A Survey of the Turkish Oncology Group (TOG): Are the Oncologists Trained for Decision Making on Geriatric Cancer Patients?

INTRODUCTION

Most newly diagnosed cancers occur in older adults, and it is important to understand a patient's underlying health status when making treatment decisions. Therefore, clinicians need enhanced competencies and skills to effectively care for this population. However, most clinicians receive minimal to no training in geriatrics. This study aims to evaluate the education and training levels in geriatric oncology among Turkish physicians and to understand the factors influencing oncologists' treatment decisions for geriatric cancer patients.

MATERIALS AND METHODS

A 24-question survey was prepared to obtain the participating physicians' demographic information, as well as to inquire whether they had received training during their medical education and residency on how to approach geriatric patients, in what process(es) they had received the training, whether they were currently treating geriatric patients, what they focused on when evaluating geriatric patients, and what they thought about their training and preparedness for approaching geriatric patients. The questionnaire was sent online to radiation and medical oncologists, and the link was published on the Turkish Society of Radiation Oncology and the Turkish Society of Medical Oncology websites.

RESULTS

Two hundred and three physicians participated in the survey, 131 of whom were women. The median age was 41.66 years (24-69 years). One hundred and fifty-six physicians (76.1%) received specialty education at the university hospital. One hundred and three of them were radiation oncologists, and 80 were medical oncologists. Of the physicians, 19.7% received education in geriatrics before they specialized in oncology, and 6.9% said they were educated after specialization. When determining suitability for radiotherapy, 10.7% of radiation oncologists said that they use geriatric assessment tools. Similarly, 13.8% of medical oncologists claimed that they used geriatric assessment tools in determining suitability for chemotherapy. Of the physicians, 177 (86.3%) thought that geriatric evaluation could independently increase patient survival rate. Furthermore, patient cognitive status, functional status, physiological age, polypharmacy, geriatric specialist recommendations, inpatient services, patient relatives, and similar factors were found to be useful in treatment decisions. Finally, 92.7% of the participants believed that receiving education would have changed their perspectives on treating geriatric patients.

CONCLUSION

Our results provide perspectives on developing knowledge on and skills in geriatric training among oncologists. Learning new approaches is necessary for oncologists who more frequently confront geriatric patients with cancer.

Drug Repurposing and Systems Biology approaches of Enzastaurin can target potential biomarkers and critical pathways in Colorectal Cancer

Colorectal cancer (CRC) is a severe health concern that results from a cocktail of genetic, epigenetic, and environmental abnormalities. Because it is the second most lethal malignancy in the world and the third-most common malignant tumor, but the treatment is unavailable. The goal of the current study was to use bioinformatics and systems biology techniques to determine the pharmacological mechanism underlying putative important genes and linked pathways in early-onset CRC. Computer-aided methods were used to uncover similar biological targets and signaling pathways associated with CRC, along with bioinformatics and network pharmacology techniques to assess the effects of enzastaurin on CRC. The KEGG and gene ontology (GO) pathway analysis revealed several significant pathways including in positive regulation of protein phosphorylation, negative regulation of the apoptotic process, nucleus, nucleoplasm, protein tyrosine kinase activity, PI3K-Akt signaling pathway, pathways in cancer, focal adhesion, HIF-1 signaling pathway, and Rap1 signaling pathway. Later, the hub protein module identified from the protein-protein interactions (PPIs) network, molecular docking and molecular dynamics simulation represented that enzastaurin showed strong binding interaction with two hub proteins including CASP3 (-8.6 kcal/mol), and MCL1 (-8.6 kcal/mol), which were strongly implicated in CRC management than other the five hub proteins. Moreover, the pharmacokinetic features of enzastaurin revealed that it is an effective therapeutic agent with minimal adverse effects. Enzastaurin may inhibit the potential biological targets that are thought to be responsible for the advancement of CRC and this study suggests a potential novel therapeutic target for CRC.

Osteonecrosis of the Jaw

Osteonecrosis of the jaw is a condition in which bone cells die due to various causes. It is classified as drug-induced jaw osteonecrosis, osteoradionecrosis, traumatic, non-traumatic, and spontaneous osteonecrosis. Antiresorptive or antiangiogenic drugs cause drug-induced osteonecrosis. The combination of medications, microbial contamination, and local trauma induces this condition. Osteoradionecrosis is a severe radiation therapy side effect that can affect people with head and neck cancer. It is described as an exposed bone area that does not heal for longer than three months after the end of radiation treatment with the absence of any indications of an original tumor, recurrence, or metastasis. Trauma (tooth extraction), tumor site, radiation dose that the patient receives, the area of the bone which is irradiated, oral hygiene, and other factors are risk factors for the development of osteonecrosis. Less frequently, osteonecrosis can also be induced by non-traumatic and traumatic causes. Non-traumatic osteonecrosis is brought on by infections, acquired and congenital disorders, as well as the impact of chemicals. Traumatic osteonecrosis is brought on by thermal, mechanical, or chemical damage. The treatment of osteonecrosis can be conservative, which aims to be beneficial for the patient's quality of life, and surgical, which involves debridement of the necrotic bone.

Molecular Subclasses of Clear Cell Ovarian Carcinoma and Their Impact on Disease Behavior and Outcomes

PURPOSE

To identify molecular subclasses of clear cell ovarian carcinoma (CCOC) and assess their impact on clinical presentation and outcomes.

