Role of APAF-1, E-cadherin and peritumoral lymphocytic infiltration in tumour budding in colorectal cancer

A prognostic mutation panel for predicting cancer recurrence in stages II and III colorectal cancer

BACKGROUND AND OBJECTIVES

Approximately 20-40% of stage II/III colorectal cancer (CRC) patients develop relapse. Clinicopathological factors alone are limited in detecting these patients, resulting in potential under/over-treatment. We sought to identify a prognostic tumor mutational profile that could predict CRC recurrence.

METHODS

Whole-exome sequencing data were obtained for 207 patients with stage II/III CRC from The Cancer Genome Atlas. Mutational landscape in relapse-free versus relapsed cohort was compared using Fisher's exact test, followed by multivariate Cox regression to identify genes associated with cancer recurrence. Bootstrap-validation was used to examine internal/external validity.

RESULTS

We identified five prognostic genes (APAF1, DIAPH2, NTNG1, USP7, and VAV2), which were combined to form a prognostic mutation panel. Patients with ≥1 mutation(s) within this five-gene panel had worse prognosis (3-yr relapse-free survival [RFS]: 53.0%), compared to patients with no mutation (3-yr RFS: 84.3%). In multivariate analysis, the five-gene panel remained prognostic for cancer recurrence independent of stage and high-risk features (hazard ratio 3.63, 95%CI [1.93-6.83], P < 0.0001). Furthermore, its prognostic accuracy was superior to the American Joint Commission on Cancer classification (concordance-index: 0.70 vs 0.54).

CONCLUSIONS

Our proposed mutation panel identifies CRC patients at high-risk for recurrence, which may help guide adjuvant therapy and post-operative surveillance protocols.

Significance of E-cadherin and CD44 expression in patients with unresectable metastatic colorectal cancer

The loss of adhesion molecules is reported to be associated with tumor invasion and metastasis in numerous types of cancer. Epithelial (E)-cadherin is an important molecule for cell-to-cell adhesion, while cluster of differentiation (CD)44 is an important molecule for cell-to-extracellular matrix adhesion. The focus of the present study was to evaluate the significance of the expression of E-cadherin and CD44 in patients with the unresectable metastatic colorectal cancer (CRC) who are undergoing palliative chemotherapy. Formalin-fixed, paraffin-embedded samples were obtained from 49 patients who underwent primary tumor resection and who were receiving palliative chemotherapy for unresectable metastatic CRC. The expression of E-cadherin and CD44 was evaluated using immunohistochemistry. The expression of E-cadherin was not significantly associated with progression-free survival (PFS; P=0.2825) or overall survival (OS; P=0.6617). The expression of CD44 was not associated with PFS (P=0.4365), but it did exhibit a certain level of association with OS (P=0.0699). However, the combined low expression of E-cadherin and CD44 demonstrated a significant association with decreased PFS (P=0.0101) and OS (P=0.0009). The combined loss of E-cadherin and CD44 expression also led to a reduction in the objective response rate and disease control rate (P=0.0076 and P=0.0294, respectively). A univariate analysis indicated that the combined low expression of E-cadherin and CD44 (P=0.0474) and sex (P=0.0330) were significantly associated with decreased PFS, and multivariate analysis confirmed combined low expression of E-cadherin and CD44 as an independent risk factor for decreased PFS [hazard ratio (HR), 8.276; 95% confidence interval (CI), 1.383-43.311; P=0.0227]. Univariate and multivariate analyses also indicated that the combined low expression of E-cadherin and CD44 expression was a significant prognostic factor for poor OS (HR, 15.118; 95% CI, 2.645-77.490; P=0.0039). Therefore the current study suggests that the combined low expression of E-cadherin and CD44 is an effective independent predictor of decreased chemotherapeutic outcome and survival in patients with unresectable metastatic CRC.

DAPK loss in colon cancer tumor buds: implications for migration capacity of disseminating tumor cells

Defining new therapeutic strategies to overcome therapy resistance due to tumor heterogeneity in colon cancer is challenging. One option is to explore the molecular profile of aggressive disseminating tumor cells. The cytoskeleton-associated Death-associated protein kinase (DAPK) is involved in the cross talk between tumor and immune cells at the invasion front of colorectal cancer. Here dedifferentiated tumor cells histologically defined as tumor budding are associated with a high risk of metastasis and poor prognosis. Analyzing samples from 144 colorectal cancer patients we investigated immunhistochemical DAPK expression in different tumor regions such as center, invasion front, and buds. Functional consequences for tumor aggressiveness were studied in a panel of colon tumor cell lines using different migration, wound healing, and invasion assays. DAPK levels were experimentally modified by siRNA transfection and overexpression as well as inhibitor treatments. We found that DAPK expression was reduced towards the invasion front and was nearly absent in tumor buds. Applying the ECIS system with HCT116 and HCT116 stable lentiviral DAPK knock down cells (HCTshDAPK) we identified an important role for DAPK in decreasing the migratory capacity whereas proliferation was not affected. Furthermore, the migration pattern differed with HCTshDAPK cells showing a cluster-like migration of tumor cell groups. DAPK inhibitor treatment revealed that the migration rate was independent of DAPK's catalytic activity. Modulation of DAPK expression level in SW480 and DLD1 colorectal cancer cells significantly influenced wound closure rate. DAPK seems to be a major player that influences the migratory capability of disseminating tumor cells and possibly affects the dynamic interface between pro- and anti-survival factors at the invasion front of colorectal cancer. This interesting and new finding requires further evaluation.

S100A8+ stroma cells predict a good prognosis and inhibit aggressiveness in colorectal carcinoma

Gene microarray and bioinformatic analysis showed that S100A8 was more abundant in the stroma surrounding tumor buddings (TBs) than in the stroma surrounding primary tumor cells in colorectal carcinomas. Here, S100A8⁺ cells in 419 colorectal carcinoma samples were stained by immunohistochemistry and counted using Image-pro plus 6.0. TBs were also counted and biomarkers associated with the epithelial-mesenchymal transition and apoptosis were assessed by immunohistochemistry. We evaluated the association between S100A8⁺ cells and clinico-pathological variables as well as survival. Migration and invasion as well as biomarkers of the epithelial-mesenchymal transition and apoptosis were tested in CRC cells, treated with graded concentrations of recombinant human S100A8 protein. We found that the density of S100A8⁺ cells in the tumor invasive front (S100A8⁺_TIF) clearly distinguished patients with 5-y survival from those who did not survive (p = 0.01). The S100A8⁺-associated tumor budding (SATB) index determined by the S100A8⁺_TIF and TB was an independent predictor of overall survival (p = 0.001) other than the S100A8⁺_TIF or TB alone. Migration and invasion properties of CRC cells were inhibited by recombinant human S100A8 treatment. The particular S100A8⁺ cells in the stroma were associated with important biomarkers of the epithelial-mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2). In conclusion, S100A8⁺ cells in the stroma predict a good prognosis in colorectal carcinoma. An index combining S100A8⁺ cells and TB independently predicts survival. Recombinant human S100A8 inhibited CRC cell migration and invasion, which was involved in epithelial-mesenchymal transition (E-cadherin and SNAIL) and apoptosis (BCL2).

Expression profiling of budding cells in colorectal cancer reveals an EMT-like phenotype and molecular subtype switching

Background:

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.

Methods:

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.

Results:

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.

Conclusions:

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.

The Potential Value of Immunotherapy in Colorectal Cancers: Review of the Evidence for Programmed Death-1 Inhibitor Therapy

Colorectal cancers (CRCs) have been identified as potential targets for immunotherapy with programmed cell death (PD)-1 inhibitors. English-language publications from MedLine and Embase that evaluated PD-1/PD ligand 1 (PD-L1) in the CRC tumor microenvironment and clinical trials that assessed PD-1 inhibitors were included. Sixteen abstracts were screened. Fifteen met the inclusion criteria. After review of the full texts, this resulted in a final reference list of 8 studies eligible for review. Five studies that assessed PD-1/PD-L1 in CRC and 3 trials that assessed PD-1 inhibitors were included. PD-1-positive (PD-1⁺) tumor-infiltrating lymphocytes and PD-L1⁺ cancer cells featured more prominently in high-level microsatellite instability (MSI-H) CRCs compared with microsatellite stable (MSS) CRCs, except in 1 study in which PD-L1 expression was higher in MSS CRCs. In the 3 trials that assessed PD-1 inhibitor, all 3 studies recruited patients with metastatic CRC (mCRC). One study also included patients with recurrent CRC. The objective response according to the Response Evaluation Criteria in Solid Tumors criteria was 0% (19 CRC patients with unknown microsatellite instability status) in the nivolumab study. In the pembrolizumab study, the objective response to PD-1 inhibitor was 40% and 0% in patients with MSI-H and MSS mCRC, respectively (10 patients in the MSI-H group, 18 patients in the MSS group). Seventy-eight percent of the patients in the MSI-H mCRC group compared with 11% in the MSS mCRC group (P < .005) showed no further disease progression at 12 weeks. In the nivolumab with or without ipilimumab study, objective partial response at 12 weeks to PD-1 inhibitor with or without cytotoxic T-lymphocyte-associated protein 4 inhibitor was 25.5% to 33.3% and 5% in the MSI-H and MSS groups, respectively (100 patients in the MSI-H group, 20 patients in the MSS group). Clinical trials that assessed PD-1 inhibitor immunotherapy in patients with CRC have recruited only small cohorts of patients with mCRC. Studies on the tumor microenvironment have been on the basis of archival specimens with different antibody PD-1 and PD-L1 preparations for immunohistochemistry, independent from immunotherapy trials. Immunotherapy with PD-1 therapy has potential benefit for immunogenic MSI-H CRCs whereas there is no evidence to date to suggest immunotherapy benefit in MSS CRCs. The available data are limited, and there is no information on non-mCRCs. Future trials are under way to determine its benefits.

