Prognostic molecular markers for planning adjuvant chemotherapy trials in Dukes' B colorectal cancer patients: how much evidence is enough?

The clinicopathological significance and potential function of ULK1 in colon cancer

Uncoordinated 51-like kinase 1 (ULK1) is an essential part involved in autophagy to maintain cell viability and homeostasis. Herein, the expression levels of ULK1 in colon cancer (CC) were investigated, and its clinicopathological features and potential function were analyzed. Data of ULK1 were obtained from a public database. UCSC XENA RNAseq data were uniformly processed by using the Toil process. STRING was employed for identification of co-expression genes and development of PPI networks whose interaction scores exceeded 0.4. The level of immune cells for tumor infiltration was calculated by means of single-sample GSEA (ssGSEA) on the basis of mRNA data of CC. The ULK1 expression was upregulated compared with both paired and unpaired normal tissues. The mRNA expression of ULK1 was upregulated in CC patients with lymph node metastasis, lymphatic invasion, and pathological stages of 3 and 4. The disease-specific survival (DSS), progression-free interval (PFI), and the overall survival (OS) of patients with upregulated mRNA expression of ULK1 were drastically reduced. Functionally, any changes related to the biological process of ULK1 may be related to macroautophagy, autophagosome organization and autophagosome assembly. As a co-expressed gene (CEG), ATG101 was up-regulated in CC tissues and indicated poor survival. ULK1 is closely related to immune cells. ULK1 expression is upregulated in CC cells and upregulation of ULK1 may serve as an accurate prognostic factor, thereby providing novel intervention targets for therapy.

Is cell regeneration and infiltration a double edged sword for porcine aortic valve deterioration? A large cohort of histopathological analysis

BACKGROUND AND OBJECTIVE

Bioprostheses are the most common prostheses used for valve replacement in the Western medicine. The major flaw of bioprostheses is the occurrence of structural valve deterioration (SVD). This study aimed to assess the pathological features of porcine aortic valve (PAV)-SVD based on histomorphological and immunopathological characteristics of a large cohort of patients.

METHODS

Histopathological data of 109 cases with resected PAV were collected. The type and amount of infiltrated cells were evaluated in the different types of bioprosthetic SVD by immunohistochemical staining.

RESULTS

The most common cause of SVD was calcification, leaflet tear, and dehiscence (23.9%, 19.3%, and 18.3%, respectively). Immunohistochemical staining demonstrated that macrophages were infiltrated in the calcified, lacerated and dehiscence PAV, in which both M1 and M2 macrophages were existed in the calcified PAV. Importantly, the higher content of M1 macrophages and less content of M2 macrophages were found in the lacerated and dehiscence PAV, and MMP-1 expression was mainly found in the lacerated PAV. The endothelialization rate of leaflet dehiscence was higher than that of calcified and lacerated leaflets. A large number of CD31+/CD11b+ cells was aggregated in the spongy layer in the lacerated and dehiscence PAV.

CONCLUSION

Cell regeneration and infiltration is a double edged sword for the PAV deterioration. Macrophage infiltration is involved in the different types of SVD, while only MMP-1 expression is involved in lacerated leaflets. The macrophage subtype of circulating angiogenic cells in dehiscence and tear PAV could be identified, which could reserve macrophages in the PAV-SVD.

Biochemical and molecular aspects of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis: a review

1,2-dimethylhydrazine (DMH) is a member in the class of hydrazines, strong DNA alkylating agent, naturally present in cycads. DMH is widely used as a carcinogen to induce colon cancer in animal models. Exploration of DMH-induced colon carcinogenesis in rodent models provides the knowledge to perceive the biochemical, molecular, and histological mechanisms of different stages of colon carcinogenesis. The procarcinogen DMH, after a series of metabolic reactions, finally reaches the colon, there produces the ultimate carcinogen and reactive oxygen species (ROS), which further alkylate the DNA and initiate the development of colon carcinogenesis. The preneolpastic lesions and histopathological observations of DMH-induced colon tumors may provide typical understanding about the disease in rodents and humans. In addition, this review discusses about the action of biotransformation and antioxidant enzymes involved in DMH intoxication. This understanding is essential to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH-induced animal colon carcinogenesis.

Prognostic meaning of tissue inhibitors of matrix metalloproteinases TIMP-1 and TIMP-2 in patients with colorectal cancer

The aim of this study was to analyze TIMP-1 and TIMP-2 serum levels in patients with colorectal cancer (CRC) and to correlate the results with the pathological stage of the disease and outcome in order to evaluate the role of TIMP-1 and TIMP-2 serum levels as prognostic markers. The investigation has been made on 82 patients with operable CRC without distant metastases, who had undergone blood tests in order to determine the TIMP-1 and TIMP-2 serum levels in the following points of time: preoperatively, as well as 3, 6, 9 and 12 months postoperatively. Significant differences were found between serum levels of TIMP-1 and TIMP-2 obtained preoperatively and postoperatively, as well as significant association of serum TIMP-1 levels obtained preoperatively in CRC patients in stage I and III, in the 3th and in the 6th month (p<0.001) postoperatively as defined points of time with the outcome of CRC patients. Serum TIMP-2 levels obtained preoperatively was significantly associated with the outcome of the CRC patients. Analysis of the obtained TIMP-1 and TIMP-2 serum levels in CRC patients showed statistically significant differences with: disease progression, occurrence of liver metastasis, prior to and post chemotherapy treatment. The results derived a conclusion that the serum levels of TIMP-1 and TIMP-2 could be indicators for occurrence and progression of CRC, as well as valuable and useful markers for following the effects of chemotherapy treatment. Keywords: colorectal cancer, TIMP-1, TIMP-2, prognosis

LncRNA and mRNA signatures associated with neoadjuvant chemoradiotherapy downstaging effects in rectal cancer

Radiotherapy plays a crucial role in combined treatment modality in local advanced rectal cancer (LARC). While neoadjuvant chemoradiotherapy responses were variable in LARC patients, so, it is important to identify genes that closely associated with short-term and long-term responses to radiotherapy. In this study, we profiled long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) expression values of LARC patients with different neoadjuvant chemoradiotherapy downstaging depth score based on Agilent Arraystar Human LncRNA V3.0 Array(Agilent, CA). LncRNAs and mRNAs with aberrant expression values between the two groups of LARC patients were identified and lncRNA-miRNA-mRNA regulation network was also obtained through the combination of miRcode and miRTarBase database. Gene interaction network and module analysis of differential expression mRNAs contained in the lncRNA-miRNA-mRNA network identified five hub genes, including KRAS, PDPK1, PPP2R5C, PPP2R1B, and YES1, that should be closely associated with LARC's response to chemoradiotherapy. Besides, Kaplan-Meier analysis based on the Cyber Research Center (CRC) data set from The Cancer Genome Atlas indicated that aberrant expression of the five hub genes is significantly associated with CRC overall survival. In conclusion, we obtained several biomarkers that should be associated with neoadjuvant chemoradiotherapy response in LARC, which should be helpful for individual treatment and prognosis improvement.

Angiodrastic Chemokines in Colorectal Cancer: Clinicopathological Correlations

Aim

To study the expression of angiodrastic chemokines in colorectal tumors and correlate findings with clinicopathological parameters and survival.

Methods

The proangiogenic factor VEGF, the angiogenic chemokines CXCL8 and CXCL6, and the angiostatic chemokine CXCL4 were measured by ELISA in tumor and normal tissue of 35 stage II and III patients and correlated with the histopathology markers Ki67, p53, p21, bcl2, EGFR, and MLH1 and 5-year survival. The Wilcoxon and chi-square tests were used for statistical comparisons.

Results

There was a significant increase of CXCL6 (p = 0.005) and VEGF (p = 0.003) in cancerous tissue compared to normal. Patients with lower levels of CXCL8 and CXCL4 lived significantly longer. Patients with loss of EGFR expression had higher levels of CXCL8 while p21 loss was associated with higher levels of CXCL6. Chemokine levels were not correlated with TNM or Dukes classification. Strong expression of p53 was accompanied by decreased survival.

Conclusions

(1) The angiogenic factors CXCL6 and VEGF are increased in colorectal cancer tissue with no association with the clinical stage of the disease or survival. (2) However, increased levels of tissue CXCL8 and CXCL4 are associated with poor survival. (3) Strong expression of p53 is found in patients with poor survival.