EXPERIMENTAL DESIGN

We profiled 421 primary CCOCs that passed quality control using a targeted deep sequencing panel of 163 putative CCOC driver genes and whole transcriptome sequencing of 211 of these tumors. Molecularly defined subgroups were identified and tested for association with clinical characteristics and overall survival.

RESULTS

We detected a putative somatic driver mutation in at least one candidate gene in 95% (401/421) of CCOC tumors including ARID1A (in 49% of tumors), PIK3CA (49%), TERT (20%), and TP53 (16%). Clustering of cancer driver mutations and RNA expression converged upon two distinct subclasses of CCOC. The first was dominated by ARID1A-mutated tumors with enriched expression of canonical CCOC genes and markers of platinum resistance; the second was largely comprised of tumors with TP53 mutations and enriched for the expression of genes involved in extracellular matrix organization and mesenchymal differentiation. Compared with the ARID1A-mutated group, women with TP53-mutated tumors were more likely to have advanced-stage disease, no antecedent history of endometriosis, and poorer survival, driven by their advanced stage at presentation. In women with ARID1A-mutated tumors, there was a trend toward a lower rate of response to first-line platinum-based therapy.

CONCLUSIONS

Our study suggests that CCOC consists of two distinct molecular subclasses with distinct clinical presentation and outcomes, with potential relevance to both traditional and experimental therapy responsiveness. See related commentary by Lheureux, p. 4838.

Osteopontin (OPN/SPP1), a Mediator of Tumor Progression, Is Regulated by the Mesenchymal Transcription Factor Slug/SNAI2 in Colorectal Cancer (CRC)

Simple Summary

Expression of the transcription factor Slug/SNAI2 is associated with the epithelial–mesenchymal transition (EMT) and is correlated with poorer disease-free survival in colorectal cancer (CRC). In order to decipher the basis for the Slug-mediated aggressive phenotype, we conducted RNAseq experiments with a panel of HT-29 CRC cells expressing different levels of Slug, both in vitro and in tumor models. Osteopontin (OPN), a mediator associated with tumor progression in different tumor types, was among the top upregulated genes in both cells and tumors and was the most overexpressed gene coding for a secreted protein. We further show that Slug is a direct regulator of osteopontin via binding to the OPN promoter. Interestingly, Slug expression and osteopontin secretion were correlated in vitro, as well as in tumor models, suggesting that liquid biopsies may be useful in estimating the aggressiveness phenotype of the tumor.

Abstract

In colorectal cancer (CRC), disease-related death is closely linked to tumor aggressiveness and metastasis. Gene expression profiling of patient tumors has suggested that a more mesenchymal phenotype, present in about one-fourth of all patients, is associated with increased aggressiveness. Accordingly, the mesenchymal transcription factor Slug/SNAI2 has been associated with decreased disease-free survival. To decipher the basis for the Slug-mediated phenotype, we conducted RNAseq experiments with a panel of HT-29 CRC cells expressing different levels of Slug, both in vitro and in tumor models. The results show that osteopontin, a secreted pleotropic protein involved in multiple steps of colorectal cancer progression, was highly upregulated by Slug in vitro, as well as in vivo. We further show that Slug is a direct regulator of osteopontin at the promoter level. The levels of secreted osteopontin were correlated with Slug expression, thereby linking the tumor phenotype to a biomarker available by liquid biopsies. The results also suggest that osteopontin neutralization may attenuate at least some of the Slug-mediated functions.

ZDQ-0620, a Novel Phosphatidylinositol 3-Kinase Inhibitor, Inhibits Colorectal Carcinoma Cell Proliferation and Suppresses Angiogenesis by Attenuating PI3K/AKT/mTOR Pathway

The PI3K/AKT pathway plays a central role in human cancers, aberrant activation of this pathway is associated with tumorigenesis, cancer progression and angiogenesis. Based on the importance of the PI3K/AKT pathway in malignancies, we developed a 4-aminoquinazoline derivative, ZDQ-0620, initially envisioned as a novel pan-PI3K inhibitor. This study aimed to evaluate the potential target of ZDQ-0620 and its anticancer effect in human colorectal carcinoma (CRC). PI3K-kinase activity test showed IC50 of ZDQ-0620 against PI3Ka was 0.5 nM; molecular docking, CETSA assay and western blotting was further performed to predict ZDQ-0620 was a PI3K/AKT pathway inhibitor by targeting PI3K. To identify the effect of ZDQ-0620 on CRC cells, Sulforhodamine B (SRB) assay, flow cytometry, and Cell morphology analysis were conducted. The results showed that ZDQ-0620 inhibited the proliferation, migration and invasion of CRC cells, induced apoptosis through G0/G1 cell cycle arrest and mitochondrial pathway. Additionally, ZDQ-0620 inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). In vivo, neovascularization of rat aortic ring and chick chorioallantoic membrane (CAM) induced by VEGF was diminished when treated with ZDQ-0620. These results indicate that ZDQ-0620 induce apoptosis and anti-angiogenesis via inhibits the PI3K/AKT pathway. We suggest that the great potential of ZDQ-0620 as an effective treatment candidate against CRC.