Loss of CDH1 (E-cadherin) expression is associated with infiltrative tumour growth and lymph node metastasis

Background:

Loss of CDH1 (E-cadherin) expression in cancer cells may promote cell migration and invasion. Therefore, we hypothesised that loss of CDH1 expression in colorectal carcinoma might be associated with aggressive features and clinical outcome.

Methods:

Utilising molecular pathological epidemiology database of 689 rectal and colon cancer cases in the Nurses' Health Study and the Health Professionals Follow-up Study, we assessed tumour CDH1 expression by immunohistochemistry. Multivariate logistic regression analysis was conducted to assess association of CDH1 loss with tumour growth pattern (expansile-intermediate vs infiltrative) and lymph node metastasis and distant metastasis, controlling for potential confounders including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, and PIK3CA, BRAF and KRAS mutations. Mortality according to CDH1 status was assessed using Cox proportional hazards model.

Results:

Loss of tumour CDH1 expression was observed in 356 cases (52%), and associated with infiltrative tumour growth pattern (odds ratio (OR), 2.02; 95% confidence interval (CI), 1.23–3.34; P=0.006) and higher pN stage (OR, 1.73; 95% CI, 1.23–2.43; P=0.001). Tumour CDH1 expression was not significantly associated with distant metastasis or prognosis.

Conclusions:

Loss of CDH1 expression in colorectal cancer is associated with infiltrative tumour growth pattern and lymph node metastasis.

Tumour budding in colorectal cancer: what do we know and what can we do?

Budding is a process during which individual or small clusters of up to five tumour cells detach from the main tumour mass and invade into the surrounding stroma. In colorectal cancer, this feature is observed in 20-40% of cases and is associated with lymphovascular invasion, lymph node and distant metastases, and poor prognosis. A variety of scoring systems for budding have been proposed but so far a gold standard is lacking, hampering implementation of a budding score in guidelines for pathological examination of colorectal cancer. Furthermore, little is known about the mechanisms which cause tumour cells to detach from the main tumour mass and obtain increased invasive potential. In this review, we present an overview of tumour budding including its definition, scoring systems, prognostic relevance and biological mechanisms involved.

Prognostic significance of Traf2- and Nck- interacting kinase (TNIK) in colorectal cancer

BACKGROUND

The potential of expression profiling using microarray analysis as a tool to predict the prognosis for different types of cancer has been realized. This study aimed to identify a novel biomarker for colorectal cancer (CRC).

METHODS

The expression profiles of cancer cells in 152 patients with stage I-III CRC were examined using microarray analysis. High expression in CRC cells, especially in patients with distant recurrences, was a prerequisite to select candidate genes. Thus, we identified seventeen candidate genes, and selected Traf2- and Nck-interacting kinase (TNIK), which was known to be associated with progression in CRC through Wnt signaling pathways. We analyzed the protein expression of TNIK using immunohistochemistry (IHC) and investigated the relationship between protein expression and patient characteristics in 220 stage I-III CRC patients.

RESULTS

Relapse-free survival was significantly worse in the TNIK high expression group than in the TNIK low expression group in stage II (p = 0.028) and stage III (p = 0.006) patients. In multivariate analysis, high TNIK expression was identified as a significant independent risk factor of distant recurrence in stage III patients.

CONCLUSION

This study is the first to demonstrate the prognostic significance of intratumoral TNIK protein expression in clinical tissue samples of CRC, in that high expression of TNIK protein in primary tumors was associated with distant recurrence in stage II and III CRC patients. This TNIK IHC study might contribute to practical decision-making in the treatment of these patients.

Overexpression of the Nek2 kinase in colorectal cancer correlates with beta-catenin relocalization and shortened cancer-specific survival

The serine/threonine kinase Nek2 (NIMA-related kinase 2) regulates centrosome separation and mitotic progression, with overexpression causing induction of aneuploidy in vitro. Overexpression may also enable tumour progression through effects upon Akt signalling, cell adhesion markers and the Wnt pathway. The objective of this study was to examine Nek2 protein expression in colorectal cancer (CRC). Nek2 protein expression was examined in a panel of CRC cell lines using Western blotting and immunofluorescence microscopy. Nek2 and beta-catenin expression were examined by immunohistochemistry in a series of resected CRC, as well as their matched lymph node and liver metastases, and correlated with clinicopathological characteristics. Nek2 protein expression in all CRC lines examined was higher than in the immortalised colonocyte line HCEC. Nek2 overexpression was present in 86.4% of resected CRC and was significantly associated with advancing AJCC tumour stage and shortened cancer-specific survival. Elevated Nek2 expression was maintained within all matched metastases from overexpressing primary tumours. Nek2 overexpression was significantly associated with lower tumour membranous beta-catenin expression and higher cytoplasmic and nuclear beta-catenin accumulation. These data support a role for Nek2 in CRC progression and confirm potential for Nek2 inhibition as a therapeutic avenue in CRC.

Micropapillary pattern and poorly differentiated clusters represent the same biological phenomenon in colorectal cancer: a proposal for a change in terminology

OBJECTIVES

Colorectal carcinomas (CRCs) with a micropapillary pattern and those showing high counts of poorly differentiated clusters (PDCs) are characterized by a higher probability to develop nodal metastases and have a worse prognosis. In light of the morphologic similarity to the micropapillary component, we aimed to verify whether PDCs also display an inverted secretory pattern.

METHODS

The immunohistochemical expression of MUC1 and E-cadherin was assessed in a cohort of CRCs with PDCs and compared with that observed in CRCs without PDCs.

RESULTS

PDCs in our cases always displayed an inverted MUC1 pattern. In addition, we found abnormal (lost or cytoplasmic) expression of E-cadherin in PDCs.

CONCLUSIONS

The altered expression of MUC1 and E-cadherin may account for the aggressive behavior and higher metastatic potential of CRCs with high PDC counts and indicate an epithelial-mesenchymal transition. Our findings suggest that regardless of the morphologic aspect, PDCs and the micropapillary component may reflect the same biological phenomenon in CRCs. Thus, we wonder whether the micropapillary areas should be considered a variant of CRCs or more objectively counted as PDCs to predict prognosis. We also believe that the term PDC better describes the biological phenomena underlying this peculiar morphologic aspect in comparison with the misnomer micropapillary.

Progressive Increase of Regulatory T Cells and Decrease of CD8+ T Cells and CD8+ T Cells/Regulatory T Cells Ratio during Colorectal Cancer Development

Background

We examined the distribution of CD8+ T cells and regulatory T cells (Tregs), measured the CD8+ T cell/Tregs ratio, investigated the relationship between Tregs and cyclooxygenase-2 (COX-2) expression during colorectal cancer (CRC) development.

Methods

We performed immunohistochemical staining for CD8, forkhead box P3, E-cadherin, and COX-2 in 32 cases of invasive CRC, 10 cases of intramucosal CRC, 27 cases of high-grade tubular adenoma, 22 cases of low-grade tubular adenoma, and 32 cases of non-neoplastic conditions.

Results

We observed a progressive increase in Tregs, and a decrease in CD8+ T cells and the CD8+ T cells/Tregs ratio during CRC development. The alterations were most severe in high-grade tubular adenoma and CRC. COX-2 expression was positively associated with Tregs infiltration. The degree of T cell infiltration differed among tumor compartment and the ratio in the tumor center was the lowest of all areas. The ratio and number of CD8+ T cells in the tumor center and the invasive front of invasive CRC were associated with gender, differentiation, node metastasis and tumor budding.

Conclusions

Alteration in the distribution of both CD8+T cells and Tregs may contribute to the generation of an immune environment suitable for the development and progression of CRC.

Downregulated E-cadherin expression indicates worse prognosis in Asian patients with colorectal cancer: evidence from meta-analysis

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays a crucial role in the progression and aggressiveness of colorectal carcinoma. E-cadherin is the best-characterized molecular marker of EMT, but its prognostic significance for patients with CRC remains inconclusive.

METHODOLOGY

Eligible studies were searched from the PubMed, Embase and Web of Science databases. Correlation between E-cadherin expression and clinicopathological features and prognosis was analyzed. Subgroup analysis was also performed according to study location, number of patients, quality score of studies and cut-off value.

