Analysis of the seventh edition of American Joint Committee on colon cancer staging

Clinical and Pathologic Predictors of Tumor Deposits in Colorectal Cancer

BACKGROUND

Tumor deposits (TDs) are a special metastatic pattern of colorectal cancer (CRC). This study aims to explore the pathological characteristics of TD and find out the risk factors of TD in CRC.

METHODS

TDs cases of CRC were selected and validated by HE staining. The correlation between TDs and T stages, N stages, and microsatellite instability was calculated by the chi-squared (χ2) test.

RESULTS

A total of 2553 patients with colorectal cancer undergoing intestinal resection were included in this study. Two hundred fifty-nine cases of TDs patients were included. The positive rate of TDs was 1.9% (2/105) in T1, 3.8% (10/266) in T2, 11% (231/2305) in T3, and 22.8% (16/77) in T4. T3 and T4 were more prone to TDs than T1 and T2, but there was no difference between T3 and T4. The positive rate of TDs was 7.2% (107/1491) in N0, 14.3% (152/1062) in N + , and N + was more prone to TDs than N0. The positive rate of TDs was 10.5% (256/2432) in MSS, 2.5% (3/121) in MSI, and MSS was more prone to TDs than MSI. Multivariate analysis showed lymph node invasion, T stage, and MSS were independent risk factors for TDs.

CONCLUSION

Lymph node invasion, T stage, and MSS were independent risk factors for TDs.

An Analysis of the Gene Expression Associated with Lymph Node Metastasis in Colorectal Cancer

Objective

This study aimed to explore the genes regulating lymph node metastasis in colorectal cancer (CRC) and to clarify their relationship with tumor immune cell infiltration and patient prognoses.

Methods

The data sets of CRC patients were collected through the Cancer Gene Atlas database; the differentially expressed genes (DEGs) associated with CRC lymph node metastasis were screened; a protein-protein interaction (PPI) network was constructed; the top 20 hub genes were selected; the Gene Ontology functions and the Kyoto Encyclopedia of Genes and Genomes pathways were enriched and analyzed. The Least Absolute Shrinkage and Selection Operator (LASSO) regression method was employed to further screen the characteristic genes associated with CRC lymph node metastasis in 20 hub genes, exploring the correlation between the characteristic genes and immune cell infiltration, conducting a univariate COX analysis on the characteristic genes, obtaining survival-related genes, constructing a risk score formula, conducting a Kaplan-Meier analysis based on the risk score formula, and performing a multivariate COX regression analysis on the clinical factors and risk scores.

Results

A total of 62 DEGs associated with CRC lymph node metastasis were obtained. Among the 20 hub genes identified via PPI, only calcium-activated chloride channel regulator 1 (CLCA1) expression was down-regulated in lymph node metastasis, and the rest were up-regulated. A total of nine characteristic genes associated with CRC lymph node metastasis (KIF1A, TMEM59L, CLCA1, COL9A3, GDF5, TUBB2B, STMN2, FOXN1, and SCN5A) were screened using the LASSO regression method. The nine characteristic genes were significantly related to different kinds of immune cell infiltration, from which three survival-related genes (TMEM59L, CLCA1, and TUBB2B) were screened. A multi-factor COX regression showed that the risk scores obtained from TMEM59L, CLCA1, and TUBB2B were independent prognostic factors. Immunohistochemical validation was performed in tissue samples from patients with rectal and colon cancer.

Conclusion

TMEM59L, CLCA1, and TUBB2B were independent prognostic factors associated with lymphatic metastasis of CRC.

Dickkopf 4 Alone and in Combination with Leucyl-tRNA Synthetase as a Good Prognostic Biomarker for Human Colorectal Cancer

The prognosis of patients with colorectal cancer (CRC) is affected by invasion and metastasis. Leucyl-tRNA synthetase (LARS) was shown to be related to the growth and migration of lung cancer cells. Dickkopf 4 (DKK4) is known as a Wnt/β-catenin pathway inhibitor, and its upregulation was reported in several cancers. However, the clinical significance of LARS and DKK4 in human CRC has not been clearly defined. We investigated the expression of LARS and DKK4 by immunohistochemical staining in tissue microarrays from 642 primary CRC patients and analyzed the relationship between their expression and the clinicopathological characteristics of CRC patients. LARS and DKK4 expressions were not related to gender, age at surgery, histologic grade, size, tumor location, tumor invasion, or metastasis, but LARS expression was significantly correlated with TNM stage, N stage, and lymph node metastasis. DKK4 expression was inversely related to the TNM stage and N stage. Survival analysis demonstrated that the OS and DFS in the LARS high expression group were not different compared to the LARS low expression group. OS and DFS in the DKK4 high expression group were significantly higher than in the DKK4 low expression group. In addition, OS and DFS in the group with the combination of the LARS high/DKK4 low expression were significantly lower than in the LARS high/DKK4 high expression group. The low expression of DKK4 alone can be used as a predictor of relapse in CRC patients. In addition, DKK4 low expression in the case of LARS high expression can be used as a poor prognostic factor in CRC patients. Thus, our findings suggest that DKK4 alone or in combination with LARS at diagnosis may be a useful prognostic factor for CRC.

Identifying the critical state of complex biological systems by the directed-network rank score method

MOTIVATION

Catastrophic transitions are ubiquitous in the dynamic progression of complex biological systems; that is, a critical transition at which complex systems suddenly shift from one stable state to another occurs. Identifying such a critical point or tipping point is essential for revealing the underlying mechanism of complex biological systems. However, it is difficult to identify the tipping point since few significant differences in the critical state are detected in terms of traditional static measurements.

RESULTS

In this study, by exploring the dynamic changes in gene cooperative effects between the before-transition and critical states, we presented a model-free approach, the directed-network rank score (DNRS), to detect the early-warning signal of critical transition in complex biological systems. The proposed method is applicable to both bulk and single-cell RNA-sequencing (scRNA-seq) data. This computational method was validated by the successful identification of the critical or pre-transition state for both simulated and six real datasets, including three scRNA-seq datasets of embryonic development and three tumor datasets. In addition, the functional and pathway enrichment analyses suggested that the corresponding DNRS signaling biomarkers were involved in key biological processes.

AVAILABILITY AND IMPLEMENTATION

The source code is freely available at https://github.com/zhongjiayuan/DNRS.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Survival Contradiction in Stage II, IIIA, And IIIB Colon Cancer: A Surveillance, Epidemiology, and End Result-Based Analysis

There exists an inconsistency between stage and survival in the current American Joint Committee on Cancer (AJCC) staging system for colon cancer. In this study, we compared the clinicopathological characteristics and prognosis of colon cancer patients with stage II, IIIA, and IIIB disease based on the surveillance, epidemiology, and end results (SEER) database. Kaplan-Meier analysis was used to generate overall survival (OS) and cancer-specific survival (CSS) curves. The Cox regression was employed to identify risk factors. The competing risk model was completed by the cumulative incidence function and Gray's test. In the final population of 31,361 colon cancer patients, Kaplan-Meier curve analysis showed that stage IIIA had the highest OS and CSS, followed by stage IIA and IIIB, and IIB and IIC showed the worst OS and CSS. In the Cox model, the stage was proven to be an independent prognostic factor. In the competing risk model, stage IIIA colon cancer patients had the lowest 5-year cancer-specific death rate in stages II, IIIA, and IIIB. In conclusion, the prognosis of colon cancer patients in stage IIA was worse than that of patients in stage IIIA, while the survival rate of stage IIB and IIC was lower than that of stage IIIB.

pT3 colorectal cancer revisited: a multicentric study on the histological depth of invasion in more than 1000 pT3 carcinomas-proposal for a new pT3a/pT3b subclassification

Background

Pathological TNM staging (pTNM) is the strongest prognosticator in colorectal carcinoma (CRC) and the foundation of its post-operative clinical management. Tumours that invade pericolic/perirectal adipose tissue generally fall into the pT3 category without further subdivision.

Methods

The histological depth of invasion into the pericolic/perirectal fat was digitally and conventionally measured in a training cohort of 950 CRCs (Munich). We biostatistically calculated the optimal cut-off to stratify pT3 CRCs into novel pT3a (≤3 mm)/pT3b (>3 mm) subgroups, which were then validated in two independent cohorts (447 CRCs, Bayreuth/542 CRCs, Mainz).