Impact of new cancer therapies on outpatient treatment delivery for colorectal cancer: A population-based study

We investigated the impact of new systemic therapies approved in Canada for colorectal cancer on the frequency, intensity and duration of oncology clinic and infusion visits over five treatment phases from diagnosis (P1, P3) to treatment (P2, P4) of primary and metastatic disease, respectively, and during the last 6 months of life (P5). In total, 15,157 adult patients with newly diagnosed colorectal cancer and referred between 2000 and 2012 to any cancer clinic in British Columbia, Canada, were included. Frequency, intensity and duration of medical oncology clinic visits (CVs), oncology infusions (OIs) and oncology prescriptions (OPs) were measured by treatment phase. Mean, total and adjusted total duration for CVs increased for P1-5. CVs increased in P1-5, and in P1-4 when adjusted by treatment length. Adjusted and unadjusted OIs decreased in P1 coinciding with the introduction of an oral treatment option, but increased in P2-5. Mean OI duration increased in P1-5, while total and adjusted total decreased in P1 and increased in P2-5. OPs increased in P2-4, but were unchanged in P1 and P5. Multi-fold increases in resources and time required per patient were also observed, which have significant implications for demand projections in cancer care planning and delivery. In conclusion, patients required more visits in almost all treatment phases, visits on average took longer and patients were in treatment for longer periods of time.

SNHG 6 promotes the progression of Colon and Rectal adenocarcinoma via miR-101-3p and Wnt/β-catenin signaling pathway

Background

Small nucleolar RNA host gene 6 (SNHG6) regulates diverse biological processes in cancers. Potential function of SNHG6 in human colon and rectal adenocarcinoma (CRC) was evaluated.

Methods

Quantitative real-time polymerase chain reaction, MTT assays, Colony formation assays, Transwell assay, Western Blotting and Luciferase reporter assays were performed to measure the biological functions and potential molecular mechanisms of SNHG6 in CRC.

Results

SNHG6 was over-expressed in CRC, and high expression of s SNHG6 were associated with short survival times. We then identified miR-101-3p as an inhibitory target of SNHG6. Knockdown of SNHG6 significantly decreased miR-101-3p expression. Moreover, silenced SNHG6 obviously inhibited CRC cell growth, weakened cell invasion capacity and blocked the Wnt/β-catenin signaling pathway.

Conclusion

SNHG6 could regulate the progression of CRC via modulating the expression levels of miR-101-3p and the activity of Wnt/β-catenin signaling.

Functional exploration of colorectal cancer genomes using Drosophila

The multigenic nature of human tumours presents a fundamental challenge for cancer drug discovery. Here we use Drosophila to generate 32 multigenic models of colon cancer using patient data from The Cancer Genome Atlas. These models recapitulate key features of human cancer, often as emergent properties of multigenic combinations. Multigenic models such as ras p53 pten apc exhibit emergent resistance to a panel of cancer-relevant drugs. Exploring one drug in detail, we identify a mechanism of resistance for the PI3K pathway inhibitor BEZ235. We use this data to identify a combinatorial therapy that circumvents this resistance through a two-step process of emergent pathway dependence and sensitivity we term ‘induced dependence'. This approach is effective in cultured human tumour cells, xenografts and mouse models of colorectal cancer. These data demonstrate how multigenic animal models that reference cancer genomes can provide an effective approach for developing novel targeted therapies.

Colorectal cancers carry multiple mutations. Here, the authors use Drosophila as a model organism and assess multiple combinations of mutations and their response to various drugs, providing further insight into drug resistance mechanisms.

A potential peptide vector that allows targeted delivery of a desired fusion protein into the human breast cancer cell line MDA-MB-231

Effective control of breast cancer has been primarily hampered by a lack of tumor specificity in treatments. One potential way to improve targeting specificity is to develop novel vectors that specifically bind to and are internalized by tumor cells. Through a phage display library, an 11-L-amino acid peptide, PI (sequence, CASPSGALRSC), was selected. PI was labeled with fluorescein isothiocyanate (FITC) and named PI-FITC. Subsequently, the specific affinity of PI-FITC to MDA-MB-231 human breast cancer cells and other cancer cell lines was observed by confocal microscopy. Our previous study established that PI-FITC also shows affinity to Calu-1 human lung carcinoma cells and major histocompatibility complex class I antigen molecules; therefore, the cytomembrane proteins of the cell lines were analyzed to determine those that were common to the two cell lines and may be associated with transmembrane transduction. To further test the delivery ability of PI to MDA-MB-231 cells, PI-glutathione-S-transferase (GST) was constructed and the internalization of this fusion protein was visualized by immunofluorescence microscopy. The results revealed that PI exhibited specific affinity to MDA-MB-231 cells. Use of membrane transport inhibitors indicated that macropinocytosis and caveolin-mediated endocytosis may be involved in the endocytosis of PI. In addition, 11 membrane proteins common to MDA-MB-231 and Calu-1 may be associated with transmembrane transduction. In summary, PI was able to deliver PI-GST into MDA-MB-231 cells. Thus, PI could be modified to be a potential vector, and may contribute to the development of targeted therapeutic strategies for breast cancer.

The efficacy and safety of panitumumab in the treatment of patients with metastatic colorectal cancer: a meta-analysis from five randomized controlled trials

Background

The efficacy of adding panitumumab to chemotherapy remains controversial in the treatment of metastatic colorectal cancer (mCRC). Thus, we conducted this meta-analysis to assess the efficacy and safety of this combination regimen in patients with mCRC.