PRINCIPAL FINDINGS

A total of 27 studies comprising 4244 cases met the inclusion criteria. Meta-analysis suggested that downregulated E-cadherin expression had an unfavorable impact on overall survival (OS) of CRC (n = 2730 in 14 studies; HR = 2.27, 95%CI: 1.63-3.17; Z = 4.83; P = 0.000). Subgroup analysis indicated that low E-cadherin expression was significantly associated with worse OS in Asian patients (n = 1054 in 9 studies; HR = 2.86, 95%CI: 2.13-3.7, Z = 7.11; P = 0.000) but not in European patients (n = 1552 in 4 studies; HR = 1.14, 95%CI: 0.95-1.35, Z = 1.39; P = 0.165). In addition, reduced E-cadherin expression indicated an unfavorable OS only when the cut off value of low E-cadherin expression was >50% (n = 512 in 4 studies; HR = 2.08, 95%CI 1.45-2.94, Z = 4.05; P = 0.000). Downregulated E-cadherin expression was greatly related with differentiation grade, Dukes' stages, lymphnode status and metastasis. The pooled OR was 0.36(95%CI: 0.19-0.7, Z = 3.03, P = 0.002), 0.34(95%CI: 0.21-0.55, Z = 6.61, P = 0.000), 0.49(95%CI: 0.32-0.74, Z = 3.02, P = 0.002) and 0.45(95%CI: 0.22-0.91, Z = 3.43, P = 0.001), respectively.

CONCLUSIONS

This study showed that low or absent E-cadherin expression detected by immunohistochemistry served as a valuable prognostic factor of CRC. However, downregulated E-cadherin expression seemed to be associated with worse prognosis in Asian CRC patients but not in European CRC patients. Additionally, this meta-analysis suggested that the negative threshold of E-cadherin should be >50% when we detected its expression in the immunohistochemistry stain.

Combined aberrant expression of E-cadherin and S100A4, but not β-catenin is associated with disease-free survival and overall survival in colorectal cancer patients

Background/Aims

Epithelial-to-mesenchymal transition (EMT) in cancers is related to metastasis, recurrence, and poor prognosis. We evaluated whether EMT-related proteins can act as prognostic biomarkers in colorectal cancer (CRC) patients.

Methods

We evaluated the expression of E-cadherin, β-catenin, and S100A4 by immunohistochemistry (IHC) in 333 CRC tissues from the tumor center and invasive margin. Tumor budding, cell grade, tumor stage, type of tumor growth, peritumoral lymphocyte infiltration (TLI), and perineural- or lymphovascular invasion were evaluated as pathological parameters. mRNA levels of E-cadherin, N-cadherin, β-catenin, and S100A4 from 68 specimens from the same set were analyzed by real time quantitative RT-PCR.

Results

Loss of E-cadherin, nuclear β-catenin, and gain of S100A4 were higher in the invasive margin than in the tumor center. Loss of E-cadherin was associated with cell grade, macroscopic type, perineural invasion, and tumor budding, β-catenin with microsatellite instability and tumor site, and S100A4 with growth type, macroscopic type, AJCC stage, lymphovascular invasion, and perineural invasion. The aberrant expression of E-cadherin and S100A4 not β-catenin in the invasive margin was a significant and independent risk factor for disease-free and overall-survival by multivariate analysis, along with AJCC stage and perineural invasion. mRNA levels of β-catenin and S100A4 were correlated with the IHC findings at the tumor invasive margin. E-cadherin and N-cadherin showed a weak inverse correlation.

Conclusions

The combination of loss of E-cadherin and gain of S100A4 in the tumor invasive margin can be used to stratify patients with the same AJCC stage into different survival groups.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9398289629244673

Proposal for a 10-high-power-fields scoring method for the assessment of tumor budding in colorectal cancer

Although tumor budding is linked to adverse prognosis in colorectal cancer, it remains largely unreported in daily diagnostic work due to the absence of a standardized scoring method. Our aim was to assess the inter-observer agreement of a novel 10-high-power-fields method for assessment of tumor budding at the invasive front and to confirm the prognostic value of tumor budding in our setting of colorectal cancers. Whole tissue sections of 215 colorectal cancers with full clinico-pathological and follow-up information were stained with cytokeratin AE1/AE3 antibody. Presence of buds was scored across 10-high-power fields at the invasive front by two pathologists and two additional observers were asked to score 50 cases of tumor budding randomly selected from the larger cohort. The measurements were correlated to the patient and tumor characteristics. Inter-observer agreement and correlation between observers' scores were excellent (P<0.0001; intraclass correlation coefficient=0.96). A test subgroup of 65 patients (30%) was used to define a valid cutoff score for high-grade tumor budding and the remaining 70% of the patients were entered into the analysis. High-grade budding was defined as an average of ≥10 buds across 10-high-power fields. High-grade budding was associated with a higher tumor grade (P<0.0001), higher TNM stage (P=0.0003), vascular invasion (P<0.0001), infiltrating tumor border configuration (P<0.0001) and reduced survival (P<0.0001). Multivariate analysis confirmed its independent prognostic effect (P=0.007) when adjusting for TNM stage and adjuvant therapy. Using 10-high-power fields for evaluating tumor budding has independent prognostic value and shows excellent inter-observer agreement. Like the BRE and Gleason scores in breast and prostate cancers, respectively, tumor budding could be a basis for a prognostic score in colorectal cancer.

Novel biomarkers for the prediction of metastasis in colorectal cancer

INTRODUCTION

In patients with metastatic colorectal cancers, multimodal management and the use of biological agents such as monoclonal antibodies have had major positive effects on survival. The ability to predict which patients may be at 'high risk' of distant metastasis could have major implications on patient management. Histomorphological, immunohistochemical or molecular biomarkers are currently being investigated in order to test their potential value as predictors of metastasis.

AREAS COVERED

Here, the author reviews the clinical and functional data supporting the investigation of three novel promising biomarkers for the prediction of metastasis in patients with colorectal cancer: tumor budding, Raf1 kinase inhibitor protein (RKIP) and metastasis-associated in colon cancer-1 (MACC1).

EXPERT OPINION

The lifespan of most potential biomarkers is short as evidenced by the rare cases that have successfully made their way into daily practice such as KRAS or microsatellite instability (MSI) status. Although the three biomarkers reviewed herein have the potential to become important predictive biomarkers of metastasis, they have similar hurdles to overcome before they can be implemented into clinical management: standardization and validation in prospective patient cohorts.

Epithelial mesenchymal transition in colorectal cancer: Seminal role in promoting disease progression and resistance to neoadjuvant therapy

BACKGROUND

Epithelial mesenchymal transition (EMT) may be physiological as part of embryological development, or pathological as part of cancer development. It is one of the key initiating events in the metastatic cascade. EMT has profound effects on tumour cell invasiveness, proliferation and motility. In the present article we aimed to review the potential role of EMT as a process to explain colorectal cancer progression and resistance to neoadjuvant therapy.

METHODS

Extensive literature searches were performed in Pubmed, EMBASE and Google Scholar databases to identify relevant articles published before March 2012.

RESULTS

There is adequate evidence to support the complex upstream signalling alterations needed for EMT to occur in colorectal cancers. Changes of EMT are likely to be found at the tumour invasive front: the deepest, growing tumour margin. Loss of E-cadherin at the cell membrane causes loss of cellular integrity, with subsequent migration of malignant cells and tumour budding. These processes are associated with metastases and recurrence of colorectal cancer. There is early evidence from a limited number of studies that resistance to neoadjuvant therapy in colorectal cancer is associated with changes of EMT. However, there is a lack of supporting evidence originating from human colorectal cancer tissues.

CONCLUSIONS

Emerging evidence demonstrates that development of EMT in colorectal cancer leads to an aggressive phenotype that may promote metastatic spread, and augment treatment resistance during neoadjuvant therapy. A clearer understanding of the processes and role of EMT in colorectal cancer may also highlight novel therapeutic strategies.

Tumour budding is a strong and independent prognostic factor in pancreatic cancer

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer that escapes detection and resists treatment. Tumour budding, defined as the presence of de-differentiated single tumour cells or small cell clusters at the invasive front of gastrointestinal carcinomas like colorectal, oesophageal, gastric and ampullary, is linked to adverse prognosis. Tumour budding has not yet been reported in PDAC.

AIM

To assess the frequency and prognostic impact of tumour budding in PDAC.

METHODS

Whole-tissue sections of 117 PDACs with full clinico-pathological and follow-up information, including postoperative therapy, were stained using a pancytokeratin marker. Tumour budding was assessed in 10 high-power fields (HPFs) by two pathologists. High-grade budding was defined as an average of >10buds across 10HPFs. Measurements were correlated to patient and tumour characteristics. The study was performed according to the REMARK guidelines.

RESULTS

Inter-observer agreement was considered strong (ICC=0.72). Low-grade budding was observed in 29.7% and high-grade budding in 70.3% cases. High-grade budding was linked to advanced pT classification (p=0.0463), lymphatic invasion (p=0.0192) and decreased disease-free (p=0.0005) and overall survival (p<0.0001). There was no association with pN, pM, R-status or blood vessel invasion. In multivariate analysis, the prognostic effect of tumour budding was independent of lymph node metastasis, lymphatic invasion and R-status (p<0.0001; HR (95% CI): 3.65 (2.1-6.4)).

