A review of oxaliplatin and its clinical use in colorectal cancer

Progress of drug-loaded polymeric micelles into clinical studies

Targeting tumors with long-circulating nano-scaled carriers is a promising strategy for systemic cancer treatment. Compared with free small therapeutic agents, nanocarriers can selectively accumulate in solid tumors through the enhanced permeability and retention (EPR) effect, which is characterized by leaky blood vessels and impaired lymphatic drainage in tumor tissues, and achieve superior therapeutic efficacy, while reducing side effects. In this way, drug-loaded polymeric micelles, i.e. self-assemblies of amphiphilic block copolymers consisting of a hydrophobic core as a drug reservoir and a poly(ethylene glycol) (PEG) hydrophilic shell, have demonstrated outstanding features as tumor-targeted nanocarriers with high translational potential, and several micelle formulations are currently under clinical evaluation. This review summarizes recent efforts in the development of these polymeric micelles and their performance in human studies, as well as our recent progress in polymeric micelles for the delivery of nucleic acids and imaging.

What could Nintedanib (BIBF 1120), a triple inhibitor of VEGFR, PDGFR, and FGFR, add to the current treatment options for patients with metastatic colorectal cancer?

Increasing knowledge of the pro-angiogenic processes involved in the progression of metastatic colorectal cancer (mCRC) has resulted in the clinical development of several anti-angiogenic agents, with bevacizumab currently being the only approved agent for mCRC. Nintedanib (BIBF 1120) has been shown to block the vascular endothelial growth factor receptor (VEGFR), the platelet-derived growth factor receptor (PDGFR), and the fibroblast growth factor receptor (FGFR). By targeting FGFR signaling, nintedanib may overcome resistance to previous anti-VEGF treatments, and may represent a better approach in patients with high basal levels of circulating FGFs. In this article, the angiogenic mechanisms implicated in mCRC are reviewed (focusing on the signaling pathways activated by VEGFR, PDGFR, and FGFR), along with the clinical data for nintedanib in the context of other anti-angiogenic tyrosine kinase inhibitors under clinical development for mCRC. Biomarkers that could predict response to nintedanib are also discussed.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic drugs used to treat many types of solid tumours are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy and safety of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related drugs.

SEARCH METHODS

On 4 March 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and CINAHL Plus for randomised trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related drugs among human patients.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs in which the participants received chemotherapy with cisplatin or related compounds, with a potential chemoprotectant (acetylcysteine, amifostine, adrenocorticotrophic hormone (ACTH), BNP7787, calcium and magnesium (Ca/Mg), diethyldithiocarbamate (DDTC), glutathione, Org 2766, oxcarbazepine, or vitamin E) compared to placebo, no treatment, or other treatments. We considered trials in which participants underwent evaluation zero to six months after completing chemotherapy using quantitative sensory testing (the primary outcome) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary outcomes).

DATA COLLECTION AND ANALYSIS

Two review authors assessed each study, extracted the data and reached consensus, according to standard Cochrane methodology.

MAIN RESULTS

As of 2013, the review includes 29 studies describing nine possible chemoprotective agents, as well as description of two published meta-analyses. Among these trials, there were sufficient data in some instances to combine the results from different studies, most often using data from secondary non-quantitative measures. Nine of the studies were newly included at this update. Few of the included studies were at a high risk of bias overall, although often there was too little information to make an assessment. At least two review authors performed a formal review of an additional 44 articles but we did not include them in the final review for a variety of reasons.Of seven eligible amifostine trials (743 participants in total), one used quantitative sensory testing (vibration perception threshold) and demonstrated a favourable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Furthermore the change measured was subclinical. None of the three eligible Ca/Mg trials (or four trials if a single retrospective study was included) described our primary outcome measures. The four Ca/Mg trials included a total of 886 participants. Of the seven eligible glutathione trials (387 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing but reported disparate results; meta-analyses of three of these trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. Similarly, none of the three eligible vitamin E trials (246 participants) reported quantitative sensory testing. The eligible single trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), oxcarbazepine (32 participants), and retinoic acid (92 participants) did not perform quantitative sensory testing. In all, this review includes data from 2906 participants. However, only seven trials reported data for the primary outcome measure of this review, (quantitative sensory testing) and only nine trials reported our objective secondary measure, nerve conduction test results. Additionally, methodological heterogeneity precluded pooling of the results in most cases. Nonetheless, a larger number of trials reported the results of secondary (non-quantitative and subjective) measures such as the National Cancer Institute Common Toxicity Criteria (NCI-CTC) for neuropathy (15 trials), and these results we pooled and reported as meta-analysis. Amifostine showed a significantly reduced risk of developing neurotoxicity NCI-CTC (or equivalent) ≥ 2 compared to placebo (RR 0.26, 95% CI 0.11 to 0.61). Glutathione was also efficacious with an RR of 0.29 (95% CI 0.10 to 0.85). In three vitamin E studies subjective measures not suitable for combination in meta analysis each favoured vitamin E. For other interventions the qualitative toxicity measures were either negative (N-acetyl cysteine, Ca/Mg, DDTC and retinoic acid) or not evaluated (oxcarbazepine and Org 2766).Adverse events were infrequent or not reported for most interventions. Amifostine was associated with transient hypotension in 8% to 62% of participants, retinoic acid with hypocalcaemia in 11%, and approximately 20% of participantss withdrew from treatment with DDTC because of toxicity.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, retinoic acid, or vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients, as determined using quantitative, objective measures of neuropathy. Amifostine, calcium and magnesium, glutathione, and vitamin E showed modest but promising (borderline statistically significant) results favouring their ability to reduce the neurotoxicity of cisplatin and related chemotherapies, as measured using secondary, non-quantitative and subjective measures such as the NCI-CTC neuropathy grading scale. Among these interventions, the efficacy of only vitamin E was evaluated using quantitative nerve conduction studies; the results were negative and did not support the positive findings based on the qualitative measures. In summary, the present studies are limited by the small number of participants receiving any particular agent, a lack of objective measures of neuropathy, and differing results among similar trials, which make it impossible to conclude that any of the neuroprotective agents tested prevent or limit the neurotoxicity of platinum drugs.