Methods

The PubMed, Embase, and Web of Science databases were comprehensively searched. Eligible studies included randomized controlled trials (RCTs) that estimated the efficacy of panitumumab with or without chemotherapy in the treatment of patients with mCRC. Hazard ratio (HR), risk ratio (RR), and 95% confidence intervals (CIs) were calculated, and heterogeneity was tested using I² statistics.

Results

Four studies involving a total of 3,066 patients were included in this meta-analysis. The addition of panitumumab to chemotherapy significantly improved progression-free survival (PFS) (HR =0.84, 95% CI =0.78–0.91, P=0.000) and the objective response rate (ORR) (RR =2.18, 95% CI =1.13–4.22, P=0.021) compared to chemotherapy alone, but no effect was noted on overall survival (OS) (HR =0.97, 95% CI =0.89–1.05, P=0.402). Subgroup analysis based on KRAS gene status revealed that the combined therapy significantly improved PFS (HR =0.71, 95% CI =0.57–0.88, P=0.002) and ORR (RR =2.43, 95% CI =1.21–4.90, P=0.013) in patients with wild-type KRAS tumors. Irinotecan-based chemotherapy plus panitumumab significantly prolonged PFS in patients with mCRC (HR =0.84, 95% CI =0.76–0.94, P=0.002). The combined treatment also increased the incidence of grade 3/4 adverse events.

Conclusion

This meta-analysis indicates that the combination of panitumumab and chemotherapy effectively improved PFS and ORR, but it did not prolong OS. However, as the number of studies in the meta-analysis was limited, more large-scale, better-designed RCTs are needed to assess the combination of panitumumab and chemotherapy.

Nintedanib: examining the development and mechanism of action of a novel triple angiokinase inhibitor

Antiangiogenic agents are effective standard-of-care options in several malignancies, but are generally associated with only modest improvements in survival, as well as leading to additional toxicities. Furthermore, almost all patients develop acquired resistance to therapy, possibly due to the activation of alternative proangiogenic pathways. Here we discuss: the rationale for developing nintedanib, an agent that simultaneously inhibits signaling pathways activated by platelet-derived growth factor, FGF, as well as VEGF; how its distinctive inhibitory and pharmacokinetic profile could underlie promising efficacy and tolerability observed in Phase II trials in patients with relapsed/refractory non-small cell lung cancer, advanced ovarian cancer and metastatic colorectal cancer; the ongoing Phase III program that is assessing nintedanib in these areas of major unmet medical need; and recent progress in the development of biomarkers that may predict response to nintedanib.

Is C-reactive protein useful in prognostication for colorectal cancer? A systematic review

AIM

With the advent of several different therapeutic strategies to manage the different stages of colorectal cancer, it would be beneficial to allow substratification of patients into groups who are most likely to benefit from costly interventions. The purpose of this review is to analyse the evidence from several retrospective studies examining the prognostic significance of C-reactive protein (CRP).

METHOD

A literature search was performed using PubMed, Embase, Cochrane Library, CINAHL and Google Scholar databases to identify studies that analysed CRP and its prognostic significance in all stages of operable colorectal cancer. The primary end-points of interest were overall survival and disease-free survival.

RESULTS

In all, 205 studies were identified by the search. Twelve involving 1705 patients fulfilled the inclusion criteria and were included. Three of the included studies including 305 patients considered Stage IV colorectal cancer and the impact of CRP on survival. Overall survival and disease-free survival were shorter in the presence of an elevated preoperative CRP in local and advanced colorectal cancer.

CONCLUSION

CRP may be useful for prognosis in patients with primary and metastatic colorectal cancer, but currently there is insufficient evidence to justify its routine use. Further well-designed prospective studies are needed to validate its role in substratification of patients for consideration of (neo)adjuvant therapies.

Association of the epithelial-to-mesenchymal transition phenotype with responsiveness to the p21-activated kinase inhibitor, PF-3758309, in colon cancer models

The p21-activated kinase (PAK) family of serine/threonine kinases, which are overexpressed in several cancer types, are critical mediators of cell survival, motility, mitosis, transcription, and translation. In the study presented here, we utilized a panel of colorectal cancer (CRC) cell lines to identify potential biomarkers of sensitivity or resistance that may be used to individualize therapy to the PAK inhibitor PF-03758309. We observed a wide range of proliferative responses in the CRC cell lines exposed to PF-03758309, this response was recapitulated in other phenotypic assays such as anchorage-independent growth, three-dimensional (3D) tumor spheroid formation, and migration. Interestingly, we observed that cells most sensitive to PF-03758309 exhibited up-regulation of genes associated with a mesenchymal phenotype (CALD1, VIM, ZEB1) and cells more resistant had an up-regulation of genes associated with an epithelial phenotype (CLDN2, CDH1, CLDN3, CDH17) allowing us to derive an epithelial-to-mesenchymal transition (EMT) gene signature for this agent. We assessed the functional role of EMT-associated genes in mediating responsiveness to PF-3758309, by targeting known genes and transcriptional regulators of EMT. We observed that suppression of genes associated with the mesenchymal phenotype conferred resistance to PF-3758309, in vitro and in vivo. These results indicate that PAK inhibition is associated with a unique response phenotype in CRC and that further studies should be conducted to facilitate both patient selection and rational combination strategies with these agents.

