Capecitabine: a review

The ABC7 regimen: a new approach to metastatic breast cancer using seven common drugs to inhibit epithelial-to-mesenchymal transition and augment capecitabine efficacy

Breast cancer metastatic to bone has a poor prognosis despite recent advances in our understanding of the biology of both bone and breast cancer. This article presents a new approach, the ABC7 regimen (Adjuvant for Breast Cancer treatment using seven repurposed drugs), to metastatic breast cancer. ABC7 aims to defeat aspects of epithelial-to-mesenchymal transition (EMT) that lead to dissemination of breast cancer to bone. As add-on to current standard treatment with capecitabine, ABC7 uses ancillary attributes of seven already-marketed noncancer treatment drugs to stop both the natural EMT process inherent to breast cancer and the added EMT occurring as a response to current treatment modalities. Chemotherapy, radiation, and surgery provoke EMT in cancer generally and in breast cancer specifically. ABC7 uses standard doses of capecitabine as used in treating breast cancer today. In addition, ABC7 uses 1) an older psychiatric drug, quetiapine, to block RANK signaling; 2) pirfenidone, an anti-fibrosis drug to block TGF-beta signaling; 3) rifabutin, an antibiotic to block beta-catenin signaling; 4) metformin, a first-line antidiabetic drug to stimulate AMPK and inhibit mammalian target of rapamycin, (mTOR); 5) propranolol, a beta-blocker to block beta-adrenergic signaling; 6) agomelatine, a melatonergic antidepressant to stimulate M1 and M2 melatonergic receptors; and 7) ribavirin, an antiviral drug to prevent eIF4E phosphorylation. All these block the signaling pathways - RANK, TGF-beta, mTOR, beta-adrenergic receptors, and phosphorylated eIF4E - that have been shown to trigger EMT and enhance breast cancer growth and so are worthwhile targets to inhibit. Agonism at MT1 and MT2 melatonergic receptors has been shown to inhibit both breast cancer EMT and growth. This ensemble was designed to be safe and augment capecitabine efficacy. Given the expected outcome of metastatic breast cancer as it stands today, ABC7 warrants a cautious trial.

MicroRNAs as a tool to aid stratification of colorectal cancer patients and to guide therapy

Colorectal cancer is a common type of malignant disease with high rates of morbidity and mortality. Although treatment options have been expanded over the last years, the mainstay of curative treatment remains surgical removal of the tumor-bearing organ. Systemic treatment options include classic cytotoxic drugs as well as some biological agents. Noncoding RNAs are an evolving field in cancer diagnosis, prognosis and possible treatment. Noncoding miRNAs are small molecules with huge impact on gene expression. They have been a substantial part of cancer research for more than a decade. In this review article, the current knowledge of miRNAs and colorectal cancer diagnosis, prognosis and novel or evolving therapeutic concepts are discussed. Examples of how miRNAs might change the management of the disease will be described.

Athymic nude mice as an experimental model for cancer treatment

Athymic nude mice, a murine strain bearing spontaneous deletion in the Foxn1 gene that causes deteriorated or absent thymus (which results in inhibited immune system with reduction of number of T cells), represent a widely used model in cancer research having long lasting history as a tool for preclinical testing of drugs. The review describes three models of athymic mice that utilize cancer cell lines to induce tumors. In addition, various methods that can be applied in order to evaluate activity of anticancer agents in these models are shown and discussed. Although each model has certain disadvantages, they are still considered as inevitable instruments in many fields of cancer research, particularly in finding new drugs that would more effectively combat the cancer disease or enhance the use of current chemotherapy. Finally, the review summarizes strengths and weaknesses as well as future perspectives of the athymic nude mice model in cancer research.

Metronomic Capecitabine Effectively Blocks Leptomeningeal Carcinomatosis From Breast Cancer: A Case Report and Literature Review

Patient: Female, 57

Final Diagnosis: Meningeal carcinomatosis from breast cancer

Symptoms: Seizures

Medication: —

Clinical Procedure: —

Specialty: Oncology

5-fluorouracil causes endothelial cell senescence: potential protective role of glucagon-like peptide 1

BACKGROUND AND PURPOSE

5-fluorouracil (5FU) and its prodrug, capecitabine, can damage endothelial cells, whilst endothelial integrity is preserved by glucagon-like peptide 1 (GLP-1). Here, we studied the effect of 5FU on endothelial senescence and whether GLP-1 antagonizes it.

EXPERIMENTAL APPROACH

EA.hy926 cells were exposed to 5FU or sera from patients taking capecitabine, with or without pre-incubation with GLP-1. Senescence was identified by expression of senescence-associated β-galactosidase and p16^INK4a and reduced cell proliferation. Soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and CD146 (marker of endothelial injury) were measured by ELISA before and at completion of capecitabine chemotherapy. RT-PCR, western blotting, functional experiments with signalling inhibitors and ERK1/2 silencing were performed to characterize 5FU-induced phenotype and elucidate the pathways underlying 5FU and GLP-1 activity.