Hypersensitivity to oxaliplatin: clinical features and risk factors

BACKGROUND

Oxaliplatin-based regimens induce a potential risk of hypersensitivity reaction (HSR), with incidence varying from 10% to 25% and lack of clearly identified risk factors. The present study aimed to assess incidence and risk factors in HSR.

METHODS

All patients treated with oxaliplatin in the Medical Oncology Department of the Lyon Sud University Hospital (Hospices Civils de Lyon, France) from October 2004 to January 2011 were enrolled. Incidence and severity of HSR were analyzed retrospectively and the potential clinicopathological covariates were tested on univariate and multivariate analysis.

RESULTS

A total of 1,221 doses of oxaliplatin were administered for 191 patients, 8.9% of whom experienced an HSR. Seventeen HSRs were observed, with 1.6% grade 3 and no grade 4 events. The first reaction appeared after a median of 3 oxaliplatin infusions. Using univariate analysis, HSR was associated with younger age (mean age, 56.2 years; p = 0.04), female gender (p = 0.01) and prior exposure to platinum salts (p = 0.02). No increased risk was associated with mean dose or with presence of atopic background. Multivariate analysis confirmed that women were at higher risk of oxaliplatin HSR than men (p < 0.05). Reintroduction of oxaliplatin was effective in 64.7% of hypersensitive patients using an appropriate premedication strategy. Patients who experienced a grade 3 HSR were not rechallenged.

CONCLUSION

The risk of developing oxaliplatin HSR should not be underestimated (8.9% of patients). The medical team's vigilance should be increased with women, younger patients and patients with prior exposure to platinum salts.

Oxaliplatin-induced neuropathy in colorectal cancer: many questions with few answers

Oxaliplatin is a chemotherapeutic agent effective against advanced colorectal cancer. Unlike with other platinum-based agents, the main side effect of oxaliplatin is polyneuropathy. Oxaliplatin-induced polyneuropathy (OIPN) has a unique profile, which can be divided into acute and chronic neurotoxicity. Early identification of the neurotoxicity and alterations in dose or schedule for the medication could prevent the development of chronic symptoms, which, once established, may take many months or years to resolve or even persist throughout life with a substantial effect on quality of life. There is no doubt that the use of pharmacogenomic methods to identify genetic bases of interindividual differences in drug response has led to what is called tailoring treatment. Yet there are some challenges regarding the application of these differences. Many efforts have been made to prevent or treat OIPN. Better understanding of the mechanisms underlying the acute and chronic forms of OIPN will be a key component of future advances in the prevention and treatment of OIPN. The aim of this review is to highlight the clinical presentation, assessment, and management of OIPN, as well as the underlying pathophysiologic and pharmacogenomic background.

Reversible Bilateral Blepharoptosis following Oxaliplatin Infusion: A Case Report and Literature Review

Oxaliplatin, a platinum analogue employed in the treatment of colorectal cancer and various other neoplasms, is characterized by a broad range of adverse events. Peripheral neuropathy is probably the most peculiar and clinically relevant toxicity associated with its use and can be distinguished into two types: acute and chronic neurotoxicity. We report a case of acute reversible bilateral palpebral ptosis and dyspnea without bronchospasm or laryngospasm which occurred at the end of the third administration of adjuvant oxaliplatin by infusion for stage III colon cancer in a 54-year-old woman. Chlorphenamine and hydrocortisone were administered with fast resolution of dyspnea and slight improvement of ptosis. Complete resolution with no sequelae occurred in one hour. No further recurrence of blepharoptosis was described during the following days. The subsequent cycles were prescribed at reduced dosage without acute complications.

Late complications related to palliative stenting in patients with obstructing colorectal cancer

INTRODUCTION

Self-expanding metal stents (SEMSs) are increasingly used for the palliative treatment of incurable obstructing colorectal cancer. The aim of the current study was to evaluate clinical outcome, including technical and clinical success of stenting, and to identify factors associated with late complications of SEMS in palliation of incurable obstructing colorectal cancer.

MATERIAL AND METHODS

Between 2003 and 2010 details of 56 patients who underwent an attempt of SEMS insertion for obstructive incurable colorectal cancer at Turku University Hospital were recorded to our database prospectively and analyzed retrospectively.