Influence of pharmacogenomic profiling prior to pharmaceutical treatment in metastatic colorectal cancer on cost effectiveness : a systematic review

BACKGROUND

Metastatic colorectal cancer (mCRC) imposes a substantial health burden on individual patients and society. Furthermore, rising costs in oncology cause a growing concern about reimbursement for innovations in this sector. The promise of pharmacogenomic profiling and related stratified therapies in mCRC is to improve treatment efficacy and potentially save costs. Among other examples, the commonly used epidermal growth factor receptor (EGFR) antibodies cetuximab and panitumumab are only effective in patients with kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type cancers. Hence, the adaptation of predictive biomarker testing might be a valid strategy for healthcare systems worldwide.

OBJECTIVE

This study aims to review the clinical and economic evidence supporting pharmacogenomic profiling prior to the administration of pharmaceutical treatment in mCRC. Moreover, key drivers and areas of uncertainty in cost-effectiveness evaluations are analysed.

METHODS

A systematic literature review was conducted to identify studies evaluating the cost effectiveness of predictive biomarkers and the result dependent usage of pharmaceutical agents in mCRC.

RESULTS

The application of predictive biomarkers to detect KRAS mutations prior to the administration of EGFR antibodies saved treatment costs and was cost effective in all identified evaluations. However, because of the lack of data regarding cost-effectiveness analyses for predictive biomarker testing, e.g. for first-line treatment, definitive conclusions cannot be stated. Key drivers and areas of uncertainty in current cost-effectiveness analyses are, among others, the consideration of predictive biomarker costs, the characteristics of single predictive biomarkers and the availability of clinical data for the respective pharmaceutical intervention. Especially the cost effectiveness of uridine diphosphate-glucuronyl transferase 1A1 (UGT1A1) mutation analysis prior to irinotecan-based chemotherapy remains unclear.

CONCLUSION

Pharmacogenomic profiling has the potential to improve the cost effectiveness of pharmaceutical treatment in mCRC. Hence, quantification of the economic impact of stratified medicine as well as cost-effectiveness analyses of pharmacogenomic profiling are becoming more important. Nevertheless, the methods applied in cost-effectiveness evaluations for the usage of predictive biomarkers for patient selection as well as the level of evidence required to determine clinical effectiveness are areas for further research. However, mCRC is one of the first indications in which stratified therapies are used in clinical practice. Thus, clinical and economic experiences could be helpful when adopting pharmacogenomic profiling into clinical practice for other indications.

Downregulation of vasohibin-2, a novel angiogenesis regulator, suppresses tumor growth by inhibiting angiogenesis in endometrial cancer cells

The vasohibin-2 (VASH2) gene was originally found to be expressed in infiltrating mononuclear cells of a mouse model of hypoxia-induced subcutaneous angiogenesis. These cells are mobilized from bone marrow to promote angiogenesis. Recently, VASH2 has been demonstrated to be expressed in several types of cancer in which it promotes tumor development through angiogenesis. However, its role in endometrial cancer remains unknown. Using quantitative reverse transcription-polymerase chain reaction (RT-PCR), we found that VASH2 was overexpressed in several human endometrial cancer cell lines, including the HEC50B cell line, which we used to further examine the role of VASH2. Although knockdown of VASH2 with stable transfection of shRNA had little effect on the proliferation of HEC50B cells in vitro, knockdown in an in vivo murine xenograft model inhibited tumor growth by decreasing tumor angiogenesis. In addition, the supernatant from HEC50B cells that expressed VASH2 significantly promoted the proliferation of human umbilical vein endothelial cells. By contrast, knockdown of VASH2 significantly attenuated the proliferative effect. These results indicate that VASH2 contributes to the development of endometrial cancer by promoting angiogenesis through a paracrine mode of action. Consequently, VASH2 may be considered to be a novel molecular target for endometrial cancer therapy.

Multifunctional nanobeacon for imaging Thomsen-Friedenreich antigen-associated colorectal cancer

This research aimed to validate the specificity of the newly developed nanobeacon for imaging the Thomsen-Friedenreich (TF) antigen, a potential biomarker of colorectal cancer. The imaging agent is comprised of a submicron-sized polystyrene nanosphere encapsulated with a Coumarin 6 dye. The surface of the nanosphere was modified with peanut agglutinin (PNA) and poly(N-vinylacetamide (PNVA) moieties. The former binds to Gal-β(1-3)GalNAc with high affinity while the latter enhances the specificity of PNA for the carbohydrates. The specificity of the nanobeacon was evaluated in human colorectal cancer cells and specimens, and the data were compared with immunohistochemical staining and flow cytometric analysis. Additionally, distribution of the nanobeacon in vivo was assessed using an "intestinal loop" mouse model. Quantitative analysis of the data indicated that approximately 2 μg of PNA were detected for each milligram of the nanobeacon. The nanobeacon specifically reported colorectal tumors by recognizing the tumor-specific antigen through the surface-immobilized PNA. Removal of TF from human colorectal cancer cells and tissues resulted in a loss of fluorescence signal, which suggests the specificity of the probe. Most importantly, the probe was not absorbed systematically in the large intestine upon topical application. As a result, no registered toxicity was associated with the probe. These data demonstrate the potential use of this novel nanobeacon for imaging the TF antigen as a biomarker for the early detection and prediction of the progression of colorectal cancer at the molecular level.