KEY RESULTS

Both 5FU and sera from capecitabine-treated patients stimulated endothelial cell senescence. 5FU-elicited senescence occurred via activation of p38 and JNK, and was associated with decreased eNOS and SIRT-1 levels. Furthermore, 5FU up-regulated VCAM1 and TYMP (encodes enzyme activating capecitabine and 5FU), and sVCAM-1 and CD146 concentrations were higher after than before capecitabine chemotherapy. A non-significant trend for higher ICAM1 levels was also observed. GLP-1 counteracted 5FU-initiated senescence and reduced eNOS and SIRT-1 expression, this protection being mediated by GLP-1 receptor, ERK1/2 and, possibly, PKA and PI3K.

CONCLUSIONS AND IMPLICATIONS

5FU causes endothelial cell senescence and dysfunction, which may contribute to its cardiovascular side effects. 5FU-triggered senescence was prevented by GLP-1, raising the possibility of using GLP-1 analogues and degradation inhibitors to treat 5FU and capecitabine vascular toxicity.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Metronomic capecitabine versus best supportive care as second-line treatment in hepatocellular carcinoma: a retrospective study

Preliminary studies suggest that capecitabine may be safe and effective in HCC patients. The aim of this study was to retrospectively evaluate the safety and efficacy of metronomic capecitabine as second-line treatment. This multicentric study retrospectively analyzed data of HCC patients unresponsive or intolerant to sorafenib treatment with metronomic capecitabine or best supportive care (BSC).Median progression free survival was 3.1 months in patients treated with capecitabine (95%CI: 2.7-3.5). Median overall survival was 12.0 months (95% CI: 10.7-15.8) in patients receiving capecitabine, while 9.0 months (95% CI: 6.5-13.9) in patients receiving BSC. The result of univariate unweighted Cox regression model shows a 46% reduction in death risk for patients on capecitabine (95%CI: 0.357-0.829; p  =0.005) compared to patients receiving BSC alone. After weighting for potential confounders, death risk remained essentially unaltered (45%; 95%CI: 0.354-0.883; p = 0.013). Metronomic capecitabine seems a safe second-line treatment for HCC patients in terms of management of adverse events, showing a potential anti-tumour activity which needs further evaluation in phase III studies.

The telomere-binding protein TRF2 is required for metronomic therapeutic effects of gemcitabine and capecitabine

Gemcitabine and capecitabine are two effective anticancer agents against solid tumors. The pharmacological mechanisms have been known as incorporation into DNA and thereby inhibition of DNA synthesis. When used as metronomic chemotherapy, they may inhibit angiogenesis and induce immunity. In our previous study, we showed that low-dose gemcitabine caused telomere shortening by stabilizing TRF2 that was required for XPF-dependent telomere loss. In this report, we established a SKOV3.ip1 ascites cell model. Tumor-bearing mice were treated with low-dose gemcitabine (GEM) or capecitabine (CAP). Both GEM and CAP caused telomere shortening and increased expression of TRF2 with improved ascites in nude mice and decreased in vitro clonogenic activity. TRF2 knockdown altered telomeres to a shortened but new status that may evade XPF-dependent telomere loss and conferred resistance of SKOV3.ip1 ascites cells to low-dose GEM and CAP. Our study provides a new mechanism of metronomic chemotherapy i.e. TRF2 is required for metronomic therapeutic effects of gemcitabine and capecitabine.

Metabolism, Biochemical Actions, and Chemical Synthesis of Anticancer Nucleosides, Nucleotides, and Base Analogs

Nucleoside, nucleotide, and base analogs have been in the clinic for decades to treat both viral pathogens and neoplasms. More than 20% of patients on anticancer chemotherapy have been treated with one or more of these analogs. This review focuses on the chemical synthesis and biology of anticancer nucleoside, nucleotide, and base analogs that are FDA-approved and in clinical development since 2000. We highlight the cellular biology and clinical biology of analogs, drug resistance mechanisms, and compound specificity towards different cancer types. Furthermore, we explore analog syntheses as well as improved and scale-up syntheses. We conclude with a discussion on what might lie ahead for medicinal chemists, biologists, and physicians as they try to improve analog efficacy through prodrug strategies and drug combinations.

Chemotherapy-Induced Constipation and Diarrhea: Pathophysiology, Current and Emerging Treatments

Gastrointestinal (GI) side-effects of chemotherapy are a debilitating and often overlooked clinical hurdle in cancer management. Chemotherapy-induced constipation (CIC) and Diarrhea (CID) present a constant challenge in the efficient and tolerable treatment of cancer and are amongst the primary contributors to dose reductions, delays and cessation of treatment. Although prevalence of CIC is hard to estimate, it is believed to affect approximately 16% of cancer patients, whilst incidence of CID has been estimated to be as high as 80%. Despite this, the underlying mechanisms of both CID and CIC remain unclear, but are believed to result from a combination of intersecting mechanisms including inflammation, secretory dysfunctions, GI dysmotility and alterations in GI innervation. Current treatments for CIC and CID aim to reduce the severity of symptoms rather than combating the pathophysiological mechanisms of dysfunction, and often result in worsening of already chronic GI symptoms or trigger the onset of a plethora of other side-effects including respiratory depression, uneven heartbeat, seizures, and neurotoxicity. Emerging treatments including those targeting the enteric nervous system present promising avenues to alleviate CID and CIC. Identification of potential targets for novel therapies to alleviate chemotherapy-induced toxicity is essential to improve clinical outcomes and quality of life amongst cancer sufferers.