RESULTS

Technical success was achieved in 42 patients (75%) and clinical success in 39 patients (70%). Late complications related to SEMS occurred in 13 patients (31%). Ten patients (24%) needed re-intervention because of a complication: Eight ostomies, one Hartmann´s procedure due to late perforation and one re-stenting because of stent migration. Three patients with stent-related complications were treated conservatively. Chemotherapy and prolonged survival were risk factors for SEMS-related late complications and re-intervention.

CONCLUSION

SEMS insertion is a feasible procedure for the palliative treatment of obstructing colorectal cancer in patients with severe comorbidities and short life expectancy. However, for patients who are candidates for chemotherapy and have a longer life expectancy, other treatment options such as palliative tumor resection should also be considered.

Safety and efficacy of calcium and magnesium infusions in the chemoprevention of oxaliplatin-induced sensory neuropathy in gastrointestinal cancers

OBJECTIVE

To derive a more precise estimation on the safety and efficacy of calcium and magnesium (Ca and Mg) infusions in the prevention of oxaliplatin-induced sensory neuropathy.

METHODS

A total of 16 studies including 1765 individuals were involved in this meta-analysis. Odds ratio (OR) and its 95% confidence interval (CI) were calculated.

RESULTS

The difference in the incidence of oxaliplatin-induced neuropathy grade ≥ 1 was statistically significant between the Ca and Mg infusions treatment group and the untreated group (National Cancer Institute common toxicity criteria [NCI CTC]: OR 0.44, 95% CI 0.31-0.62, P = 0.000; oxaliplatin-specific scale [OSS]: OR 0.30, 95% CI 0.20-0.45, P = 0.000). Similar results were found in the incidences of oxaliplatin-induced neuropathy grade ≥ 2 (NCI CTC: OR 0.60, 95% CI 0.46-0.77, P = 0.000; OSS: OR 0.45, 95% CI 0.30-0.67, P = 0.000). However, we did not detect a trend of fewer oxaliplatin-induced neuropathy grade ≥ 3 incidences in the Ca and Mg infusions treatment group than the untreated group (NCI CTC: OR 0.67, 95% CI 0.44-1.01, P = 0.054; OSS: OR 0.66, 95% CI 0.34-1.29, P = 0.224). There was no difference in the response rate between the Ca and Mg treated group and the untreated group (OR 0.89, 95% CI 0.67-1.17, P = 0.391).

CONCLUSION

Ca and Mg infusions do not alter the efficacy of oxaliplatin-based chemotherapy in gastrointestinal cancers, which may be reasonable to add them to lessen the incidence of neuropathy.

An investigation of the effect of thiamine pyrophosphate on cisplatin-induced oxidative stress and DNA damage in rat brain tissue compared with thiamine

This study investigated the effects of thiamine pyrophosphate (TPP) at dosages of 10 and 20 mg/kg on oxidative stress induced in rat brain tissue with cisplatin and compared this with thiamine. Cisplatin neurotoxicity represents one of the main restrictions on the drug being given in effective doses. Oxidative stress is considered responsible for cisplatin toxicity. Our results showed that cisplatin increased the levels of oxidant parameters such as lipid peroxidation (thio barbituric acid reactive substance (TBARS)) and myeloperoxidase (MPO) in brain tissue and suppressed the effects of antioxidants such as total glutathione (GSH) and superoxide dismutase (SOD). TPP, especially at a dosage of 20 mg/kg, significantly reduced TBARS and MPO levels that increase with cisplatin administration compared with the thiamine group, while TPP significantly increases GSH and SOD levels. In addition, the level of 8-Gua (guanine), a product of DNA damage, was 1.7 ± 0.12 8-hydroxyl guanine (8-OH Gua)/105 Gua in brain tissue in the control group receiving cisplatin, compared with 0.97 ± 0.03 8-OH Gua/105 Gua in the thiamine pyrophosphate (20 mg/kg) group and 1.55 ± 0.11 8-OH Gua/105 Gua in the thiamine (20 mg/kg) group. These results show that thiamine pyrophosphate significantly prevents oxidative damage induced by cisplatin in brain tissue, while the protective effect of thiamine is insignificant.

Peripheral neurotoxicity of oxaliplatin in combination with 5-fluorouracil (FOLFOX) or capecitabine (XELOX): a prospective evaluation of 150 colorectal cancer patients

BACKGROUND

To report our prospective experience on the incidence and pattern of oxaliplatin (OXA)-induced peripheral neuropathy (OXA-IPN) in patients with colorectal cancer (CRC) treated with either FOLFOX-4 or XELoda + OXaliplatin (XELOX).

PATIENTS AND METHODS

One hundred and fifty patients scheduled to be treated with either FOLFOX or XELOX for CRC were prospectively monitored at baseline and followed-up during chemotherapy. The incidence and severity of symptoms secondary to OXA-IPN were recorded using three different types of assessment, i.e. the motor and neurosensory National Cancer Institute common toxicity criteria, version 3.0 (NCI-CTCv3), the clinical version of the total neuropathy score (TNSc) and electrophysiological scores.