Strategies of targeting oral drug delivery systems to the colon and their potential use for the treatment of colorectal cancer

Colorectal cancer (CRC) is the third most common cause of cancer-related death in both men and women. Often, surgical intervention remains the choice in treating CRC. Traditional dosage forms used for treating CRC deliver drug to wanted as well as unwanted sites of drug action resulting in several adverse side effects. Targeted oral drug delivery systems are being investigated to target and deliver chemotherapeutic and chemopreventive agents directly to colon and rectum. Site-specific delivery of a drug to colon increases its concentration at the target site, and thus requires a lower dose with reduced incidence of side effects. The major obstacle to be overcome for successful targeting of drug to colon through oral route is that drug absorption/degradation must be avoided in stomach and small intestine before the dosage form reaches colon. The review includes discussion of physiological factors that must be considered when targeting drugs directly to colorectal region, an outline on drugs used for treatment and prevention of CRC, and a brief description of various types of colon-targeted oral drug delivery systems. The focus is on the assessment of various formulation approaches being investigated for oral colon-specific delivery of drugs used in the treatment and prevention of CRC.

Phosphatase and tensin homolog expression related to cetuximab effects in colorectal cancer patients: A meta-analysis

AIM: To investigate the correlation between expression of phosphatase and tensin homolog (PTEN) and cetuximab effects in colorectal cancer.

METHODS: We searched PubMed, EMBASE and ASCO to identify eligible studies. Finally, 8 randomized control studies were included in the meta-analysis. STATA 10.0 Software was used to investigate heterogeneity among individual studies and to summarize all the studies. Risk ratios (RRs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were used to assess the strength of the association.

RESULTS: Compared with 20 of 266 patients with loss of PTEN, 206 of 496 patients with intact PTEN protein expression had a better objective response rate to cetuximab-based therapy (RR, 4.75; 95% CI, 2.59-8.72; P < 0.001). PTEN positivity was associated with better progression-free survival (PFS) (HR, 0.675; 95% CI, 0.473-0.964; P = 0.031) but not with better overall survival (OS) (HR, 0.608; 95% CI, 0.411-0.899; P = 0.013). In patients with KRAS wild-type status, PTEN positivity did not predict a longer PFS or OS (PFS: HR, 0.707; 95% CI, 0.440-1.138; P = 0.154; OS: HR, 0.943; 95% CI, 0.646-1.377; P = 0.761).

CONCLUSION: Expression of PTEN is related to the effect of cetuximab in colorectal cancer patients and should be considered in treatment with cetuximab.

The effect of anti-VEGF drugs (bevacizumab and aflibercept) on the survival of patients with metastatic colorectal cancer (mCRC)

Significant progression has been achieved in the treatment of metastatic colorectal cancer (mCRC) in recent years. This has been partly attributed to successfully incorporating new drugs into combination chemotherapy. In addition to the traditional cytotoxic chemotherapeutic agents, molecularly targeted agents began to play an important role in the treatment of advanced solid tumors. To date, two classes of molecularly targeted agents have been approved for treatment of patients with mCRC: (1) antivascular endothelial growth factor (anti-VEGF) agents (such as bevacizumab and aflibercept) and (2) antiendothelial cell growth factor receptor (anti-EGFR) agents (such as cetuximab and panitumumab). Aflibercept is a new member of anti-VEGF agents which has demonstrated efficacy for treatment of mCRC. With the commencement of clinical trials and basic research into aflibercept, more data from the bedside and the bench have been obtained. This review will outline the application of anti-VEGF agents by reviewing clinic experiences of bevacizumab and aflibercept, and try to add perspectives on the use of anti-VEGF agents in mCRC.

Pharmacogenomics and personalized medicine: wicked problems, ragged edges and ethical precipices

In the age of genomic medicine we can often now do the genetic testing that will permit more accurate personal tailoring of medications to obtain the best therapeutic results. This is certainly a medically and morally desirable result. However, in other areas of medicine pharmacogenomics is generating consequences that are much less ethically benign and much less amenable to a satisfactory ethical resolution. More specifically, we will often find ourselves left with 'wicked problems,' 'ragged edges,' and well-disguised ethical precipices. This will be especially true with regard to these extraordinarily expensive cancer drugs that generally yield only extra weeks or extra months of life. Our key ethical question is this: Does every individual faced with cancer have a just claim to receive treatment with one of more of these targeted cancer therapies at social expense? If any of these drugs literally made the difference between an unlimited life expectancy (a cure) and a premature death, that would be a powerful moral consideration in favor of saying that such individuals had a strong just claim to that drug. However, what we are beginning to discover is that different individuals with different genotypes respond more or less positively to these targeted drugs with some in a cohort gaining a couple extra years of life while others gain only extra weeks or months. Should only the strongest responders have a just claim to these drugs at social expense when there is no bright line that separates strong responders from modest responders from marginal responders? This is the key ethical issue we address. We argue that no ethical theory yields a satisfactory answer to this question, that we need instead fair and respectful processes of rational democratic deliberation.