Prognostic Relevance of MLH1 and MSH2 Mutations in Hereditary Non-Polyposis Colorectal Cancer Patients

Aims and Background

Colorectal carcinoma patients from hereditary non-polyposis colorectal cancer families are suggested to have a better prognosis than sporadic colorectal carcinoma cases. Since the majority of hereditary non-polyposis colorectal cancer-related colorectal carcinomas are characterized by microsatellite instability due to germline mutations in DNA mismatch repair genes, this is consistent with the prolonged survival observed in sporadic microsatellite instability-positive colorectal carcinoma compared to microsatellite stable cases. However, a fraction of colorectal carcinoma cases belongs to families that, despite fulfilling the clinical criteria for hereditary non-polyposis colorectal cancer, do not carry mismatch repair gene mutations. Our aim was to verify to what extent the genotypic heterogeneity influences the prognosis of hereditary non-polyposis colorectal cancer patients.

Methods

A survival analysis was performed on 526 colorectal carcinoma cases from 204 Amsterdam Criteria-positive hereditary non-polyposis colorectal cancer families. Enrolled cases were classified as MLH1-positive, MSH2-positive and mutation-negative, according to the results of genetic testing in each family.

Results

Five-year survival rates were 0.73 (95% CI, 0.66-0.80), 0.75 (95% CI, 0.66-0.84) and 0.62 (95% CI, 0.55-0.68) for MLH1-positive, MSH2-positive and mutation-negative groups, respectively (logrank test, P = 0.01). Hazard ratio, computed using Cox regression analysis and adjusted for age, sex, tumor site and stage, was 0.71 (95% CI, 0.51-0.98) for the mutation-positive compared to the mutation-negative group. Moreover, in the latter group, patients with microsatellite instability-positive colorectal carcinomas showed a better outcome than microsatellite stable cases (5-year survival rates, 0.81 and 0.60, respectively; logrank test, P = 0.006).

Conclusions

Our results suggest that the prognosis of hereditary non-polyposis colorectal cancer-related colorectal carcinoma patients depends on the associated constitutional mismatch repair genotype.

A network-based predictive gene-expression signature for adjuvant chemotherapy benefit in stage II colorectal cancer

Background

The clinical benefit of adjuvant chemotherapy for stage II colorectal cancer (CRC) is controversial. This study aimed to explore novel gene signature to predict outcome benefit of postoperative 5-Fu-based therapy in stage II CRC.

Methods

Gene-expression profiles of stage II CRCs from two datasets with 5-Fu-based adjuvant chemotherapy (training dataset, n = 212; validation dataset, n = 85) were analyzed to identify the indicator. A systemic approach by integrating gene-expression and protein-protein interaction (PPI) network was implemented to develop the predictive signature. Kaplan-Meier curves and Cox proportional hazards model were used to determine the survival benefit of adjuvant chemotherapy. Experiments with shRNA knock-down were carried out to confirm the signature identified in this study.

Results

In the training dataset, we identified 44 PPI sub-modules, by which we separate patients into two clusters (1 and 2) having different chemotherapeutic benefit. A predictor of 11 PPI sub-modules (11-PPI-Mod) was established to discriminate the two sub-groups, with an overall accuracy of 90.1%. This signature was independently validated in an external validation dataset. Kaplan-Meier curves showed an improved outcome for patients who received adjuvant chemotherapy in Cluster 1 sub-group, but even worse survival for those in Cluster 2 sub-group. Similar results were found in both the training and the validation dataset. Multivariate Cox regression revealed an interaction effect between 11-PPI-Mod signature and adjuvant therapy treatment in the training dataset (RFS, p = 0.007; OS, p = 0.006) and the validation dataset (RFS, p = 0.002). From the signature, we found that PTGES gene was up-regulated in CRC cells which were more resistant to 5-Fu. Knock-down of PTGES indicated a growth inhibition and up-regulation of apoptotic markers induced by 5-Fu in CRC cells.

Conclusions

Only a small proportion of stage II CRC patients could benefit from adjuvant therapy. The 11-PPI-Mod as a potential predictor could be helpful to distinguish this sub-group with favorable outcome.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3821-4) contains supplementary material, which is available to authorized users.

Prognostic impact of mismatch repair genes germline defects in colorectal cancer patients: are all mutations equal?

BACKGROUND

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome, caused by germline mutations in MisMatch Repair (MMR) genes, particularly in MLH1, MSH2 and MSH6. Patients with LS seem to have a more favourable prognosis than those with sporadic CRC, although the prognostic impact of different mutation types is unknown. Aim of our study is to compare survival outcomes of different types of MMR mutations in patients with LS-related CRC.

METHODS

302 CRC patients were prospectively selected on the basis of Amsterdam or Revised Bethesda criteria to undergo genetic testing: direct sequencing of DNA and MLPA were used to examine the entire MLH1, MSH2 and MSH6 coding sequence. Patients were classified as mutation-positive or negative according to the genetic testing result.

RESULTS

A deleterious MMR mutation was found in 38/302 patients. Median overall survival (OS) was significantly higher in mutation-positive vs mutation-negative patients (102.6 vs 77.7 months, HR:0.63, 95%CI:0.46-0.89, p = 0.0083). Different types of mutation were significantly related with OS: missense or splicing-site mutations were associated with better OS compared with rearrangement, frameshift or non-sense mutations (132.5 vs 82.5 months, HR:0.46, 95%CI:0.16-0.82, p = 0.0153).

CONCLUSIONS

Our study confirms improved OS for LS-patients compared with mutation-negative CRC patients. In addition, not all mutations could be considered equal: the better prognosis in CRC patients with MMR pathogenic missense or splicing site mutation could be due to different functional activity of the encoded MMR protein. This matter should be investigated by use of functional assays in the future.

Does preoperative depression and/or serotonin transporter gene polymorphism predict outcome after laparoscopic cholecystectomy?

OBJECTIVE

To determine whether preoperative psychological depression and/or serotonin transporter gene polymorphism are associated with poor outcomes after the common procedure of laparoscopic cholecystectomy.

DESIGN

Patients undergoing laparoscopic cholecystectomy were genotyped for the serotonin transporter gene 5-HTTLPR polymorphism and assessed for psychological morbidity before and 6 weeks after surgery. The main outcome was postoperative depression; secondary outcomes included fatigue, perceived pain, quality of life and subjective perception about return to usual.

RESULTS

Full genetic and psychological data were obtained from 273 out of 330 patients consented to the study (82% female). Significantly fewer people with preoperative depression (Beck Depression Inventory (BDI) score >5) had returned to employment (57% vs 86%, p<0.001) or made a full recovery (11% vs 44%, p<0.001) 6 weeks after surgery. Independent predictors for subjective return to usual after surgery included preoperative depression, body mass index and postoperative pain scores. Independent predictors of postoperative depression included preoperative antidepressant use and preoperative depression. SS genotype was associated with use of antidepressants preoperatively and higher anxiety levels after surgery. However, it was not associated with other salient postoperative psychosocial outcomes.

CONCLUSIONS

Depressive psychological morbidity preoperatively, pain and body mass index appear to be important factors in predicting recovery after this common surgical procedure. There may be a place to include preoperative brief psychological screening to enable targeted support. Our results suggest that the serotonin transporter gene is unlikely to be a useful clinical predictor of outcome in this group.

TRIAL REGISTRATION NUMBER

ISRCTN40219584.

Prognostic significance of PLA2G4C gene polymorphism in patients with stage II colorectal cancer

BACKGROUND

Phospholipase A2 Group IV C (PLA2G4C) catalyzes the release of certain fatty acids from phospholipids and plays a role in a range of physiological functions, such as remodeling of cell membranes and the production of prostaglandins. Furthermore, it has been proposed that PLA2G4C plays an important role in breast cancer cell chemotaxis. This study aimed to investigate the effect of a single nucleotide polymorphism (SNP) rs1549637 (T>A) of the PLA2G4C gene on the prognosis of colorectal cancer (CRC).

MATERIAL AND METHODS

Whole blood DNA was extracted from 381 patients with CRC and 618 controls, and a TaqMan SNP genotyping assay was used to determine the distribution of the genotypes. Cancer-specific and disease-free survival was analyzed by Kaplan-Meier graphs and by uni- and multivariable Cox regression.