Results

Compared to pT3a tumours, pT3b CRCs showed significantly worse disease-specific survival, including in pN0 vs pN+ and colonic vs. rectal cancers (DSS: P < 0.001, respectively, pooled analysis of all cohorts). Furthermore, the pT3a/pT3b subclassification remained an independent predictor of survival in multivariate analyses (e.g. DSS: P < 0.001, hazard ratio: 4.41 for pT3b, pooled analysis of all cohorts). While pT2/pT3a CRCs showed similar survival characteristics, pT3b cancers remained a distinct subgroup with dismal survival.

Discussion

The delineation of pT3a/pT3b subcategories of CRC based on the histological depth of adipose tissue invasion adds valuable prognostic information to the current pT3 classification and implementation into current staging practices of CRC should be considered.

Comparison of Long-Term Survival Outcomes of T4a and T4b Colorectal Cancer

Background

Although T4b is known to have worse oncologic outcomes, it is unclear whether it truly shows a worse prognosis. This study aims to compare the survival differences between T4a and T4b.

Methods

Patients who were pathologically diagnosed with T3 and T4 colorectal adenocarcinoma from 2010 to 2014 were included (T3, n = 1822; T4a, n = 424; T4b, n = 67). Overall survival (OS) and cancer-specific survival (CSS) were compared between T4a and T4b using the Kaplan-Meier method and log-rank test.

Results

In stage II, T4a had better OS and CSS than T4b (5-year OS, 89.5% vs. 72.6%; 5-year CSS, 94.4% vs. 81.7%, all p < 0.05), however, in stage III, there were no significant differences in survivals between groups (all p > 0.05). In multivariable analysis, T classification was not an independent risk factor for OS (p > 0.05). However, for CSS, when respectively compared to T3, T4b (HR 3.53, p < 0.001) showed a relatively higher hazard ratio than T4a (HR 2.27, p < 0.001).

Conclusions

T4a showed more favorable OS and CSS than T4b, especially in stage II. Our findings support the current AJCC guidelines, in which T4b is presented as a more advanced stage than T4a.

CaMKII Mediates TGFβ1-Induced Fibroblasts Activation and Its Cross Talk with Colon Cancer Cells

INTRODUCTION

Cancer-associated fibroblasts (CAFs), as the activated fibroblasts in tumor stroma, are important modifiers of tumor progression. TGFβ1 has been the mostly accepted factor to fuel normal fibroblasts transformation into CAFs. Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) is thought to play an important role in fibroblasts activation induced by TGFβ1. The aim of this study is to investigate the potential role of CaMKII in TGFβ1-induced fibroblasts activation and CAF-like differentiation. Cross talk between CaMKII-dependent fibroblasts and colon cancer in colon cancer progression also was addressed RESULTS: Immunostaining demonstrated that in colon cancer stroma, CaMKII overexpressed in stromal CAFs. In vitro, TGFβ1 increased CAF markers expression in human colon fibroblasts CCD-18Co, but not in CaMKII depletion fibroblasts. CaMKII knockdown by CaMKII shRNA significantly inhibited TGFβ1-induced fibroblasts activation and CAF-like differentiation. Smad3, AKT, and MAPK were targeted in TGFβ1-CaMKII-mediated pathway. Human colon cancer cell line HCT-116 activated fibroblasts directly, whereas CaMKII depletion dragged CCD-18Co fibroblasts undergoing CAF-associated trans-differentiation. Furthermore, increased proliferation, migration, and invasion of colon cancer cells were stimulated when co-cultured with normal fibroblasts, but not with CaMKII depletion fibroblasts.

CONCLUSIONS

These findings provide evidence that CaMKII is a critical mediator in TGFβ1-induced fibroblasts activation and is involved in the cross talk with colon cancer cells. CaMKII is a potentially effective target for future treatment of colon cancer.

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification: the Japanese study group for postoperative follow-up of colorectal cancer

PURPOSE

The purpose of the study was to compare staging of stage II colon cancer using the number of retrieved lymph nodes (RN) to current TNM staging for stratification of prognosis.

METHODS

The subjects were 6307 patients with stage II colon cancer who underwent curative resection at 24 Japanese institutions. The cutoff for the number of RN was established using Akaike information criterion (AIC) values for relapse-free survival (RFS) and overall survival (OS). Comparison of survival using TNM and T + RN (TRN) staging was performed using a Cox proportional hazards regression model.

RESULTS

AIC was lowest for 14 retrieved lymph nodes for RFS and OS. This number was used as the cutoff. In multivariate analysis, age (≥ 69), male gender, V1, CEA (> 5), pT (T4a, T4b), and RN-L were independent factors associated with RFS and OS. Six combinations of pT and RN categories were used to establish three subgroups: TRN stages IIA, IIB, and IIC. The 5-year RFS was 83.9%, 72.3%, and 71.8% in TNM stages IIA, IIB, and IIC; and 86.0%, 76.9%, and 60.3% in TRN stages IIA, IIB, and IIC. The 5-year OS was 90.0%, 81.3%, and 82.6% for the TNM stages; and 91.6%, 85.0%, and 71.9% for the TRN stages. The AIC for RFS was lower for TRN (22,318.2) than for TNM (22,390.6), and that for OS was also lower for TRN (16,285.3) than for TNM (16,355.1).

CONCLUSION

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification.

Diffusion tensor imaging of rectal carcinoma: Clinical evaluation and its correlation with histopathological findings

OBJECTIVE

This study sought to assess the feasibility of diffusion tensor imaging (DTI) to noninvasively evaluate histological grade and lymph node metastasis in patients with rectal carcinoma (RC).

METHODS

Thirty-seven consecutive patients with histologically confirmed RC were examined by 1.5-T MRI. DTI was performed using a single-shot echo-planar imaging sequence with b values of 0 and 1000 s/mm² and motion-probing gradients in nine noncollinear directions. Fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) maps were compared with histopathological findings.

RESULTS

The FA values (0.357 ± 0.047) of the RCs were significantly lower than those of the normal rectal wall, muscle, prostate, and uterus (P < 0.001 for all), while the AD, MD, and RD values (1.221 ± 0.131, 0.804 ± 0.075, and 0.667 ± 0.057 × 10^-3 mm²/s, respectively) were also significantly lower than their respective normal values (P < 0.001 for all). The FA, AD, MD, and RD values for RC additionally showed significant inverse correlations with histological grades (r = -0.781, r = -0.750, r = -0.718, and r = -0.682, respectively; P < 0.001 for all). Further, the FA (0.430 vs. 0.611), AD (1.246 vs. 1.608 × 10^-3 mm²/s), MD (0.776 vs. 1.036 × 10^-3 mm²/s), and RD (0.651 vs. 0.824 × 10^-3 mm²/s) (P < 0.001 for all) of the metastatic and nonmetastatic lymph nodes were significantly different.

CONCLUSIONS

DTI may be clinically useful for the noninvasive evaluation of histological grade and lymph node metastasis in patients with RC.

Prognostic value of CXCL17 and CXCR8 expression in patients with colon cancer

C-X-C motif chemokine ligand 17 (CXCL17) is a mucous chemokine and its expression is highly correlated with that of G protein-coupled receptor 35 (GPR35), which has been confirmed as its receptor and named C-X-C motif chemokine receptor 8 (CXCR8). CXCL17 is upregulated in several types of cancer. However, the biological role of this chemokine in colon cancer remains unknown. In the present study, the expression levels of CXCL17 and CXCR8 were examined using immunohistochemistry in 101 colon cancer tissues and 79 healthy tumour-adjacent tissues. CXCL17 and CXCR8 expression levels were increased in the colon cancer samples compared with tumour-adjacent samples. Patients with high CXCL17 expression had longer overall survival (OS) compared with patients with low expression of CXCL17 (log-rank test; P=0.027). However, CXCR8 expression, but not CXCL17, was an independent prognostic factor for OS in patients with colon cancer. The expression of CXCR8 correlated positively with that of CXCL17 in colon cancer samples (ρ=0.295; P=0.003). Furthermore, the combined high expression of CXCL17 and CXCR8 was a significant independent prognostic factor for OS in patients with colon cancer (P=0.001). In subgroups with a TNM stage of I–II, the patients with combined high expression of CXCL17 and CXCR8 had a longer survival compared with those without combined high expression (P=0.001). However, this difference was not observed in subgroups with a TNM stage of III–IV. Collectively, these findings suggest that CXCL17/CXCR8 signalling may be involved in colon cancer and contribute to improved patient outcomes.