Chemoprevention in colorectal cancer--where we stand and what we have learned from twenty year's experience

INTRODUCTION

Colorectal chemoprevention is a strategy aimed at preventing tumour progression before irreversible changes to the proteome are in full progress. Chemoprevention is not a new concept. In fact, medical practitioners since the early 19th century have tried various herbal and medicinal products as methods that could prevent tumours. The current understanding of tumourigenesis and cellular signalling focuses on a more targeted approach and paves the way for better understanding of colorectal chemoprevention.

METHODS

The online databases PubMed, Medline, Medscape Oncology and Scirrus were searched for articles of relevance. The Keyword involved the following words: "Colorectal Cancer Chemoprevention", "Colorectal Cancer", "Chemoprevention", "Adenoma-Carcinoma Sequence" and "Colorectal Polyps". The search was started from the period of June 1995 until September 2010 inclusive.

RESULTS

More than 50 natural and synthetic compounds have been shown to have chemotherapeutic effect but the majority of these agents are still in their early experimental stages and hence far from our subject of discussion. Our discussion will focus on large scale randomised trials on human subjects or established compounds. Within the context of chemoprevention, Non-steroidal anti-inflammatory agents have undergone extensive research and have shown promising results with large scale randomised trials. Additionally, metformin, resveratrol, Histone deacetylase inhibitors, Src kinases as well monoclonal antibodies have shown promising results as well.

CONCLUSION

Colorectal cancer is the fourth most common cancer in the world. In the UK alone the number of cases reported in 2008 was almost 40,000 which make it the third most common tumour nationwide. Curative intent surgery or Colectomy is the treatment of choice for most cases of bowel cancer; however, in a select subpopulation of patients who have been colonoscopically diagnosed to harbour pre-malignant lesions, have a family history of colorectal cancer, or have been genetically diagnosed and treated surgically for colorectal tumours; chemoprevention might play a crucial role in deterring further tumour progression. The very latest studies that are in publication or are just accruing results are giving us encouraging data that might suggest whether mass scale ingestion of a specific medication might deter colorectal tumour progression.

[Prognostic factors and functional imaging in rectal cancer]

The outcome of treatment for rectal cancer in recent years has been improved by diverse advances in the field of surgery and in neoadjuvant oncologic therapies. Heald's introduction of the concept of the mesorectum as an anatomical unit (total mesorectal excision) in 1982 and the generalization of preoperative radiochemotherapy have improved the prognosis in a significant number of patients. Owing to these advances, it has become necessary for imaging studies to define a series of prognostic factors for tumors, both before and after neoadjuvant treatment, to make it possible to tailor treatment for individual patients with rectal tumors. On the other hand, the advent of functional and molecular imaging techniques has provided a way to study a series of distinctive tumor characteristics in vivo, including the angiogenesis, metabolism, or cellularity of rectal tumors, and these techniques are making a growing contribution to the prognosis, staging, treatment planning, and evaluation of the response to therapy in patients with rectal cancer.

Biomarker-based selection of therapy for colorectal cancer

Colorectal cancer (CRC) has been re-classified based on molecular analyses of various genes and proteins capable of separating morphologic types of tumors into molecular categories. The diagnosis and management of CRC has evolved with the discovery and validation of a wide variety of biomarkers designed to facilitate a personalized approach for the treatment of the disease. In addition, a number of new prognostic and predictive individual genes and proteins have been discovered that are designed to reflect the sensitivity and/or resistance of CRC to existing therapies. Multigene predictors have also been developed to predict the risk of relapse for intermediate-stage CRC after completion of surgical resection. Finally, a number of biomarkers have been proposed as specific predictors of chemotherapy and radiotherapy response and, in some instances, drug toxicity. In this article, a series of novel biomarkers are considered and compared with standard-of-care markers for their potential use as pharmacogenomic and pharmacogenetic predictors of disease outcome.

Identification of microRNA-target interaction in APRIL-knockdown colorectal cancer cells

MicroRNAs (miRNAs) regulate mammalian gene expression by targeting mRNAs and have key roles in several cellular processes, including differentiation, development, apoptosis and cancer pathomechanisms. Our previous studies have confirmed that a proliferation-inducing ligand (APRIL) gene is overexpressed in colorectal cancer (CRC) tumors and SW480 cells. To study the potential mechanisms of APRIL gene in the occurrence and development of the CRC, herein, we investigated whether APRIL-knockdown had the inhibitory effect on the growth of SW480 cells and had the simultaneous expression changes of miRNAs and mRNAs by microarrays. Our results suggest that siRNA-APRIL can effectively inhibit the growth of SW480 cells in vitro and in vivo and several miRNAs via specific pathways might be involved in regulating the phenotype of loss-of-function in APRIL-knockdown SW480 cells. Thus, our study highlights the possible mechanisms of miRNA-target regulating the function of APRIL gene in CRC cells, moreover, siRNA-APRIL holds great promise as a novel gene therapy approach for APRIL- positive CRC treatment.

Advances in cancer therapeutics and patient access to new drugs

Globally, there are approximately 7.4 million cancer deaths annually, approximately 13% of deaths from all causes. Cancer is a disease of older people and, as the population ages over the next 10-20 years, we can expect an increase in the cancer incidence. Encouragingly, cancer mortality has stabilized in many countries. Part of this success may be attributed to the development of new cancer agents, collectively called 'targeted therapies', that are more specific to key components of tumour growth. Worldwide, however, one of the main factors that limit patient access to these important new drugs is their cost, which is higher than traditional chemotherapy. In this review, the clinical and pharmacoeconomic data of selected targeted agents are discussed. In the second part of this article, the challenges faced by healthcare systems in making such drugs available to patients is reviewed. Current strategies used by many countries around the world to manage cancer drug budgets are presented, along with a proposed approach using pharmacoeconomic methodology that may increase patient access.