RESULTS

Patients treated with either FOLFOX-4 or XELOX manifested similar incidence rates and severities of acute OXA-IPN. However, FOLFOX-4 was associated with increased incidence of chronic neurotoxicity, compared with XELOX-treated patients (n = 64/77 versus 44/73; P = 0.002), at a very similar OXA median cumulative dose during both regimens. Both the NCI-CTCv3 and TNSc demonstrated that the severity of cumulative OXA-IPN in FOLFOX-4-treated patients is higher than in those treated with XELOX.

CONCLUSION

The incidence of acute neurotoxicity during FOLFOX-4 therapy is similar to XELOX. However, it seems that FOLFOX-4 is more neurotoxic than XELOX in terms of cumulative OXA-IPN, despite comparable OXA cumulative dose.

Clinical pattern and associations of oxaliplatin acute neurotoxicity: a prospective study in 170 patients with colorectal cancer

BACKGROUND

The objective of the current prospective, multicenter, international study was to trace the incidence and severity of acute oxaliplatin-induced peripheral neuropathy (OXLIPN) and to determine its clinical pattern. The authors also specifically tested whether patients who had more symptoms of acute OXLIPN eventually would develop a more severe chronic, cumulative form of OXLIPN.

METHODS

One hundred seventy patients (mean ± standard deviation age, 63.7 ± 8.7 years) who were scheduled to receive either combined leucovorin, 5-fluoruracil, and oxaliplatin (FOLFOX) or combined capecitabine and oxaliplatin (XELOX) for metastatic colorectal cancer were monitored prospectively at baseline and were followed in 4 European sites. The incidence of hyperexcitability symptoms secondary to acute OXLIPN was assessed by using a descriptive questionnaire (yes/no question) at each clinical evaluation. Motor and neurosensory criteria according to version 3 of the National Cancer Institute's Common Toxicity Criteria were applied to clinically grade the severity of OXLIPN.

RESULTS

Acute OXLIPN was present in 146 of 170 patients (85.9%). The vast majority of these patients manifested cold-induced perioral (95.2%) or pharyngolaryngeal (91.8%) dysesthesias. Severe acute OXLIPN that required prolongation of oxaliplatin infusion from 2 hours to 4 to 6 hours occurred in 32 of 146 patients (21.9%). The increased number of acute OXLIPN symptoms was correlated significantly (Spearman rho correlation coefficient [r]) with both the development (r = 0.602; P < .001) and the degree of the chronic, cumulative form (r = 0.702; P < .001).

CONCLUSIONS

The current results indicated that the vast majority of patients with colorectal cancer who receive oxaliplatin-based chemotherapy will manifest symptoms of a transient acute syndrome soon after oxaliplatin administration. Patients who have a more complex combination of acute phenomena related to axonal hyperexcitability are those who eventually develop more severe OXLIPN. Therefore, it may be advisable to test agents against acute OXLIPN to verify their effects on the chronic form.

Literature review and practical aspects on the management of oxaliplatin-associated toxicity

Colorectal cancer is currently a public health priority because it is the second leading cause of cancer deaths in Western countries. Combination regimes of oxaliplatin and infusional fluorouracil/leucovorin or capecitabine have emerged as important options in the palliative and adjuvant treatment of colorectal cancer. Although better tolerated than cisplatin, oxaliplatin displays a characteristic profile of adverse events whose recognition and management are essential for physicians who treat patients with colorectal cancer and other malignancies that benefit from the use of oxaliplatin. Peripheral neuropathy is probably the most frequent and clinically relevant adverse event associated with the use of oxaliplatin, and several measures have been proposed to mitigate this toxicity. Temporary interruption of oxaliplatin before limiting neurotoxicity develops during therapy is a potential approach to avoid the problem of oxaliplatin-associated neuropathy in patients with metastatic colorectal cancer. Calcium and magnesium infusions have no effect on chemotherapy efficacy and also constitute a useful approach in clinical practice. Finally, the incidence and severity of chronic peripheral neuropathy in patients treated with oxaliplatin may be reduced by the use of neuroprotective agents, for example, venlafaxine. Other adverse events, such as gastrointestinal and liver toxicity, thrombocytopenia, and hypersensitivity reactions, are also reviewed in this article, and suggestions are made for their management.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (25 August 2010), the Cochrane Central Register of Controlled Trials (Issue 3, 2010 in The Cochrane Library), MEDLINE (January 1966 to August 2010), EMBASE (January 1980 to August 2010), LILACS (January 1982 to August 2010), CINAHL (January 1982 to August 2010) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients.

SELECTION CRITERIA

Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential chemoprotectant (acetylcysteine, amifostine, ACTH, BNP7787, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary).

DATA COLLECTION AND ANALYSIS

We identified 16 randomized trials involving five possible chemoprotective agents in the initial 2006 review. Each study was reviewed by two authors who extracted the data and reached consensus. The 2010 update identified 11 additional randomized trials consisting of nine possible chemoprotective agents, including three treatments (acetylcysteine, calcium and magnesium, and oxcarbazepine) not among those described in the 2006 review. The included trials in the updated review involved eight unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances.