RESULTS

The cancer-specific survival differed between the genotypes (p = 0.019) and the carriers of the A allele were associated with the highest risk of CRC death, with a hazard ratio (HR) of 1.72 [95% confidence interval (CI) 1.17-2.53, p = 0.006] compared with homozygous carriers of the T allele. This increased mortality in the carriers with the allele A was especially marked in stage II with an HR of 3.84 (95% CI 1.51-9.78, p = 0.005).

CONCLUSION

The A allele in PLA2G4C SNP (rs1549637) is associated with a worse prognosis in patients with CRC, especially in stage II disease, and it could be a potential prognostic biomarker in the planning of individual adjuvant therapy in stage II patients.

High expression levels of unc-51-like kinase 1 as a predictor of poor prognosis in colorectal cancer

Colorectal cancer (CRC) is one of the most common and lethal cancers worldwide. Unc-51-like kinase 1 (ULK1) plays an important role in autophagy, which is widely involved in human CRC. The aim of the present study was to investigate the clinical and prognostic significance of the expression of ULK1 in human CRC. Expression of ULK1 in 339 CRC specimens (tumor-node-metastasis stages I-IV) was assessed by immunohistochemistry. The optimal cutpoint of the expression of ULK1 was assessed by the X-tile program, and the patients were divided into 2 groups of high or low expression levels of ULK1, accordingly. Correlation analysis between the expression of ULK1 and the clinicopathological variables in CRC demonstrated that the expression of ULK1 was significantly associated with gender and tumor differentiation. Univariate Cox regression analysis indicated that high expression levels of ULK1 were a risk factor for overall and disease-free survival. Therefore, the high expression levels of ULK1 may be a useful independent biomarker for predicting a poor prognosis in patients with CRC.

Nuclear Factor Kappa B, Matrix Metalloproteinase-1, p53, and Ki-67 Expressions in the Primary Tumors and the Lymph Node Metastases of Colorectal Cancer Cases

Colorectal cancer (CRC) is the third most frequent malignancy. Many factors such as NF-κB, matrix metalloproteinase-1 (MMP-1), p53, and Ki-67 are likely to be involved in its development and progression. Lymph node metastases indicate increased tumor burden and tumor cell heterogeneity and affect both the treatment strategies and the prognosis. In this study, expressions of NF-κB, MMP-1, p53, and Ki-67 were between the primary tumors and lymph node metastases in 110 Dukes' stage C, CRC cases by immunohistochemical methods, related to patients' clinical outcomes. NF-κB, p53, and Ki-67 expressions were significantly higher in the metastatic lymph nodes compared to the primary tumor tissues (P = 0.04, P = 0.04, and P = 0.01, resp.). In the metastatic lymph nodes NF-κB expression was correlated with both p53 (r = 0.546, P = 0.003) and Ki-67 (r = 0.586, P = 0.0001) expressions. The univariant and multivariant analyses showed that only “pT stage” preserved an independent prognostic significance for recurrence-free survival rates and 5-year overall survival rates (P < 0.001 for both). Metastatic cells can acquire different biological characteristics compared to their primaries. Elucidation of properties acquired by metastatic cells is important in order to better determine prognosis, reverse drug resistance, and discover new treatment alternatives.

Molecular markers for colon diagnosis, prognosis and targeted therapy

Colorectal adenocarcinoma (CRC), the second leading cancer-related death in the United States, remains a global public health issue. Sporadic CRC is considered the result of sequential mucosal changes from normal colonic mucosa to adenocarcinoma. Efforts in understanding the molecular pathways leading to CRC tumorigenesis may lead to identifying novel, individually tailored therapeutic targets for patients. In this review, we focus on well-published prognostic and predictive markers in CRC and examine their role in clinical practice.

A systematic review and meta-analysis of diagnostic and prognostic serum biomarkers of colorectal cancer

BACKGROUND

Our systematic review summarizes the evidence concerning the accuracy of serum diagnostic and prognostic tests for colorectal cancer (CRC).

METHODS

The databases MEDLINE and EMBASE were searched iteratively to identify the relevant literature for serum markers of CRC published from 1950 to August 2012. The articles that provided adequate information to meet the requirements of the meta-analysis of diagnostic and prognostic markers were included. A 2-by-2 table of each diagnostic marker and its hazard ratio (HR) and the confidence interval (CI) of each prognostic marker was directly or indirectly extracted from the included papers, and the pooled sensitivity and specificity of the diagnostic marker and the pooled HR and the CI of the prognostic marker were subsequently calculated using the extracted data.

RESULTS

In total, 104 papers related to the diagnostic markers and 49 papers related to the prognostic serum markers of CRC were collected, and only 19 of 92 diagnostic markers were investigated in more than two studies, whereas 21 out of 44 prognostic markers were included in two or more studies. All of the pooled sensitivities of the diagnostic markers with > = 3 repetitions were less than 50%, and the meta-analyses of the prognostic markers with more than 3 studies were performed, VEGF with highest (2.245, CI: 1.347-3.744) and MMP-7 with lowest (1.099, CI: 1.018-1.187)) pooled HRs are presented.

CONCLUSIONS

The quality of studies addressing the diagnostic and prognostic accuracy of the tests was poor, and the results were highly heterogeneous. The poor characteristics indicate that these tests are of little value for clinical practice.

Epigenetic inactivation of the novel candidate tumor suppressor gene ITIH5 in colon cancer predicts unfavorable overall survival in the CpG island methylator phenotype

Inter-α-trypsin inhibitor heavy chain 5 (ITIH5) is supposed to be involved in extracellular matrix stability and thus may play a key role in the inhibition of tumor progression. The current study is the first to analyze in depth ITIH5 expression as well as its potential clinical and functional impact in colon cancer. Based on 30 tumor and 30 adjacent normal tissues we examined ITIH5 mRNA expression and promoter methylation, whose significance was further validated by independent data sets from The Cancer Genome Atlas (TCGA) platform. In addition, ITIH5 protein expression was evaluated using immunohistochemistry. ITIH5 mRNA expression loss was significantly associated (P<0.001) with hypermethylation of the ITIH5 promoter in primary colon tumors. In addition, treatment of tumor cell lines with demethylating (DAC) and histone acetylating (TSA) agents induced ITIH5 expression. In line, independent TCGA data revealed a significant expression loss of ITIH5, particularly in the MSI-high and CIMP-positive phenotype concordant with an increased ITIH5 hypermethylation in CIMP-positive colon tumors (P<0.001). In proximal, i.e., right-sided tumors, abundant ITIH5 expression was associated with longer overall survival (OS, P = 0.049) and the CIMP-positive (P = 0.032) subgroup. Functionally, ITIH5 re-expression mediated a reduced proliferation in HCT116 and CaCo2 cells. In conclusion, our results indicate that ITIH5 is a novel putative tumor suppressor gene in colon cancer with a potential impact in the CIMP-related pathway. ITIH5 may serve as a novel epigenetic-based diagnostic biomarker with further clinical impact for risk stratification of CIMP-positive colon cancer patients.

Prognostic value of CpG island methylator phenotype among colorectal cancer patients: a systematic review and meta-analysis

BACKGROUND

Divergent findings regarding the prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer (CRC) patients exist in current literature. We aim to review data from published studies in order to examine the association between CIMP and CRC prognosis.

MATERIALS AND METHODS

A comprehensive search for studies reporting disease-free survival (DFS), overall survival (OS), or cancer-specific mortality of CRC patients stratified by CIMP is carried out. Study findings are summarized descriptively and quantitatively, using adjusted hazard ratios (HRs) as summary statistics.