MicroRNA-196b-5p promotes malignant progression of colorectal cancer by targeting ING5

Background

miR-196b-5p expression is deregulated in many malignant tumors. Although miR-196b-5p has been implicated in the malignant transformation of colorectal cancer, its role in this specific type of cancer has not been fully explored. Thus, the present study was aimed to examine the cellular function of miR-196b-5p and its role in malignant biological behavior in colorectal cancer.

Methods

miR-196b-5p expression was measured in colorectal cancer tissues and cell lines using quantitative real-time PCR. Cell counting kit-8 (CCK-8) assay and Transwell assay were used to detect proliferation, migration, and invasion in cell lines, whereas flow cytometry was applied to study apoptosis. Western blot analysis was performed to measure the protein levels. Dual luciferase reporter assay was used to investigate the interaction between miR-196b-5p and ING5. Tumor formation was evaluated in mice.

Results

MiR-196b-5p was abundantly expressed in colorectal cancer tissues and cell lines, whereas ING5 was expressed at low levels. MiR-196b-5p was successfully overexpressed or knocked down in colorectal cancer cells. We found that miR-196b-5p overexpression significantly accelerated the proliferation, cell cycle, migration and invasion, while inhibited cell apoptosis in colorectal cancer cells. However, miR-196b-5p inhibitor showed the opposite effects. Moreover, ING5 overexpression or knockdown was successfully performed in colorectal cancer cells. ING5 overexpression suppressed proliferation, migration, invasion, the phosphorylation of PI3K, Akt as well as MEK, and promoted cell apoptosis, which could be reversed by ING5 knockdown. Additionally, ING5 was identified as a target of miR-196b-5p through bioinformatics analysis and a luciferase activity assay. Furthermore, ING5 knockdown could attenuate the decrease in proliferation, migration, invasion, and the protein levels of p-PI3K, p-Akt, and p-MEK, which were induced by miRNA-196b-5p inhibitor. Besides, miR-196b-5p knockdown inhibited tumor growth, whereas ING5 knockdown elevated it in vivo.

Conclusions

In conclusion, miR-196b-5p promotes cell proliferation, migration, invasion, and inhibits apoptosis in colorectal cancer by targeting ING5.

Development of novel predictive miRNA/target gene pathways for colorectal cancer distance metastasis to the liver using a bioinformatic approach

Background

Liver metastases are the major cause of colorectal cancer (CRC)-related deaths. However, there is no reliable clinical predictor for CRC progression to liver metastasis. In this study, we investigated possible predictors (miRNAs and biomarkers) for clinical application.

Methodology

The Gene Expression Omnibus (GEO) datasets GSE49355, GSE41258 and GSE81558 for genes and GSE54088 and GSE56350 for miRNAs were used to identify common differentially expressed genes (DEGs) and miRNAs between primary CRC tissues and liver metastases. The identified miRNAs and their targets from the DEGs were verified in datasets comprising gene, miRNA and miRNA exosome profiles of CRC patients with no distant metastases (M0) and distant metastases (M1); the interaction networks and pathways were also mapped.

Results

There were 49 upregulated and 13 downregulated DEGs and 16 downregulated and 14 upregulated miRNAs; between the DEGs and miRNA targets, there were five upregulated and four downregulated genes. MiR-20a was strongly correlated with the status of liver metastasis. MiR-20a, miR499a, and miR-576-5p were highly correlated with the metastatic outcomes. MiR-20a was significantly highly expressed in the M1 group. In an analysis of the miRNA target genes, we found that CDH2, KNG1, and MMP2 were correlated with CRC metastasis. We demonstrated a new possible pathway for CRC metastasis: miR-576-5p/F9, miR20a/MMP2, CTSK, MMP3, and miR449a/P2RY14. The regulation of IGF transport and uptake by IGFBPs, extracellular matrix organization, signal transduction and the immune system were the enriched pathways.

Conclusion

This model can predict CRC to liver metastases and the pathways involved, which can be clinically applicable.

Stage II-III colon cancer: a comparison of survival calculators

Background

Individualized postoperative survival calculators for patients with cancer can be an aid for predicting prognosis and clinical decision making, such as the use of adjuvant chemotherapy. The aim of this study was to compare existing survival calculators for colon cancer and determine their performance using an independent cohort of patients.

Methods

A retrospective analysis of a multi-site institutional experience was performed on patients diagnosed with stage II-III colon cancer between January 2012 and March 2013. Patient survival rates were estimated using Roswell Park Comprehensive Cancer Center (RPCCC), Memorial Sloan Kettering Cancer Center (MSKCC), and MD Anderson Cancer Center (MDACC) calculators. These calculators vary in the number and breadth of variables that are included. The agreement between selected models was obtained through a scatter plot matrix and related intra-class correlation coefficient (ICC). Calculators' performances were compared using time-dependent receiver operating characteristic (ROC) curves and corresponding area under the curve (AUC) values.

Results

After the application of inclusion and exclusion criteria, a total of 97 patients were included in the analysis. Survival data were available for all patients. Median follow-up was 57.6 months, and the overall 5-year survival rate was 0.74 (95% CI: 0.64-0.82). Overall, the different calculators tended to predict survival similarly (ICC =0.017). However, there was variation among calculator performance with the RPCCC calculator showing the highest performance (AUC =0.913), followed by the MSKCC calculator (AUC =0.803), and the MDACC calculator (AUC =0.644).

Conclusions

Prognostic models incorporating a more comprehensive amount of patient and tumor specific variables may provide a more accurate estimate of individual patient survival rates. These tools can be an actual aid in the clinical practice, allowing physicians to personalize treatment and follow-up for patients with colon cancer.

miR-125a-5p suppresses colorectal cancer progression by targeting VEGFA

Background

MiR-125a-5p has been reported to be involved in the development and progression of various cancers. However, the biological function and underlying mechanisms in colorectal cancer(CRC) still remain unclear. Here, we explored the potential biological roles of miR-125a-5p in CRC.

Methods

The expression of miR-125a-5p was detected using quantitative real-time PCR (qRT-PCR), biological functions of miR-125a-5p were assessed by cell counting kit-8, wound-healing, transwell invasion, and human umbilical vein endothelial cell (HUVEC) tube formation assays in vitro and animal experiments in vivo.

Results

We found that miR-125a-5p was downregulated in CRC tissues and cell lines, it inhibited CRC cell proliferation, migration, and invasion and reduced the ability of HUVECs to form tubes. Moreover, we verifed that miR-125a-5p suppressed CRC growth and metastasis in vivo. Additionally, we showed that VEGFA, a direct target gene of miR-125a-5p, could reverse the inhibitory effect caused by miR-125a-5p overexpression.

Conclusion

miR-125a-5p might serve as a tumor suppressor in CRC and could be regarded as a potential therapeutic candidate for CRC.

miR-410 acts as an oncogene in colorectal cancer cells by targeting dickkopf-related protein 1 via the Wnt/β-catenin signaling pathway

Colorectal cancer (CRC) is a common malignancy with high morbidity. MicroRNAs (miRNAs or miRs) have been demonstrated to be critical post-transcriptional regulators in tumorigenesis. The current study aimed to investigate the effect of miR-410 on the proliferation and metastasis of CRC. The expression of miR-410 was examined in CRC cell lines. SW-480 and HCT-116 CRC cell lines were employed and transfected with miR-410 inhibitor or miR-410 mimics. The association between miR-410 and dickkopf-related protein 1 (DKK-1) was verified by luciferase reporter assay. Cell viability and apoptosis were detected by Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Cell migration and invasion capacity were determined by Transwell assay. The protein level of DKK1, β-catenin and phosphorylated glycogen synthase kinase-3β (pGSK-3β) were analyzed by western blotting. miR-410 was revealed to be upregulated in CRC cell lines. Further studies identified DKK-1 as a direct target of miR-410. In addition, knockdown of miR-410 promoted the expression of DKK, inhibited CRC cell proliferation, migration and invasion capacity, and induced cell apoptosis, while overexpression of miR-410 reversed these results. miR-410 silencing also decreased β-catenin and pGSK-3β levels. The current study indicated that miR-410 negatively regulates the expression of DKK-1 in vitro. miR-410 promotes malignancy phenotypes in CRC cell lines. This regulatory effect of miR-410 may be associated with the Wnt/β-catenin signaling pathway. Therefore, miR-410 could be used as a biomarker for predicting the progression of CRC.

