Adjuvant therapy in colon cancer

miR-497/195 Cluster Affects the Development of Colorectal Cancer by Targeting FRA1

The miR-497-195 cluster facilitates the occurrence and development of cancer. This study aims to investigate whether the miR-195-497 cluster could regulate the progression of colorectal cancer by regulating the common target gene, FOS-related antigen 1 (FRA1). Overexpression of the miR-195/497 vector was used to evaluate the effect of overexpression of miR-195-497 clusters on the biological behavior of colon cancer cells. In animal experiments, tumor growth and metastasis were recorded by constructing a nude mouse model of a subcutaneously implanted tumor. miR-195 and miR-497 were expressed to varying degrees in Caco-2, LoVo, and HT-29 cells. Overexpression of miR-195/497 and inhibition of FRA1 decreased HT-29 cell proliferation, inhibited cell invasion and migration, and promoted Epithelial-mesenchymal transition (EMT). In vivo experiments showed that the overexpression of miR-195/497 or inhibition of FRA1 inhibited tumor growth, affected EMT in tumor cells, and inhibited the expression of FRA1. Additionally, the aforementioned conditions had the best effect when used together. The miR-195-497 cluster can regulate the proliferation, EMT, invasion, and migration of colorectal cancer cells by regulating the common target gene FRA1, thereby affecting the development of colorectal cancer.

Polysaccharides from Passion Fruit Peels: From an Agroindustrial By-Product to a Viable Option for 5-FU-Induced Intestinal Damage

Gastrointestinal mucositis is a serious and dose-limiting toxic side effect of oncologic treatment. Interruption of cancer treatment due to gastrointestinal mucositis leads to a significant decrease in cure rates and consequently to the deterioration of a patient's quality of life. Natural polysaccharides show a variety of beneficial effects, including a gastroprotective effect. Treatment with soluble dietary fiber (SDF) from yellow passion fruit (Passiflora edulis) biomass residues protected the gastric and intestinal mucosa in models of gastrointestinal injury. In this study, we investigated the protective therapeutic effect of SDF on 5-FU-induced mucositis in male and female mice. Oral treatment of the animals with SDF did not prevent weight loss but reduced the disease activity index and preserved normal intestinal function by alleviating diarrhea and altered gastrointestinal transit. SDF preserved the length of the colon and histological damage caused by 5-FU. SDF significantly restored the oxidative stress and inflammation in the intestine and the enlargement and swelling of the spleen induced by 5-FU. In conclusion, SDF may be a promising adjuvant strategy for the prevention and treatment of intestinal mucositis induced by 5-FU.

Hybrid-DIA: intelligent data acquisition integrates targeted and discovery proteomics to analyze phospho-signaling in single spheroids

Achieving sufficient coverage of regulatory phosphorylation sites by mass spectrometry (MS)-based phosphoproteomics for signaling pathway reconstitution is challenging, especially when analyzing tiny sample amounts. To address this, we present a hybrid data-independent acquisition (DIA) strategy (hybrid-DIA) that combines targeted and discovery proteomics through an Application Programming Interface (API) to dynamically intercalate DIA scans with accurate triggering of multiplexed tandem mass spectrometry (MSx) scans of predefined (phospho)peptide targets. By spiking-in heavy stable isotope labeled phosphopeptide standards covering seven major signaling pathways, we benchmark hybrid-DIA against state-of-the-art targeted MS methods (i.e., SureQuant) using EGF-stimulated HeLa cells and find the quantitative accuracy and sensitivity to be comparable while hybrid-DIA also profiles the global phosphoproteome. To demonstrate the robustness, sensitivity, and biomedical potential of hybrid-DIA, we profile chemotherapeutic agents in single colon carcinoma multicellular spheroids and evaluate the phospho-signaling difference of cancer cells in 2D vs 3D culture.

Pharmacogenetics of Anticancer Drugs: Clinical Response and Toxicity

Cancer is the most challenging disease for medical professionals to treat. The factors underlying the complicated situation include anticancer drug-associated toxicity, non-specific response, low therapeutic window, variable treatment outcomes, development of drug resistance, treatment complications, and cancer recurrence. The remarkable advancement in biomedical sciences and genetics, over the past few decades, however, is changing the dire situation. The discovery of gene polymorphism, gene expression, biomarkers, particular molecular targets and pathways, and drug-metabolizing enzymes have paved the way for the development and provision of targeted and individualized anticancer treatment. Pharmacogenetics is the study of genetic factors having the potential to affect clinical responses and pharmacokinetic and pharmacodynamic behaviors of drugs. This chapter emphasizes pharmacogenetics of anticancer drugs and its applications in improving treatment outcomes, selectivity, toxicity of the drugs, and discovering and developing personalized anticancer drugs and genetic methods for prediction of drug response and toxicity.

Functional assessment of miR‑1291 in colon cancer cells

miR‑1291 exerts an anti‑tumor effect in a subset of human carcinomas, including pancreatic cancer. However, its role in colorectal cancer (CRC) is largely unknown. In the present study, the expression and effect of miR‑1291 in CRC cells was investigated. It was identified that miR‑1291 significantly suppressed the proliferation, invasion, cell mobility and colony formation of CRC cells. Additionally, miR‑1291 induced cell apoptosis. A luciferase reporter assay revealed that miR‑1291 directly bound the 3'‑untranslated region sequence of doublecortin‑like kinase 1 (DCLK1). miR‑1291 also suppressed DCLK1 mRNA and protein expression in HCT116 cells that expressed DCLK1. Furthermore, miR‑1291 suppressed cancer stem cell markers BMI1 and CD133, and inhibited sphere formation. The inhibitory effects on sphere formation, invasion and mobility in HCT116 cells were also explored and verified using DCLK1 siRNAs. Furthermore, miR‑1291 induced CDK inhibitors p21WAF1/CIP1 and p27KIP1 in three CRC cell lines, and the overexpression of DCLK1 in HCT116 cells led to a decrease of p21WAF1/CIP1 and p27KIP1. Intravenous administration of miR‑1291 loaded on the super carbonate apatite delivery system significantly inhibited tumor growth in the DLD‑1 xenograft mouse model. Additionally, the resultant tumors exhibited significant upregulation of the p21WAF1/CIP1 and p27KIP1 protein with treatment of miR‑1291. Taken together, the results indicated that miR‑1291 served an anti‑tumor effect by modulating multiple functions, including cancer stemness and cell cycle regulation. The current data suggested that miR‑1291 may be a promising nucleic acid medicine against CRC.

Development and validation of a novel miRNA classifier as a prognostic signature for stage II/III colorectal cancer

Background

The TNM staging remains the gold standard for determining the prognosis of patients with colorectal cancer (CRC), which is inadequate at identifying the subset of high-risk stage II and III patients that have a high potential of developing tumor recurrence and may experience death. Emerging evidence indicates that not only microRNAs (miRNAs) play important functional role in CRC development but may serve as important disease biomarkers. In this study we aimed to develop a miRNA-based classifier as a prognostic signature for improving the clinical outcome of patients with stage II/III CRC.