RESULTS

Thirty-three studies reporting survival in 10 635 patients are included for review. Nineteen studies provide data suitable for meta-analysis. The definition of CIMP regarding gene panel, marker threshold, and laboratory method varies across studies. Pooled analysis shows that CIMP is significantly associated with shorter DFS (pooled HR estimate 1.45; 95% confidence interval (CI) 1.07-1.97, Q = 3.95, I(2) = 0%) and OS (pooled HR estimate 1.43; 95% CI 1.18-1.73, Q = 4.03, I(2) = 0%) among CRC patients irrespective of microsatellite instability (MSI) status. Subgroup analysis of microsatellite stable (MSS) CRC patients also shows significant association between shorter OS (pooled HR estimate 1.37; 95% CI 1.12-1.68, Q = 4.45, I(2) = 33%) and CIMP. Seven studies have explored CIMP's value as a predictive factor on stage II and III CRC patient's DFS after receiving adjuvant 5-fluorouracil (5-FU) therapy: of these, four studies showed that adjuvant chemotherapy conferred a DFS benefit among CIMP(+) patients, one concluded to the contrary, and two found no significant correlation. Insufficient data was present for statistical synthesis of CIMP's predictive value among CRC patients receiving adjuvant 5-FU therapy.

CONCLUSION

CIMP is independently associated with significantly worse prognosis in CRC patients. However, CIMP's value as a predictive factor in assessing whether adjuvant 5-FU therapy will confer additional survival benefit to CRC patients remained to be determined through future prospective randomized studies.

Promoter CpG island methylation of RET predicts poor prognosis in stage II colorectal cancer patients

Improved prognostic stratification of patients with TNM stage II colorectal cancer (CRC) is desired, since 20-30% of high-risk stage II patients may die within five years of diagnosis. This study was conducted to investigate REarranged during Transfection (RET) gene promoter CpG island methylation as a possible prognostic marker for TNM stage II CRC patients. The utility of RET promoter CpG island methylation in tumors of stage II CRC patients as a prognostic biomarker for CRC related death was studied in three independent series (including 233, 231, and 294 TNM stage II patients, respectively) by using MSP and pyrosequencing. The prognostic value of RET promoter CpG island methylation was analyzed by using Cox regression analysis. In the first series, analyzed by MSP, CRC stage II patients (n = 233) with RET methylated tumors had a significantly worse overall survival as compared to those with unmethylated tumors (HRmultivariable = 2.51, 95%-CI: 1.42-4.43). Despite a significant prognostic effect of RET methylation in stage III patients of a second series, analyzed by MSP, the prognostic effect in stage II patients (n = 231) was not statistically significant (HRmultivariable = 1.16, 95%-CI 0.71-1.92). The third series (n = 294), analyzed by pyrosequencing, confirmed a statistically significant association between RET methylation and poor overall survival in stage II patients (HRmultivariable = 1.91, 95%-CI: 1.04-3.53). Our results show that RET promoter CpG island methylation, analyzed by two different techniques, is associated with a poor prognosis in stage II CRC in two independent series and a poor prognosis in stage III CRC in one series. RET methylation may serve as a useful and robust tool for clinical practice to identify high-risk stage II CRC patients with a poor prognosis. This merits further investigation.

The comparison of thrombocytosis and platelet-lymphocyte ratio as potential prognostic markers in colorectal cancer

The aim of the present study was to analyse the preoperative platelet count and the platelet-lymphocyte ratio (PLR) in patients with colorectal cancer (CRC) of different stages and with hepatic metastasis of CRC (mCRC) and to compare these factors as potential prognostic markers. Clinicopathological data of 10 years were collected retrospectively from 336 patients with CRC and 118 patients with mCRC. Both in the CRC and the mCRC group overall survival (OS) was significantly worse in patients who had elevated platelet count (hazard ratio [HR] = 2.2, p < 0.001 and HR = 2.9, p = 0.018, respectively). Multivariate analysis indicated that elevated platelet count was an independent prognostic factor of CRC (HR = 1.7, p = 0.035) and mCRC (HR = 3.1, p = 0.017). Disease-free survival (DFS) was significantly worse in patients with elevated platelet count in the CRC group (HR = 2.0, p = 0.011). In the multivariate analysis the PLR was not a prognostic factor in either of the two cohorts (HR = 0.92, p < 0.001 and HR = 0.89, p = 0.789, respectively). The platelet count is a valuable prognostic marker for the survival in patients both with CRC and mCRC while the PLR is not prognostic in either group.

Biological predictors of survival in stage II colorectal cancer

The routine use of postoperative adjuvant chemotherapy in patients with stage II colorectal cancer is not recommended. However, the incidence of tumor recurrence or distant metastasis in these patients is reported to be 25–35%. The identification of high-risk patients with stage II colorectal cancer remains difficult. Therefore, the aim of this study was to determine the risk factors that may help identify stage II colorectal cancer patients with unfavorable prognosis. Paraffin-embedded tissue samples from 109 patients with stage II colorectal cancer following curative operation were analyzed. Thirteen clinicopathological variables and 5 biological markers were assessed using immunohistochemistry, including p53 (tumor suppressor gene), CD10 (tumor invasion marker), CD34 (angiogenic marker), Ki-67 (cell proliferation index) and CAM 5.2 (marker of lymph node micrometastasis) and investigated for associations with disease-specific survival. Univariate analysis revealed bowel obstruction, lymph node micrometastasis and lymphatic invasion (P<0.01) to be highly significant factors for determining the 5-year disease-specific survival. By contrast, the multivariate analysis revealed lymph node micrometastasis and lymphatic invasion to be independent prognostic factors. Stage II colorectal cancer patients with lymph node micrometastasis and lymphatic invasion may therefore be suitable candidates for adjuvant chemotherapy to improve prognosis.

Impact of the bowel-screening programme on the diagnosis of colorectal cancer in Ayrshire and Arran

AIM

Bowel screening aims to reduce colorectal-cancer mortality by the detection and treatment of early-stage asymptomatic disease and the removal of precancerous adenomas. Bowel screening started in Ayrshire and Arran in September 2007. We report the impact of this screening on the diagnosis and stage of colorectal cancer and characterize screen-detected cancers in comparison with those diagnosed through other pathways.

METHOD

Diagnoses were identified from an audit database. Referrals were grouped into screen detected, routine, urgent and emergency presentations.

RESULTS

Between January 2001 and December 2010, 2289 diagnoses of colorectal cancer were made. From 2001 to 2006, the mean (range) number of new colorectal-cancer diagnoses per year was 210 (198-220). Between 2007 and 2010, the mean (range) number of diagnoses per year was 256 (239-274), a significant (P = 0.008) increase. Since September 2007, 877 colorectal cancers have been diagnosed: 17% were screen detected; 11% were detected as a result of routine GP referral; 51% were detected after urgent GP referral; and 21% were emergency presentations. TNM stage increased with urgency of referral. Approximately two-thirds (66%) of screen-detected colorectal cancers were node negative vs 25% of emergency presentations (P < 0.001). Most screen-detected cancers were distal to the splenic flexure (75%). Screened cancers had favourable pathology; lower T and N stages (both P < 0.001), less venous invasion (P < 0.001) and better differentiation (P < 0.05). Similar results were seen after stratification for TNM stage. Screening has not yet resulted in a significant shift towards early-stage disease since 2007.

CONCLUSION

Screening has been associated with an increase in the numbers of both new and early-stage colorectal cancers. Screen-detected cancers are predominantly early-stage disease with favourable pathology. At present, it remains to be seen whether screening will ultimately translate into an overall reduction in advanced-stage disease.

Elevated preoperative carcinoembryonic antigen (CEA) and Ki67 is predictor of decreased survival in IIA stage colon cancer

BACKGROUND

The present study was designed to investigate the prognostic factors of stage IIA (pT3N0M0) colon cancer.

METHODS

We retrospectively reviewed consecutive patients with stage IIA colon cancer treated with curative surgery alone from January 2004 to June 2008 in Peking University Cancer Hospital. Patient demographics, and clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were carried out to identify prognostic factors associated with 3-year disease-free survival (DFS).

RESULTS

For the 84 valid cases reviewed in this study, the 3-year DFS was 88.1 %. That for a group with elevated CEA was 77.1 % and for a group with a normal CEA level, it was 95.9 %, with statistical difference (p = 0.007). Multivariate analysis demonstrated that CEA level (p = 0.012, OR = 8.013, 1.573-40.817), expression of Ki67 (p = 0.099, OR = 3.298, 0.799-3.610), male gender (p = 0.024, OR = 7.212, 1.293-40.237), and anemia (p = 0.011, OR = 6.461, 1.537-27.151) were the independent prognostic factors for 3-year DFS. Stratified analysis revealed that an elevated CEA level combined with high expression of Ki67 was associated with poorer prognosis (3-year DFS 70 %).