MAIN RESULTS

One of four eligible amifostine trials (541 total participants in all four trials) used quantitative sensory testing and demonstrated a favorable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Of the six eligible glutathione trials (354 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The single eligible trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), calcium and magnesium (33 participants), and oxcarbazepine (32 participants) and the two eligible trials involving vitamin E (57 participants) did not perform quantitative sensory testing. In all, data from 1,537 participants were included.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Genetic polymorphisms in GST genes and survival of colorectal cancer patients treated with chemotherapy

Glutathione S-transferases (GSTs) participate in the detoxification of chemotherapeutic agents. Genetic polymorphisms in GST genes (GSTP1 Ile105Val, copy-number variants of GSTM1 and GSTT1) that lead to diminished enzyme activity have been associated with increased chemotherapeutic treatment benefit in colorectal cancer patients.

AIMS

We assessed the effect of genetic polymorphisms in GST genes on survival in colorectal cancer patients treated with adjuvant/palliative chemotherapy. As GSTs participate in the metabolism of platinum metabolites, we also assessed the association between genetic variants in GST genes and survival of colorectal cancer patients who received treatment with oxaliplatin.

MATERIALS & METHODS

We followed 338 colorectal cancer patients treated with chemotherapy for a median of 36.4 months since treatment start. A total of 65 of the patients received treatment with oxaliplatin. Polymorphisms were genotyped by fluorescence-based melting curve analysis (GSTP1 Ile105Val), a relative quantification method (copy-number variants of GSTM1 and GSTT1), and PCR followed by gel electrophoresis (null/non-null genotypes for GSTM1 and GSTT1). Associations between genotypes and overall survival were assessed using Kaplan-Meier curves and Cox proportional hazards regression.

RESULTS

As hypothesized, GSTM1 copy number variant was inversely associated with survival in colorectal cancer patients treated with chemotherapy. Mortality was significantly reduced in patients with one GSTM1 copy (hazard ratio: 0.45, 95% CI: 0.23-0.90, p = 0.02) and nonsignificantly reduced in those with the null genotype (HR: 0.67, 95% CI: 0.35-1.27, p = 0.22) compared with carriers of two copies. Both GSTP1 genotype and GSTT1 genotype were not associated with survival.

CONCLUSION

This is the first study to provide suggestive evidence for an effect of copy-number variation of GSTM1 on survival in colorectal cancer patients who received chemotherapy. Large studies are warranted to establish the impact of GST genotypes on treatment outcome in colorectal cancer patients.

Incidence and characteristics of peripheral neuropathy during oxaliplatin-based chemotherapy for metastatic colon cancer

AIM

The current prospective study sought to trace the incidence and severity of oxaliplatin-induced peripheral neuropathy (OXLIPN) and to determine its clinical and electrophysiological pattern.

PATIENTS AND METHODS

Twenty-five adult patients scheduled to be treated with 12 courses of the oxaliplatin-based regimen, FOLFOX-4, for metastatic colon cancer participated in this study. Patients were clinically and electrophysiologically monitored at baseline and followed-up during chemotherapy. The severity of OXLIPN was summarized by means of a modified Total Neuropathy Score (TNS).

RESULTS

Evidence of OXLIPN was disclosed in 16 of the 25 patients (64%). The mean TNS values for patients manifesting some grade of OXLIPN were 13.9 +/- 5.8 (range 7-28). All longitudinal comparisons concerning the motor conduction parameters failed to reach significance. By contrast, comparisons of the median changes at baseline and each of the follow-up studies revealed significant decrease in all sensory action potentials examined.

CONCLUSION

Our results indicate that the majority of patients treated with the FOLFOX-4 regimen would manifest an axonal, predominately sensory peripheral neuropathy, of mild to moderate severity.

Early effects of FOLFOX treatment of colorectal tumour in an animal model: assessment of changes in gene expression and FDG kinetics

PURPOSE

The very early chemotherapeutic effects of the FOLFOX (fluorouracil, folinic acid, oxaliplatin) protocol were assessed in mice implanted with a human colorectal cell line. The aim of this study was to identify changes in gene expression patterns and to detect combinations of PET parameters that may be helpful in identifying treated tumours early after chemotherapy using dynamic PET studies.

METHODS

A human colorectal cell line (HCT 116) was used in nude mice. Dynamic PET studies were performed in untreated (n = 13) and treated (n = 12) animals. The data were assessed using compartmental and noncompartmental analysis. The removed tumour specimens were assessed by gene array analysis to obtain quantitative information on gene expression.

RESULTS

One chemotherapeutic treatment using the FOLFOX protocol resulted in an upregulation of 2,078 gene probes by more than 25%, while 2,254 probes were downregulated following treatment. The gene array data demonstrated primarily an enhancement of genes related to apoptosis. In particular, the apoptosis antigen 1 (APO-1), p21 and the G protein-coupled receptor 87 (G-87) were 2.6- to 3.3-fold upregulated as compared to the expression in untreated animals. There was a 100% separation of untreated and treated animals on the basis of these three genes. The SUV and the FDG kinetic parameters obtained by compartmental and noncompartmental fitting were not significantly different when individual parameters were compared between groups. However, classification analysis of the combination of the PET parameters VB, K1, k3, and influx revealed an overall accuracy of 84%. We were able to identify 91.7% (11/12) of the treated animals and 76.9% (10/13) of the untreated animals correctly using the classification analysis of PET data.

CONCLUSION

Even one chemotherapeutic treatment using FOLFOX has an impact on gene expression and significantly modulates FDG kinetics. Quantitative assessment of the tracer kinetics and the application of classification analysis to the data are promising tools to identify those tumours that demonstrate a chemotherapeutic effect very early following treatment.