Methods

We performed a systematic and comprehensive discovery step to identify differentially expressed miRNAs in CRC. We subsequently determined the prognostic relevance of these miRNAs in stage II/III patients using qRT-PCR and developed a miRNA-based classifier for predicting disease-free survival (DFS) in a clinical cohort (n=186).

Results

Based upon miRNA expression profiling studies, we identified a panel of 10 miRNAs which are consistently differentially expressed in CRC vs. normal tissues. By using cox proportional hazard models, we then developed 6-miRNA-classifier (miR-183, -20a, -21, -195, -139 and -20a) to predict prognosis in clinical cohort, that had significantly superior predictive performance compared to other clinicopathological factors, and could successfully identify high-risk stage II and III CRC patients with poor prognosis [hazard ratio (HR) =2.16; P=0.0048]. In a multivariate analysis, this miRNA-based classifier emerged as an independent prognostic signature for poor DFS.

Conclusions

Our miRNA-based classifier is a reliable predictive tool for determining prognosis in patents with stage II/III CRC, and might be able to identify high-risk patients that are candidates for more targeted personalized clinical management and surveillance.

Assessment of the Circulating Tumor Cells and Microsatellite Instability in Colorectal Cancer Patients: Prognostic and Diagnostic Value

Background

Microsatellite instability (MSI) and circulating tumor cells (CTCs) play important roles in the diagnosis, prognosis and management of colorectal cancer (CRC) patients.

Methods

CTCs and MSI were assessed in the blood and representative tumor tissues of 100 CRC patients by flow cytometry (FCM) and PCR amplification. The data were correlated to relevant clinicopathological features of the patients, progression-free survival (PFS) and overall survival (OS) rates.

Results

MSI-high was detected in 44 (44.0%) patients, MSI-low in 37 (37%), and microsatellite stable (MSS) in 19 (19.0%) patients (P=0.007). The baseline CTCs count (<4 cells/7mL blood) was reported in 39% of the patients, and CTCs ≥4 cells/7mL blood in 61% of the patients (P=0.028). Improved PFS and OS rates were associated significantly with MSI-high (P<0.001), decreased CTC levels during the course of treatment (P<0.001) and post-treatment CTCs (P=0.008). There was no significant association between MSI-high and PFS or OS in early-stage patients (P=0.187 and P=0.187; respectively); however, it was associated significantly with better PFS and OS in late-stage patients (P<0.001). Multivariate analysis showed that only a change in serial CTC levels is considered an independent prognostic factor for OS (P<0.012). Post-treatment CTCs level, serial CTCs level changes during the course of treatment, lymph nodes and distant metastasis were independent prognostic factors for PFS (P<0.001, P= 0.047, P=0.001 and P<0.001; respectively).

Conclusion

MSI and CTCs could be used as accurate, reliable and sensitive diagnostic and prognostic biomarkers for CRC patients’ survival rates and outcomes.

Prognostic Value of MicroRNAs in Stage II Colorectal Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

We performed a systematic review and meta-analysis to identify and underline multiple microRNAs (miRNAs) as biomarkers of disease prognosis in stage II colorectal cancer (CRC) patients.

METHODS AND ANALYSIS

This systematic review and meta-analysis study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The required articles were collected from online bibliographic databases from January 2011 to November 2019 with multiple permutation keywords. Quantitative data synthesis was based on a meta-analysis with pooled data to observe and analyse the outcome measures and effect estimates by using the random effect model. The subgroup analysis was performed from demographic characteristics and the available data.

RESULTS

Eighteen articles were included in this study, 16 of which were incorporated for meta-analysis to examine the stage II CRC prognosis with up- and downregulated miRNA expressions. The pooled hazard ratio (HR) for death in stage II CRC patients was 1.90 (95% confidence interval 1.63-2.211), with a significant p value. A subgroup analysis based on up- or downregulated miRNA expression individually and any deregulated miRNA was also associated with a worse prognosis. The subgroup analysis included parameters such as age, gender, stage II and III combined patients' survival and the repetitive miRNAs (miR21, miR215, miR143-5p, miR106a and miR145) individually.

CONCLUSION

MicroRNAs play a significant role in determining prognosis in stage II CRC patients, with upregulation of miR21, miR215, miR143-5p and miR106a, in particular, portending a worse prognosis. These miRNAs could be considered for further evaluation as biomarkers of prognosis and to guide the decision to administer adjuvant chemotherapy.

5-FU promotes stemness of colorectal cancer via p53-mediated WNT/β-catenin pathway activation

5-Fluorouracil (5-FU) remains the first-line treatment for colorectal cancer (CRC). Although 5-FU initially de-bulks the tumor mass, recurrence after chemotherapy is the barrier to effective clinical outcomes for CRC patients. Here, we demonstrate that p53 promotes WNT3 transcription, leading to activation of the WNT/β-catenin pathway in Apc^Min/+/Lgr5^EGFP mice, CRC patient-derived tumor organoids (PDTOs) and patient-derived tumor cells (PDCs). Through this regulation, 5-FU induces activation and enrichment of cancer stem cells (CSCs) in the residual tumors, contributing to recurrence after treatment. Combinatorial treatment of a WNT inhibitor and 5-FU effectively suppresses the CSCs and reduces tumor regrowth after discontinuation of treatment. These findings indicate p53 as a critical mediator of 5-FU-induced CSC activation via the WNT/β-catenin signaling pathway and highlight the significance of combinatorial treatment of WNT inhibitor and 5-FU as a compelling therapeutic strategy to improve the poor outcomes of current 5-FU-based therapies for CRC patients.

Multiple gene promoter methylation and clinical stage in adjacent normal tissues: Effect on prognosis of colorectal cancer in Taiwan

This study provide an insight that the panel genes methylation status in different clinical stage tended to reflect a different prognosis even in matched normal tissues, to clinical recommendation. We enrolled 153 colorectal cancer patients from a medical center in Taiwan and used the candidate gene approach to select five genes involved in carcinogenesis pathways. We analyzed the relationship between DNA methylation with different cancer stages and the prognostic outcome. There were significant trends of increasing risk of 5-year time to progression and event-free survival of subjects with raising number of hypermethylation genes both in normal tissue and tumor tissue. The group with two or more genes with aberrant methylation in the advanced cancer stages (Me/advanced) had lower 5-year event-free survival among patients with colorectal cancer in either normal or tumor tissue. The adjusted hazard ratios in the group with two or more genes with aberrant methylation with advanced cancer stages (Me/advanced) were 8.04 (95% CI, 2.80–23.1; P for trend <0.01) and 8.01 (95% CI, 1.92–33.4; P for trend <0.01) in normal and tumor tissue, respectively. DNA methylation status was significantly associated with poor prognosis outcome. This finding in the matched normal tissues of colorectal cancer patients could be an alternative source of prognostic markers to assist clinical decision making.