CONCLUSIONS

An elevated preoperative serum level of CEA and high expression of Ki67 in tumor tissue were predictors of poor prognosis for patients with stage IIA colon cancer. These patients should therefore be considered candidates for receiving intensive surveillance. Future clinical trials using multicenter patient cohorts should be prospectively performed to evaluate whether these high-risk patients could benefit from adjuvant chemotherapy to improve prognosis.

Epithelial cell adhesion molecule is an independent prognostic marker in clear cell renal carcinoma

Epithelial cell adhesion molecule (EPCAM) has recently attained a renewed interest as a candidate protein in diagnosis, prognostication and therapy of various tumor entities. The molecular epidemiology and prognostic relevance of EPCAM in renal cell carcinoma (RCC) and amongst the histological subtypes of RCC are unclear. We analyzed the prevalence and prognostic significance of EPCAM in a tumor tissue microarray composed of 1,088 independent RCCs samples by immunohistochemistry (IHC). We found significant variations of EPCAM IHC staining intensities in between the RCC subtypes: in papillary and chromophobe RCC, the majority of tumors (89-93%) showed an at least weak EPCAM protein expression. In the largest subgroup, the clear cell (cc)RCC (n = 767), a negative EPCAM IHC was found in 1/3 of the patients and was associated with high-grade disease and nodal metastases. Kaplan-Meier analyses demonstrated a significant association between positive EPCAM IHC and prolonged overall survival, even in a subset of low-risk ccRCC. In multivariable analyses, EPCAM represented an independent risk factor of survival throughout all subgroups. For localized, low-grade ccRCC, information of EPCAM IHC raised predictive accuracy of a multivariate model by ∼5%, compared to T-stage and grade alone. Our findings indicate that EPCAM is an independent prognostic molecular marker in ccRCC and, especially in localized ccRCC, might be able to provide auxiliary information for a better prognostication.

Norcantharidin anti-angiogenesis activity possibly through an endothelial cell pathway in human colorectal cancer

The present study was based on the unexpected discovery that norcantharidin exerted anti-angiogenesis activity when effects on growth of human colon cancer were studied. The aim was to further verify this finding and explore possible mechanisms using a tumor xenograft model in nude mice. We confirmed that norcantharidin (5 or 15 mg/kg) could inhibit angiogenesis of human colon cancer in vivo. In vitro, crossing river assay, cell adhesion assay and tube formation assay indicated that NCTD could reduce the migration, adhesion and vascular network tube formation ability of HUVECs. At the same time, the expression levels of VEGF and VEGFR-2 proteins which play important roles in angiogenesis were reduced as examined by western blotting analysis. Taken together, the results firstly showed NCTD could inhibit angiogenesis of human colon cancer in vivo, probably associated with effects on migration, adhesion and vascular network tube formation of HUVECs and expression levels of VEGF and VEGFR-2 proteins.

Expression of cell cycle regulators p21 and p27 as predictors of disease outcome in colorectal carcinoma

BACKGROUND

Recent studies suggest that aberrations in cell cycle checkpoint controllers are a common feature in human malignancies and predict prognosis independent of stage.

OBJECTIVES

This study correlated two cell cycle regulators (p27 and p21) with clinical and pathological variables in colorectal cancer (CRC) patients to assess their role as prognostic factors.

PATIENTS AND METHODS

A series of 65 CRC patients were analyzed for p27 and p21 expression in their tumors using immunohistochemistry.

RESULTS

Forty-six percent of tumors showed positive nuclear p27 expression, whereas 72% of cases were completely p21 negative. There were no significant correlations between p27 and p21 expression and gender, age, lymph node involvement, stage, and grade. However, p27 (but not p21) expression revealed highly significant correlation with tumor location (p < 0.01), depth of invasion (p < 0.03), and lympho-vascular invasion (p < 0.02). Tumors with high p27 expression showed a higher recurrence rate than tumors with no expression (p < 0.03). In Kaplan-Meier survival analysis, there was a significant (p = 0.046) difference in disease-free survival (DFS) between p27-positive and p27-negative tumors in favor of the latter. p21 did not show any predictive value of DFS (p < 0.7). Neither p27 nor p21 did predict disease-specific survival (DSS) in Kaplan-Meier analysis, but DSS time was much shorter for p27-positive tumors. In multivariate (Cox) model, p27 lost its value as independent predictor of DFS, and none of the covariates were independent predictors of DSS.

CONCLUSION

p27 expression seems to be more powerful than p21 expression in providing useful prognostic information in CRC, particularly in predicting the patients at high risk for recurrent disease. Larger cohort and longer follow-up are needed to fully elucidate the value of p27 (and p21) as independent predictors of disease outcome.

Impact of preoperative thrombocytosis on the survival of patients with primary colorectal cancer

BACKGROUND

Although thrombocytosis has been reported in patients with various types of cancer, the association between thrombocytosis and the clinicopathological features of patients with colorectal cancer (CRC) has not been fully investigated. We evaluated the clinical features associated with thrombocytosis in CRC.

MATERIALS AND METHODS

The medical records of 636 consecutive CRC patients undergoing surgery in our department between January 2002 and July 2008 were retrospectively reviewed. The correlation between the clinicopathological variables and the preoperative platelet count was analyzed by univariate and multivariate analyses. The impact of thrombocytosis on the prognosis of these patients was assessed, in comparison with the other clinicopathological variables.

RESULTS

Platelet count showed significant correlation with gender, age, venous involvement, tumor size, depth of invasion, regional lymph node metastasis, distant metastasis in univariate analysis, and tumor size and depth of invasion were independent factors in multivariate analysis. The cancer-specific survival (CSS) of CRC patients with thrombocytosis was significantly shorter than that for those without thrombocytosis (P < 0.001), specifically in patients with stage III CRC (P < 0.001). Multivariate analysis indicated that thrombocytosis was an independent prognostic factor of CSS (hazard ratio = 2.96, 95% confidence interval [CI] = 1.72-5.00). Moreover, within stage II CRC, the univariate analysis revealed that disease-free survival (DFS) was associated with preoperative thrombocytosis, but not the other clinicopathological variables.

CONCLUSIONS

Preoperative thrombocytosis is not only an independent indicator of poor CSS in CRC patients but also an independent predictor of poor DFS in patients with stage II CRC.

Promoter CpG island methylation markers in colorectal cancer: the road ahead

Despite increasing knowledge on the biology, detection and treatment of colorectal cancer (CRC), the disease is still a major health problem. Hypermethylation of promoter regions of genes has been studied extensively as a contributor in CRC carcinogenesis. In addition, it is the topic of many studies focusing on biomarkers for the early detection, prediction of prognosis and treatment outcome. Methylation markers may be preferred over current screening and test methods as they are stable and easy to detect. However, almost no methylation marker is currently being used in clinical practice, often due to a lack of sensitivity, specificity, or validation of the results. This review summarizes the current knowledge of hypermethylation biomarkers for CRC detection, progression and treatment outcome.

The role of Cathepsin S as a marker of prognosis and predictor of chemotherapy benefit in adjuvant CRC: a pilot study

Background:

The aim of this pilot retrospective study was to investigate the immunohistochemical expression of Cathepsin S (CatS) in three cohorts of colorectal cancer (CRC) patients (n=560).

Methods:

Prevalence and association with histopathological variables were assessed across all cohorts. Association with clinical outcomes was investigated in the Northern Ireland Adjuvant Chemotherapy Trial cohort (n=211), where stage II/III CRC patients were randomised between surgery-alone or surgery with adjuvant fluorouracil/folinic acid (FU/FA) treatment.

Results:

Greater than 95% of tumours had detectable CatS expression with significantly increased staining in tumours compared with matched normal colon (P>0.001). Increasing CatS was associated with reduced recurrence-free survival (RFS; P=0.03) among patients treated with surgery alone. Adjuvant FU/FA significantly improved RFS (hazard ratio (HR), 0.33; 95% CI, 0.12–0.89) and overall survival (OS; HR, 0.25; 95% CI, 0.08–0.81) among 36 patients with high CatS. Treatment did not benefit the 66 patients with low CatS, with a RFS HR of 1.34 (95% CI, 0.60–3.19) and OS HR of 1.33 (95% CI, 0.56–3.15). Interaction between CatS and treatment status was significant for RFS (P=0.02) and OS (P=0.04) in a multivariate model adjusted for known prognostic markers.