CONCLUSIONS

Our results show that high-grade tumour budding occurs frequently in PDAC and is a strong, independent and reproducible, highly unfavourable prognostic factor that could be used to guide future individualised therapeutic approaches.

Improving colorectal cancer management: the potential of proteomics

Colorectal cancer (CRC) is the third most common cancer worldwide. Successful treatment is heavily dependent on tumor stage at the time of detection, but unfortunately CRC is often only detected in advanced stages. New biomarkers in the form of genes or proteins that can be used for diagnosis, prognostication, follow-up, and treatment selection and monitoring could be of great benefit for the management of CRC. Furthermore, proteins could prove valuable new targets for therapy. Therefore, clinical proteomics has gained a lot of scientific interest in this regard. To get an overall insight into the extent to which this research has contributed to a better management of CRC, we give a comprehensive overview of the results of proteomics research on CRC, focusing on expression proteomics, in other words, protein profiling studies. Furthermore, we evaluate the potential of the discriminating proteins identified in this research for clinical use as biomarkers for (early) diagnosis, prognosis and follow-up of CRC or as targets for new therapeutic regimens.

The expression of the high-mobility group A2 protein in colorectal cancer and surrounding fibroblasts is linked to tumor invasiveness

Tumor staging of colorectal cancer is typically based on conventional TNM and Dukes classifications. However, additional information could be useful, and there is a significant interest in identifying molecular markers that are related to genetic or epigenetic processes. Using immunohistochemistry, we analyzed the expression of the high-mobility group A2 (previously high-mobility group 1-C [HMGI-C]) protein in 103 colorectal cancer cases to determine its use as a biomarker in colorectal cancer to integrate morphological staging. We found a progressive increase of the high-mobility group A2 protein expression in colorectal cancer tumor samples from cases in which all of the tumor cells were negative up to cases in which all of the tumor cells stained positive. Increased high-mobility group A2 expression is strongly associated with an increase in tumor invasiveness, which was measured through both budding and vascular invasion (P < .0001). Kaplan-Meier estimates showed a decrease in overall survival when vascular invasion is present (P = .023). Moreover, a fraction of the analyzed samples showed high-mobility group A2-positive stromal fibroblasts. Although high-mobility group A2-positive tumors were associated with cell invasiveness, high-mobility group A2-positive stromal fibroblasts were correlated with less invasive tumors. High-mobility group A2 protein expression could be used as a prognostic marker to provide prospective information on patient outcome, complementing the data obtained using conventional pathologic staging systems.

In situ identification and localization of IGHA2 in the breast tumor microenvironment by mass spectrometry

Modifications in the tumor microenvironment (TME) play a major role in the establishment, progression, and metastasis of cancer. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) is a powerful technique that enables the simultaneous identification and localization of biological compounds within tissues. To detect markers of early TME remodeling in invasive breast cancer, we used MALDI-MSI to compare the molecular profiles of tissues from the breast cancer interface zone, tumor zone, and normal-tissue zone. Using direct-tissue MALDI tandem mass spectrometry (MS/MS), we identified immunoglobulin heavy constant alpha 2 (IGHA2) as a new, zone-specific protein in the breast TME. The zone-specific expression of IGHA2 was verified by immunoblotting and immunohistochemical analysis. IGHA2 expression was consistently positive in tumor cells that were metastatic to regional nodes, with intense expression along the cytoplasmic borders. As a factor related to an increased percentage of nodes with tumor metastasis, IGHA2 expression was upregulated 3.745-fold in cases with an increased number of cancerous nodes (p = 0.0468). Our results provide the first evidence of IGHA2 as a marker of the early process of TME remodeling in invasive breast cancer. Furthermore, IGHA2 may be a novel marker for regional metastases in the lymph nodes of patients with breast cancer.

Tumor budding and recurrence in submucosal invasive colorectal cancers of favorable histology: case reports of two early colorectal cancers with advanced recurrences

Complete resection of submucosal invasive colorectal cancer (SICC) showing favorable histology is regarded as curative. We report on two cases of SICC showing recurrence within 5 years despite complete resection. The first patient was a 68-year-old woman with well differentiated rectal adenocarcinoma invading the superficial submucosa, which recurred after 4.7 years. The second patient was a 53-year-old man with pT1N0 moderately differentiated colonic adenocarcinoma. He developed widespread tumor recurrence after 3.9 years. Retrospective pathologic review of the original tumors showed multiple foci of tumor budding at the invasive front. Immunohistochemical staining for D2-40 of deeper levels of the paraffin blocks showed rare foci of small lymphatic invasion. Tumor budding at the invasive front may be an important indicator for SICC aggressiveness or may reflect early lymphatic invasion. More aggressive pathologic examination and follow-up is required for patients with SICC showing tumor budding, even in the absence of unfavorable histologic findings.

Characterization of the immunological microenvironment of tumour buds and its impact on prognosis in mismatch repair-proficient and -deficient colorectal cancers

AIMS

Tumour budding in colorectal cancer is established as a poor prognostic factor. The inverse correlation of tumour buds with peritumoural lymphocytic inflammation suggests an interaction with specific immune responses. The aims of this study were to characterize the immunological microenvironment of tumour buds and its impact on prognosis in mismatch repair (MMR)-proficient and -deficient colorectal cancers.

METHODS AND RESULTS

A total of 297 colorectal cancers were double-immunostained for CK22 plus one of the following: CD138, CD16, CD20, CD21, CD56, CD68, CD8, forkhead box P2 (FoxP3), granzyme B, mast cell tryptase, CD3 or T cell intracellular antigen-1 (TIA)-1. Tumour buds and immune cells within the region of densest budding were evaluated [×40 high-power field (HPF)] simultaneously. In both MMR-proficient and -deficient cancers, CD8(+), FoxP3(+) and CD68(+) cells were observed most frequently (>40 cells/HPF) and were independent prognostic factors. A combined prognostic score of tumour budding and CD8(+), FoxP3(+) and CD68(+) distinctly identified patients with low-, moderate- or high-risk colorectal cancers with 5-year survival rates of 75.2% [confidence interval 95% (CI): 66-83], 56.3% (95% CI: 43-68) and 25.2% (95% CI: 14-38), respectively, in MMR-proficient and -deficient cancers.

CONCLUSION

The combined assessment of tumour budding with CD8, FoxP3 and CD68 lymphocytes could represent a basis for a prognostic score similar to the Bloom Richardson grade (BRE) and Gleason scores for breast and prostatic cancers.

ADAM15 to α5β1 integrin switch in colon carcinoma cells: a late event in cancer progression associated with tumor dedifferentiation and poor prognosis

ADAM15, a member of the A Disintegrin And Metalloproteinase (ADAM) family, is a membrane protein containing an adhesion domain that binds to α5β1 integrin through a unique RGD domain. ADAM15, expressed by human normal colonocytes, is involved in epithelial wound healing and tissue remodeling in inflammatory bowel disease. The aims of our study were (i) to analyze ADAM15 expression in a series of colon carcinomas and paired normal mucosa and (ii) to integrate the spatial relationship of ADAM15 with its binding partners α5β1 integrin, a mesenchymal marker, as well as with other adhesion molecules, α3β1 integrin and E-cadherin. A series of 94 colon carcinomas of the non other specified category were graded according to the World Health Organization classification. Immunohistochemistry was performed on frozen tissue sections using antibodies directed to ADAM15, α5β1 and α3β1 integrins, and E-cadherin. ADAM15 was quantified at the mRNA level. Finally, promoter methylation of ADAM15 was examined as well as the microsatellite instability status (MSS/MSI). Thirty-six percent of colorectal carcinomas displayed a reduced expression of ADAM15 in cancer cells, confirmed at the mRNA level in most cases, without promoter methylation. ADAM15 down-regulation was associated with histologically poorly differentiated carcinomas. In addition, it was associated with the acquisition of α5β1 by cancer cells and down-regulation of α3β1 integrin and E-cadherin. Finally this profile that includes characteristic of epithelial to mesenchymal transition is a late progression event of colon cancer with a poor prognosis.