The Developing Story of Predictive Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is the third most common malignancy worldwide. Surgery remains the most important treatment for non-metastatic CRC, and the administration of adjuvant chemotherapy depends mainly on the disease stage, which is still the strongest prognostic factor. A refined understanding of the genomics of CRC has recently been achieved thanks to the widespread use of next generation sequencing with potential future therapeutic implications. Microsatellite instability (MSI) has been suggested as a predictive marker for response to anti-programmed-cell-death protein 1 (PD-1) therapy in solid tumors, including CRC. It should be noted that not all cancers with MSI phenotype respond to anti-PD-1 immunotherapy, highlighting the urgent need for even better predictive biomarkers. Mitogen-Activated Protein Kinase (MAPK) pathway genes KRAS, NRAS, and BRAF represent important molecular targets and could serve as independent prognostic biomarkers in CRC, and identify those who potentially benefit from anti-epidermal growth factor receptor (EGFR) treatment. Emerging evidence has attributed a significant role to inflammatory markers including blood cell ratios in the prognosis and survival of CRC patients; these biomarkers can be easily assessed in routine blood exams and be used to identify high-risk patients or those more likely to benefit from chemotherapy, targeted therapies and potentially immunotherapy. Analysis of cell-free DNA (cfDNA), circulating tumor cells (CTC) and/or micro RNAs (miRNAs) could provide useful information for the early diagnosis of CRC, the identification of minimal residual disease and, the evaluation of the risk of recurrence in early CRC patients. Even the selection of patients suitable for the new targeted therapy is becoming possible with the use of predictive miRNA biomarkers. Finally, the development of treatment resistance with the emergence of chemo-resistance clones after treatment remains the most important challenge in the clinical practice. In this context it is crucial to identify potential biomarkers and therapeutic targets which could lead to development of new and more effective treatments.

Computational analysis of mRNA expression profiles identifies a novel triple-biomarker model as prognostic predictor of stage II and III colorectal adenocarcinoma patients

Introduction

Although remarkable progress has been made to determine the prognosis of patients with colorectal cancer (CRC), it is inadequate to identify the subset of high-risk TNM stage II and stage III patients that have a high potential of developing tumor recurrence and may experience death. In this study, we aimed to develop biomarkers as a prognostic signature for the clinical outcome of CRC patients with stage II and stage III.

Materials and methods

We performed a systematic and comprehensive discovery step to identify recurrence-associated genes in CRC patients through publicly available GSE41258 (n=253) and GSE17536 (n=107) datasets. We subsequently determined the prognostic relevance of candidate genes in stage II and III patients and developed a triple-biomarker for predicting RFS in GSE17536, which was later validated in an independent cohort GSE33113 dataset (n=90).

Results

Based upon mRNA expression profiling studies, we identified 45 genes which differentially expressed in recurrent vs non-recurrent CRC patients. By using Cox proportional hazard models, we then developed a triple-marker model (THBS2, SERPINE1, and FN1) to predict prognosis in GSE17536, which successfully identified poor prognosis in stage II and stage III, particularly high-risk stage II CRC patients.

Discussion

Notably, we found that our triple-marker model once again predicted recurrence in stage II patients in GSE33113. Kaplan-Meier survival analysis demonstrated that patients with high scores have a poor outcome compared to those with low scores. Our triple-marker model is a reliable predictive tool for determining prognosis in CRC patients with stage II and stage III, and might be able to identify high-risk patients that are candidates for more targeted personalized clinical management and surveillance.

Assessment of dose-response relationship of 5-fluorouracil to murine intestinal injury

5-Fluorouracil (5-FU) is the most frequently prescribed anti-tumor drug, but has been reported to result in intestinal injury. Although some progress has been made in understanding the intestinal toxicity of 5-FU, confusion remains about animal models of 5-FU-induced intestinal injury, especially the dosage of 5-FU. This study aims to assess the dose-response relationship between the severity of intestinal injury and different doses of 5-FU, and to determine a proper dosing for the murine model. We found that mice in the 5-FU groups gradually lost body weight over time. Increasing doses of 5-FU resulted in more severe diarrhea, with a concomitant increase in mortality. Histopathological damage was more severe in mice that received higher doses of 5-FU. In addition, plasma diamine oxidase (DAO) activity decreased in experimental mice with intestinal injury in a dose-dependent way. TUNEL and western blot analysis showed cell apoptosis in the ileum and colon related to 5-FU dosage. However, administration of 200 and 400 mg/kg 5-FU caused extremely high mortality, severe diarrhea and histopathological damage, but 25 mg/kg 5-FU did not result in significant intestinal injury. The severity of intestinal injury induced by 5-FU appeared to be dose-dependent and we concluded that the proper dosage of 5-FU to induce a murine model with intestinal mucositis ranged from 50 mg/kg to 100 mg/kg.

Transcriptional signatures for coupled predictions of stage II and III colorectal cancer metastasis and fluorouracil-based adjuvant chemotherapy benefit

The current study suggests that the identification of predictive signatures of fluorouracil (5-FU) response for stage II and III colorectal cancer (CRC) could be confounded by chemotherapy-irrelevant low relapse risk. Using the samples of patients with stage II and III CRC who were treated with curative surgery only, we identified a signature with which to predict chemotherapy-irrelevant relapse risk for patients after curative surgery. By applying this signature to the samples of patients with stage II and III CRC who were treated with 5-FU-based adjuvant chemotherapy (ACT) after surgery, we predicted the relapse risk if treated with surgery only. From high-risk samples, we further identified another signature with which to predict therapeutic benefit from 5-FU-based ACT. On the basis of the relative expression orderings of gene pairs, a postsurgery relapse risk signature that consisted of 44 gene pairs was developed and verified in 3 independent data sets. A 5-FU therapeutic benefit signature that consisted of 4 gene pairs was then developed to predict the response of 5-FU-based ACT for those patients with high relapse risk after curative surgery. The signature was verified in 4 independent datasets. For patients with stage II and III CRC, the coupled signatures can first identify patients with high relapse risk after curative surgery, then predict therapeutic benefit from 5-FU-based ACT.-Song, K., Guo, Y., Wang, X., Cai, H., Zheng, W., Li, N., Song, X., Ao, L., Guo, Z., Zhao, W. Transcriptional signatures for coupled predictions of stage II and III colorectal cancer metastasis and fluorouracil-based adjuvant chemotherapy benefit.

Survival and time interval from surgery to the start of chemotherapy for patients with stage II and III colon cancer

Background.

Usually adjuvant chemotherapy is started within 12 weeks of surgery, but the evidence on the commencing time is lacking. Our aim was to investigate the association of initiating post-surgery treatment within six weeks vs. six to ten weeks vs. more than ten weeks with survival.

Methods.

We analysed the association of treatment and its timing with survival among patients who were diagnosed and underwent surgery for stage II or III colon cancer from 2012 to 2013 at the National Cancer Institute, Lithuania.

Results.

Of the 86 patients, 78% were still alive on December 31, 2013. Patients who received chemotherapy within six weeks after surgery were more likely to survive. However, those who received chemotherapy 6–10 weeks after surgery had better survival (p – 0.014, hazard ratio 0.80, 95% CI 0.60–0.99) than those who began chemotherapy treatment more than ten weeks after surgery (p – 0.173 hazard ratio 0.55, 95% CI 0.12–0.99).

Conclusions.

The results from this study show that optimal timing of adjuvant chemotherapy for patients with resected colon cancer within six weeks and associated with better survival.