Incidence and risk factors for capecitabine-induced symptomatic cardiotoxicity: a retrospective study of 452 consecutive patients with metastatic breast cancer

OBJECTIVES

Case reports of capecitabine cardiotoxicity resemble those seen with intravenous 5-fluorouracil (5-FU) with chest pain as the predominant manifestation, but few studies of capecitabine cardiotoxicity are available. We aimed to determine the incidence of symptomatic cardiotoxicity from capecitabine in patients with breast cancer and to identify risk factors.

METHODS

We reviewed medical records of consecutive women with breast cancer treated with capecitabine (1000 mg/m² two times per day) from 2002 to 2012 at one institution.

RESULTS

22 of 452 patients (4.9%) (95% CI 2.9% to 6.9%) had symptoms of cardiotoxicity (chest pain: n=13, dyspnoea: n=9, palpitations: n=2). 11 patients had changes on ECG (atrial fibrillation: n=5, ST deviations: n=3, T-wave abnormalities: n=2 and QTc prolongation: n=1). 2 patients (0.4%) sustained acute myocardial infarction. 1 patient (0.2%) developed cardiac arrest with lethal outcome. 4 of 6 patients (66%) retreated with capecitabine had recurrent symptoms at retreatment. Cardiac comorbidity (p=0.001), hypercholesterolaemia (p=0.005) and current smoking (p=0.023) were risk factors for cardiotoxicity in univariate analyses and remained significant when adjusted for age. Patients with cardiac comorbidity were 5.5 times (95% CI 2.0 to 14.8) more likely to develop cardiotoxicity. In the subgroup of patients with apparently no cardiac comorbidity, the incidence of cardiotoxicity was lower (3.7%) and hypercholesterolaemia (p=0.035) and current smoking (p=0.020) were risk factors of cardiotoxicity.

CONCLUSIONS

The incidence of cardiotoxicity from capecitabine resembles that of intravenous 5-FU (≈5%). Cardiac comorbidity, hypercholesterolaemia and current smoking were associated with development of cardiotoxicity.

Efficacy of low dose capecitabine and sorafenib in patients with advanced alfa-fetoprotein secreting hepatocellular carcinoma: a 1 year experience

BACKGROUND

There is no global consensus for the optimal management of HCC. Most of patients at the time of diagnosis are not candidate for potentially curative therapy. The study aimed to evaluate the efficacy of low dose capecitabine combined with sorafenib in subset of Egyptian HCV patients presented with advanced HCC unfit for surgical or locoregional therapies.

METHODS

15 patients with advanced HCC, unfit for surgical or locoregional intervention, with PS <2 recieved Capecitabine 500 mg/day with sorafeneb 200 mg twice daily till normalization of AFP then the treatment was modified to capecitabine 250 mg every other day and sorafenib 400 mg once daily. They were followed every 3 months for size, number of focal masses and AFP. 30 patients were selected as a control group, they received supportive therapy (n = 15) or sorafenib only (n = 15).

RESULTS

After 10 months of therapy, 6 patients showed complete response (40 %) with complete recanalization of portal vein (n = 2) and treatment was stopped and the others (n = 4) showed partial portal vein recanalization so, treatment is continued till now. 1 patient (6.7 %) showed recurrence of the disease and died after 1 month, 8 patients showed partial response (53.3 %) and still on treatment. The control groups showed a highly significant reduction in survival when compared to patients who received capecitabine and sorafenib (12.9 ± 2.1, 7.9 ± 0.9, 4.5 ± 1.3 months, p = 0.000).

CONCLUSIONS

Combined low dose capecitabine and sorafenib proved to be safe with low toxicity profile and deserves further attention as a convenient, outpatient-based chemotherapy in patients with advanced HCC.

A first case report of diffuse acneiform eruption caused by capecitabine in a patient with small-cell neuroendocrine lung carcinoma

Capecitabine is a chemotherapeutic agent which is converted to fluorouracil by thymidine phosphorylase in human body. It is one of the commonly used agents in colorectal and metastatic breast cancers. Hand-foot syndrome is most commonly observed adverse effect of capecitabine; however, it has several adverse cutaneous and mucosal effects. To the best of our knowledge, no case with acneiform eruption has been reported so far. Here, we presented a 54-year-old man with development of capecitabine-related acneiform drug eruption.

CE: A Review of Common Oral Treatments for Breast Cancer: Improving Patient Safety in Nononcology Settings

: Breast cancer patients are living longer with the disease than ever before. According to the National Cancer Institute, more than 3 million women in the United States are currently living with a breast cancer diagnosis, and many seek care in nononcology settings, whether for treatment, acute symptoms and complaints related to their cancer diagnosis, or unrelated concerns. Yet many nononcology providers are unfamiliar with the various oral agents used to treat breast cancer, and their possible adverse effects and drug interactions. It is imperative that all providers be aware of these agents and know when a patient is currently taking or has taken them. This article provides an overview of the most common oral treatments for breast cancer and discusses common adverse effects and management.