Effects of bevacizumab in mouse model of endometrial cancer: Defining the molecular basis for resistance

Endometrial cancer is the most frequent gynecologic cancer in women. Long-term outcomes for patients with advanced stage or recurrent disease are poor. Targeted molecular therapy against the vascular endothelial growth factor (VEGF) and its receptors constitute a new therapeutic option for these patients. The goal of our study was to assess the potential effectiveness of inhibition of VEGF/VEGFR signaling in a xenograft model of endometrial cancer using bevacizumab (Avastin, a humanized antibody against VEGFA). We also aimed to identify molecular markers of sensitivity or resistance to this agent. We show that bevacizumab retards tumor growth in athymic mice by inhibiting molecular components of signaling pathways that sustain cell survival and proliferation. We also demonstrate that resistance to bevacizumab may involve up-regulation of anti-apoptotic genes and certain proto-oncogenes. We propose that down-regulation of ARHGAP6 and MMP15 transcripts indicates that tumors are sensitive to bevacizumab whereas inhibition of PKCδ- or S6K-dependent signaling and up-regulation of TNFRS4 or MMP13 and MMP14 mark a developing resistance to bevacizumab therapy. Interestingly, the significant activation of c-Jun oncogene detected in bevacizumab-treated tumors suggests that, in endometrial cancers, the c-Jun-mediated pathway(s) contribute to bevacizumab resistance.

Visualization of gold and platinum nanoparticles interacting with Salmonella enteritidis and Listeria monocytogenes

PURPOSE

Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively), with Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive), to reveal possibilities of constructing bacteria-nanoparticle vehicles.

METHODS

Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope.

RESULTS

Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterial cell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis.

CONCLUSION

The results indicate that the bacteria could be used as a vehicle to deliver nano-Pt to specific points in the body.

Biomarker-based prediction of response to therapy for colorectal cancer: current perspective

The diagnosis and management of colorectal cancer (CRC) has been impacted by the discovery and validation of a wide variety of biomarkers designed to facilitate a personalized approach for the treatment of the disease. Recently, CRC has been reclassified based on molecular analyses of various genes and proteins capable of separating morphologic types of tumors into molecular categories. At the same time, a number of new prognostic and predictive single genes and proteins have been discovered that are designed to reflect sensitivity and/or resistance to existing therapies. Multigene predictors have also been developed to predict the risk of relapse for intermediate-stage CRC after completion of surgical extirpation. More recently, a number of biomarkers tested by a variety of methods have been proposed as specific predictors of chemotherapy and radiotherapy response. Other markers have been successfully used to predict toxic effects of standard therapies. In this review, a series of novel biomarkers are considered and compared with standard-of-care markers for their potential use as pharmacogenomic and pharmacogenetic predictors of disease outcome.

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.

Panitumumab: a review of its use in metastatic colorectal cancer

Panitumumab (Vectibix(R)) is a recombinant, fully human, IgG2 anti-epidermal growth factor receptor (EGFR) monoclonal antibody. This article reviews the clinical efficacy of intravenous panitumumab in combination with chemotherapy in the first- and second-line treatment of metastatic colorectal cancer and as monotherapy in chemotherapy-refractory metastatic colorectal cancer, as well as summarizing its pharmacological properties and tolerability. Panitumumab is indicated for use in patients with wild-type rather than mutant KRAS tumours. The efficacy of intravenous panitumumab 6 mg/kg administered every 2 weeks was examined in randomized, open-label, multicentre, phase III trials in patients with metastatic colorectal cancer. When administered as first- or second-line treatment in combination with chemotherapy, panitumumab plus chemotherapy prolonged progression-free survival to a significantly greater extent than chemotherapy alone in patients with wild-type KRAS tumours; no significant between-group difference in overall survival was seen in the second-line treatment trial. In patients with mutant KRAS tumours, progression-free survival was significantly shorter with panitumumab plus oxaliplatin-based chemotherapy than with oxaliplatin-based chemotherapy alone in the first-line treatment trial, with no significant difference between patients receiving panitumumab plus irinotecan-based chemotherapy (FOLFIRI) and those receiving FOLFIRI alone in the second-line treatment trial. In chemotherapy-refractory patients with metastatic colorectal cancer, panitumumab monotherapy plus best supportive care prolonged progression-free survival to a significantly greater extent than best supportive care alone in both the overall population and in patients with wild-type KRAS tumours, but not in those with mutant KRAS tumours; there was no significant between-group difference in overall survival. Panitumumab has an acceptable tolerability profile when administered as monotherapy or in combination with chemotherapy. It is associated with the skin-related toxicities characteristic of EGFR inhibitors and appears to have a low risk of immunogenicity. In conclusion, in patients with wild-type KRAS tumours, panitumumab is a useful option in combination with chemotherapy for the first- and second-line treatment of metastatic colorectal cancer or as monotherapy for the treatment of chemotherapy-refractory metastatic colorectal cancer.