumor location

The conventional histologic grading of colorectal cancer (CRC) is less suited for resected rectal cancer following neoadjuvant chemoradiation. Enumeration of poorly differentiated clusters (PDC) is a recently proposed histologic grading scheme. We aimed to apply PDC grading to treated rectal cancer and to test the prognostic significance of this novel approach. Archived hematoxylin and eosin slides of 72 rectal adenocarcinomas resected following neoadjuvant treatment were retrieved. PDC, tumor budding, and tumor regression were assessed. The parameters were correlated with clinicopathological features and survival. PDC was strongly associated with tumor budding, perineural invasion (PNI), metastasis, and low degree of tumor regression. Tumor budding was significantly associated with lymphovascular invasion and PNI, and metastasis. Tumors with a lower degree of regression were more likely to show high pathologic T stage and advanced clinical stage. Local recurrence was associated with poor survival. PDC did not correlate with overall survival. PDC grading is applicable to resected rectal cancer status post neoadjuvant treatment and correlates with established histopathological prognosticators. PDC and tumor budding may represent a histologic spectrum reflective of the same biological significance. Validation and incorporation of these simple histologic grading schemes may strengthen the prognostic power of the histologic parameters that influence the oncologic outcome in treated rectal cancer. Further study to evaluate the significance of PDC as an oncologic prognosticator is warranted.

• Histologic grading
• poorly differentiated clusters
• rectal cancer
• tumor budding
• tumor regression

• budding
• colorectal cancer
• cytokeratin
• interobserver variability
• pathological diagnosis

• Colorectal Neoplasms/metabolism
• Colorectal Neoplasms/pathology
• Humans
• Immunohistochemistry
• Keratins/metabolism
• Lymphatic Metastasis
• Neoplasm Grading
• Observer Variation
• Reproducibility of Results

• cancer metastasis
• drug resistance
• epithelial-mesenchymal transition
• microenvironment
• tumor budding

• colorectal cancer
• lymphocyte
• neutrophil
• prognosis

• Early colon cancer
• Endoscopic resection
• Lymph node harvesting
• Lymphovascular invasion
• Submucosal invasion
• Tattooing

• Colorectal cancer
• Epithelial-mesenchymal transition
• Metastasis
• Prognostic factor
• Tumor budding

Metastatic dissemination can exist before a pathologically and clinically detectable manifestation. The structural heterogeneity of colon cancer (CC) in histological sections with respect to the morphology of tumor aggressiveness and composition of the tumor microenvironment raises the question of whether the microscopical tumor architecture enables a discrimination of groups with different metastatic potential. This would result in an assessment of the prognosis and provision of an ancillary tool for the therapeutic management after surgery, beside the estimation of the local tumor extent.

In order to identify predictive biomarkers for metastasis of locally advanced CC, which can easily be integrated into the pathologist’s daily routine diagnostic activity, we determined tumor budding, peritumoral inflammation, extent of desmoplasia and necrosis, density of macro- and microvascular blood vessels and functional state of lymphatics in the tumor center, invasive margin and tumor-free surrounding tissue in 86 non-metastatic, lymphogenous-metastatic and haematogenous-metastatic, subserosa-invasive CC.

Features influencing nodal metastasis in the univariate analysis included high tumor budding (p = 0.004), high large vessel density in the subserosa (p = 0.043), abundant desmoplasia (p = 0.049), non-finger-like desmoplastic pattern (p = 0.051) and absent lymphocellular intratumoral inflammation (p = 0.084). In the multivariate analysis, with the exception of large vessel density, these pathomorphological features were independent risk factors for lymphogenous metastasis (p = 0.023, p = 0.017, p = 0.037, p = 0.012, respectively) with a good discrimination ability (AUC of 0.853). Features associated with distant metastasis in the univariate analysis included high tumor budding (p = 0.002), low intratumoral small vessel density (p = 0.013), absent lymphocellular intratumoral inflammation (p = 0.048) and abundant necrosis (p = 0.073). In the multivariate analysis only tumor budding was an independent predictor for haematogenous metastasis (p = 0.007) with a good discrimination ability (AUC of 0.829).

Thus, mainly tumor budding but also the described structural characteristics of the peritumoral tissue appears to reflect the metastatic potential of locally advanced CC and therefore should be stated in pathological reports.

• early colorectal cancer
• lymph node metastasis
• prognostic factor

In colorectal cancer (CRC), tumour budding at the invasion front is associated with lymph node (LN) and distant metastasis. Interestingly, tumour budding can also be detected in biopsies (intratumoural budding; ITB) and may have similar clinical importance. Here we investigate whether ITB in preoperative CRC biopsies can be translated into daily diagnostic practice.