Cancer stem cell associated eight gene-based signature predicts clinical outcomes of colorectal cancer

Previous studies have suggested that cancer stem cells serve crucial functions in tumorigenesis, metastasis and therapy failure. Stem cell signaling transduction pathways are frequently dysregulated in cancer and associated with tumorigenesis, metastasis and the cell cycle, which are necessary for cancer proliferation. However, cancer stem cell-associated gene signatures have not been established for predicting patient outcomes in colorectal cancer. Using a gene-mining approach, the present study performed mRNA expression profiling in large colorectal cancer cohorts from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database, including a TCGA colorectal cancer cohort (n=383) and three independent validation series GSE39582 (n=582), GSE17536 (n=177) and GSE17537 (n=55). The present study identified that an eight-gene signature in cancer stem cell signaling was associated with the overall survival and disease/recurrence-free survival of patients with colorectal. On the basis of this signature, patients in the TCGA training sets were divided into high-risk and low-risk subgroups with a significantly different overall survival rate (hazard ratio, 2.38; P=0.0005). The prognostic value of this signature was confirmed using three independent GEO colorectal cancer sets. Identifying this prognostic stem cell signaling signature may provide an efficient classification tool for clinical prognosis evaluation, and facilitate cancer stem cell-targeted therapy.

Long noncoding RNA DANCR promotes colorectal cancer proliferation and metastasis via miR-577 sponging

Long non-coding RNAs (lncRNAs) play key roles in various malignant tumors, including colorectal cancer (CRC). Long non-coding RNA differentiation antagonizing non-protein coding RNA (DANCR) is overexpressed in CRC patients, but whether it affects CRC proliferation and metastasis via regulation of heat shock protein 27 (HSP27) remains unclear. In the present study, we found that DANCR was highly expressed and correlated with proliferation and metastasis in CRC. In addition, we demonstrated that DANCR and HSP27 were both targets of microRNA-577 (miR-577) and shared the same binding site. Furthermore, we revealed that DANCR promoted HSP27 expression and its mediation of proliferation/metastasis via miR-577 sponging. Finally, using an in vivo study, we confirmed that overexpression of DANCR promoted CRC tumor growth and liver metastasis. The present study demonstrated the function of DANCR in CRC and might provide a new target in the treatment of CRC.

miR-888 functions as an oncogene and predicts poor prognosis in colorectal cancer

MicroRNAs (miRNAs) are important regulators of tumor formation, progression and metastasis. The present study characterized a novel miRNA (miR)-888, as a potent oncomiR in human colorectal cancer (CRC). The clinicopathological investigation on 126 cases of CRC patients demonstrated that the expression level of miR-888 was significantly upregulated in tumors compared with adjacent healthy tissue, and was associated with tumor stage and histological differentiation. A Kaplan-Meier analysis and log-rank test demonstrated that CRC patients with increased miR-888 expression exhibited a decreased overall survival (OS) and disease-free survival (DFS) compared with patients with low miR-888 expression. Further univariate and multivariate analyses identified miR-888 as an independent prognostic factor for poor survival outcome in CRC patients. To determine the biological role of miR-888 in human CRC, in vitro Cell Counting kit-8, wound healing and transwell assays were performed and demonstrated that miR-888 contributed greatly to CRC cell proliferation, invasion and metastasis. Furthermore, potential targets of miR-888 were investigated using a luciferase reporter assay, followed by polymerase chain reaction and western blot analysis. The findings revealed that miR-888 directly bound to the 3′-untranslated region of mothers against decapentaplegic-4 and thus inhibited its expression and promoted the tumor growth factor-1-induced cancer metastasis signaling. The results of the present study identified miR-888 as an oncogenic miRNA in CRC and provide a foundation for promising research in the future regarding this predictive and prognostic biomarker.

Survival Contradiction Between Stage IIA and Stage IIIA Rectal Cancer: A Retrospective Study

Background: When compared with patients harboring stage IIB and stage IIC disease, those with stage IIIA colorectal cancer have a better prognosis. We aimed to compare the cause-specific survival (CSS) of the patients with stage IIA rectal cancer with that of the patients with stage IIIA rectal cancer.

Methods: Data analyzed about patients with stage IIA and stage IIIA rectal cancer was from the US Surveillance, Epidemiology, and End Results (SEER) database. We then validated the results using data derived from Fudan University Shanghai Cancer Center (FUSCC).

Results: A total of 16,788 patients (13,551 staged IIA and 3,237 staged IIIA) were identified in SEER database. A multivariate analysis manifested that patients with stage IIIA disease were more likely to have a better CSS (HR 0.894, 95% CI 0.816-0.979, p=0.016) compared with patients with stage IIA rectal cancer. In the subgroup of patients whose number of lymph nodes harvested (LNH) <12, multivariate analysis signified that patients with stage IIIA disease were more prone to have favorable CSS (HR 0.805, 95% CI 0.719-0.901, p<0.001) compared with patients with stage IIA rectal cancer. In LNH≥12 subgroup, the Kaplan-Meier analysis revealed no significant difference between patients experiencing stage IIA and IIIA rectal cancer (p=0.618). Validation of data from FUSCC proved that patients with stage IIIA rectal cancer were more inclined to have better CSS (HR 0.407, 95% CI 0.187-0.885, p=0.019) in comparison to those with stage IIA rectal cancer. Specifically, in LNH<12 subgroup, the survival outcomes of stage IIIA patients were significantly better than that of the stage IIA patients (p=0.019), while there was no statistical significance between these two stages in the subgroup of patients with LNH≥12 (p=0.180).

Conclusions: Patients with stage IIA rectal cancer have poorer CSS than patients with stage IIIA rectal cancer, particularly when inadequate lymph nodes are harvested.

The survival and clinicopathological differences between patients with stage IIIA and stage II rectal cancer: An analysis of 12,036 patients in the SEER database

BACKGROUND

Stage IIIA rectal cancer has distinctive oncological features, including limited depth of intestinal wall invasion and early regional lymph node metastasis. We aim to compare survival outcomes and clinicopathological features for stage IIIA rectal cancer with those for stage II rectal cancer.

METHODS

We analyzed patients with stage II or stage IIIA rectal cancer treated with surgery without receiving preoperative radiotherapy based on data from the US Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2003. Survival curves were plotted using the Kaplan-Meier method. Multivariate Cox proportional analyses were utilized to analyze independent prognostic factors for cancer-specific survival (CSS).

RESULTS

We included 12,036 rectal cancer patients (10,132 stage II and 1,904 stage IIIA) from the SEER database. Patients with stage IIIA rectal cancer had smaller tumor size than patients with stage II rectal cancer. A multivariate analysis suggested that compared with patients with stage IIIA rectal cancer, patients with stage II disease were more likely to have more unfavorable CSS (HR 1.195, 95% CI 1.079-1.324, p=0.001). When stage II rectal cancer was further analyzed as stage IIA, IIB and IIC rectal cancer, the multivariate analysis indicated that compared with patients with stage IIIA rectal cancer, patients with stage IIA rectal cancer (HR 1.113, 95% CI 1.003-1.235, p=0.044), stage IIB rectal cancer (HR 1.493, 95% CI 1.267-1.758, p<0.001) and stage IIC rectal cancer (HR 2.712, 95% CI 2.319-3.171, p<0.001) were also more likely to exhibit more unfavorable CSS.

CONCLUSIONS

Patients with stage IIIA rectal cancer had more favorable survival outcomes and smaller tumor size compared with patients with stage II rectal cancer.