Adherence and Patients' Experiences with the Use of Capecitabine in Daily Practice

Introduction: Capecitabine is a widely prescribed oral anticancer agent. We studied medication adherence and explored its use in daily practice from a patients' perspective.

Patients and Methods: Patients (n = 92) starting capecitabine were followed up to five 3-week cycles. Adherence was assessed using a pill count, pharmacy data and dosing information from the patients' medical file. Self-reported adherence was measured using the Medication Adherence Report Scale (MARS). At baseline and during week 2 of cycles 1, 3, and 5, patients filled out questionnaires about quality of life, symptoms, attitude toward medicines and disease and use in daily practice. Simultaneously, blood samples were taken to determine the area under the curve (AUC) of 5′-deoxy-5-fluorouridine (5′-DFUR), 5-fluorouracil (5-FU), and α-fluoro-β-alanine (FBAL) by a population pharmacokinetic model. Associations between AUCs and patient-reported symptoms were tested for cycles 3 and 5.

Results: Most patients (84/92; 91%) had an adherence rate of ≥95 and ≤ 105%. The percentage of patients reporting any non-adherence behavior measured with MARS increased from 16% at cycle 1 to 29% at cycle 5. Symptoms were reported frequently and the dosing regimen was adjusted by the physician at least once in 62% of patients. In multivariate analysis the probability of an adjustment increased with the number of co-medication (OR 1.19, 95% CI: 1.03–1.39) and a stronger emotional response to the disease (OR 1.32, 95% CI: 1.10–1.59). The AUC of 5′-DFUR was associated with weight loss (OR 1.10, 95% CI: 1.01–1.19), AUC of FBAL with hand-foot syndrome (OR 0.90, 95% CI: 0.83–0.99), rhinorrhea (OR 1.21, 95% CI: 1.03–1.42 weight loss (OR 1.09, 95% CI: 1.00–1.20) and depression (OR 0.90, 95% CI: 0.82–0.99). Side effects were reported by one third of patients as the reason to discontinue treatment.

Conclusion: Adherence to capecitabine was generally high. Nevertheless, adherence measured with MARS decreased over time Adherence management to support implementation of correct capecitabine use is specifically relevant in longer term treatment. In addition, it appears that adverse event management is important to support persistence. With the extending armamentarium of oral targeted anticancer agents and prolonged treatment duration, we expect the issue of medication adherence of increasing importance in oncology.

New Perspectives in the Treatment of Advanced Gastric Cancer: S-1 as a Novel Oral 5-FU Therapy in Combination with Cisplatin

Oral fluoropyrimidines have been available for more than 10 years. Capecitabine is well established in treating solid tumors in Europe. S-1 (Teysuno®), an oral formulation containing the 5-fluorouracil (5-FU) prodrug tegafur and the two enzyme modulators gimeracil and oteracil, has not been available in non-Asia countries until recently. In Japan, S-1 in combination with cisplatin is the recommended first-line treatment in patients with gastric cancer. In Europe, the first trials with S-1 were disappointing due to high unacceptable incidences of adverse events. Pharmacokinetic studies showed differences in Asian and Caucasian patients; therefore, a new non-Asian study program was initiated, which led to the pivotal phase 3 trial First-Line Advanced Gastric Cancer Study (FLAGS). In FLAGS, 1,053 patients with advanced gastric cancer from 24 non-Asian countries were enrolled. S-1 plus cisplatin showed no overall survival (OS) benefit when compared to 5-FU plus cisplatin. The primary endpoint superior OS was not met but better tolerability was shown. A post hoc noninferiority OS and safety analysis showed that S-1 plus cisplatin has the same efficacy as 5-FU plus cisplatin but a more favorable safety profile. This led to the approval of S-1 in combination with cisplatin in gastric cancer in Europe in 2011. This article reviews the mode of action of S-1, pivotal study results from an EU point of view, and future perspectives.

Inventory of oral anticancer agents: Pharmaceutical formulation aspects with focus on the solid dispersion technique

Dissolution from the pharmaceutical formulation is a prerequisite for complete and consistent absorption of any orally administered drug, including anticancer agents (oncolytics). Poor dissolution of an oncolytic can result in low oral bioavailability, high variability in blood concentrations and with that suboptimal or even failing therapy. This review discusses pharmaceutical formulation aspects and absorption pharmacokinetics of currently licensed orally administered oncolytics. In nearly half of orally dosed oncolytics poor dissolution is likely to play a major role in low and unpredictable absorption. Dissolution-limited drug absorption can be improved with a solid dispersion which is a formulation method that induces super-saturated drug dissolution and with that it enhances in vivo absorption. This review discusses formulation principles with focus on the solid dispersion technology and how it works to enhance drug absorption. There are currently three licensed orally dosed oncolytics formulated as a solid dispersion (everolimus, vemurafenib and regorafenib) and these formulations result in remarkably improved dissolution and absorption compared to what can be achieved with conventional formulations of the respective oncolytics. Because of the successful implementation of these three solid dispersion formulations, we encourage the application of this formulation method for poorly soluble oral oncolytics.