Adoption of self-expanding metallic stents in the palliative treatment of obstructive colorectal cancer-look out for perforations!

Self-expanding metallic stents (SEMSs) are increasingly used for the palliative treatment of inoperable colorectal cancer. The aim of the current study was to analyze the safety and efficacy of SEMS in the palliative treatment of obstructive colorectal cancer. Between 2003 and 2006, SEMS placement was attempted in 26 patients suffering from inoperable obstructive colorectal cancer. The recovery of the patients and the outcome of this treatment modality were analyzed prospectively. SEMS was successfully inserted in 19 (73%) of 26 patients. In 16 (84%) of these 19 cases, the placement of SEMS was the definitive treatment of colorectal obstruction and no additional surgical palliation was needed. There were 3 (16%) colonic perforations related to stent application. SEMS insertion seems to be an effective alternative in the palliative treatment of patients with malignant colorectal obstruction. However, perforation is a dangerous complication of the procedure.

Pharmacogenetics in colorectal cancer: a systematic review

Pharmacological treatment of colorectal cancer has improved survival rates in recent years. Individual genetic variation in genes associated with metabolism and targets of commonly used drugs can be responsible for variability in treatment outcome and toxicity. Diverse study designs have been used and heterogeneous end points evaluated by studies assessing the association of genetic markers with treatment outcome. We conducted this systematic review, including 51 studies, to present a comprehensive overview and draw further conclusions. To facilitate comparison of reported study results, risk estimates for observed genetic variants in 33 key genes are presented using defined reference categories and recalculated risk estimates based on data provided in original publications, where necessary. Overall, evidence indicates associations of the UGT1A1(*) 28 variant genotype with toxicity after irinotecan treatment, mutations in GSTP1-105 with improved treatment outcome and the XPD-751 variant genotype with poor treatment outcome after oxaliplatin treatment, and amplification of the EGFR gene with improved treatment outcome after therapy with monoclonal antibodies. Adequately powered prospective investigations designed specifically for pharmacogenetics are needed.

Chemotherapy in elderly patients with colorectal cancer

Significant advancements in chemotherapy for metastatic colorectal cancer (mCRC) have been achieved over the past decade, and the median overall survival duration is now close to 24 months with appropriate treatment. The most widely recommended chemotherapy regimens are based on the use of irinotecan or oxaliplatin in combination with 5-fluorouracil and leucovorin; some data suggest further benefit with the addition of the targeted agents bevacizumab or cetuximab. Colorectal cancer primarily affects the elderly; however, much of the defining clinical research in this field has excluded subjects of advanced age or with a poor performance status, making it difficult for clinicians to interpret current treatment paradigms for their older patients. Most clinical trials that have included elderly patients document similar survival rates and toxicity profiles to those seen in younger patients. Moreover, survey data suggest that >70% of elderly patients with cancer are willing to undergo strong, palliative chemotherapy. While these findings suggest that age itself should not determine candidacy for chemotherapy, it is important to note the great heterogeneity of the elderly population with regard to overall health, independence, and performance status. The use of a comprehensive geriatric assessment is recommended to evaluate chemotherapy appropriateness. The management of frail elderly patients and those with a short life expectancy should be focused on palliation, while fit elderly patients can receive aggressive therapy in a similar fashion to younger patients.

The effects of oxaliplatin, an anticancer drug, on potassium channels of the peripheral myelinated nerve fibres of the adult rat

Oxaliplatin is a novel chemotherapeutic agent which is effective against advanced colorectal cancer, but at the same time causes severe neuropathy in the peripheral nerve fibres, affecting mainly the voltage-gated sodium (Na(+)) channels (VGNaCs), according to literature. In this study the effects of oxaliplatin on the peripheral myelinated nerve fibres (PMNFs) were investigated in vitro using the isolated sciatic nerve of the adult rat. The advantage of this nerve-preparation was that stable in amplitude evoked compound action potentials (CAP) were recorded for over 1000min. Incubation of the sciatic nerve fibres in 25, 100 and 500microM oxaliplatin, for 300-700min caused dramatic distortion of the waveform of the CAP, namely broadening the repolarization phase, repetitive firing and afterhyperpolarization (AHP), related to the malfunction of voltage-gated potassium (K(+)) channels (VGKCs). At a concentration of 5microM, oxaliplatin caused broadening of the repolarization phase of the CAP only, while the no observed effect concentration was estimated to be 1microM. These findings are indicative of severe effects of oxaliplatin on the VGKCs. In contrast, the amplitude and the rise-time of the depolarization of the CAP did not change significantly, a clear indication that the VGNaCs of the particular nerve preparation were not affected by oxaliplatin. The effects of oxaliplatin on the PMNFs were similar to those of 4-aminopyridine (4-AP), a classical antagonist of VGKCs. These similarities in the pattern of action between oxaliplatin and 4-AP combined with the fact that the effects of oxaliplatin were more pronounced and developed at lower concentrations suggest that oxaliplatin acts as a potent VGKCs antagonist.