Conclusion:

These results signify that CatS may be an important prognostic biomarker and predictive of response to adjuvant FU/FA in CRC.

Role of endoglin and VEGF family expression in colorectal cancer prognosis and anti-angiogenic therapies

Colorectal cancer (CRC) is one of the cancer models and most of the carcinogenic steps are presently well understood. Therefore, successful preventive measures are currently used in medical practice. However, CRC is still an important public health problem as it is the third most common cancer and the fourth most frequent cause of cancer death worldwide. Nowadays, pathologic stage is a unique and well-recognized prognostic indicator, however, more accurate indicators of the biologic behavior of CRC are expected to improve the specificity of medical treatment. Angiogenesis plays an important role in the growth and progression of cancer but its role as a prognostic factor is still controversial. Probably the most important clinical implication of tumor angiogenesis is the development of anti-angiogenic therapy. The goal of this review is to critically evaluate the role of angiogenic markers, assessed by either endoglin-related microvessel density or expression of vascular endothelial growth factor family members in the CRC setting and discuss the role of these angiogenic markers in anti-angiogenic therapies.

Preoperative Vascular Endothelial Growth Factor Levels as a Prognostic Marker for Stage II or III Colorectal Cancer Patients

Background

The aim of the present study was to determine whether serum vascular endothelial growth factor (VEGF) can provide prognostic information independent of carcinoembryonic antigen levels in patients undergoing curative surgery.

Methods

Serum samples were collected from 158 patients with colorectal cancer and from 100 controls. Serum and tissue levels of VEGF were measured by enzyme-linked immunosorbent assay. Serum VEGF levels in colorectal cancer patients were compared with those in healthy controls, and we retrospectively assessed the association between serum VEGF levels and clinicopathologic findings and survival.

Results

VEGF expression was significantly higher in colorectal cancer tissue compared with nontumor tissue. Mean serum VEGF levels in patients were significantly higher than those in controls, and significantly higher in patients with large tumors, lymph node involvement, and distant metastases.

Conclusion

Elevated serum VEGF was significantly associated with poor survival, but was only an independent risk factor for poor survival in Stage II and/or III disease. Elevated serum VEGF is significantly associated with development of colorectal cancer, and lymph or distant invasive phenotypes and survival, especially in Stage II and III patients.

Hierarchical clustering analysis of pathologic and molecular data identifies prognostically and biologically distinct groups of colorectal carcinomas

This work has evaluated the potential superiority of a morphomolecular classification based on the combination of clinicopathologic and molecular features of colorectal cancers. A cohort of 126 colorectal carcinomas was investigated by unsupervised hierarchical clustering analysis to combine 13 routinely assessed clinicopathologic features and all five molecular markers recently suggested by Jass' classification to distinguish four molecular subtypes of sporadic colorectal carcinomas. Survival analysis was assessed by a Cox proportional hazards model. A clear separation into three prognostically significant groups was identified: cluster A and cluster C were associated with good prognosis and cluster B with poor prognosis (P=0.006). Clinicopathologic and molecular features of cluster A and cluster B tumors were strongly concordant with colorectal cancer profiles characterized by microsatellite instability or by chromosomal instability, respectively. The clinicopathologic features of cluster C tumors were suggestive of a less aggressive disease than cluster B tumors. Genetically, they appeared intermediate between cluster A and cluster B tumors, as they were mainly microsatellite stable tumors showing high levels of both MGMT methylation and loss of heterozygosity. Chromosomal instability was significantly lower in cluster C than in cluster B tumors. A more accurate tumor classification should combine the prognostic power of clinicopathologic parameters with molecular biomarkers that provide information regarding the natural history of the cancer. Hierarchical clustering seems to be a useful, promising and powerful tool for further translational studies and should lead us to define a diagnostic and prognostic signature for different carcinomas.

The prognostic value of c-Kit, K-ras codon 12, and p53 codon 72 mutations in Egyptian patients with stage II colorectal cancer

BACKGROUND

The prognosis for patients with colorectal cancer (CRC) depends mainly on standard clinicopathologic factors. However, patients with similar disease characteristics exhibit various outcomes, especially in stage II. Therefore, the identification of molecular prognostic markers is needed to predict patient outcomes.

METHODS

The authors assessed the prognostic value of c-Kit (also called cluster of differentiation 117 [CD117] or KIT), cyclooxygenase-2 (COX-2), tumor protein 53 (p53), and Kirsten rat sarcoma viral oncogene homolog (K-ras) aberrations in 90 patients with stage II CRC using immunohistochemistry and molecular techniques. The results were correlated with standard clinicopathologic prognostic factors, overall survival (OS), and disease-free survival (DFS).

RESULTS

COX2 and c-Kit overexpression was detected in 54.6% and 59.3% of patients, respectively. Overexpression of p53 was detected in 47 patients, including 29 who had mutations, and a unique mutation pattern was detected with 3 hotspots at codons 72, 245, and 273. Overexpression of ras was detected in 44 patients, including 37 who had mutations. On multivariate analysis, c-Kit overexpression, p53 codon 72 mutations, perforation, and performance status were independent prognostic factors for DFS (P=.054, P=.015, P<.0001, and P=.043, respectively); whereas codon 12 K-ras mutation, performance status, and perforation were independent prognostic factors for OS (P=.033, P=.006, and P<.0001, respectively).

CONCLUSIONS

The current results provide evidence for the prognostic value of c-Kit overexpression in patients with stage II CRC. The high p53 mutation rate and the unique hotspot in codon 72 have not been reported previously in CRC. This may be related to environmental or racial features that are unique to the studied population.

KRAS mutation detection and prognostic potential in sporadic colorectal cancer using high-resolution melting analysis

BACKGROUND

The development of targeted therapies has created a pressing clinical need for molecular characterisation of cancers. In this retrospective study, high-resolution melting analysis (HRMA) was validated and implemented for screening of 164 colorectal cancer (CRC) patients to detect KRAS hot-spot mutations and to evaluate its prognostic value. Direct sequencing was used to confirm and characterise HRMA results.

METHODS

After establishing its sensitivity, HRMA was validated on seven cell lines and inter- and intra-variation were analysed. The prognostic value of KRAS mutations in CRC was evaluated using survival analysis.

RESULTS

HRMA revealed abnormal melting patterns in 34.1% CRC samples. Kaplan-Meier survival curves revealed a significantly shorter overall (OS) and disease-free survival (DFS) for CRC patients harbouring a KRAS mutation. In the Cox regression analysis, only when colon and rectal cancer were analysed separately, KRAS mutation was a negative predictor for OS in patients with rectal cancer and DFS in those with stage II colon cancer.

CONCLUSIONS

HRMA was found to be a valid screening method for KRAS mutation detection. The KRAS mutation came forward as a negative predictive factor for OS in patients with rectal cancer and for DFS in stage II colon cancer patients.

Biological variations in plasma VEGF and VEGFR-1 may compromise their biomarker value in colorectal cancer

INTRODUCTION

Vascular Endothelial Growth Factor (VEGF) plays a prominent role in tumor angiogenesis and plasma VEGF concentration may carry prognostic information in colorectal cancer. The VEGF receptor 1 (VEGFR-1) is a regulatory receptor which is shredded into plasma of patients with colorectal cancer. For both molecules, large biological variation and lack of standardization of assay procedures are major challenges.

METHODS

We investigated pre-analytical, analytical, as well as short term and long term biological variation of plasma VEGF and VEGFR-1 in volunteers. In addition, we evaluated plasma VEGF and VEGFR-1 as markers of colorectal disease in a case-control study on four groups of 77 individuals undergoing bowel endoscopy. Groups were categorized as 'no findings', 'non-malignant findings', 'adenoma', or 'colorectal cancer'.

RESULTS

In the studies on variation, temperature and delay before centrifugation significantly influenced plasma VEGF and, to a minor extent, plasma VEGFR-1 concentrations. In addition, we found large biological variations with CV up to 69.2% for VEGF and CV up to 35.9% for VEGFR-1. For both molecules the intra-subject variation exceeded the inter-subject variation. In the case control study neither plasma VEGF nor VEGFR-1 was able to differentiate between the four groups of individuals although plasma VEGFR-1 was significantly lower in patients with 'no findings'.