Peroxisome proliferator-activated receptor γ coactivator-1α is a predictor of lymph node metastasis and poor prognosis in human colorectal cancer

Peroxisome proliferator-activated receptor γ (PPARγ) and PPARγ coactivator-1α (PGC-1α) expression levels are correlated with clinical outcome in breast cancer. However, the potential biological and clinical significance of PPARγ and PGC-1α in colorectal cancer remains unknown. Here we investigated PPARγ and PGC-1α expression in colorectal cancer, and the associations of these expression levels with clinicopathological features. We also evaluated the roles of PPARγ and PGC-1α as prognostic factors in colorectal cancer. We performed immunohistochemical analysis to investigate PPARγ and PGC-1α expression in human colorectal cancer tissues and adjacent normal tissues from 108 primary colorectal cancer patients. We then examined how these expression levels correlated with clinicopathological features. Using the Kaplan-Meier method, we evaluated 3-year disease-free survival (DFS) and overall survival (OS) in patients with tumors expressing different levels of PPARγ and PGC-1α. Our results revealed that PPARγ expression was not significantly correlated with age at surgery, gender, differentiation, depth of infiltration, relapse, or TNM stage. Additionally, PGC-1α expression was not significantly correlated with age at surgery, differentiation, depth of infiltration, relapse, or TNM stage. However, PGC-1α expression was significantly correlated with nodal metastasis (p=0.020). Survival analysis demonstrated reduced OS in the PGC-1α-positive group compared to the PGC-1α-negative group (p=0.03). Our present findings suggest that PGC-1α may be useful for predicting nodal metastasis, and may represent a biomarker for poor prognosis in colorectal cancer.

Ca2+/calmodulin-dependent protein kinase II regulates colon cancer proliferation and migration via ERK1/2 and p38 pathways

AIM

To investigate the role of calmodulin-dependent protein kinase II (CaMKII) in colon cancer growth, migration and invasion.

METHODS

CaMKII expression in colon cancer and paracancerous tissues was evaluated via immunochemistry. Transcriptional and posttranscriptional levels of CaMKIIin tissue samples and MMP2, MMP9 and TIMP-1 expression in the human colon cancer cell line HCT116 were assessed by qRT-PCR and western blot. Cell proliferation was detected with the MTT assay. Cancer cell migration and invasion were investigated with the Transwell culture system and wound-healing assay.

RESULTS

We first demonstrated that CaMKII was over-expressed in human colon cancers and was associated with cancer differentiation. In the human colon cancer cell line HCT116, the CaMKII-specific inhibitor KN93, but not its inactive analogue KN92, decreased cancer cell proliferation. Furthermore, KN93 also significantly prohibited HCT116 cell migration and invasion. The specific inhibition of ERK1/2 or p38 decreased the proliferation and migration of colon cancer cells.

CONCLUSION

Our findings highlight CaMKII as a potential critical mediator in human colon tumor development and metastasis.

Repeated faecal occult blood testing is associated with decreased advanced colorectal cancer risk: A population-based study

OBJECTIVE

To evaluate the association between repeated faecal occult blood testing and advanced colorectal cancer risk at population level in Canada.

METHODS

A retrospective cohort study of all Ontario residents aged 56-74 diagnosed with colorectal cancer from 1 April 2007 to 31 March 2010, identified using health administrative data. The primary outcome was stage IV colorectal cancer, and primary exposure was faecal occult blood testing use within five years prior to colorectal cancer diagnosis. Patients were categorized into four mutually exclusive groups based on their exposure to faecal occult blood testing in the five years prior to colorectal cancer diagnosis: none, pre-diagnostic, repeated, and sporadic. Logistic regression was utilized to adjust for confounders.

RESULTS

Of 7753 patients (median age 66, interquartile range 61-70, 62% male) identified, 1694 (22%) presented with stage I, 2056 (27%) with stage II, 2428 (31%) with stage III, and 1575 (20%) with stage IV colorectal cancer. There were 4092 (53%) with no record of prior faecal occult blood testing, 1485 (19%) classified as pre-diagnostic, 1693 (22%) as sporadic, and 483 (6%) as repeated faecal occult blood testing. After adjusting for confounders, patients who had repeated faecal occult blood testing were significantly less likely to present with stage IV colorectal cancer at diagnosis (Odds ratio 0.46, 95% Confidence Interval 0.34-0.62) than those with no prior faecal occult blood testing.

CONCLUSIONS

Repeated faecal occult blood testing is associated with a decreased risk of advanced colorectal cancer. Our findings support the use of organized screening programmes that employ repeated faecal occult blood testing to improve colorectal cancer outcomes at population level.

Expression of chicken ovalbumin upstream promoter-transcription factor II and liver X receptor as prognostic indicators for human colorectal cancer

Cholesterol increases the risk of colorectal cancer. Liver X receptor (LXR), retinoid X receptor (RXR)α and sterol regulatory element binding protein (SREBP)-1c are transcriptional regulators of lipid metabolism. Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) serves an essential role in angiogenesis and development, but its role in cancer is controversial. The expression of COUP-TFII, LXR, RXRα and SREBP-1c in colorectal cancer, as well as their association with clinicopathologic features, was assessed, and their utility as prognostic indicators in colorectal cancer evaluated. Colorectal cancer samples (n=707 patients) were analyzed for COUP-TII, LXR, RXRα and SREBP-1c expression by immunohistochemistry. Overall survival curves of patients with tumors expressing different levels of these proteins were produced and risk factors were assessed. Of the 707 patients, 32.7, 50.9, 56.4, and 41.7% were positive for COUP-TFII, LXR, RXRα, and SREBP-1c, respectively. The lack of COUP-TFII or LXR expression was associated with lower overall survival rates (P=0.0154 for COUP-TFII, and 0.0113 for LXR). Following adjustment for other clinical risk factors (age, sex, tumor size, grade, vascular invasion, and Tumor-Node-Metastasis stage), the lack of COUP-TFII or LXR expression was a negative independent prognostic factor for survival. The expression of COUP-TFII and LXR alone or in combination may be biomarkers to indicate a positive prognosis in patients with colorectal cancer.

Significance of inflammation-based indices in the prognosis of patients with non-metastatic colorectal cancer

Previous studies demonstrated that several inflammation-based hematological indices are closely related to various malignancies, including colorectal cancer (CRC). In this study, the prognostic value of inflammation-based markers, including a combination index termed coNLR-PDW, comprising the preoperative neutrophil-to-lymphocyte ratio (NLR) and the platelet distribution width (PDW), was evaluated in 206 patients with non-metastatic CRC treated with surgery at a single medical center. The association of patient demographics, blood chemistry, and serum biochemical indices with recurrence-free survival (RFS) and overall survival (OS) were examined through univariate and multivariate analysis. Receiver operating characteristic curve analysis revealed the optimal cut-off values of the NLR and lymphocyte-to-monocyte ratio (LMR) to be, respectively, 2.0 and 3.32 for both RFS and OS. For PDW, cut-off values of 17.25% and 17.35% were defined for RFS and OS, respectively. On univariate analysis, lymph node involvement, stage, presence of intravascular emboli (IVE), carbohydrate antigen 199 (CA199) ≥ 35 kU/L, NLR ≥ 2.0, LMR ≤ 3.32, elevated PDW, a high coNLR-PDW score, high blood glucose, and high neutrophil and lymphocyte percentages correlated with poorer RFS and OS (P < 0.05). On multivariate analysis, lymph node involvement, IVE, CA199, PDW, and coNLR-PDW correlated with both RFS and OS (P < 0.05), while NLR correlated only with OS (P = 0.001). These results highlight the usefulness of the coNLR-PDW index as a prognostic marker of non-metastatic CRC outcome. In clinical practice, its assessment could contribute to establishing more personalized regimes for patients undergoing tumor resection surgery.