Improved anti-tumor efficacy via combination of oxaliplatin and fibrin glue in colorectal cancer

Colorectal cancer is very common worldwide and advanced colorectal cancer exhibited very poor clinical outcome. Oxaliplatin (OXP) is one of the principal chemotherapeutic agents in colorectal cancer treatment presenting impressive anti-tumor ability, limited by adverse effect in clinical practice. Fibrin glue (FG) is a biocompatible formulation made of fibrinogen and thrombin, extensively used in surgery for hemostasis, tissue adhesion and sealing. In this study, FG was innovatively applied as OXP delivery system and results showed enhanced anti-tumor performance in subcutaneous model and abdominal metastasis model of murine colorectal cancer compared with that of OXP used alone. It is revealed that combination of OXP and FG could increase activated CD8⁺ T cells, reduce regulatory T (Treg) cells and increase interferon-γ (IFN-γ). Furthermore, results showed promoted tumor apoptosis, decreased proliferation and inhibited tumor angiogenesis by OXP and FG combination. No obvious systemic toxicity was observed in this study. Finally, our findings provided basis for promising application of OXP and FG combination in colorectal cancer treatment.

MicroRNAs in the etiology of colorectal cancer: pathways and clinical implications

MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present in the human genome, ∼250 miRNAs are reported to have changes in abundance or altered functions in colorectal cancer. Thousands of studies have documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their frequent participation in feedback loops, which probably serve to reinforce or magnify biological outcomes to manifest a particular cellular phenotype. Here, we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs (anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability in patient-derived samples and ease of detection with standard and novel techniques, we also discuss the potential use of miRNAs as biomarkers in the diagnosis of colorectal cancer and as prognostic indicators of this disease. MiRNAs also represent attractive candidates for targeted therapies because their function can be manipulated through the use of synthetic antagonists and miRNA mimics.

Summary: This Review provides an overview of some important microRNAs and their roles in colorectal cancer.

Mitochondrial protein 18 (MTP18) plays a pro-apoptotic role in chemotherapy-induced gastric cancer cell apoptosis

One of the severe limitations of chemotherapy is the development of drug resistance. However, the mechanisms underlying chemotherapy resistance remain to be elucidated. Mitochondrial mediated apoptosis is a form of cell death induced by chemotherapy. Several chemotherapeutic agents have been shown to induce mitochondrial fission, and finally activate the apoptosis cascade in various cancer cells. Here, we report that the mitochondrial membrane protein 18 (MTP18) induced mitochondrial fragmentation in gastric cancer cells under doxorubicin (DOX) exposure. Upon over-expression of MTP18, a sub-cytotoxic dose of DOX could sensitize a significant number of cells to undergo mitochondrial fission and subsequent apoptosis. These findings suggest that MTP18 can enhance the sensitivity of gastric cancer cells to DOX. Mechanistically, we found that MTP18 enriched dynamic-related protein 1 (DRP1) accumulation in mitochondria and it was responsible for mediating DOX-induced signaling required for mitochondrial fission. Intriguingly, MTP18 expression was downregulated during DOX treatment. Thus, down-regulation of MTP18 expression could be one of the resistance factors interfering with DOX-induced apoptosis in gastric cancer cells.

Inhibition of GOT1 sensitizes colorectal cancer cells to 5-fluorouracil

PURPOSE

Almost all colorectal cancer (CRC) cell lines are known to overexpress aspartate aminotransferase (GOT1), which potentially regulates the intracellular levels of reactive oxygen species (ROS) via the production of NADPH, and supports tumor growth. In our study, the role of GOT1 in the anticancer efficacy of 5-fluorouracil (5-FU) was examined.

METHODS

HCT116, SW480, and HT-29 cells were transfected with lentiviral vectors expressing short hairpin RNA (shRNA) against GOT1. Following 5-FU treatment, cellular proliferation was evaluated, the NADP⁺/NADPH ratio was monitored, ROS was measured, and intracellular levels of glutamine (Gln), Aspartate (Asp), oxaloacetate (OAA), malate, and pyruvate were investigated using liquid chromatography-mass spectrometry (LC-MS). A CRC subcutaneous tumor model was performed to determine the impact of GOT1 inhibition on 5-FU efficacy in vivo.

RESULTS

In response to 5-FU administration, CRC cells undergo metabolic adaptation, resulting in increased glutamine flux for the synthesis of aspartate. GOT1 is responsible for the conversion of glutamine-derived aspartate into OAA, which subsequently can be converted into malate and pyruvate. The GOT1-mediated metabolic process is able to maintain the NADP⁺/NADPH ratio, which counteracts 5-FU-induced oxidative stress. Inhibition of GOT1 impaired the defense against 5-FU-induced ROS, thereby sensitizing cells to 5-FU. The importance of GOT1 in supporting tumor growth during 5-FU treatment was also indicated in an in vivo tumor model of CRC.

CONCLUSION

These findings show that GOT1 could serve as a promising target for increasing the anticancer efficacy of the conventional therapy in patients with CRC.

Epigenomics alternations and dynamic transcriptional changes in responses to 5-fluorouracil stimulation reveal mechanisms of acquired drug resistance of colorectal cancer cells

A drug-induced resistant cancer cell is different from its parent cell in transcriptional response to drug treatment. The distinct transcriptional response pattern of a drug-induced resistant cancer cell to drug treatment might be introduced by acquired DNA methylation aberration in the cell exposing to sustained drug stimulation. In this study, we performed both transcriptional and DNA methylation profiles of the HCT-8 wild-type cells (HCT-8/WT) for human colorectal cancer (CRC) and the 5-fluorouracil (5-FU)-induced resistant cells (HCT-8/5-FU) after treatment with 5-FU for 0, 24 and 48 h. Integrated analysis of transcriptional and DNA methylation profiles showed that genes with promoter hypermethylation and concordant expression silencing in the HCT-8/5-FU cells are mainly involved in pathways of pyrimidine metabolism and drug metabolism-cytochrome P450. Transcriptional analysis confirmed that genes with transcriptional differences between a drug-induced resistant cell and its parent cell after drug treatment for a certain time, rather than their primary transcriptional differences, are more likely to be involved in drug resistance. Specifically, transcriptional differences between the drug-induced resistant cells and parental cells after drug treatment for 24 h were significantly consistent with the differentially expressed genes (termed as CRG_5-FU) between the tissues of nonresponders and responders of CRCs to 5-FU-based therapy and the consistence increased after drug treatment for 48 h (binomial test, P-value=1.88E−06). This study reveals a major epigenetic mechanism inducing the HCT-8/WT cells to acquire resistance to 5-FU and suggests an appropriate time interval (24–48 h) of 5-FU exposure for identifying clinically relevant drug resistance signatures from drug-induced resistant cell models.