Drug-induced hepatotoxicity in cancer patients - implication for treatment

INTRODUCTION

All anticancer drugs can cause idiosyncratic liver injury. Therefore, hepatoprotective agents assume particular importance to preserve liver function. Hepatic injury represents 10% of cases of acute hepatitis in adults; drug-related damage is still misjudged because of relative clinical underestimation and difficult differential diagnosis. Chemotherapeutic agents can produce liver toxicity through different pathways, resulting in different categories of liver injuries, but these drugs are not homogeneously hepatotoxic. Frequently, anticancer-induced hepatotoxicity is idiosyncratic and influenced by multiple factors.

AREAS COVERED

The aim of this paper is to perform a review of the literature regarding anticancer-induced liver toxicity. We described hepatotoxicity mechanisms of principal anticancer agents and respective dose reductions. Furthermore, we reviewed studies on hepatoprotectors and their optimal use. Tiopronin, magnesium isoglycyrrhizinate and S-Adenosylmethionine (AdoMet) demonstrated, in some small studies, a potential hepatoprotective activity.

EXPERT OPINION

Actually, in the literature only small experiences are reported. Even though hepatoprotective agents seem to be useful in the oncologic setting, the lack of well-designed prospective Phase III randomized controlled trials is a major limit in the introduction of hepatoprotectors in cancer patients and these kind of studies are warranted to support their use and to give further recommendations for the clinical practice.

Therapeutic drug monitoring of 5-fluorouracil

PURPOSE

For over 50 years, 5-FU has played a critical role in the systemic chemotherapy of cancer patients. 5-FU serves as the main backbone of combination chemotherapy for patients with colorectal cancer in both the adjuvant and metastatic disease settings. Herein, we review the current status of 5-FU therapeutic drug monitoring (TDM) and discuss its potential role in the clinical practice setting.

METHOD

PubMed and abstracts from the American Society of Clinical Oncology were searched up through September 2015 for clinical data relating to 5-FU TDM.

RESULTS

5-FU dosing has been typically determined by using body surface area (BSA). However, it is now well established that BSA-based 5-FU dosing is correlated with a wide variation of 5-FU systemic exposure. Pharmacokinetic (PK) studies of 5-FU systemic exposure have shown a wide range of interpatient variation of 5-FU plasma drug levels. Over the past 30 years, increasing efforts have been placed on optimizing 5-FU dosing with the main goals of increasing antitumor efficacy while reducing drug-associated toxicity. There is growing evidence to show that 5-FU dosing based on plasma 5-FU drug level is feasible and that 5-FU TDM can improve clinical outcomes by improving efficacy of 5-FU-based combination regimens and reducing toxicities.

CONCLUSION

Dose adjustment of 5-FU is feasible, and PK-based dosing can significantly improve clinical outcomes by reducing toxicities and improving efficacy.

Capecitabine for treating head and neck cancer

INTRODUCTION

With an increasing incidence, over half a million cases of head and neck cancer (HNC) are diagnosed annually worldwide. Various chemotherapeutic agents are utilized to achieve adequate locoregional control. Cisplatin, fluorouracil (FU), and taxanes are often used to treat HNC but these regimens have shown high toxicity and poor patient compliance. Capecitabine is an orally administered prodrug that is preferentially converted to FU in tumor cells in comparison to normal cells.

AREA COVERED

In this review, the authors evaluate the role of capecitabine in radical and palliative settings either alone or in combination with other chemotherapeutic drugs in the management of HNC. In addition, metabolic conversion, pharmacokinetics, pharmacodynamics, and toxicity profile of capecitabine are discussed.

EXPERT OPINION

Various phase II trials conducted on capecitabine in the management of recurrent HNC have shown comparable results and tolerable toxic effects especially in pre-treated fragile patients. Capecitabine, used in induction or concurrent settings in the radical management of locoregionally advanced HNC, have also shown promising results. Randomized trials are needed to validate the role of capecitabine in the management of HNC.

Capecitabine-related liver lesions: sinusoidal dilatation mimicking liver metastasis

A 30‐year‐old lady treated with capecitabine for primary colon adenocarcinoma developed liver lesions suspicious for metastasis. Liver biopsies showed sinusoidal dilatation thought to be secondary to capecitabine. This case highlights the importance of differentiating between benign and malignant liver lesions during cancer surveillance preventing unnecessary liver resections for benign disease.