Intratumoral budding as a potential parameter of tumor progression in mismatch repair-proficient and mismatch repair-deficient colorectal cancer patients

In colorectal cancer, tumor budding at the invasive front (peritumoral budding) is an established prognostic parameter and decreased in mismatch repair-deficient tumors. In contrast, the clinical relevance of tumor budding within the tumor center (intratumoral budding) is not yet known. The aim of the study was to determine the correlation of intratumoral budding with peritumoral budding and mismatch repair status and the prognostic impact of intratumoral budding using 2 independent patient cohorts. Following pancytokeratin staining of whole-tissue sections and multiple-punch tissue microarrays, 2 independent cohorts (group 1: n = 289; group 2: n = 222) with known mismatch repair status were investigated for intratumoral budding and peritumoral budding. In group 1, intratumoral budding was strongly correlated to peritumoral budding (r = 0.64; P < .001) and less frequent in mismatch repair-deficient versus mismatch repair-proficient cases (P = .177). Sensitivity and specificity for lymph node positivity were 72.7% and 72.1%. In mismatch repair-proficient cancers, high-grade intratumoral budding was associated with right-sided location (P = .024), advanced T stage (P = .001) and N stage pN (P < .001), vascular invasion (P = .041), infiltrating tumor margin (P = .003), and shorter survival time (P = .014). In mismatch repair-deficient cancers, high intratumoral budding was linked to higher tumor grade (P = .004), vascular invasion (P = .009), infiltrating tumor margin (P = .005), and more unfavorable survival time (P = .09). These associations were confirmed in group 2. High-grade intratumoral budding was a poor prognostic factor in univariate (P < .001) and multivariable analyses (P = .019) adjusting for T stage, N stage distant metastasis, and adjuvant therapy. These preliminary results on 511 patients show that intratumoral budding is an independent prognostic factor, supporting the future investigation of intratumoral budding in larger series of both preoperative and postoperative rectal and colon cancer specimens.

Systematic analysis of proteins from different signaling pathways in the tumor center and the invasive front of colorectal cancer

In colorectal cancer, the functional impact of proteins from different signaling pathways varies between tumor center and tumor front. Our objective was to identify differential protein expression profiles between the tumor center and the tumor front of colorectal cancer. Twenty proteins from different signaling pathways (epidermal growth factor receptor [EGFR], phosphorylated extracellular signal regulated kinase [pERK], receptor for hyalouronic acid mediated motility [RHAMM], Raf-1 kinase inhibitor protein [RKIP], β-catenin, E-cadherin, phosphorylated AK transforming [pAKT], p16, p21, Ki-67, B-cell Lymphoma-2 [BCL2], vascular endothelial growth factor, apoptosis protease activating factor 1 [APAF-1], mucin1 [MUC1], ephrin B2 receptor [EphB2], matrix metalloproteinase 7 [MMP7], phosphorylated mothers against decapentaplegic 2 [pSMAD2], caudal type homeobox transcription factor 2 [CDX2], Laminin5γ2, and mammalian sterile 20-like kinase 1 [MST1]) involved in colorectal cancer progression were studied immunohistochemically on 220 well-characterized patients using a multiple-punch tissue microarray including 437 and 430 samples from the tumor center and the invasive front, respectively. Mean expression between the tumor center and the tumor front varied statistically significantly for pSMAD2, pERK, Raf-1 kinase inhibitor protein, E-cadherin, pAKT, BCL2, vascular endothelial growth factor, EphB2, matrix metalloproteinase 7, CDX2, Laminin5γ2, MST1, and APAF-1. Overexpression of pAKT, BCL2, vascular endothelial growth factor, APAF-1, pERK, EphB2, Raf-1 kinase inhibitor protein, CDX2, E-cadherin, MST1 (P < .001 each), and pSMAD2 (P = .002) was more frequently observed in the tumor center, whereas matrix metalloproteinase 7 and Laminin5γ2 (P < .001 each) overexpression was associated with the invasive front. In multivariate analysis, vascular endothelial growth factor (P < .001), Raf-1 kinase inhibitor protein (P = .009), and Laminin5γ2 (P < .001) were the most relevant proteins with the multimarker phenotypes positive/positive/negative and negative/negative/positive being most discriminating between the tumor center and the tumor front. Moreover, the combination negative/negative/positive vascular endothelial growth factor/Raf-1 kinase inhibitor protein/Laminin5γ2 at the tumor front was associated with vascular/lymphatic invasion (P = .014), distant metastasis (P = .019), higher tumor grade (P < .001), and poorer survival (P = .05). Our findings show that, in colorectal cancer progression, vascular endothelial growth factor overexpression seems to play a role in the tumor center, whereas Laminin5γ2-positivity combined with Raf-1 kinase inhibitor protein loss is associated with tumor invasion at the front.

Comprehensive analysis of CpG island methylator phenotype (CIMP)-high, -low, and -negative colorectal cancers based on protein marker expression and molecular features

CpG island methylator phenotype (CIMP) is being investigated for its role in the molecular and prognostic classification of colorectal cancer patients but is also emerging as a factor with the potential to influence clinical decision-making. We report a comprehensive analysis of clinico-pathological and molecular features (KRAS, BRAF and microsatellite instability, MSI) as well as of selected tumour- and host-related protein markers characterizing CIMP-high (CIMP-H), -low, and -negative colorectal cancers. Immunohistochemical analysis for 48 protein markers and molecular analysis of CIMP (CIMP-H: ≥ 4/5 methylated genes), MSI (MSI-H: ≥ 2 instable genes), KRAS, and BRAF were performed on 337 colorectal cancers. Simple and multiple regression analysis and receiver operating characteristic (ROC) curve analysis were performed. CIMP-H was found in 24 cases (7.1%) and linked (p < 0.0001) to more proximal tumour location, BRAF mutation, MSI-H, MGMT methylation (p = 0.022), advanced pT classification (p = 0.03), mucinous histology (p = 0.069), and less frequent KRAS mutation (p = 0.067) compared to CIMP-low or -negative cases. Of the 48 protein markers, decreased levels of RKIP (p = 0.0056), EphB2 (p = 0.0045), CK20 (p = 0.002), and Cdx2 (p < 0.0001) and increased numbers of CD8+ intra-epithelial lymphocytes (p < 0.0001) were related to CIMP-H, independently of MSI status. In addition to the expected clinico-pathological and molecular associations, CIMP-H colorectal cancers are characterized by a loss of protein markers associated with differentiation, and metastasis suppression, and have increased CD8+ T-lymphocytes regardless of MSI status. In particular, Cdx2 loss seems to strongly predict CIMP-H in both microsatellite-stable (MSS) and MSI-H colorectal cancers. Cdx2 is proposed as a surrogate marker for CIMP-H.

Epithelial mesenchymal transition and tumor budding in aggressive colorectal cancer: tumor budding as oncotarget

Epithelial mesenchymal transition (EMT) is proposed as a critical mechanism for the acquisition of malignant phenotypes by epithelial cells. In colorectal cancer, tumor cells having undergone EMT are histologically represented by the presence of tumor buds defined as single cells or small clusters of de-differentiated tumor cells at the invasive front. Tumor budding is not a static, histological feature rather it represents a snap-shot of a dynamic process undertaken by an aggressive tumor with the potential to disseminate and metastasize. Strong, consistent evidence shows that tumor budding is a predictor of lymph node metastasis, distant metastatic disease, local recurrence, worse overall and disease-free survival time and an independent prognostic factor. Moreover, the International Union against Cancer (UICC) recognizes tumor budding as a highly relevant, additional prognostic parameter. The aim of this review is to summarize the evidence supporting the implementation of tumor budding into diagnostic pathology and patient management and additionally to illustrate its worthiness as a potential therapeutic target.

The prognostic influence of tumour-infiltrating lymphocytes in cancer: a systematic review with meta-analysis

Background:

Tumour-infiltrating lymphocytes (TILs) are often found in tumours, presumably reflecting an immune response against the tumour. We carried out a systematic review and meta-analysis, aiming to establish pooled estimates for survival outcomes based on the presence of TILs in cancer.

Methods:

A Pubmed and Embase literature search was designed. Studies were included, in which the prognostic significance of intratumoural CD3+, CD4+, CD8+, and FoxP3+ lymphocytes, as well as ratios between these subsets, were determined in solid tumours.

Results:

In pooled analysis, CD3+ TILs had a positive effect on survival with a hazard ratio (HR) of 0.58 (95% confidence interval (CI) 0.43–0.78) for death, as did CD8+ TILs with a HR of 0.71 (95% CI 0.62–0.82). FoxP3+ regulatory TILs were not linked to overall survival, with a HR of 1.19 (95% CI 0.84–1.67). The CD8/FoxP3 ratio produced a more impressive HR (risk of death: HR 0.48, 95% CI 0.34–0.68), but was used in relatively few studies. Sample size and follow-up time seemed to influence study outcomes.

Conclusion:

Any future studies should be carefully designed, to prevent overestimating the effect of TILs on prognosis. In this context, ratios between TIL subsets may be more informative.

Loss of E-cadherin independently predicts the lymph node status in colorectal cancer

BACKGROUND

The identification of biomarkers that improve risk stratification in patients with colorectal cancer (CRC) is still a challenge. The objective of our study was to identify independent protein markers as predictors of lymph node (N) stage in CRC.

METHODS

Tumour specimens from 221 CRC patients were mounted onto a multiple-punch tissue microarray and evaluated for 21 tumour related factors and one host related factor involved in CRC carcinogenesis, namely β-catenin, E-cadherin, EGFR, pERK, RHAMM, pAKT, pSMAD2, p21, p16, Bcl-2, Ki-67, APAF-1, MST1, RKIP, VEGF, EphB2, MMP7, Laminin5γ2, MUC1, CDX2, caspase-3 as well as intra-tumoural and stromal CD8+ tumour infiltrating lymphocytes (iTILs and sTILs).