CONCLUSION

There was no difference in plasma VEGF or VEGFR-1 between patients with no findings, benign disease, pre-malignant findings, and malignant findings after endoscopy. The poor discrimination between patients may be explained by the large inter- and intra-subject variations found for both molecules in volunteers.

Lymphangiogenesis: A new player in cancer progression

Lymph node metastasis is the hallmark of colon cancer progression, and is considered one of the most important prognostic factors. Recently, there has been growing evidence that tumor lymphangiogenesis (formation of new lymphatic vessels) plays an important role in this process. Here, we review the latest findings of the role of lymphangiogenesis in colorectal cancer progression, and discuss its clinical application as a biomarker and target for new therapy. Understanding the molecular pathways that regulate lymphangiogenesis is mandatory to pave the way for the development of new therapies for cancer. In the future, tailored treatments consisting of combinations of chemotherapy, other targeted therapies, and anti-lymphangiogenesis agents will hopefully improve patient outcomes. This progression to the clinic must be guided by new avenues of research, such as the identification of biomarkers that predict response to treatment.

A review of the most promising biomarkers in colorectal cancer: one step closer to targeted therapy

Rapidly growing insights into the molecular biology of colorectal cancer (CRC) and recent developments in gene sequencing and molecular diagnostics have led to high expectations for the identification of molecular markers to be used in optimized and tailored treatment regimens. However, many of the published data on molecular biomarkers are contradictory in their findings and the current reality is that no molecular marker, other than the KRAS gene in the case of epidermal growth factor receptor (EGFR)- targeted therapy for metastatic disease, has made it into clinical practice. Many markers investigated suffer from technical shortcomings, resulting from lack of quantitative techniques to capture the impact of the molecular alteration. This understanding has recently led to the more comprehensive approaches of global gene expression profiling or genome-wide analysis to determine prognostic and predictive signatures in tumors. In this review, an update of the most recent data on promising biological prognostic and/or predictive markers, including microsatellite instability, epidermal growth factor receptor, KRAS, BRAF, CpG island methylator phenotype, cytotoxic T lymphocytes, forkhead box P3-positive T cells, receptor for hyaluronic acid-mediated motility, phosphatase and tensin homolog, and T-cell originated protein kinase, in patients with CRC is provided.

Therapeutic modulation of k-ras signaling in colorectal cancer

KRAS has an important role in colorectal carcinogenesis and mutant KRAS leads to a permanently activated k-ras protein. To exert its biological activity, k-ras requires post-translational modification by prenylation. K-ras modulation has become a promising concept for new therapies, mostly by interference with the mevalonate pathway and subsequently by the prenylation of k-ras. Clinical data of agents interfering with the mevalonate pathway and the prenylation of ras are summarized and suggest that these agents might be effective when administered in combination with anticancer drugs that target k-ras. Here, we discuss the novel concept that modulation of k-ras might potentiate EGFR therapy by altering the KRAS phenotype.

Analysis of post-operative changes in serum protein expression profiles from colorectal cancer patients by MALDI-TOF mass spectrometry: a pilot methodological study

BACKGROUND

Mass spectrometry-based protein expression profiling of blood sera can be used to discriminate colorectal cancer (CRC) patients from unaffected individuals. In a pilot methodological study, we have evaluated the changes in protein expression profiles of sera from CRC patients that occur following surgery to establish the potential of this approach for monitoring post-surgical response and possible early prediction of disease recurrence.

METHODS

In this initial pilot study, serum specimens from 11 cancer patients taken immediately prior to surgery and at approximately 6 weeks following surgery were analysed alongside 10 normal control sera by matrix-assisted laser desorption ionisation time of-flight-mass spectrometry (MALDI-TOF MS). Using a two-sided t-test the top 20 ranked protein peaks that discriminate normal from pre-operative sera were identified. These were used to classify post-operative sera by hierarchical clustering analysis (Spearman's Rank correlation) and, as an independent 'test' dataset, by k-nearest neighbour and weighted voting supervised learning algorithms.

RESULTS

Hierarchical cluster analysis classified post-operative sera from all six early Dukes' stage (A and B) patients as normal. The remaining five post-operative sera from more advanced Dukes' stages (C1 and C2) were classified as cancer. Analysis by supervised learning algorithms similarly grouped all advanced Dukes' stages as cancer, with four of the six post-operative sera from early Dukes' stages being classified as normal (P = 0.045; Fisher's exact test).

CONCLUSIONS

The results of this pilot methodological study illustrate the proof-of-concept of using protein expression profiling of post-surgical blood sera from individual patients to monitor disease course. Further validation on a larger patient cohort and using an independent post-operative sera dataset would be required to evaluate the potential clinical relevance of this approach. Prospective data, including follow-up on patient survival, could in the future, then be evaluated to inform decisions on individualised treatment modalities.

Prognostic significance of matrix metalloproteinase-9 (MMP-9) in stage II colorectal carcinoma

BACKGROUND

Approximately 30% of all colorectal cancer patients are diagnosed with stage II disease. Adjuvant therapy is not widely recommended. However, it is well-established that a subgroup of patients with stage II is at high risk for recurrence within their life time and should be considered for adjuvant chemotherapy. The present work was designed to assess the value of matrix metalloproteinase-9 (MMP-9) as a predictor of disease outcome in a series of 202 stage II colorectal cancer (CRC) patients with long-term follow-up.

METHODS

The present study comprises a series of 202 patients who underwent bowel resection for stage II CRC at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with MMP-9 antibody.

RESULTS

Forty-eight percent of all CRC samples were positive for MMP-9. There was no significant correlation between MMP-9 expression and age, depth of invasion, and lymph node status. However, MMP-9 expression was significantly related to histological grade (p = 0.03) and location of the tumor (p = 0.01), therefore, being lower in high-grade tumors and most intense in carcinomas of the descending colon and rectum. Tumors with high MMP-9 expression showed a higher recurrence rate than tumors with low expression (p = 0.02). MMP-9 negative tumors had a more favorable disease-free survival (DFS) than those expressing MMP-9 (p = 0.03). The same was true with disease-specific survival (DSS; p = 0.02) as well, high expression of MMP-9 being associated with shorter survival rates. In multivariate (Cox) survival analysis, MMP-9 expression proved to be an independent predictor of DFS, but not DSS, which was predicted by age and sex only.

CONCLUSION

Quantification of MMP-9 expression seems to provide valuable prognostic information in stage II CRC, particularly, in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.

Prognostic role of vasculogenic mimicry in colorectal cancer

PURPOSE

Angiogenesis, as measured by degree of microvessel density, has been associated with tumor progression in many tumor types but does not always correlate with clinical outcome. In 1999, aggressive tumor cells were shown to form blood-conducting tubes not lined by endothelial cells, and this phenomenon was termed vasculogenic mimicry. We investigated angiogenesis and the presence of vasculogenic mimicry in colorectal carcinoma in relation to tumor stage, patient survival, and genetic indicators of tumor cell plasticity.

METHODS

Paraffin-embedded tissue samples were examined from a study of 117 patients with colorectal carcinoma with a 12-year follow-up. Immunohistochemical analysis was used to measure microvessel density and proliferating endothelial cells and to detect vasculogenic mimicry (scored by 3 independent observers). Cell cultures from 7 colon cell lines, real-time polymerase chain reaction (PCR) on cell lines, frozen tissue material from 4 colorectal cancer patients with and 4 without vasculogenic mimicry, and fresh colorectal cancer tissue from 2 patients were used to investigate the relationship between vasculogenic mimicry and tumor cell plasticity.

RESULTS

Microvessel density was not a prognostic marker in our patients. We found vasculogenic mimicry in 23 (19.7%) of 117 colorectal tumor samples. Cell culture experiments and real-time PCR on human colorectal carcinoma material showed evidence for vasculogenic mimicry with overexpression of EPHA2 and LAMC2, known to be important for the tube-forming capacity of melanoma tumor cells. The presence of vasculogenic mimicry was associated with significantly shortened survival, both overall (P < 0.0001) and within intermediate cancer stages (Dukes B, P = 0.0277; Dukes C, P < 0.0001).

CONCLUSIONS

Vasculogenic mimicry can occur in colorectal carcinoma and appears to be comparable to vasculogenic mimicry described in other tumors. Moreover, vasculogenic mimicry in colorectal carcinoma may be a strong independent prognostic marker for survival.