Histone H3K27 Trimethylation Modulates 5-Fluorouracil Resistance by Inhibiting PU.1 Binding to the DPYD Promoter

The antimetabolite 5-fluorouracil (5-FU) is one of the most widely used chemotherapy drugs. Dihydropyrimidine dehydrogenase (DPD) is a major determinant of 5-FU response and toxicity. Although DPYD variants may affect 5-FU metabolism, they do not completely explain the reported variability in DPD function or the resultant differences in treatment response. Here, we report that H3K27 trimethylation (H3K27me3) at the DPYD promoter regulated by Ezh2 and UTX suppresses DPYD expression by inhibiting transcription factor PU.1 binding, leading to increased resistance to 5-FU. Enrichment of H3K27me3 at the DPYD promoter was negatively correlated with both DPYD expression and DPD enzyme activity in peripheral blood specimens from healthy volunteers. Lastly, tumor expression data suggest that DPYD repression by Ezh2 predicts poor survival in 5-FU-treated cancers. Collectively, the findings of the present article suggest that a previously uncharacterized mechanism regulates DPD expression and may contribute to tumor resistance to 5-FU. Cancer Res; 76(21); 6362-73. ©2016 AACR.

Multi-omics landscapes of colorectal cancer subtypes discriminated by an individualized prognostic signature for 5-fluorouracil-based chemotherapy

Until recently, few prognostic signatures for colorectal cancer (CRC) patients receiving 5-fluorouracil (5-FU)-based chemotherapy could be used in clinical practice. Here, using transcriptional profiles for a panel of cancer cell lines and three cohorts of CRC patients, we developed a prognostic signature based on within-sample relative expression orderings (REOs) of six gene pairs for stage II-III CRC patients receiving 5-FU-based chemotherapy. This REO-based signature had the unique advantage of being insensitive to experimental batch effects and free of the impractical data normalization requirement. After stratifying 184 CRC samples with multi-omics data from The Cancer Genome Atlas into two prognostic groups using the REO-based signature, we further revealed that patients with high recurrence risk were characterized by frequent gene copy number aberrations reducing 5-FU efficacy and DNA methylation aberrations inducing distinct transcriptional alternations to confer 5-FU resistance. In contrast, patients with low recurrence risk exhibited deficient mismatch repair and carried frequent gene mutations suppressing cell adhesion. These results reveal the multi-omics landscapes determining prognoses of stage II-III CRC patients receiving 5-FU-based chemotherapy.

Methylation status at HYAL2 predicts overall and progression-free survival of colon cancer patients under 5-FU chemotherapy

DNA methylation variations in gene promoter regions are well documented tumor-specific alterations in human malignancies including colon cancer, which may influence tumor behavior and clinical outcome. As a subset of colon cancer patients does not benefit from adjuvant chemotherapy, predictive biomarkers are desirable. Here, we describe that DNA methylation levels at CpG loci of hyaluronoglucosaminidase 2 (HYLA2) could be used to identify stage II and III colon cancer patients who are most likely to benefit from 5-flourouracil (5-FU) chemotherapy with respect to overall survival and progression-free survival.

Sentinel lymph node biopsy and nodal ultrastaging in colorectal cancer

The tumor status of the regional lymph nodes is the most important prognostic indicator in colorectal cancer (CRC), as it is in other solid tumors. Sentinel lymph node biopsy (SLNB), which has profoundly impacted the treatment of melanoma and breast cancer, has been applied in CRC in an attempt to improve nodal staging accuracy. The challenge lies in identifying patients who have tumor-negative nodes but are at high risk of regional or distant failure and therefore may benefit from adjuvant chemotherapy. Because standard pathological analysis of lymph nodes may incorrectly stage colon cancer, multiple studies have investigated nodal ultrastaging based on identification and immunohistochemical and/or molecular assessment of the sentinel node. This review focuses on the technique of SNLB, its feasibility and validity, and the controversies that remain regarding the clinical significance of nodal ultrastaging in CRC.

Improved survival with early adjuvant chemotherapy after colonic resection for stage III colonic cancer: A nationwide study

BACKGROUND AND OBJECTIVES

In stage III colonic cancer, time from surgery to start of adjuvant chemotherapy may influence survival. In this study, we evaluated the effect of timing of adjuvant therapy on survival.

METHODS

Database study from the Danish Colorectal Cancer Group's national database. Data on patients with stage III colonic cancer operated between January 1, 2005 and August 31, 2012 were retrieved. Perioperative variables, surgical modality, and time to adjuvant therapy (<4, 4-8, or >8 weeks) were evaluated and Cox regression was performed to identify factors influencing survival.

RESULTS

The final population included 1,827 patients scheduled for adjuvant chemotherapy. Adjuvant therapy started within 4 and 8 weeks improved survival when compared to start later than 8 weeks (HR [95%CI]: 1.7 [1.1-2.6]; P = 0.024 and 1.4 [1.07-1.8]; P = 0.013, respectively), whereas there was no significant difference in survival with start after 4 versus 8 weeks (1.2 [0.8-1.8]; P = 0.37).

CONCLUSIONS

Survival increased when adjuvant therapy was started within 8 weeks after surgery for stage III colonic cancer.

Rectal and colon cancer: Not just a different anatomic site

Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.

Efficacy of Adjuvant 5-Fluorouracil Therapy for Patients with EMAST-Positive Stage II/III Colorectal Cancer

Elevated Microsatellite Alterations at Selected Tetranucleotide repeats (EMAST) is a genetic signature found in up to 60% of colorectal cancers (CRCs) that is caused by somatic dysfunction of the DNA mismatch repair (MMR) protein hMSH3. We have previously shown in vitro that recognition of 5-fluorouracil (5-FU) within DNA and subsequent cytotoxicity was most effective when both hMutSα (hMSH2-hMSH6 heterodimer) and hMutSβ (hMSH2-hMSH3 heterodimer) MMR complexes were present, compared to hMutSα > hMutSβ alone. We tested if patients with EMAST CRCs (hMutSβ defective) had diminished response to adjuvant 5-FU chemotherapy, paralleling in vitro findings. We analyzed 230 patients with stage II/III sporadic colorectal cancers for which we had 5-FU treatment and survival data. Archival DNA was analyzed for EMAST (>2 of 5 markers mutated among UT5037, D8S321, D9S242, D20S82, D20S85 tetranucleotide loci). Kaplan-Meier survival curves were generated and multivariate analysis was used to determine contribution to risk. We identified 102 (44%) EMAST cancers. Ninety-four patients (41%) received adjuvant 5-FU chemotherapy, and median follow-up for all patients was 51 months. Patients with EMAST CRCs demonstrated improved survival with adjuvant 5FU to the same extent as patients with non-EMAST CRCs (P<0.05). We observed no difference in survival between patients with stage II/III EMAST and non-EMAST cancers (P = 0.36). There is improved survival for stage II/III CRC patients after adjuvant 5-FU-based chemotherapy regardless of EMAST status. The loss of contribution of hMSH3 for 5-FU cytotoxicity may not adversely affect patient outcome, contrasting patients whose tumors completely lack DNA MMR function (MSI-H).

Prognostic Effect of Ultra-Staging Node-Negative Colon Cancer Without Adjuvant Chemotherapy: A Prospective National Cancer Institute-Sponsored Clinical Trial

BACKGROUND

We recently reported, in a prospective randomized trial, that ultra-staging of patients with colon cancer is associated with significantly improved disease-free survival (DFS) compared with conventional staging. That trial did not control for lymph node (LN) number or adjuvant chemotherapy use.