Upregulation of microRNA-125b by G-CSF promotes metastasis in colorectal cancer

Although there are reports of miR-125b being dysregulated in colorectal cancer (CRC) and associated with CRC progression, little is known about its intrinsic regulatory mechanisms. Here we detected the expression of miR-125b in CRC tissues, subsequently investigated the effect of miR-125b on the proliferation, apoptosis, cell cycle and metastasis on CRC cells. Our results showed that the expression of miR-125b was significantly decreased in CRC tissues comparing to adjacent tissues. However, with the stimulation of Granulocyte colony-stimulating factor (G-CSF), which was highly expressed in CRC tissues, the expression of miR-125b could be improved. Analysis of patient samples revealed that miR-125b presented a clear association with poor differentiation, positive lymph node metastasis, and advanced TNM stage. Overexpression of miR-125b inhibited cell proliferation, triggered G2/M cell cycle arrest, induced subsequent apoptosis, and promoted cell migration and invasion. Moreover, luciferase reporter assays and western blot clarified that the myeloid cell leukemia 1 (MCL1) was a direct target of miR-125b. Thus overexpression of MCL1 attenuated the pro-metastasis function of miR-125b in CRC cell lines. In addition, the protein expression level of MCL1 was decreased in CRC tissues from patients with positive lymph node metastasis, which had high miR-125b expression. Collectively, our study suggested that miR-125b induced by G-CSF plays a promoting role in the metastasis of CRC by targeting MCL1, which may serve as a novel therapeutic target for CRC metastasis.

Complete response to capecitabine in a frail, elderly patient with metastatic colorectal cancer: A case report

The clinical management of frail, elderly patients affected by colorectal cancer (CRC) remains a subject of debate. The present study reports the case of an elderly man with metastatic CRC (mCRC) who was successfully treated with capecitabine. The patient survived for 29 months, thus highlighting its potential activity in terms of obtaining a complete response and high efficacy. A 77-year-old man presented with adenocarcinoma of the rectum with multiple and synchronous liver metastases, in addition to several comorbidities. The patient received single-agent capecitabine chemotherapy (825 mg/mq twice a day) on days 1-14 of a 21-day cycle. Following 12 cycles of well-tolerated therapy, a computed tomography scan revealed a complete response with no evidence of liver metastases. An overall survival of 29 months was documented, and the patient eventually succumbed to a diabetes-related complication. In compromised patients with mCRC, reduced-dose capecitabine is an excellent therapeutic option due to its positive safety profile, activity and efficacy.

Clinicopathologic significance of TRAP1 expression in colorectal cancer: a large scale study of human colorectal adenocarcinoma tissues

Background

Colorectal cancer is the major cause of cancer mortality, despite development of therapeutic strategies. The novel marker tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial heat shock protein that has been related to drug resistance and protection from apoptosis in colorectal cancer. This study aims to delineate the clinicopathologic significance of TRAP1 expression in colorectal cancer.

Methods

Seven-hundred and fourteen FFPE tissues were collected from colorectal cancer patients who underwent surgery from February 2002 to July 2011 at Dong-A University Medical Center, Busan, South Korea. We performed TRAP1 immunohistochemistry using tissue microarray, and divided into two groups, TRAP1 high expression group and low expression group. Statistical analysis was utilized to evaluate the association of TRAP1 with clinicopathologic characteristics and disease-specific survival of patients.

Results

High TRAP1 expression was observed in 564 cases (79%) and low expression was 150 cases (21%). TRAP1 expression was significantly increased in colorectal cancer with advanced pathologic T-stage compared with that in early T-stage (p = 0.008). By univariate survival analysis, high TRAP1 expression was significantly associated with worse disease-specific survival (p = 0.01). But, TRAP1 expression was marginally associated with lymph node involvement and tumor differentiation (p = 0.085, p = 0.082, respectively). Multivariate analysis indicated that TRAP1 expression (hazard ratio, 1.947; 95% CI, 1.270 to 2.984; p = 0.002), and pathologic T stage (hazard ratio, 3.190; 95% CI, 1.275 to 7.983; p = 0.013) were independent prognostic factors for colorectal adenocarcinomas.

Conclusions

Here, we found that overexpression of TRAP1 might contribute to tumor cell local invasion of colorectal cancer. The association between TRAP1 overexpression and worse disease-specific survival also suggested that TRAP1 protein expression might have oncogenic role. Consequently, our data demonstrated that TRAP1 expression was a good prognostic biomarker for depth of invasion and disease-specific survival in colorectal cancer.

Bevacizumab Combined with Chemotherapy Improves Survival for Patients with Metastatic Colorectal Cancer: Evidence from Meta Analysis

Background

Colorectal cancer is one of the leading causes of cancer deaths in both sexes in the world. Improvement of existing therapy modalities and implementing new ones in order to improve survival of patients with colorectal cancer represents a great challenge for medicine. The aim of this paper was to assess the impact that adding bevacizumab to chemotherapy has on survival in patients with metastatic colorectal cancer, compared to the use of chemotherapy alone.

Methods

Hazard ratios (HRs) with their 95% confidence intervals (CI) were determined from the studies and pooled. Two-sided p values were reported and considered to indicate statistical significance if less than 0.05.

Results

A total of 12 studies that meet the inclusion criteria were identified in the literature search, 3 phase II studies and 9 phase III studies. Based on the random effects meta-analysis, a statistically significant improvement was identified for both overall survival (HR = 0.84; 95% CI: 0.74–0.94; p = 0.003) and progression free survival (HR = 0.64; 95% CI: 0.55–0.73; p<0.00001) in patients with metastatic colorectal cancer when bevacizumab was added to chemotherapy, compared to chemotherapy treatment alone.

Conclusion

The findings of this meta analysis confirm the benefit of adding bevacizumab to chemotherapy in terms of survival and progression free survival, but the magnitude of this effect is not consistent throughout the included studies. This suggests the need for further research of interaction of bevacizumab with chemotherapeutic agents as well as recognition of patients’ characteristics important for the treatment selection criteria.

A seven-gene signature predicts overall survival of patients with colorectal cancer

Colorectal cancer (CRC) is a major cause of global cancer mortality. Gene expression profiles can help predict prognosis of patients with CRC. In most of previous studies, disease recurrence was analyzed as the survival endpoint. Thus we aim to build a robust gene signature for prediction of overall survival (OS) in patients with CRC. Fresh frozen CRC tissues from 64 patients were analyzed using Affymetrix HG-U133plus 2.0 gene arrays. By performing univariate survival analysis, 6487 genes were found to be associated with the OS in our cohort. KEGG analysis revealed that these genes were mainly involved in pathways such as endocytosis, axon guidance, spliceosome, Wnt signalling and ubiquitin mediated proteolysis. A seven-gene signature was further selected by a robust likelihood-based survival modelling approach. The prognostic model of seven-gene signature (NHLRC3, ZDHHC21, PRR14L, CCBL1, PTPRB, PNPO, and PPIP5K2) was constructed and weighted by regression coefficient, which divided patients into high- and low-risk groups. The OS for patients in high-risk group was significantly poorer compared with patients in low-risk group. Moreover, all seven genes were found to be differentially expressed in CRC tissues as compared with adjacent normal tissues, indicating their potential role in CRC initiation and progression. This seven-gene signature was further validated as an independent prognostic marker for OS prediction in patients with CRC in other two independent cohorts. In short, we developed a robust seven-gene signature that can predict the OS for CRC patients, providing new insights into identification of CRC patients with high risk of mortality.

MicroRNA-375 suppresses human colorectal cancer metastasis by targeting Frizzled 8

microRNAs are aberrantly expressed during the development and progression of a variety of human cancers, including colorectal cancer (CRC). Of these microRNAs, microRNA-375 (miR-375) was previously observed to be downregulated in human colorectal cancer(CRC) plasma and tissues, but its functions are largely unknown. Here, we investigated the impact of miR-375 on CRC metastasis. Specifically, miR-375 expression was significantly decreased in human CRC tissues compared with their matched noncancerous tissues (NCTs), and low levels of miR-375 predicted tumor metastatic potential. The up-regulation of miR-375 suppressed colorectal cancer cell migration and invasion in vitro and reduced tumor metastases in murine models established by both orthotopic implantation and spleen injection. Furthermore, we identified Frizzled 8 (FZD8) as a direct target of miR-375 in CRC, and miR-375 negatively regulated Wnt/β-catenin signaling by suppressing FZD8. More importantly, FZD8 expression inversely correlated with overall survival in human CRC patients and is a likely independent predictor of survival. Therefore, we concluded that miR-375 functions as a tumor-suppressive microRNA by directly acting upon FZD8, which may serve as a new therapeutic target to inhibit tumor metastasis in CRC.