RESULTS

Node positive cancers showed significant losses for p21 (p = 0.026), Bcl-2 (p = 0.027), APAF-1 (p = 0.033), EphB2 (p = 0.006), E-cadherin (p < 0.001), RKIP (p = 0.019), CD8+ iTILs and sTILs (p < 0.001 and p = 0.008, respectively) and cytoplasmic MST1 (p = 0.014). Based on the area under the receiver operating characteristic curve (AUC) EphB2, E-cadherin, iTILs and sTILs were identified as potential predictors of N stage (AUC values >0.6), but only loss of E-cadherin was an independent predictor in multivariate analysis.

CONCLUSIONS

E-cadherin appears to be a strong predictor of N stage in CRC and should be considered in pre-operative and post-operative management of colon and rectal cancer patients.

Clinical significance of osteoprotegerin expression in human colorectal cancer

PURPOSE

This study aimed to identify a novel biomarker or a target of treatment for colorectal cancer (CRC).

EXPERIMENTAL DESIGN

The expression profiles of cancer cells in 104 patients with CRC were examined using laser microdissection and oligonucleotide microarray analysis. Overexpression in CRC cells, especially in patients with distant metastases, was a prerequisite to select candidate genes. The mRNA expression of candidate genes was investigated by quantitative reverse transcriptase PCR (RT-PCR) in 77 patients as a validation study. We analyzed the protein expression and localization of the candidate gene by immunohistochemical study and investigated the relationship between protein expression and clinicopathologic features in 274 CRC patients.

RESULTS

Using microarray analysis, we identified 6 candidate genes related to distant metastases in CRC patients. Among these genes, osteoprotegerin (OPG) is known to be associated with aggressiveness in several cancers through inhibition of apoptosis via neutralization of the function of TNF-related apoptosis-inducing ligand. The mRNA expression of OPG in cancer tissues was significantly higher in patients with distant metastases than those without metastases. Overexpression of OPG protein was associated with significantly worse overall survival and relapse-free survival. Moreover, overexpression of the OPG protein was an independent risk factor for CRC recurrence.

CONCLUSION

Overexpression of OPG may be a predictive biomarker of CRC recurrence and a target for treatment of this disease.

Systematic assessment of protein phenotypes characterizing high-grade tumour budding in mismatch repair-proficient colorectal cancer

AIMS

A tumour bud is defined as a single tumour cell or tumour cell cluster of up to five cells at the invasive tumour front. Significant differences in survival have been detected in colorectal cancer patients with low- compared to high-grade budding. The aim of this study was to identify potential multi-marker phenotypes characterizing low- and high-grade budding in mismatch repair (MMR)-proficient colorectal cancer.

METHODS AND RESULTS

Established and promising prognostic proteins such as epidermal growth factor receptor (EGFR), pERK, RHAMM, RKIP, beta-catenin, E-cadherin, pAKT, p16, p21, Ki67, Bcl-2, vascular endothelial growth factor (VEGF), apoptotic protease activating factor-1 (APAF-1), MUC1, EphB2, matrix metalloproteinase 7, pSMAD2, CDX2, laminin5gamma2 and MST1 were analysed on 208 MMR-proficient colorectal cancers with complete clinicopathological data. The most accurate markers for predicting high-grade budding (more than six tumour buds) were EphB2 (P < 0.001), Bcl-2 (P < 0.001), RKIP (P < 0.001), E-cadherin (P = 0.004), laminin5gamma2 (P = 0.004) and APAF-1 (P = 0.005). On multivariable analysis, only loss of Bcl-2 (P < 0.001) and EphB2 (P < 0.001) were independent predictors of high-grade budding. Bcl-2-/EphB2- tumours were more frequently poorly differentiated (P < 0.001), of advanced pT stage (P = 0.002), lymph node positive (P = 0.023), presented vascular (P = 0.053) and lymphatic invasion (P = 0.005) and had a negative impact on patient survival (P = 0.012).

CONCLUSIONS

The multi-marker phenotype EphB2-/Bcl-2- is an independent predictor of high-grade budding and implies increased aggressive behaviour in MMR-proficient colorectal cancer.

Tumor budding predicts response to anti-EGFR therapies in metastatic colorectal cancer patients

AIM: To investigate whether the evaluation of tumor budding can complement K-RAS analysis to improve the individualized prediction of response to anti-epidermal growth factor receptor based therapies in metastatic colorectal cancer (mCRC) patients.

METHODS: Forty-three patients with mCRC treated with cetuximab or panitumumab were entered into this study. According to the Response Evaluation Criteria in Solid Tumors criteria, 30 patients had stable or progressive disease (non-responsive), while 13 patients had a partial response. Tumor buds were evaluated from whole tissue sections stained for pan-cytokeratin, evaluated in the densest region using a 40 × objective and “high-grade” tumor budding was defined as 15 buds/high-power field.

RESULTS: Tumor buds and K-RAS mutation both correctly classified 68% of patients. All patients with K-RAS mutation (n = 7) or high-grade tumor budding (n = 11) were non-responsive, of which 4 patients had both features. All 13 partial responders were K-RAS wild-type with low-grade tumor budding. Combined, the predictive value of K-RAS and tumor budding was 80%. Additionally, high-grade tumor budding was significantly related to worse progression-free survival [HR (95% CI): 2.8 (1.3-6.0, P = 0.008)].

CONCLUSION: If confirmed in larger cohorts, the addition of tumor budding to K-RAS analysis may represent an effective approach for individualized patient management in the metastatic setting.

Tumour budding, uPA and PAI-1 are associated with aggressive behaviour in colon cancer

AIMS

The proteases PAI-1 and uPA play a major role in extracellular matrix degradation, which facilitates tumour progression. Tumour budding is a histomorphological expression of enhanced tumour cell migration.

MATERIALS AND METHODS

To investigate their prognostic value for and correlation with colon cancer, a prospective study was performed. We analysed tissue levels of uPA and PAI-1 of 55 colon cancer tumours employing a commercially available enzyme-linked immunosorbent assay (ELISA). Tumour budding was analysed on cytokeratin-stained slides.

RESULTS

There was a strong correlation between uPA and tumour budding (R = 0.440; P < 0.001). uPA levels were increased in high grade tumours, whereas PAI-1 was elevated in cases with venous invasion (P = 0.004 and P = 0.028). PAI-1 values and tumour budding are associated significantly with the occurrence of distant metastases (P < 0.001 and P = 0.034, respectively). Tumour budding was significantly associated with lymph node metastases (P = 0.034). Multivariate analysis revealed PAI-1 and lymph node metastases to be independently predictive of distant metastases (P = 0.007 and P = 0.004, respectively).

CONCLUSIONS

The results of our study show that tumour budding and the plasmin/plasminogen system are related. PAI-1 was independently predictive for the occurrence of distant metastasis.

Histopathologic features of the tumor budding in adenocarcinoma of the lung: tumor budding as an index to predict the potential aggressiveness

INTRODUCTION

The term tumor budding has been applied to single cells or small clusters of up to four cells within the stromal tissue at the invasive margin of colorectal cancers. This morphologic feature is increasingly being recognized as an adverse prognostic factor. The purpose of this study was to evaluate the clinicopathologic significance of tumor budding in adenocarcinomas of the lung.

METHODS

We investigated the relationship between tumor budding and clinicopathologic parameters of adenocarcinomas of the lung and the prognostic significance of tumor budding by reviewing the cases of 201 consecutive patients who had undergone complete resection of adenocarcinoma of the lung measuring 30 mm or less in diameter. We examined immunohistochemical profile of budding cells (BCs) by immunohistochemical staining with 14 antibodies.

RESULTS

Tumor budding was observed in 78 (43.1%) of the 181 cases with invasive adenocarcinoma. The presence of tumor budding was significantly associated with lymph node metastasis (p = 0.005), pathologic stage (p < 0.001), vascular invasion (p = 0.003), lymphatic invasion (p = 0.009), and pleural invasion (p = 0.029). Examination of the relation between the presence of tumor budding and the predominant histologic subtype revealed that the predominant papillary subtype was significantly associated with the presence of tumor budding (p = 0.0023), whereas the predominant bronchioloalveolar carcinoma subtype was significantly associated with the absence of tumor budding (p < 0.001). The overall 5-year survival rates of the group with budding and the group without budding was 67.5% and 88.3%, respectively, and difference was significant (p = 0.0057). Compared with cancer cells forming nests, BCs displayed reduced expression of cellular adhesion molecule, E-cadherin, and beta-catenin (p < 0.05 and p < 0.05, respectively) and increased expression of laminin5-gamma2 (p < 0.05). However, BCs displayed reduced expression of differentiation marker, surfactant protein A (p < 0.05). Multivariate analysis revealed that tumor budding was significant independent prognostic factor of the small-sized adenocarcinoma of the lung.

CONCLUSIONS

Our data showed that tumor budding in adenocarcinoma of the lung is a distinct morphologic feature that has biologic and prognostic significance.

Prognostic impact of the expression of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and ALDH1 in colorectal cancer

Background:

The aim of this study was to elucidate the prognostic impact of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and aldehyde dehydrogenase-1 (ALDH1) in colorectal cancer.