STUDY DESIGN

The current international prospective multicenter cooperative group trial (ClinicalTrials.gov identifier NCT00949312; "Ultra-staging in Early Colon Cancer") evaluates the 12-LN quality measure and nodal ultra-staging impact on DFS in patients not receiving adjuvant chemotherapy. Eligibility criteria included biopsy-proven colon adenocarcinoma; absence of metastatic disease; >12 LNs staged pathologically; pan-cytokeratin immunohistochemistry (IHC) of hematoxylin and eosin (H&E)-negative LNs; and no adjuvant chemotherapy.

RESULTS

Of 445 patients screened, 203 patients were eligible. The majority of patients had intermediate grade (57.7%) and T3 tumors (64.9%). At a mean follow-up of 36.8 ± 22.1 months (range 0 to 97 months), 94.3% remain disease free. Recurrence was least likely in patients with ≥12 LNs, H&E-negative LNs, and IHC-negative LNs (pN0i-): 2.6% vs 16.7% in the pN0i+ group (p < 0.0001).

CONCLUSIONS

This is the first prospective report to demonstrate that patients with optimally staged node-negative colon cancer (≥12 LNs, pN0i-) are unlikely to benefit from adjuvant chemotherapy; 97% remain disease free after primary tumor resection. Both surgical and pathologic quality measures are imperative in planning clinical trials in nonmetastatic colon cancer.

Randomized phase III clinical trial comparing the combination of capecitabine and oxaliplatin (CAPOX) with the combination of 5-fluorouracil, leucovorin and oxaliplatin (modified FOLFOX6) as adjuvant therapy in patients with operated high-risk stage II or stage III colorectal cancer

BACKGROUND

The aim of the trial was to compare two active adjuvant chemotherapy regimens in patients with early stage colorectal cancer (CRC).

METHODS

Patients were assigned to oxaliplatin, leucovorin and 5-FU for 12 cycles (group A, FOLFOX6) or oxaliplatin and capecitabine for eight cycles (group B, CAPOX). Primary endpoint was disease-free survival (DFS). Tumors were classified as mismatch repair proficient (pMMR) or deficient (dMMR) according to MLH1, PMS2, MSH2 and MSH6 protein expression. KRAS exon two and BRAF V600E mutational status were also assessed.

RESULTS

Between 2005 and 2008, 441 patients were enrolled, with 408 patients being eligible. After a median follow-up of 74.7 months, 3-year DFS was 79.8 % (95 % CI 76.5-83.4) in the FOLFOX group and 79.5 % (95 % CI 75.9-83.1) in the CAPOX group (p = 0.78). Three-year OS was 87.2 % (95 % CI 84.1-91.1) in the FOLFOX and 86.9 % (95 % CI 83.4-89.9) in the CAPOX group (p = 0.84). Among 306 available tumors, 11.0 % were dMMR, 34.0 % KRAS mutant and 4.9 % BRAF mutant. Multivariate analysis showed that primary site in the left colon, earlier TNM stage and the presence of anemia at diagnosis were associated with better DFS and overall survival (OS), while grade one-two tumors were associated with better OS. Finally, a statistically significant interaction was detected between the primary site and MMR status (p = 0.010), while KRAS mutated tumors were associated with shorter DFS. However, the sample was too small for safe conclusions.

CONCLUSIONS

No significant differences were observed in the efficacy of FOLFOX versus CAPOX as adjuvant treatment in high-risk stage II or stage III CRC patients, but definitive conclusions cannot be drawn because of the small sample size.

TRIAL REGISTRATION

ANZCTR 12610000509066 . Date of Registration: June 21, 2010.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/-) and wild-type (APOE+/+) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/- -challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

Virgin olive oil phenolics extract inhibit invasion of HT115 human colon cancer cells in vitro and in vivo

The decreased cancer risk associated with consumption of olive oil may be due to the presence of phenolics which can modulate pathways including apoptosis and invasion that are relevant to carcinogenesis. We have previously shown that a virgin olive oil phenolics extract (OVP) inhibited invasion of HT115 colon cancer cells in vitro. In the current study we assessed the in vitro effects of OVP (25 μg mL(-1)) on HT115 cell migration, spreading and integrin expression. Furthermore, the anti-metastatic activity of OVP - at a dose equivalent to 25 mg per kg per day for 2, 8 or 10 weeks - was assessed in a Severe Combined ImmunoDeficiency (SCID) Balb-c mouse model. After 24 h OVP did not inhibit cell migration but significantly reduced cell spreading on fibronectin (65% of control; p < 0.05) and expression of a range of α and β integrins was modulated. In vivo, OVP by gavage significantly (p < 0.05) decreased not only tumour volume but also the number of metastases in SCID Balb-c mice. Collectively, the data suggest that - possibly through modulation of integrin expression - OVP decreases invasion in vitro and also inhibits metastasis in vivo.

Conditioned media from human macrophages of M1 phenotype attenuate the cytotoxic effect of 5‑fluorouracil on the HT‑29 colon cancer cell line

Resistance of tumor cells to chemotherapy, such as 5-fluorouracil (5-FU), is an obstacle for successful treatment of cancer. As a follow-up of a previous study we have investigated the effect of conditioned media (CM) from macrophages of M1 or M2 phenotypes on 5-FU cytotoxicity on the colon cancer cell lines HT-29 and CACO-2. HT-29 cells, but not CACO-2 cells, having been treated with a combination of M1 CM and 5-FU recovered their cell growth to a much larger extent compared to cells having been treated with 5-FU alone when further cultured for 7 days in fresh media. M1 CM treatment of HT-29, but not CACO-2 cells, induced cell cycle arrest in the G₀/G₁ and G₂/M phases. 5-FU treatment induced accumulation of cells in S-phase in both HT-29 and CACO-2 cells. This accumulation of cells in S-phase was attenuated by combined M1 CM and 5-FU treatment in HT-29 cells, but not in CACO-2 cells. The mRNA expression of cell cycle regulatory proteins and 5-FU metabolic enzymes were analyzed in an attempt to find possible mechanisms for the M1 CM induced attenuation of 5-FU cytotoxicity in HT-29. Thymidylate synthetase (TS) and thymidine phosphorylase (TP) were found to be substantially downregulated and upregulated, respectively, in HT-29 cells treated with M1 CM, making them unlikely as mediators of reduced 5-FU cytotoxicity. Among cell cycle regulating proteins, p21 was induced in HT-29 cells, but not in CACO-2 cells, in response to M1 CM treatment. However, small interfering RNA (siRNA) knockdown of p21 had no effect on the M1 CM induced cell cycle arrest seen in HT-29 and neither did it change the growth recovery after combined treatment of HT-29 cells with M1 CM and 5-FU. In conclusion, treatment of HT-29 cells with M1 CM reduces the cytotoxic effect of 5-FU and this is mediated by a M1 CM induced cell cycle arrest in the G₀/G₁ and G₂/M phases. So far, we lack an explanation why this action is absent in the CACO-2 cells. The current findings may be important for optimization of chemotherapy in colon cancer.

Complete mesocolic resection and extended lymphadenectomy for colon cancer: a systematic review

AIM

Complete mesocolic excision (CME) and extended lympha-denectomy (EL) have been proposed as safe procedures for improving colon cancer survival outcomes. The aim of this study was to evaluate the evidence regarding oncological outcomes, morbidity and mortality after such techniques for colon cancer.