Preoperative biopsies from 133 CRC patients (no neoadjuvant therapy) underwent immunohistochemistry for pan-cytokeratin marker AE1/AE3. Across all biopsies for each patient, the densest region of buds at × 40 (high-power field; HPF) was identified and buds were counted.

A greater number of tumour buds in the biopsy was associated with pT stage (P=0.0143), LN metastasis (P=0.0007), lymphatic (P=0.0065) and venous vessel invasion (P=0.0318) and distant metastasis (cM1) (P=0.0013). Using logistic regression, a ‘scale' was developed to estimate the probability of LN and distant metastasis using the number of tumour buds (e.g. 10 buds per HPF: 64% chance of LN metastasis; 30 buds per HPF: 86% chance). Inter-observer agreement for ITB was excellent (intraclass correlation coefficient: 0.813).

Tumour budding can be assessed in the preoperative biopsy of CRC patients. It is practical, reproducible and predictive of LN and distant metastasis. Intratumoural budding qualifies for further investigation in the prospective setting.

• Early colorectal cancer
• histological differentiation
• lymph node metastasis
• lymphovascular invasion
• submucosal invasion
• tumour budding

• Basement Membrane/metabolism
• Basement Membrane/pathology
• Cadherins/genetics
• Cadherins/metabolism
• Cell Line, Tumor
• Cell Movement/genetics
• Colorectal Neoplasms/genetics
• Colorectal Neoplasms/metabolism
• Colorectal Neoplasms/pathology
• Disease Progression
• Down-Regulation
• Epithelial-Mesenchymal Transition/genetics
• Gene Expression Regulation, Neoplastic
• Humans
• Lymphatic Metastasis/genetics
• MicroRNAs/genetics
• MicroRNAs/metabolism
• Neoplasm Invasiveness/genetics
• Stromal Cells/metabolism
• Stromal Cells/pathology

This study was designed to identify risk factors for lymph node metastasis of early stage colorectal cancer, which was confirmed to a carcinoma that invaded the submucosa after radical resection.

In total, 55 patients revealing submucosal invasive colorectal carcinoma on pathology who underwent curative radical resection at the Department of Surgery, St. Vincent’s Hospital, The Catholic University of Korea from January 2007 to September 2010 were evaluated retrospectively. Tumor size, depth of submucosal invasion, histologic grade, lymphovascular invasion, tumor budding, and microacinar structure were reviewed by a single pathologist. Student t-test for continuous variables and Chi-square test for categorical variables were used for comparing the clinicopathological 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.

The mean age of 55 patients (34 males and 21 females) was 61.2 ± 9.6 years (range, 43–83). Histologically, eight (14.5%) patients had metastatic lymph node. In the univariate analysis, tumor budding (P = 0.047) was the only factor that was significantly associated with lymph node metastasis. Also, the tumor budding had a sensitivity of 83.3%, a specificity of 60.5%, and a negative predictive value of 0.958 for lymph node metastasis in submucosal invasive T1 colorectal cancer.

The tumor budding seems to have a high sensitivity (83.3%), acceptable specificity (60.5%), and a high negative predictive value (0.958). A close examination of pathologic finding including tumor budding should be performed in order to manage early CRC properly.

• cancerised adenoma
• colon
• early cancer

• Colorectal neoplasms
• Recurrence
• Risk factors

• Colon cancer
• Lymph node
• Quality indicator
• Rectal cancer
• Survival

• Adenocarcinoma/mortality
• Adenocarcinoma/pathology
• Aged
• Aged, 80 and over
• Cell Dedifferentiation
• Female
• Gallbladder Neoplasms/mortality
• Gallbladder Neoplasms/pathology
• Humans
• Kaplan-Meier Estimate
• Male
• Middle Aged
• Neoplasm Staging
• Prognosis
• Proportional Hazards Models

• Cell Dedifferentiation/physiology
• Epithelial-Mesenchymal Transition
• Gastrointestinal Neoplasms/pathology
• Humans
• Lymphatic Metastasis
• Neoplasm Invasiveness
• Neoplasm Metastasis
• Neoplasm Staging/methods
• Prognosis

Prediction of prognosis in colorectal cancer is vital for the choice of therapeutic options. Histopathological factors remain paramount in this respect. Factors such as tumor size, histological type and subtype, presence of signet ring morphology and the degree of differentiation as well as the presence of lymphovascular invasion and lymph node involvement are well known factors that influence outcome. Our understanding of these factors has improved in the past few years with factors such as tumor budding, lymphocytic infiltration being recognized as important. Likewise the prognostic significance of resection margins, particularly circumferential margins has been appreciated in the last two decades. A number of molecular and genetic markers such as KRAS, BRAF and microsatellite instability are also important and correlate with histological features in some patients. This review summarizes our current understanding of the main histopathological factors that affect prognosis of colorectal cancer.