Colon-targeted delivery of live bacterial cell biotherapeutics including microencapsulated live bacterial cells

There has been an ample interest in delivery of therapeutic molecules using live cells. Oral delivery has been stipulated as best way to deliver live cells to humans for therapy. Colon, in particular, is a part of gastrointestinal (GI) tract that has been proposed to be an oral targeted site. The main objective of these oral therapy procedures is to deliver live cells not only to treat diseases like colorectal cancer, inflammatory bowel disease, and other GI tract diseases like intestinal obstruction and gastritis, but also to deliver therapeutic molecules for overall therapy in various diseases such as renal failure, coronary heart disease, hypertension, and others. This review provides a comprehensive summary of recent advancement in colon targeted live bacterial cell biotherapeutics. Current status of bacterial cell therapy, principles of artificial cells and its potentials in oral delivery of live bacterial cell biotherapeutics for clinical applications as well as biotherapeutic future perspectives are also discussed in our review.

A review on oxaliplatin-induced peripheral nerve damage

Platinum compounds are a class of chemotherapy agents that posses a broad spectrum of activity against several solid malignancies. Oxaliplatin (OXL) is a third-generation organoplatinum compound with significant activity mainly against colorectal cancer (CRC). Peripheral neuropathy is a well recognized toxicity of OXL, usually resulting in dose modification. OXL induces two types of peripheral neuropathy; acute and chronic. The acute oxaliplatin-induced peripheral neuropathy (OXLIPN) may be linked to the rapid chelation of calcium by OXL-induced oxalate and OXL is capable of altering the voltage-gated sodium channels through a pathway involving calcium ions. On the other hand, decreased cellular metabolism and axoplasmatic transport resulting from the accumulation of OXL in the dorsal root ganglia cells is the most widely accepted mechanism of chronic oxaliplatin-induced peripheral neuropathy (OXLIPN). As a result, OXL produces a symmetric, axonal, sensory distal primary neuronopathy without motor involvement. The incidence of OXLIPN is usually related to various risk factors, including treatment schedule, dosage, cumulative dose and time of infusion. The assessment of OXLIPN is primarily based on neurologic clinical examination and quantitative methods, such as nerve conduction study. To date, several neuroprotective agents including thiols, neurotrophic factors, anticonvulsants and antioxidants have been tested for their ability to prevent OXLIPN. However, the clinical data are still controversial. We herein review and discuss the pathogenesis, incidence, risk factors, diagnosis, characteristics and management of OXLIPN. We also highlight areas of future research.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents among human patients.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register (January 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1 2005), MEDLINE from (January 1966 to March 2005), EMBASE (from January 1980 to March 2005), LILACS (from January 1982 to March 2005), CINAHL (from January 1982 to March 2005) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients.

SELECTION CRITERIA

Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential neuroprotectant (amifostine, diethyldithiocarbamate, glutathione, Org 2766, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary).

DATA COLLECTION AND ANALYSIS

We identified 16 randomized trials involving five possible chemoprotective agents. Each study was reviewed by two authors who extracted the data and reached consensus. The included trials involved five unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances.

MAIN RESULTS

The one of five eligible amifostine trials (541 participants) using quantitative sensory testing demonstrated a favorable outcome in terms of amifostine neuroprotection, but the subclinical result was based on 14 participants receiving amifostine. Of the five eligible glutathione trials (327 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The one eligible diethyldithiocarbamate trial (214 participants) and the one eligible vitamin E trial (27 participants) did not perform quantitative sensory testing.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude if any of the purported neuroprotective agents (amifostine, diethyldithiocarbamate, glutathione, Org 2766, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Multiple-target Chemotherapy (Lv-modulated 5-FU Bolus and Continuous Infusion, Oxaliplatin, CPT-11) in Advanced 5-Fu-refractory Colorectal Cancer: Mtd Definition and Efficacy Evaluation. A Phase I-II Study

Aims and Background

To identify the maximum tolerated doses and to define the activity of a regimen incorporating leucovorin (LV)-modulated 5-fluorouracil (5-FU) bolus and continuous infusion, oxaliplatin (I-OHP) and irinotecan (CPT-11) in patients with advanced, 5-FU-refractory colorectal cancer (CRC).

Patients and Methods

Starting doses: LV 100 mg/m2 as a 2-hour infusion followed by 5-FU 300 mg/m2 bolus administration followed by 5-FU 500 mg/m2 as a 22-hour infusion on days 1 and 2; I-OHP 65 mg/m2 as a 2-hour infusion concomitantly with LV on day 1; CPT-11 90 mg/m2 concomitantly with LV on day 2. Planned cycle interval: 2 weeks.

Results

Two hundred twenty-six cycles were administered to 27 patients. Recommended doses were 5-FU bolus 300 mg/m2, 5-FU protracted infusion 500 mg/m2, l-OHP 75 mg/m2, and CPT-11 150 mg/m2. Among 25 patients evaluable for response we observed 13 disease stabilizations (52%; 95% CI: 33-71%), 6 instances of disease progression and 6 responses (24%; 95% CI: 7-41%). Median time to progression and overall survival were 24 and 60 weeks, respectively. A cycle delay >3 days was observed in 134/199 cycles (67%).

Conclusions

This study confirms the feasibility of triplet chemotherapy in patients with advanced 5-FU-refractory CRC.