METHOD

A systematic review of the literature was conducted to evaluate evidence regarding oncological outcomes, morbidity and mortality after CME or EL. Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The review included original articles reporting outcomes after CME or EL from January 1950 to July 2012.

RESULTS

Twenty-one, predominately retrospective, studies involving 5246 patients (mean age 68.2 years, 56.5% men) were included. Reporting of outcomes was inconsistent. Median follow up was 60 months. The operative mortality rate was 3.2% and the cumulative morbidity rate was 21.5%. The weighted mean local recurrence rate and the 5-year overall and disease-free survival rates were 4.5%, 58.1% and 77.4%, respectively.

CONCLUSION

The available data for CME and EL have numerous fundamental limitations that prohibit adoption. Contemporary controlled studies are required before universal recommendation.

Oncological superiority of extralevator abdominoperineal resection over conventional abdominoperineal resection: a meta-analysis

PURPOSE

The oncological superiority, i.e., lower circumferential resection margin (CRM) involvement, lower intraoperative perforation (IOP), and local recurrence (LR) rates, of extralevator abdominoperineal resection (EAPR) over conventional abdominoperineal resection (APR) for rectal cancer is inconclusive. This meta-analysis systematically compared the rates of CRM involvement, IOP, and LR of rectal cancer patients treated by EAPR and APR, respectively.

METHODS

An electronic literature search of MEDLINE, EMBASE, and Cochrane Library through May 2013 was performed by two investigators independently to identify studies evaluating the CRM involvement, IOP, and LR rates of EAPR and APR, and search results were cross-checked to reach a consensus. Data was extracted accordingly. A Mantel-Haenszel random effects model was used to calculate the odds ratio (OR) with 95 % confidence intervals (95 % CI).

RESULTS

Six studies with a total of 881 patients were included. Meta-analysis of CRM involvement and IOP data from all six studies demonstrated significant lower CRM involvement (OR, 0.36; 95%CI, 0.23-0.58; P < 0.0001) and IOP (OR, 0.31; 95%CI, 0.12-0.80; P = 0.02) rates of EAPR. Data from four studies also showed that EAPR was associated with a lower LR rate than APR (OR, 0.27; 95%CI, 0.08-0.95; P = 0.04). No differences of between-study heterogeneity or publication bias were seen in any of the meta-analyses.

CONCLUSIONS

Extralevator abdominoperineal resection could achieve better CRM involvement outcome and lower IOP and LR rates, demonstrating an oncological superiority over conventional abdominoperineal resection.

Chemotherapy and targeted therapy for patients with initially unresectable colorectal liver metastases, focusing on conversion hepatectomy and long-term survival

BACKGROUND

Eight years have passed since the introduction of chemotherapy (chemo) and targeted therapy regimens for colorectal liver metastases (CRLM). This study aimed to clarify the effectiveness of chemo and targeted therapy in facilitating conversion hepatectomy and improving long-term survival in Japanese patients with CRLM.

METHODS

A total of 199 patients with CRLM were treated between May 2005 and August 2012. Initial therapies for these patients included straightforward hepatic resection (n = 48; 24 %), induction chemotherapy (n = 148; 74 %), and radiofrequency ablation (n = 3; 2 %).

RESULTS

In 56 of 137 patients (40.1 %) with initially unresectable CRLM, 7.5 courses of chemo and targeted therapy downsized and converted tumors to resectable tumors. The 5-year cumulative overall survival (OS) rate and the median survival time were significantly higher for the resectable CRLM than for the unresectable CRLM (54.6 vs. 5.3 % and 77.3 vs. 21.3 months, respectively; P < .0001). Multivariate analysis revealed that conversion hepatectomy (hazard ratio [HR] 0.19; P < .001) and responder to chemo and targeted therapy (HR 0.46; P < .01) were independent prognostic factors for OS. Multivariate analysis also revealed that left-sided colon or rectal cancer (odds ratio [OR] 8.4; P < .05), H1/H2 metastases (OR 7.3; P < .05), no extrahepatic metastases (OR 52.6; P < .001), and responder to chemo and targeted therapy (OR 6.1; P < .05) were significant predictors of conversion hepatectomy.

CONCLUSIONS

A chemo and targeted therapy can facilitate conversion hepatectomy and allow for an excellent prognosis in patients with initially unresectable CRLM.

Differences in colon and rectal cancer chemosensitivity

SUMMARY Adjuvant chemotherapy of rectal cancer is not well established. The aim of this review was to compare results of adjuvant treatment of colon and rectal cancer to identify possible clues for the differences in chemosensitivity. Adjuvant chemotherapy of 5-fluorouracil with folinic acid increased survival in colon cancer, but not in rectal cancer. A similar trend is seen for the addition of oxaliplatin. Using identical adjuvant treatment in colon and rectal cancer revealed a similar frequency of liver metastases, but a significant difference in the occurrence of lung (7.3 vs 12.7%) and peritoneal metastases (8.9 vs 4.0%). We hypothesize that the observed difference may be due to the influence of the microenvironment and differences in the expression of resistance genes such as the gene coding for thymidylate synthase. In conclusion, the differing effectiveness of adjuvant treatment of rectal and colon cancer may at least in part be caused by differing patterns of metastases associated with differing chemosensitivity.

Secular trends in colon and rectal cancer relative survival

BACKGROUND

Treatment options for colorectal cancer (CRC) have improved substantially over the past 25 years. Measuring the impact of these improvements on survival outcomes is challenging, however, against the background of overall survival gains from advancements in the prevention, screening, and treatment of other conditions. Relative survival is a metric that accounts for these concurrent changes, allowing assessment of changes in CRC survival. We describe stage- and location-specific trends in relative survival after CRC diagnosis.

METHODS

We analyzed survival outcomes for 233965 people in the Surveillance Epidemiology and End Results (SEER) program who were diagnosed with CRC between January 1, 1975, and December 31, 2003. All models were adjusted for sex, race (black vs white), age at diagnosis, time since diagnosis, and diagnosis year. We estimated the proportional difference in survival for CRC patients compared with overall survival for age-, sex-, race-, and period-matched controls to account for concurrent changes in overall survival using two-sided Wald tests.

RESULTS

We found statistically significant reductions in excess hazard of mortality from CRC in 2003 relative to 1975, with excess hazard ratios ranging from 0.75 (stage IV colon cancer; P < .001) to 0.32 (stage I rectal cancer; P < .001), indicating improvements in relative survival for all stages and cancer locations. These improvements occurred in earlier years for patients diagnosed with stage I cancers, with smaller but continuing improvements for later-stage cancers.

CONCLUSIONS

Our results demonstrate a steady trend toward improved relative survival for CRC, indicating that treatment and surveillance improvements have had an impact at the population level.

Short-course radiotherapy followed by neo-adjuvant chemotherapy in locally advanced rectal cancer--the RAPIDO trial

BACKGROUND

Current standard for most of the locally advanced rectal cancers is preoperative chemoradiotherapy, and, variably per institution, postoperative adjuvant chemotherapy. Short-course preoperative radiation with delayed surgery has been shown to induce tumour down-staging in both randomized and observational studies. The concept of neo-adjuvant chemotherapy has been proven successful in gastric cancer, hepatic metastases from colorectal cancer and is currently tested in primary colon cancer.