Anastomotic recurrence of colon cancer: Genetic analysis challenges the widely held theories of cancerous cells' intraluminal implantation and metachronous carcinogenesis

BACKGROUND AND OBJECTIVES

Anastomotic recurrence (AR), whose etiopathogenesis is attributed to intraluminal implantation of cancerous cells or metachronous carcinogenesis, is a major issue for patients undergoing colon cancer (CC) resection. The objective of the study is to throw some light on AR etiopathogenesis and to identify risk factors of AR in selecting patients to undergo early endoscopy.

METHODS

An analysis of clinical and histopathological parameters, including MSI and LOH of seven sites (Myc-L, BAT26, BAT40, D5S346, D18S452, D18S64, D16S402) was performed in primary CC and AR of 18 patients. They were then compared to 36 controls not developing AR.

RESULTS

A genetic instability was present in 16/18 patients, with distinct genetic patterns between primaries and ARs. LOH at 5q21 and/or 18p11.23 were found in both primary and AR in >50% of cases, but this rate was no different from control population. CEA resulted as associated with AR (P = 0.03), whereas N status presented a borderline result (P = 0.08).

CONCLUSIONS

Our findings challenge present theories about AR development. No "genetic marker" has been found. CEA and, to a lesser extent, N status, appear associated with AR. Rectal washout is seemingly meaningless. Iterative resection should be recommended since a long survival may be expected. J. Surg. Oncol. 2016;114:228-236. © 2016 Wiley Periodicals, Inc.

CT predictors of overall survival at initial diagnosis in patients with stage IV colorectal cancer

PURPOSE

We investigated whether the initial CT distribution of metastatic disease is predictive of overall survival in patients with stage IV colorectal cancer.

MATERIALS AND METHODS

A retrospective study of 65 patients (37 males, 28 females, mean age 56, range 28-88 years) with stage IV colorectal cancer was derived from an institutional database. Inclusion criteria required KRAS mutation testing and pretreatment CT examinations to be available (65 abdomen/pelvis, 63 chest). Disease burden was jointly characterized by two radiologists in consensus. Median follow-up was 39 months (range 8-115 months). Survival was assessed using Cox proportional hazards models.

RESULTS

Univariate analysis showed that stratified site(s) of measurable disease and counts of measurable lesions ≥1 cm in the liver, peritoneum, and retroperitoneum were statistically significant risk factors for overall mortality [univariate HR 8.2 (CI 2.7-25.4) for isolated peritoneal disease, HR 1.11 per 5 lesions (CI 1.05-1.17) for liver lesions, HR 1.15 per lesion (CI 1.05-1.26) for peritoneal lesions, and HR 1.11 (CI 1.03-1.19) for retroperitoneal lymph nodes ≥1 cm in short axis]. The stratified site(s) of disease and counts of measurable liver lesions remained significant in the multivariate model (p < 0.0001 for isolated peritoneal disease and count of liver lesions). Thoracic metastases were not statistically significant predictors of overall mortality in this cohort.

CONCLUSION

This study identified site(s) of measurable metastasis and counts of measurable liver lesions as independent predictors of overall survival. These findings may have value for future prognostic assessments once validated in a larger, independent, and potentially prospective cohort.

FBXW7 mutation analysis and its correlation with clinicopathological features and prognosis in colorectal cancer patients

PURPOSE

This study aimed to determine the prognostic value of mutations in the tumor suppressor gene FBXW7 for clinical outcomes in colorectal cancer (CRC).

METHODS

Between January 2000 and December 2009, FBXW7 mutations in tumor tissues from 1,519 CRC patients at Taipei Veterans General Hospital were assessed using a MassArray system. We compared the clinicopathological variables and prognosis between the wild-type and mutant tumor tissue groups.

RESULTS

FBXW7 mutations were present in 114/1,519 CRC patients (7.5%). In stage I/II CRC patients, mutant FBXW7 was more common than wild-type FBXW7 (62.3% vs. 50.8%). CRC patients with FBXW7 mutations did not differ significantly in their 5-year overall survival (OS). Stage I/II CRC patients with FBXW7 mutations had lower OS, but this difference was not significant (71.6% vs. 78.2%). Among FBXW7 tumors, S582L was the most frequent mutation type (19.3%), followed by R465H (16.6%), R505C (14.9%) and R479Q (14.9%). Subgroup analysis of FBXW7 mutants showed that R465H/R465C/R479Q had better 5-year OS than other mutant types (76.9% vs. 56.0%; p=0.012).

CONCLUSIONS

There was no strong association between patient prognosis and FBXW7 mutations in our large-scale study.

Accuracy of TNM staging in colorectal cancer: a review of current culprits, the modern role of morphology and stepping-stones for improvements in the molecular era

Colorectal cancer (CRC) is the third most common cancer worldwide. Survival is largely stage-dependant, guided by the tumor-node-metastases (TNM) system for TNM assessment. Histopathological evaluation, including assessment of lymph node status, is important for correct TNM staging. However, recent updates in the TNM system have resulted in controversy. A continued debate on definitions resulting in potential up- and downstaging of patients, which may obscure survival data, has led the investigators to investigate other or alternative staging tools. Consequently, additional prognostic factors have been searched for using the regular light microscopy. Among the factors evaluated by histopathology include the evaluation of tumor budding and stromal environment, angiogenesis, as well as involvement of the immune system (including the 'Immunoscore'). We review the current role of histopathology, controversies in TNM-staging and suggested alternatives to better predict outcome for CRC patients in the era of genomic medicine.

Lymph node ratio improves TNM and Astler-Coller's assessment of colorectal cancer prognosis: an analysis of 761 node positive cases

BACKGROUND

Prognosis assessment of node-positive colorectal cancer patients by Astler-Coller (AC) and TNM classifications is suboptimal. Recently, several versions of lymph node ratio (LNR; ratio metastatic/examined nodes) have been proposed but are still mostly unused.

METHODS

The prognostic value of several criteria, including LNR (two classes-LNR1 and LNR2-identified by a 15% cut-off) was studied in 761 consecutive patients, from 2000 through 2010. The relationships between total examined nodes, N, T and LNR were also analysed. LNR1 and LNR2 patients' survival was analysed within AC and TNM subgroups, and then coupled with them.

RESULTS

Age, tumour location and LNR are independent factors predicting survival. The relationships between LNR, N stage and T stage with examined nodes suggest confusing factors. LNR allows for identification of subgroups with different survival within AC and TNM classifications (p < 0.0001). Patients with LNR class discordant from AC stage (LNR1-C2 and LNR2-C1) have a similar 5-year survival (54 and 57%, respectively). LNR2 and TNM stage IIIC define a poor 5-year prognosis (33%).

CONCLUSIONS

LNR is a powerful prognosis predictor, easily integrated with TNM and AC classifications to improve prognosis assessment and facilitate clinical use. Possible confusing factors should be considered in future studies.

Concomitant depletion of PTEN and p27 and overexpression of cyclin D1 may predict a worse prognosis for patients with post-operative stage II and III colorectal cancer

Prognostic markers for colorectal cancer (CRC) have not yet been fully investigated. Phosphatase and tensin homolog (PTEN), p27 and Cyclin D1 play significant roles in tumorigenesis and cell cycle regulation, and therefore require evaluation for their prognostic value in this disease. The aim of the present study was to assess the prognostic value of the single and combined expression of PTEN, p27 and Cyclin D1 in CRC patients. Protein expression levels of PTEN, p27 and Cyclin D1 were examined by immunohistochemistry from 61 patients with CRC in either stage II or III. In the CRC tissues, the frequencies of PTEN(−), p27(−) and Cyclin D1(+) expression were 42.62% (26/61), 32.79% (20/61) and 45.90% (28/61), respectively. Depletion of PTEN and p27 was more common with respect to stage III, low grade and lymph node metastasis compared with stage II, moderate grade and no lymph node metastasis (P<0.05). Cyclin D1-positive expression was frequently detected in CRC of stage III, with lymph node metastasis and deeper invasion (P<0.05). The depletion of PTEN was significantly correlated with the loss of p27 (P<0.001) and with the increased expression of Cyclin D1 (P<0.001). PTEN(−) and/or p27(−) expression was significantly correlated with Cyclin D1(+) expression (P<0.05). Combined PTEN(−)/p27(−)/Cyclin D1(+) expression was correlated with a significant decrease in overall survival time (P<0.05). Combined p27(−) and Cyclin D1(+) expression indicated a worse overall survival time than other combined expression patterns. These findings indicate that the single expression of PTEN(−), p27(−) and Cyclin D1(+) and the combined detection of p27(−) and Cyclin D1(+) may be used as prognostic markers for overall survival time in CRC.