Synthesis and anticancer activity of some 5-fluoro-2'-deoxyuridine phosphoramidates

Two series of novel 4-chlorophenyl N-alkyl phosphoramidates of 3'-O-(t-butoxycarbonyl)-5-fluoro-2'-deoxyuridine (3'-BOC-FdU) (9a-9j) and 5-fluoro-2'-deoxyuridine (FdU) (10a-10j) were synthesized by means of phosphorylation of 3'-BOC-FdU (4) with 4-chlorophenyl phosphoroditriazolide (7), followed by a reaction with the appropriate amine. Phosphoramidates 9a-9j were converted to the corresponding 10a-10j by removal of the 3'-t-butoxycarbonyl protecting group (BOC) under acidic conditions. The synthesized phosphoramidates 9a-9j and 10a-10j were evaluated for their cytotoxic activity in five human cancer cell lines: cervical (HeLa), nasopharyngeal (KB), breast (MCF-7), liver (HepG2), osteosarcoma (143B) and normal human dermal fibroblast cell line (HDF) using the sulforhodamine B (SRB) assay. Two phosphoramidates 9b and 9j with the N-ethyl and N-(methoxy-(S)-alaninyl) substituents, respectively, displayed remarkable activity in all the investigated cancer cells, and the activity was considerably higher than that of the parent nucleoside 4 and FdU. Among phosphoramidates 10a-10j compound 10c with the N-(2,2,2-trifluoroethyl) substituent showed the highest activity. Phosphoramidate 10c was more active than the FdU in all the cancer cell lines tested.

3'-O- and 5'-O-Propargyl Derivatives of 5-Fluoro-2'-Deoxyuridine: Synthesis, Cytotoxic Evaluation and Conformational Analysis

A series of new 3'-O- and 5'-O-propargyl derivatives of 5-fluoro-2'-deoxyuridine (1-4) was synthesized by means of propargyl reaction of properly blocked nucleosides (2,4), followed by the deprotection reaction with ammonium fluoride. The synthesized propargylated 5-fluoro-2'-deoxyuridine analogues (1-4) were evaluated for their cytotoxic activity in three human cancer cell lines: cervical (HeLa), oral (KB) and breast (MCF-7), using the sulforhodamine B (SRB) assay. The highest activity and the best SI coefficient in all of the investigated cancer cells were displayed by 3'-O-propargyl-5-fluoro-2'-deoxyuridine (1), and its activity was higher than that of the parent nucleoside. The other new compounds exhibited moderate activity in all of the used cell lines.

Preparation of a ZnO nanoparticles/multiwalled carbon nanotubes/carbon paste electrode as a sensitive tool for capecitabine determination in real samples

The present study describes the fabrication of a sensitive electrochemical sensor for the determination of capecitabine (Cap).

A Two-Photon Ratiometric Fluorescent Probe for Imaging Carboxylesterase 2 in Living Cells and Tissues

In this study, a two-photon ratiometric fluorescent probe NCEN has been designed and developed for highly selective and sensitive sensing of human carboxylesterase 2 (hCE2) based on the catalytic properties and substrate preference of hCE2. Upon addition of hCE2, the probe could be readily hydrolyzed to release 4-amino-1,8-naphthalimide (NAH), which brings remarkable red-shift in fluorescence (90 nm) spectrum. The newly developed probe exhibits good specificity, ultrahigh sensitivity, and has been successfully applied to determine the real activities of hCE2 in complex biological samples such as cell and tissue preparations. NCEN has also been used for two-photon imaging of intracellular hCE2 in living cells as well as in deep-tissues for the first time, and the results showed that the probe exhibited high ratiometric imaging resolution and deep-tissue imaging depth. All these findings suggested that this probe holds great promise for applications in bioimaging of endogenous hCE2 in living cells and in exploring the biological functions of hCE2 in complex biological systems.

Efficacy of capecitabine monotherapy as the first-line treatment of metastatic HER2-negative breast cancer

AIMS AND BACKGROUND

Capecitabine is a potent and safe agent that can be used after anthracycline and taxane treatment in patients with metastatic breast cancer (MBC). The purpose of this study was to investigate the efficacy and safety of capecitabine monotherapy as a first-line treatment in human epidermal receptor 2 (HER2)-negative patients with MBC.

METHODS AND STUDY DESIGN

In this single-center trial, a total of 109 HER2-negative patients with MBC who received capecitabine monotherapy as first-line treatment between 2003 and 2014 were retrospectively analyzed. Kaplan-Meier survival analysis was carried out for progression-free survival (PFS) and for overall survival (OS). Two-sided p values of <0.05 were considered statistically significant.

RESULTS

Median PFS was 7.0 ± 0.67 (confidence interval (CI) 5.6-8.3) months and median OS was 30 ± 4.1 (CI 21.8- 38.1) months. First-line capecitabine treatment for HER2-negative MBC was more effective in the estrogen receptor (ER)-positive patient population compared to the ER-negative group (median PFS 9 vs 4 months (p = 0.002), median OS 33 vs 21 months (p = 0.01)). Indeed, the overall response rate in the ER-negative group was 16%, while this was calculated as 38% for ER-positive cases. While most of our patient population was treated with a higher dose (1250 mg/m2), the observed grade 3-4 toxicities were lower compared to some previously reported phase II and phase III capecitabine studies.

CONCLUSIONS

Capecitabine monotherapy is an effective and safe regimen for ER-positive, HER2-negative patients with MBC. Its low toxicity profile compared to other intravenous cytotoxic agents and the ease of its oral administration make this agent a preferable option for both physicians and patients.