METHODS AND DESIGN

Patients with rectal cancer with high risk features for local or systemic failure on magnetic resonance imaging are randomized to either a standard arm or an experimental arm. The standard arm consists of chemoradiation (1.8 Gy x 25 or 2 Gy x 25 with capecitabine) preoperatively, followed by selective postoperative adjuvant chemotherapy. Postoperative chemotherapy is optional and may be omitted by participating institutions. The experimental arm includes short-course radiotherapy (5 Gy x 5) followed by full-dose chemotherapy (capecitabine and oxaliplatin) in 6 cycles before surgery. In the experimental arm, no postoperative chemotherapy is prescribed. Surgery is performed according to TME principles in both study arms. The hypothesis is that short-course radiotherapy with neo-adjuvant chemotherapy increases disease-free and overall survival without compromising local control. Primary end-point is disease-free survival at 3 years. Secondary endpoints include overall survival, local control, toxicity profile, and treatment completion rate, rate of pathological complete response and microscopically radical resection, and quality of life.

DISCUSSION

Following the advances in rectal cancer management, increased focus on survival rather than only on local control is now justified. In an experimental arm, short-course radiotherapy is combined with full-dose chemotherapy preoperatively, an alternative that offers advantages compared to concomitant chemoradiotherapy with or without postoperative chemotherapy. In a multi-centre setting this regimen is compared to current standard with the aim of improving survival for patients with locally advanced rectal cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01558921.

Adrenal incidentalomas in cancer patients are not always "innocent": a case report and review of the literature

Herein, we report an unusual case of a 78-year-old woman with synchronous presentation of sigmoid cancer and a nonfunctioning primary adrenal cortex carcinoma, who developed superior vena cava syndrome due to metastatic lymphadenopathy from the latter malignancy. Our case suggests that adrenal incidentalomas during initial staging evaluation after cancer diagnosis are not always “innocent” and should not be “a priori” considered incidental findings attributed to hyperplasia, adenoma or even a non life-threatening metastasis from the primary tumor. It also emphasizes the importance of a continuous assessment of patients with synchronous primary malignancies, in order to timely evaluate changes in clinical or biological behavior and administrate the appropriate treatment.

What is the optimal means of staging colon cancer?

Although staging for colon cancer has become more complex over time, it is not clear that this complexity has improved prognostic assessment. Even with revisions in the 7th edition of the AJCC staging system, a clear rank order of prognosis from substage to substage has not been established. Improved staging models will need to be developed, and attempts at further identifying those high-risk patients within each stage may be clinically useful. Through improved quality measures with lymph node yield, advances in colon cancer staging accuracy have been made over the last decade. Determining how to incorporate ultrastaging and molecular techniques will be the challenge for future staging models.

Evaluation of survival benefits by platinums and taxanes for an unfavourable subset of carcinoma of unknown primary: a systematic review and meta-analysis

Background:

Although chemotherapeutic regimens containing a taxane or platinum agent have been widely recommended for unfavourable carcinoma of unknown primary (CUP), no evidence exists for the superiority of any administered regimens. To date, the efficacy has been mostly assessed in the limited setting of phase II trials, and few attempts have been made to synthesise all available data for survival outcomes.

Methods:

Electronic databases were searched from 1980 to 2011. Survival results were combined for each pre-specified category of regimens using a random-effects model, and meta-regression models were used to adjust for heterogeneity in some known prognostic factors.

Results:

A total of 32 studies were included for meta-analysis. Tendency towards better survival outcome by platinums or taxanes was indicated. After adjustment for important prognostic factors, however, the difference between the platinum-based and non-platinum regimens became no longer significant. Survival benefits by the taxane-based regimens remained significant, with a prolonged median survival time of 1.52 months (P=0.03) and a higher 1-year survival rate of 6.25% (P=0.05), but the benefit did not sustain for 2 years.

Conclusion:

Although no effective therapies have been established, this meta-analysis helps to fill an important gap of evidence. However, caution should still be taken because of the potential unmeasured confounding.

Angiogenesis-related microRNAs in colon cancer

INTRODUCTION

Angiogenesis, for its fundamental role in cancer growth and metastasis, has become an appealing target in cancer therapy. A number of angiogenesis-related microRNAs (miRNAs) are under investigation and they can affect the cancerous phenotype of malignant cells.

AREAS COVERED

The authors review the recent advances in angiogenesis-related miRNAs in human colon cancer. They also envisage future developments toward potential miRNA-based applications to cancer treatment.

EXPERT OPINION

Angiogenesis-related miRNAs may reasonably be considered as a valuable cancer therapeutic tool. More investigations should be performed to promote therapeutic-clinical research of miRNAs in patients with colon cancer.

Polymer nanoparticulate drug delivery and combination cancer therapy

This review describes the scientific background, current achievement and future perspective of combination therapy using polymer nanoparticle drug carriers in cancer treatment. Nanotechnology-based drug delivery is expected to dramatically change combination cancer therapy by controlling accumulation and distribution patterns of multiple drugs selectively in disease sites. Rationally designed polymer materials can produce functional nanoparticulate drug carriers that can be used in various biomedical applications. In comparison with conventional drug combination approaches, using polymer nanoparticle drug carriers appears to suppress tumor growth more efficiently, potentially overcoming multidrug resistance in many cancers. It also provides versatile combination options for a variety of therapeutic agents, molecular targeting agents and nucleotide drugs.

Estimated mean sojourn time associated with hemoccult SENSA for detection of proximal and distal colorectal cancer

BACKGROUND

Sojourn time is the length of the preclinical screen-detectable phase, a period when a test can detect asymptomatic disease. Mean sojourn time (MST) is an important factor in determining appropriate screening intervals. Available estimates of MST for colorectal cancer (CRC) are imprecise and are associated with the older Hemoccult II test. This article presents MST estimates associated with the newer Hemoccult SENSA test and describes differences in MST by the location of cancer in the colorectum and age at the time of screening.

METHODS

MST was estimated from a cohort of 42,079 patients who underwent Hemoccult SENSA between January 1, 1997 and December 31, 2010. The precision of MST estimates was improved by incorporating information from a meta-analysis of the sensitivity of Hemoccult SENSA into the analytic model.

RESULTS

Estimated MST for cancers in the proximal and distal colorectum, with 95% credible intervals (CrI) in years, were: 3.86 (1.55-6.91) and 3.35 (2.11-4.93) among 45- to 54-year olds; 3.78 (2.18-5.77) and 2.24 (1.48-3.17) among 55- to 64-year olds; and 2.70 (1.41-4.31) and 2.10 (1.34-3.04) among 65- to 74-year olds.

CONCLUSIONS

MST associated with Hemoccult SENSA was longer for CRC in the proximal versus distal colon. We found no evidence that MST increases with age and some evidence that it may decrease.

IMPACT

These results add new information about the natural history of CRC and information about the performance of Hemoccult SENSA.