Methods:

A tissue microarray of 1420 primary colorectal cancers and 57 normal mucosa samples was immunostained for CD133, CD166, CD44s, EpCAM, and ALDH1 in addition to 101 corresponding whole tissue sections. Invasive potential of three colorectal cancer cell lines was tested.

Results:

Differences between normal tissue and cancer were observed for all markers (P<0.001). Loss of membranous CD166 and CD44s were linked to higher pT (P=0.002, P=0.014), pN (P=0.004, P=0.002), an infiltrating growth pattern (P<0.001, P=0.002), and worse survival (P=0.015, P=0.019) in univariate analysis only. Loss of membranous EpCAM expression was also linked to higher pN (P=0.023) and infiltrating growth pattern (P=0.005). The CD44s, CD166, and EpCAM expression were lost towards the invasive front. The CD44−/CD166− cells from three colorectal cancer cell lines exhibited significantly higher invasive potential in vitro than their positive counterparts.

Conclusions:

Loss, rather than overexpression, of membranous CD44s, CD166, and EpCAM is linked to tumour progression. This supports the notion that the membranous evaluation of these proteins assessed by immunohistochemistry may be representative of their cell adhesion rather than their intra-cellular functions.

Prognostic immunophenotypic biomarker studies in diffuse large B cell lymphoma with special emphasis on rational determination of cut-off scores

A number of biomarkers, particularly proteins that contribute to prognosis in diffuse large B cell lymphoma (DLBCL), have been identified. However, translation into accepted standards to predict survival has not yet been accomplished, primarily due to contradictory reports in the literature resulting from, among other factors, arbitrary methodologies used to set cut-off values for determining positivity. Some of these problems might be resolved by application of rational statistical methods for determination of cut-off scores. Herein, we critically address issues on in situ phenotypic prognostic tumor-related biomarkers in DLBCL with a particular and practical emphasis on tools for cut-off level determination, especially receiver operating characteristic curve analysis. Moreover, we candidly illustrate the application of these tools for efficient disease-specific survival prognostication on a tissue microarray collective of 240 primary DLBCL using the common prognostic biomarkers Bcl-2, Bcl-6, CD10, FOXP1, MUM1, and Cyclin E. Comparison of the results relative to disease-specific survival unequivocally showed the superior discriminatory power of the cut-off levels calculated by receiver operating curves and the Youden's index, compared to arbitrary cut-off values from the literature, advocating fundamental application of rational methods for determination of clinically relevant prognostic biomarkers' cut-off scores.

Solitary cell infiltration is a novel indicator of poor prognosis and epithelial-mesenchymal transition in pancreatic cancer

Pancreatic cancer is one of the most aggressive and lethal human malignancies in the Western world. A wide variety of intratumor glandular differentiation, including solitary infiltrating cancer cells, is a prominent microscopic finding in pancreatic cancer. We reviewed 114 resected cases of pancreatic ductal adenocarcinoma to investigate the prognostic impact of the degree of solitary cell infiltration, defined by the number of solitary infiltrating cancer cells. The clinicopathologic correlation of solitary cell infiltration was further evaluated. Seventy-six (67%) cases showed 7 or more solitary infiltrating cancer cells in 10 high-power fields and were labeled as having a high degree of solitary cell infiltration. A high degree of solitary cell infiltration correlated significantly with poor overall survival, the grade, lymphatic invasion, and lymph node metastasis. Multivariate analysis revealed that the degree of solitary cell infiltration, the grade, and the margin status were independent prognostic factors. Grade 1 and 2 tumors with a high degree of solitary cell infiltration, compared with low infiltration, correlated significantly with poor overall survival. Grade 3 tumors showed a worse overall survival than grade 1 and 2 tumors with either a high or a low degree of solitary cell infiltration. Immunohistochemical analysis showed that a high degree of solitary cell infiltration correlated with reduced E-cadherin and increased vimentin expression. In conclusion, solitary cell infiltration is a significant prognostic indicator and serves as a morphological clue to epithelial-mesenchymal transition in pancreatic cancer.

Role of the VEGF ligand to receptor ratio in the progression of mismatch repair-proficient colorectal cancer

BACKGROUND

The VEGF family of ligands and receptors are intimately involved in tumor angiogenesis, lymphangiogenesis and metastasis. The evaluation of VEGF ligand/receptor ratios may provide a more profound understanding of the involvement of these proteins in colorectal tumour progression. The aim of this study was to elucidate the role of the VEGF ligand/receptor ratios on tumour progression and metastasis in patients with mismatch repair-proficient colorectal cancer.

METHODS

Immunohistochemistry for VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGFR1, VEGFR2 and VEGF3 was carried out on 387 mismatch repair-proficient colorectal cancers using a tissue microarray. Evaluation of immunoreactivity was performed semi-quantitatively and the ligand/receptor expression ratio was obtained.

RESULTS

An increased VEGF-A/VEGFR1 ratio, VEGF-A and VEGFR1 was linked to the presence of peritumoral lymphocytic inflammation at the invasive front (p = 0.032; p = 0.005; p = 0.032, respectively). VEGFR1 expression was related to poorer outcome in multivariable analysis with pT stage, pN stage, vascular invasion, and post-operative therapy. A higher ratio of VEGF-A/VEGFR2 was linked to advanced TNM stage (p = 0.005) while VEGF-A and VEGFR2 were elevated in tumours with an infiltrating tumour growth pattern (p = 0.006; p = 0.014; p = 0.006). No effect of VEGF-A/VEGFR2, VEGF-A or VEGFR2 on survival time was noted.

CONCLUSIONS

Our findings highlight an involvement of VEGF-A, VEGR1 and VEGFR2 in events occurring at the invasive tumour front and a potential prognostic role of VEGFR1 expression in mismatch repair-proficient colorectal cancers. The VEGF-A ligand to VEGFR1 or VEGFR2 ratio may represent an alternative evaluation system for identifying patients with poorer clinical outcome.

ABCG5-positivity in tumor buds is an indicator of poor prognosis in node-negative colorectal cancer patients

AIM: To analyze the expression of 8 putative cancer stem cell (CSC) markers within colorectal cancer tumor buds and to determine their prognostic impact in patients with this disease.

METHODS: Immunohistochemistry was performed on 101 colorectal cancer resections for CK22 (to identify tumor buds) as well as CD133, CD166, CD24, CD44s, CD90, EpCAM, ALDH1, and ABCG5, and their expression within tumor buds was evaluated.

RESULTS: CD90, CD44s, and CD133 expression in tumor buds was found in less than 5% of all cases. ALDH1, CD24, CD166 were expressed in 16.5%, 16.2%, and 34% cases, respectively, while ABCG5 and EpCAM expression was more frequent and found in 35% and 69% of cases, respectively. Of the 8 markers studied, EpCAM and ABCG5 positivity in tumor buds were significantly associated with poor prognosis (P = 0.023, P = 0.038, respectively) in multivariable analysis with pT and pN classification [P = 0.048; hazard ratio (HR): 2.64; 95% CI: 1.0-6.9, for EpCAM and P = 0.029; HR: 2.22; 95% CI: 1.0-4.5, for ABCG5]. Poor survival time was particularly striking for lymph node-negative patients with ABCG5-positive buds (P < 0.001).

CONCLUSION: Expression of putative stem cell markers EpCAM and ABCG5 within the tumor buds of colorectal cancer are frequently noted and are associated with poor prognosis.

Systematic assessment of the prognostic impact of membranous CD44v6 protein expression in colorectal cancer

AIMS

To assess systematically the membranous expression of CD44v6 in colorectal cancer by immunohistochemistry to determine its prognostic impact, the differential expression between primary and metastatic tumours and expression differences between the tumour centre and invasive front.

METHODS AND RESULTS

Immunohistochemistry was performed for CD44v6 on two tissue microarrays. The first included 1279 colorectal tumours with full clinicopathological data. The second consisted of 50 matched primary and metastatic tumours sampled from the tumour centre and the invasive margin. A scoring system was tested by multiple observers. Receiver-operating characteristic curve analysis was used for cut-off point determination. Loss of membranous CD44v6 was associated with pT stage (P = 0.016; sensitivity 85.8%, specificity 20.1%), lymph node metastasis (P = 0.015; sensitivity 52.8%, specificity 55%), an infiltrating tumour margin (P < 0.001; sensitivity 71.4%, specificity 40%) and adverse prognosis (P = 0.011; hazard ratio 0.79, 95% confidence interval 0.7, 0.9), but was not an independent prognostic factor on multivariable analysis. Loss of expression occurred at the invasive front in both primary and metastatic lesions (P < 0.001).

CONCLUSIONS

This study outlines an approach to help standardize the immunohistochemical evaluation of CD44v6 and similar markers in colorectal cancer and highlights a significant role for loss of membranous CD44v6 expression in colorectal cancer progression and prognosis.