Quantification of tumour budding, lymphatic vessel density and invasion through image analysis in colorectal cancer

BACKGROUND

Tumour budding (TB), lymphatic vessel density (LVD) and lymphatic vessel invasion (LVI) have shown promise as prognostic factors in colorectal cancer (CRC) but reproducibility using conventional histopathology is challenging. We demonstrate image analysis methodology to quantify the histopathological features which could permit standardisation across institutes and aid risk stratification of Dukes B patients.

METHODS

Multiplexed immunofluorescence of pan-cytokeratin, D2-40 and DAPI identified epithelium, lymphatic vessels and all nuclei respectively in tissue sections from 50 patients diagnosed with Dukes A (n = 13), Dukes B (n = 29) and Dukes C (n = 8) CRC. An image analysis algorithm was developed and performed, on digitised images of the CRC tissue sections, to quantify TB, LVD, and LVI at the invasive front.

RESULTS

TB (HR =5.7; 95% CI, 2.38-13.8), LVD (HR =5.1; 95% CI, 2.04-12.99) and LVI (HR =9.9; 95% CI, 3.57-27.98) were successfully quantified through image analysis and all were shown to be significantly associated with poor survival, in univariate analyses. LVI (HR =6.08; 95% CI, 1.17-31.41) is an independent prognostic factor within the study and was correlated to both TB (Pearson r =0.71, p <0.0003) and LVD (Pearson r =0.69, p <0.0003).

CONCLUSION

We demonstrate methodology through image analysis which can standardise the quantification of TB, LVD and LVI from a single tissue section while decreasing observer variability. We suggest this technology is capable of stratifying a high risk Dukes B CRC subpopulation and we show the three histopathological features to be of prognostic significance.

MicroRNA-126 functions as a tumor suppressor in colorectal cancer cells by targeting CXCR4 via the AKT and ERK1/2 signaling pathways

Recent evidence shows that altered microRNA-126 (miR-126) expression is implicated in the progression of colorectal cancer (CRC). However, the precise roles and mechanisms of miR-126 in CRC remain unclear. The aim of this study was to investigate the roles of miR-126 in CRC cells and to elucidate miR-126-mediated mechanisms in CRC cells. First, miR-126 expression was analyzed using qRT-PCR in 4 human CRC cell lines (SW480, SW620, HT-29 and HCT-116). Furthermore, the biological properties of miR-126 in CRC cells in vitro were examined by applying Cell Counting Kit 8, cell cycle, cell apoptosis and transwell assays. The mechanisms and pathways of miR-126-mediated in CRC cells were detected by using qRT-PCR, western blotting and luciferase reporter assay. We found that miR-126 overexpression inhibited cell proliferation, migration and invasion, and induced cell arrest in the G0/G1 phase of CRC cells, suggesting that miR-126 functions as a tumor suppressor in CRC cells. Furthermore, we identified the CXC chemokine receptor 4 (CXCR4) as a target of miR-126, and showed that it was negatively regulated by miR-126. We demonstrated that miR-126-mediated tumor suppression might be partly dependent on AKT and ERK1/2 signaling pathways. In conclusion, our data revealed that miR-126 functions as a tumor suppressor in CRC cells by regulating CXCR4 expression via the AKT and ERK1/2 signaling pathways and might be a novel target for therapeutic strategies in CRC.

Diabetes, metformin use, and colorectal cancer survival in postmenopausal women

BACKGROUND

Observational studies have associated metformin use with lower colorectal cancer (CRC) incidence but few studies have examined metformin's influence on CRC survival. We examined the relationships among metformin use, diabetes, and survival in postmenopausal women with CRC in the Women's Health Initiative (WHI) clinical trials and observational study.

METHODS

2066 postmenopausal women with CRC were followed for a median of 4.1 years, with 589 deaths after CRC diagnosis from all causes and 414 deaths directly attributed to CRC. CRC-specific survival was compared among women with diabetes with metformin use (n=84); women with diabetes with no metformin use (n=128); and women without diabetes (n=1854). Cox proportional hazard models were used to estimate associations among metformin use, diabetes and survival after CRC. Strategies to adjust for potential confounders included: multivariate adjustment with known predictors of colorectal cancer survival and construction of a propensity score for the likelihood of receiving metformin, with model stratification by propensity score quintile.

RESULTS

After adjusting for age and stage, CRC specific survival in women with diabetes with metformin use was not significantly different compared to that in women with diabetes with no metformin use (HR 0.75; 95% CI 0.40-1.38, p=0.67) and to women without diabetes (HR 1.00; 95% CI 0.61-1.66, p=0.99). Following propensity score adjustment, the HR for CRC-specific survival in women with diabetes with metformin use compared to non-users was 0.78 (95% CI 0.38-1.55, p=0.47) and for overall survival was 0.86 (95% CI 0.49-1.52; p=0.60).

CONCLUSIONS

In postmenopausal women with CRC and DM, no statistically significant difference was seen in CRC specific survival in those who used metformin compared to non-users. Analyses in larger populations of colorectal cancer patients are warranted.

Is the prediction of prognosis not improved by the seventh edition of the TNM classification for colorectal cancer? Analysis of the surveillance, epidemiology, and end results (SEER) database

BACKGROUND

Whether the 7th edition of American Joint Committee on Cancer (AJCC) TNM staging system (AJCC-7) is a successful revision remains debatable. We aimed to compare the predictive capacity of the AJCC-7 for colorectal cancer with the 6th edition of the AJCC TNM staging system (AJCC-6).

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) dataset consisting of 158,483 records was used in this study. We evaluated the predictive capacity of the two editions of the staging system using Harrell's C index and Bayesian Information Criterion (BIC).

RESULTS

There was a significant prognostic difference between patients at stage IIB and IIC (P < 0.001). Stage III patients with similar prognoses were adequately sub-grouped in the same stage according to AJCC-7. The Harrell's C index revealed a value of 0.7692 for AJCC-7, which was significantly better than 0.7663 for AJCC-6 (P < 0.001). BIC analysis provided consistent results (P < 0.001).

CONCLUSIONS

This study demonstrates that AJCC-7 is superior to the AJCC-6 staging system in predictive capacity.

Oncologic Outcomes of Stage IIIA Colon Cancer for Different Chemotherapeutic Regimens

Purpose

Adjuvant chemotherapy is currently recommended for Stage IIIA colon cancers. This study aimed to elucidate the oncologic outcomes of Stage IIIA colon cancer according to the chemotherapeutic regimen based on a retrospective review.

Methods

From 1995 to 2008, Stage IIIA colon cancer patients were identified from a prospectively maintained database at a single institution. Exclusion criteria were as follows: rectal cancer, another malignancy other than colon cancer, no adjuvant chemotherapy and unknown chemotherapeutic regimen. One hundred thirty-one patients were enrolled in the study, and the clinicopathologic and the oncologic characteristics were analyzed. The number of males was 72, and the number of females was 59; the mean age was 59.5 years (range, 25 to 76 years), and the median follow-up period was 33 months (range, 2 to 127 months).

Results

Of the 131 patients, fluorouracil/leucovorin (FL)/capecitabine chemotherapy was performed in 109 patients, and FOLFOX chemotherapy was performed in 22 patients. When the patients who received FL/capecitabine chemotherapy and the patients who received FOLFOX chemotherapy were compared, there was no significant difference in the clinicopathologic factors between the two groups. The 5-year overall survival and the 5-year disease-free survival were 97.2% and 94.5% in the FL/capecitabine patient group and 95.5% and 90.9% in the FOLFOX patient group, respectively, and no statistically significant differences were noted between the two groups.

Conclusion

Stage IIIA colon cancer showed good oncologic outcomes, and the chemotherapeutic regimen did not seem to affect the oncologic outcome.