Discovery of novel mutations in the dihydropyrimidine dehydrogenase gene associated with toxicity of fluoropyrimidines and viewpoint on preemptive pharmacogenetic screening in patients

Background

Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme of the metabolic pathway of 5-fluorouracil (5-FU) and other fluoropyrimidines to inactive compounds. For this reason, severe, life-threatening toxicities may occur in patients with deficient DPD activity when administered standard doses of 5-FU and its prodrugs.

Materials and methods

We selected three patients with colorectal adenocarcinoma who displayed unexpected severe adverse reactions after treatment with 5-FU and capecitabine. To investigate the possible involvement of deficient variants of the DPD gene (DPYD), a denaturing HPLC (dHPLC) approach followed by target exon sequencing of DPYD was performed on DNA extracted from peripheral blood.

Results

Three novel non-synonymous mutations of DPYD, c.2509-2510insC, c.1801G>C, and c.680G>A, were detected in these subjects. Due to the absence of other deficient variants of DPYD and the compatibility of adverse reactions with fluoropyrimidine treatment, the novel variants were associated with a poor-metabolizer phenotype.

Conclusions

Stratification of patients on the basis of their genotype may help prevent toxicity, and the large body of evidence about the pathogenesis of fluoropyrimidine-induced adverse reactions strongly encourages the adoption of best practice recommendations to appropriately address this important clinical issue. This approach is of utmost importance within a preventive, prognostic, and personalized approach to patient care in the oncology setting.

MicroRNAs predict and modulate responses to chemotherapy in colorectal cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-related death globally. Chemotherapy regimens consisting of 5-fluorouracil (5-FU) in combination with either oxaliplatin or irinotecan are the first-line options for treatment of metastatic CRC. However, primary or acquired resistance to these chemotherapeutics is a major clinical challenge. MicroRNAs (miRNAs) are a group of small non-coding RNAs that regulate gene expression post-transcriptionally. miRNAs play important roles in many cancer-related processes, including cell proliferation, apoptosis and invasion, and their dysregulation is implicated in colorectal tumourigenesis. Pertinent to chemotherapy, increasing evidence has revealed that miRNAs can be directly linked to chemosensitivity in CRC. In this review, we summarize current evidence concerning the role of miRNAs in prediction and modulation of cellular responses to 5-FU, oxaliplatin and irinotecan in CRC. We also discuss the possible targets and intracellular pathways involved in these processes.

Adherence to capecitabine treatment and contributing factors among cancer patients in Malaysia

Ensuring adherence to chemotherapy is important to prevent disease progression, prolong survival and sustain good quality of life. Capecitabine is a complex chemotherapeutic agent with many side effects that might affect patient adherence to treatment. This cross sectional study aimed to determine adherence to capecitabine and its contributing factors among cancer outpatients in Malaysia. One hundred and thirteen patients on single regime capecitabine were recruited from Hospital Sultan Ismail and Hospital Kuala Lumpur from October 2013 to March 2014. Adherence was determined based on adherence score using validated Medication Compliance Questionnaire. Patient socio-demographics, disease, and treatment characteristics were obtained from medical records. Satisfaction score was measured using the validated Patient Satisfaction with Healthcare questionnaire. The mean adherence score was 96.1% (standard deviation: 3.29%). The significant contributing factors of adherence to capecitabine were Malay ethnicity [β=1.3; 95% confidence interval (CI): 0.21, 2.43; p value=0.020], being female [β=1.8; 95%CI: 0.61, 2.99; p value=0.003]), satisfaction score [β=0.08; 95%CI: 0.06, 1.46; p value=0.035], presence of nausea or vomiting [β=2.3; 95%CI: 1.12, 3.48; p value <0.001] and other side effects [β=1.45; 95%CI: 0.24, 2.65; p value=0.019]. Adherence to capecitabine was generally high in our local population. Attention should be given to non-Malay males and patients having nausea, vomiting or other side effects. Sufficient information, proactive assessment and appropriate management of side effects would improve patient satisfaction and thus create motivation to adhere to treatment plans.

Benign dermoscopic parallel ridge pattern in plantar hyperpigmentation due to capecitabine

We report the case of a 37-year-old woman (phototype II) who presented at our outpatient clinic with a two-month history of hyperpigmented plantar macules. Medical history revealed that the patient had taken capecitabine in the past three months as adjuvant chemotherapy for recurrent breast cancer. Dermoscopic examination of the plantar macules showed parallel ridge pattern with pigmentation in the furrows without obliteration of eccrine gland apertures. Besides in acral melanoma, parallel ridge pattern can also be observed in benign plantar lesions, such as congenital or acquired acral nevi, subcorneal hemorrhage, dye-related pigmentation and drug-induced hyperpigmentation, especially in patients with phototypes III–VI. The few reported cases of capecitabine-induced hyperpigmentation have been associated with hand and foot syndrome in patients with phototypes IV–V and palmar as well as plantar involvement.