Invasive front of colorectal cancer: Dynamic interface of pro-/anti-tumor factors

Tumor-host interaction at the invasive front of colorectal cancer represents a critical interface encompassing a dynamic process of de-differentiation of colorectal carcinoma cells known as epithelial mesenchymal transition (EMT). EMT can be identified histologically by the presence of “tumor budding”, a feature which can be highly specific for tumors showing an infiltrating tumor growth pattern. Importantly, tumor budding and tumor border configuration have generated considerable interest as additional prognostic factors and are also recognized as such by the International Union Against Cancer. Evidence seems to suggest that the presence of tumor budding or an infiltrating growth pattern is inversely correlated with the presence of immune and inflammatory responses at the invasive tumor front. In fact, several tumor-associated antigens such as CD3, CD4, CD8, CD20, Granzyme B, FOXP3 and other immunological or inflammatory cell types have been identified as potentially prognostic in patients with this disease. Evidence seems to suggest that the balance between pro-tumor (including budding and infiltrating growth pattern) and anti-tumor (immune response or certain inflammatory cell types) factors at the invasive front of colorectal cancer may be decisive in determining tumor progression and the clinical outcome of patients with colorectal cancer. On one hand, the infiltrating tumor border configuration and tumor budding promote progression and dissemination of tumor cells by penetrating the vascular and lymphatic vessels. On the other, the host attempts to fend off this attack by mounting an immune response to protect vascular and lymphatic channels from invasion by tumor buds. Whereas standard pathology reporting of breast and prostate cancer involves additional prognostic features, such as the BRE and Gleason scores, the ratio of pro- and anti-tumor factors could be a promising approach for the future development of a prognostic score for patients with colorectal cancer which could complement tumor node metastasis staging to improve the clinical management of patients with this disease.

CD8+ lymphocytes/ tumour-budding index: an independent prognostic factor representing a 'pro-/anti-tumour' approach to tumour host interaction in colorectal cancer

Background:

The tumour-host interaction at the invasive front of colorectal cancer, including the epithelial–mesenchymal transition and its hallmark ‘tumour budding’, is an important area of investigation in terms of prognosis. The aim of this study was to determine the prognostic impact of a ‘pro-/anti-tumour’ approach defined by an established ‘pro-tumour’ (tumour budding) and host-related ‘anti-tumour’ factor of the adaptive immunological microenvironment (CD8+ lymphocytes).

Methods:

Double immunostaining for CK22/CD8 on whole tissue sections (n=279; Cohort 1) and immunohistochemistry for CD8+ using tissue microarrays (n=191; Cohort 2) was carried out. Tumour buds, CD8+ and CD8+ T-lymphocytes : tumour buds indices were evaluated per high-power field.

Results:

In Cohort 1, a low-CD8+/ buds index was associated with lymph node metastasis (P<0.001), vascular invasion (P=0.009), worse survival in univariate (P<0.001) and multivariable (P<0.001) analysis, and furthermore in lymph node-negative patients (P=0.002). In Cohort 2, the CD8+/ buds index was associated with T stage (P<0.001), N stage (P=0.041), vascular invasion (P=0.005) and survival in patients with TNM stage II (P=0.019), stage III (P=0.004), and adjuvantly untreated (P=0.009) and treated patients (P<0.001).

Conclusion:

The CD8+ lymphocyte : tumour-budding index is an independent prognostic factor in colorectal cancer and a promising approach for a future prognostic score for patients with this disease.

Urokinase-type plasminogen activator is a marker of aggressive phenotype and an independent prognostic factor in mismatch repair-proficient colorectal cancer

The aim of this study was to determine the prognostic significance of urokinase-type plasminogen activator (uPA) and its receptor (uPAR) in colorectal cancer stratified by mismatch repair status and to determine their contribution to the aggressive phenotype predicted by loss of E-cadherin and apoptosis protease activating factor-1 (APAF-1). Immunohistochemistry for uPA and uPAR was performed on a tissue microarray comprising 811 mismatch repair-proficient and 164 mismatch repair-deficient colorectal cancers. Immunoreactivity was scored semiquantitatively and the interobserver agreement between multiple pathologists was determined. Optimal cutoff scores for uPA and uPAR positivity were obtained by receiver operating characteristic curve analysis. Agreement between pathologists was excellent for uPA and uPAR. Cutoff scores of 60% for uPA and 75% for uPAR were validated by resampling of the data. In mismatch repair-proficient colorectal cancer, overexpression of uPA and uPAR was associated with advanced pT stage (P = .009, both), an infiltrating margin (P = .009 and P = .033, respectively), and poor prognosis (P = .002 and P < .001, respectively). uPA, but not uPAR, maintained its significant prognostic effect in multivariable analysis (P = .037). In addition to loss of APAF-1 (P = .002) and E-cadherin (P < .001), uPA independently predicted an infiltrating margin (P = .016). Our findings suggest that uPA, but not uPAR, is an independent prognostic factor and that this negative effect on survival is relevant specifically for mismatch repair-proficient colorectal cancers. Moreover, the combination of uPA with E-cadherin and APAF-1 is linked to an aggressive tumor phenotype and highly predictive of an infiltrating growth pattern.

HLA-DR expression is associated with better prognosis in sporadic Australian clinicopathological Stage C colorectal cancers

Predicting patient outcome for colorectal carcinoma (CRC) with lymph node but not distant metastases remains challenging. Various prognostic markers have been identified including microsatellite instability (MSI) and possibly expression of the MHC Class II protein, HLA-DR. About 15% of sporadic CRC exhibits MSI associated with methylation of the DNA mismatch repair gene hMLH1 promoter. In addition, a significant proportion of unselected CRC demonstrates expression of HLA-DR. We sought to examine the relationship between HLA-DR expression, MSI status and prognosis in sporadic Australian Clinicopathological (ACP) Stage C CRC. Two hundred seventy consecutive patients with sporadic ACP Stage C CRC were treated at Concord Repatriation General Hospital between 1986 and 1992. None of these patients received adjuvant chemotherapy and all were followed for a minimum of 5 years or until death. DNA was extracted from paraffin sections and MSI status determined by PCR. HLA-DR expression was determined immunohistochemically using an antibody against the HLA-DR alpha chain. MSI status could be assigned in 235 cases: 176 CRCs (74.9%) were microsatellite stable, whereas 23 (9.8%) had high levels of MSI (MSI-H) and 36 (15.3%) had low levels of MSI (MSI-L). HLA-DR expression by CRC cells was seen in 148 (60.1%) cases and correlated with the presence of tumor-infiltrating lymphocytes (p = 0.0005) and peritumoral lymphocytes (p = 0.003), but not other clinicopathological features or MSI status. HLA-DR-positive CRCs were strongly associated with better patient outcome (p < 0.0001).

Apoptosis signaling proteins as prognostic biomarkers in colorectal cancer: a review

Colorectal cancer is a leading cause of cancer related mortality in the Western world. In recent years, combination 5-fluorouracil based adjuvant chemotherapy as first line treatment of this disease has led to improved disease free and overall survival. However drug resistance, both innate and acquired, remains an obstacle in the effective treatment of this disease. Apoptotic pathways are frequently altered in both tumor progression and drug resistance; therefore proteins associated with this pathway may have potential as prognostic biomarkers for this disease. Identification of clinical biomarkers that are able to identify patients who are more likely to respond to specific chemotherapy will lead to more personalized, effective, and less toxic therapy. This review focuses on the current status of apoptosis related proteins as biomarkers for colorectal cancer and discusses the possible application of systems approaches in this context.

Local recurrence in mismatch repair-proficient colon cancer predicted by an infiltrative tumor border and lack of CD8+ tumor-infiltrating lymphocytes

PURPOSE

The identification of colon cancer patients at high risk of local recurrence is necessary to improve the selection of patients for more tailored treatment protocols. The aim of this study was to develop a predictive model of local recurrence by assessing the independent predictive effect of 7 clinicopathologic features, 24 protein markers of tumor progression, and their multifeature combinations in mismatch repair-proficient colon cancers.

EXPERIMENTAL DESIGN

Immunohistochemistry for 24 protein markers was done on 269 patients with complete clinicopathologic data. After univariate and multivariable analyses, independent predictors of local recurrence were identified and their multifeature combinations were analyzed. Kaplan-Meier and Cox proportional hazards regression were done for survival analysis.

RESULTS

Local recurrence was observed in 119 patients (55.8%). Independent predictors of tumor recurrence were lymph node involvement (P = 0.006), absence of CD8+ tumor-infiltrating lymphocytes (TIL; P < 0.001), and infiltrative tumor margin (P < 0.001). This independent effect persisted after adjusting for adjuvant therapy. Risk of recurrence was 0.75 and the 5-year survival rate was 8.8% in patients with these three adverse features. Node-negative patients with an infiltrative tumor margin and absence of CD8+ TILs were identified as high risk with a probability of 0.55 for recurrence and a 60% 5-year survival rate. The remaining node-negative cases fared significantly better with risks ranging from 8% to 26% and 5-year survival rates reaching 97.6%.

CONCLUSIONS

An infiltrative tumor margin and absence of CD8+ TILs are highly predictive of local recurrence in node-negative mismatch repair-proficient colon cancer and may help to identify high-risk patients who may benefit from adjuvant chemotherapy.