KRAS mutation and microsatellite instability: two genetic markers of early tumor development that influence the prognosis of colorectal cancer

INTRODUCTION

We examined two genetic markers established early in colorectal tumor development, microsatellite instability (MSI) and mutation of the KRAS proto-oncogene, to see if these genetic changes influence metastatic disease progression and survival.

PATIENTS AND METHODS

MSI and KRAS mutation status were assessed in 532 primary adenocarcinomas (stage I-IV) from patients treated by colon resection. Median follow-up was 4.1 years (range 0-13.3 years) overall, 5.4 years for survivors.

RESULTS

MSI and KRAS mutation were detected in 12 and 36% of cases, respectively. MSI was more common in early-stage disease (I, 15%; II, 21%; III, 10%; IV, 2%; P = 0.0001). Prevalence of KRAS mutation did not vary with stage (I, 36%; II, 34%; III, 35%; IV, 40%; P = ns). Disease-specific survival was far superior for MSI tumors than for microsatellite stability (MSS) tumors (5-year survival 92 vs. 59%, P < 0.0001). KRAS mutation was a marker of poor survival (5-year survival 55 vs. 68%, P = 0.0002). Using Cox regression analysis MSI, KRAS mutation, and stage were strong independent predictors of survival in the entire patient population. A high-mortality group with MSS/KRAS-mutant tumors was identified within the stage I and II cohort.

CONCLUSIONS

MSI and KRAS mutation provide fundamental genetic signatures influencing tumor behavior across patient subsets and stages of tumor development.

Elevated expressions of MMP7, TROP2, and survivin are associated with survival, disease recurrence, and liver metastasis of colon cancer

PURPOSE

Colorectal cancer is one of the most common cancers worldwide. We tested the hypothesis that differences in the expression of certain molecular markers of colon cancer may account for different clinical outcomes.

METHODS

Tissue microarray technology was used to assay the expression of 17 biological markers [beta-catenin, CD44v7, c-myc, cyclin D1, estrogen receptor beta, mitogen-activated protein kinase/extracellular signal-regulated kinase, maspin, matrix metalloproteinase-7 (MMP7), p53, Pin1, peroxisome proliferators-activated receptor-gamma, survivin, T cell transcription factor 4 (TCF4), transforming growth factor beta receptor II (TGFbetaR II), TGFbeta, TROP2, and Wnt] by immunohistochemistry in 620 colon cancer patients. The Cox proportional hazards regression model was applied to analyze the lifetime data, including time to death, time to recurrence, and time to liver metastasis.

RESULTS

All the markers were present at significantly higher expression levels in tumor specimens than in normal colonic specimens. Kaplan-Meier analysis showed that high expression of TROP2, MMP7, and survivin were related to decreased survival; TCF4 and TROP2 were related to disease recurrence; and CD44v7, cyclin D1, MMP7, p53, survivin, and TCF4 were related to liver metastasis. However, the results of the multivariate analysis only showed that expression of MMP7, survivin, and TROP2 were significant predictors of lower patient survival, while TROP2 and MMP7 were significantly related to disease recurrence and liver metastasis, respectively.

CONCLUSIONS

We conclude that elevated survivin, MMP7, and TROP2 expression levels are related to decreased survival. In addition, elevated MMP7 and TROP2 expression levels are predictors of disease recurrence and liver metastasis, respectively.

TSPAN1 protein expression: A significant prognostic indicator for patients with colorectal adenocarcinoma

AIM: To determine if TSPAN1 overexpression is associated with clinicopathological and prognostic factors in human colorectal adenocarcinoma.

METHODS: Total RNA was extracted in 20 human adenocarcinoma tissues for TSPAN1 mRNA assay by RT-PCR. Eighty-eight specimens of human colorectal adenocarcinoma were surgically removed. TSPAN1 protein levels in cancer tissues were determined by immunohistochemistry using a polyclonal antibody against self-prepared TSPAN1. The correlation between TSPAN1 expression and the clinicopathological factors and the overall survival rate was analyzed by univariate and multivariate assay.

RESULTS: TSPAN1 mRNA was detected in 90.0% (18/20) of cancerous tissues. The light density of TSPAN1 mRNA expression levels was 0.89 ± 0.30 in adenocarcinoma by gel-image system. TSPAN1 protein expression was detected in 78.41% (69/88) and weakly expressed in 40% normal colorectal tissues. There were significant differences between colorectal adenocarcinoma and normal control epithelium (P < 0.05). TSPAN1 protein expression in colorectal cancerous tissue was significantly correlated with the histological grade, cell expression PCNA, lymph nodal metastasis and TNM staging of the disease. Patients with TSPAN1 protein overexpression had a significantly shorter survival period than that in patients with TSPAN1 protein negative or weak expression, respectively (P < 0.05). Furthermore, by multivariate analysis, TSPAN1 protein expression demonstrated an independent prognostic factor for human colorectal cancers (P < 0.05, relative risk 0.755; 95% confidence interval 0.302-1.208).

CONCLUSION: The expression of TSPAN1 gene is increased in colorectal carcinoma, suggesting that TSPAN1 might serve as an independent prognostic factor for the colorectal adenocarcinoma patients.

Preoperative serum vascular endothelial growth factor-a is a marker for subsequent recurrence in colorectal cancer patients

PURPOSE

Serum vascular endothelial growth factor-A has been associated with stage of disease and prognosis in colorectal cancer. In this study, the clinical usefulness of preoperative serum vascular endothelial growth factor-A concentrations in the long-term follow-up of colorectal cancer patients was evaluated.

METHODS

Serum vascular endothelial growth factor-A levels were determined by quantitative enzyme-linked immunosorbent assay in 93 patients prior to resection for colorectal cancer: node-negative (n = 41) and node-positive (n = 52). Median follow-up for patients without cancer death was 54 (interquartile range, 24-63.5) months.

RESULTS

The median preoperative serum vascular endothelial growth factor-A level of these patients was 168 (interquartile range, 48-414) pg/ml. Seven patients had local recurrences with a median time of 6 (interquartile range, 4-12) months. Patients (n = 17) that developed metastasis had a median time of 17 (interquartile range, 7-42) months. Patients with local recurrence had significantly higher levels of serum vascular endothelial growth factor-A (P = 0.01). By classifying the patients into two groups, using the maximal chi-squared value of the Cox's regression based on our previous work, it was found that a serum vascular endothelial growth factor-A level >575 pg/ml is an independent prognostic factor for predicting tumor recurrence.

CONCLUSION

Patients with colorectal cancer who have preoperative serum vascular endothelial growth factor-A levels >575 pg/ml are more likely to develop recurrence. Trials are warranted to investigate the efficacy of adjuvant therapy for this high-risk group.

PLA2 (group IIA phospholipase A2) as a prognostic determinant in stage II colorectal carcinoma

BACKGROUND

Approximately 30% of all colorectal cancer (CRC) patients are diagnosed with stage II disease. Adjuvant therapy is not widely recommended. However, it is well established that a subgroup of patients with stage II are at high risk for recurrence within their lifetime and should be considered for adjuvant chemotherapy. The present work was designed to assess the value of group IIA phospholipase A2 (PLA2) as a predictor of disease outcome in stage II CRC patients with long-term follow-up.

PATIENTS AND METHODS

The present study comprises a series of 116 patients who underwent bowel resection for stage II CRC during 1981-1990 at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with PLA2.

RESULTS

Fifty-five percent of all tumors were positive for PLA2. There was no significant correlation between PLA2 expression and age, sex, depth of invasion and lymph node status. In Kaplan-Meier survival analysis, there was a significant (P = 0.010) difference in disease-free survival (DFS) between patients with negative tumors (longer DFS) and those with positive tumors. The same was true with disease-specific survival (DSS), patients with PLA2-negative tumors living significantly longer (P = 0.025). In multivariate (Cox) survival analysis, however, PLA2 was not an independent predictor of DFS or DSS. In subgroup analysis, the right-sided tumors with negative PLA2 staining had remarkably better prognosis (P = 0.010) than PLA2-positive left-sided tumors.

CONCLUSIONS

Quantification of PLA2 expression seems to provide valuable prognostic information in stage II CRC, particularly in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.