Trial watch - inhibiting PARP enzymes for anticancer therapy

Poly(ADP-ribose) polymerases (PARPs) are a members of family of enzymes that catalyze poly(ADP-ribosyl)ation (PARylation) and/or mono(ADP-ribosyl)ation (MARylation), two post-translational protein modifications involved in crucial cellular processes including (but not limited to) the DNA damage response (DDR). PARP1, the most abundant family member, is a nuclear protein that is activated upon sensing distinct types of DNA damage and contributes to their resolution by PARylating multiple DDR players. Recent evidence suggests that, along with DDR, activated PARP1 mediates a series of prosurvival and proapoptotic processes aimed at preserving genomic stability. Despite this potential oncosuppressive role, upregulation and/or overactivation of PARP1 or other PARP enzymes has been reported in a variety of human neoplasms. Over the last few decades, several pharmacologic inhibitors of PARP1 and PARP2 have been assessed in preclinical and clinical studies showing potent antineoplastic activity, particularly against homologous recombination (HR)-deficient ovarian and breast cancers. In this Trial Watch, we describe the impact of PARP enzymes and PARylation in cancer, discuss the mechanism of cancer cell killing by PARP1 inactivation, and summarize the results of recent clinical studies aimed at evaluating the safety and therapeutic profile of PARP inhibitors in cancer patients.

Metronomic capecitabine as second-line treatment in hepatocellular carcinoma after sorafenib failure

BACKGROUND

No standard second-line treatments are available for hepatocellular carcinoma patients who fail sorafenib therapy. We assessed the safety and efficacy of metronomic capecitabine after first-line sorafenib failure.

METHODS

Retrospective analysis of consecutive hepatocellular carcinoma patients receiving metronomic capecitabine between January 2012 and November 2014. The primary end-point was safety, secondary end-point was efficacy, including time-to-progression and overall survival.

RESULTS

Twenty-six patients (80% Child-Pugh A, 80% Barcelona Clinic Liver Cancer stage C) received metronomic capecitabine (500 mg/bid). Median treatment duration was 3.2 months (range 0.6-31). Fourteen (53%) patients experienced at least one adverse event. The most frequent drug-related adverse events were bilirubin elevation (23%), fatigue (15%), anaemia (11%), lymphoedema (11%), and hand-foot syndrome (7.6%). Treatment was interrupted in 19 (73%) for disease progression, in 4 (15%) for liver deterioration, and in 1 (3.8%) for adverse event. Disease control was achieved in 6 (23%) patients. Median time-to-progression was 4 months (95% confidence interval 3.2-4.7). Median overall survival was 8 months (95% confidence interval 3.7-12.3).

CONCLUSIONS

Metronomic capecitabine was well tolerated in hepatocellular carcinoma patients who had been treated with sorafenib. Preliminary data show potential anti-tumour activity with long-lasting disease control in a subgroup of patients that warrants further evaluation in a phase III study.

Systemic therapy for colorectal cancer: patterns of chemotherapy and biologic therapy use in nationally representative US claims database

BACKGROUND

Treatment strategies for colorectal cancer (CRC) are highly variable. The aim of this study is to examine the patterns of chemotherapy and biologic therapy use for CRC patients in a national medical claims database.

METHODS

A retrospective and observational analysis was performed using the i3 Innovus claims database to identify healthcare services consumed by patients aged 18 years and older, diagnosed with CRC between 1 January 2005 and 30 June 2009 in commercial health plans.

RESULTS

Of 9,876 subjects diagnosed with CRC, fluorouracil (23.5 %) and capecitabine (10.0 %) were the dominant first-line monotherapies, followed by bevacizumab (3.2 %) and oxaliplatin (2.9 %). The most common combination regimen at first line and first and second line was FOLFOX (fluorouracil, leucovorin, and oxaliplatin; more than 25 %). The combinations FOLFIRI (fluorouracil, leucovorin, and irinotecan) plus bevacizumab (14.2 %) and FOLFOX plus bevacizumab (13.9 %) were significantly more frequent in third and successive lines of CRC therapy than other regimens (χ(2) = 191.2; P < 0.01). Additionally, the average annualized cost of CRC treatment for all patients was $US66,452, and the adjusted analysis demonstrated that patients receiving FOLFOX-A (FOLFOX + avastin) or FOLFIRI-A (FOLFIRI + avastin) had higher costs for CRC treatment.

CONCLUSIONS

With the exception of a sizeable portion of patients on monotherapy, the treatment patterns for CRC were largely consistent with National Comprehensive Cancer Network (NCCN) guidelines.

Colorectal cancer stem cell and chemoresistant colorectal cancer cell phenotypes and increased sensitivity to Notch pathway inhibitor

Colorectal cancer stem cells (Co-CSCs) are a small subpopulation of tumor cells which have been proposed to be tumor-initiating cells in colorectal cancer (CRC) and to be implicated in resistance to standard chemotherapy. Chemoresistance is a common problem in the clinic. However, the interrelation between Co-CSCs and chemoresistant cells has yet to be elucidated. The present study investigated the Co-CSC phenotype in colonospheres and chemoresistant CRC cell lines and aimed to identify targets for therapy. Colonospheres and chemoresistant CRC cells were found to be enriched with the CSC markers CD133 and CD44, and exhibited similar phenotypes. Furthermore, it was found that Notch signaling may simultaneously regulate Co-CSCs and chemoresistant cells and may represent a novel strategy for targeting this pathway in CRC.