Management of advanced colorectal cancer: state of the art

Colorectal cancer (CRC) caused over 500 000 deaths worldwide in 2002. Recent advances in the treatment of advanced disease include the incorporation of two new cytotoxic agents, irinotecan and oxaliplatin, into first-line regimens. The concept of planned sequential therapy involving three active agents during the course of a patient's treatment is evolving. Coupled with the integrated use of targeted monoclonal antibodies, we can now expect overall survival rates for advanced disease to exceed 20 months. This review considers current treatments and suggests where future progress may occur.

Oral Xeloda plus bi-platinu two-way combined chemotherapy in treatment of advanced gastrointestinal malignancies

AIM: To compare the effect, adverse events, cost-effectiveness and dose intensity (DI) of oral Xeloda vs calcium folinate (CF)/5-FU combination chemotherapy in patients with advanced gastrointestinal malignancies, both combined with bi-platinu two-way chemotherapy.

METHODS: A total of 131 patients were enrolled and randomly selected to receive either oral Xeloda (X group) or CF/5-FU (control group). Oral Xeloda 1 000 mg/m² was administered twice daily from d 1 to 14 in X group, while CF 200 mg/m² was taken as a 2-h intravenous infusion followed by 5-FU 600 mg/m² intravenously for 4-6 h on d 1-5 in control group. Cisplatin and oxaliplatin were administered in the same way to both the groups: cisplatin 60-80 mg/m² by hyperthermic intraperitoneal administration, and oxaliplatin 130 mg/m² intravenously for 2 h on d 1. All the drugs were recycled every 21 d, with at least two cycles. Pyridoxine 50 mg was given t.i.d. orally for prophylaxis of the hand-foot syndrome (HFS). Then the effect, adverse events, cost-effectiveness and DI of the two groups were evaluated.

RESULTS: Hundred and fourteen cases (87.0%) finished more than two chemotherapy cycles. The overall response rate of them was 52.5% (X group) and 42.4% (control group) respectively. Tumor progression time (TTP) was 7.35 mo vs 5.95 mo, and 1-year survival rate was 53.1% vs 44.5%. There was a remarkable statistical significance of TTP and 1-year survival between the two groups. The main Xeloda-related adverse events were myelosuppression, gastrointestinal toxicity, neurotoxicity and HFS, which were mild and well tolerable. Therefore, no patients withdrew from the study due to side effects before two chemotherapy cycles were finished. Both groups finished pre-arranged DI and the relative DI was nearly 1.0. The average cost for 1 patient in one cycle was ￥9 137.35 (X group) and ￥8 961.72 (control group), or US $1 100.89 in X group and $1 079.73 in control group. To add 1% to the response rate costs ￥161.44 vs￥210.37 respectively (US $19.45 vs $25.35). One-month prolongation of TTP costs ￥1 243.18 vs ￥1 506.17 (US $149.78 vs$181.47). Escalation of 1% of 1-year survival costs ￥172.74 vs ￥201.64 (US $20.75 vs $24.29).

CONCLUSION: Oral Xeloda combined with bi-platinu two-way combination chemotherapy is efficient and tolerable for patients with advanced gastrointestinal malignancies; meanwhile the expenditure is similar to that of CF/5-FU combined with bi-platinu chemotherapy, and will be cheaper if we are concerned about the increase of the response rate, TTP or 1-year-survival rate pharmacoeconomically.

Clinical management of oxaliplatin-associated neurotoxicity

In recent years, oxaliplatin-based chemotherapy protocols, particularly oxaliplatin in combination with infusional 5-fluorouracil/leucovorin (FOLFOX or FUFOX), have emerged as the standard of care in first- and second-line therapy of advanced-stage colorectal cancer. Although oxaliplatin by itself has only mild hematologic and gastrointestinal side effects, its clinically dominating toxicity affects the peripheral sensory nervous system in the form of 2 distinct types of neurotoxicity: (1) a unique, frequent, acute sensory neuropathy that is triggered or aggravated by exposure to cold but at the same time is rapidly reversible without persistent impairment of sensory functions; (2) the dose-limiting toxicity of oxaliplatin, a cumulative, chronic sensory neurotoxicity that resembles that of cisplatin with the important difference of its being more rapidly and completely reversible. This chronic sensory neurotoxicity is highly predictable, being closely associated with the cumulative dose of oxaliplatin that is administered. Various strategies have been proposed to prevent or treat oxaliplatin-induced neurotoxicity. The stop-and-go concept uses the predictability and reversibility of neurologic symptoms to allow patients to stay on an oxaliplatin-containing first-line therapy for a prolonged period. Several neuromodulatory agents such as calcium-magnesium infusions; antiepileptic drugs like carbamazepine, gabapentin, and venlafaxine; amifostine; a-lipoic acid; and glutathione have demonstrated some activity in the prophylaxis and treatment of oxaliplatin-induced acute neuropathy. However, randomized trials demonstrating a prophylactic or therapeutic effect on oxaliplatin's cumulative neurotoxicity are still lacking. The predictability of neurotoxicity associated with oxaliplatin-based therapy should allow patients and doctors to develop strategies to manage this side effect in view of the individual patient's clinical situation. This is of increasing importance, because the addition of bevacizumab to FOLFOX will conceivably further prolong the progression-free survival achieved with FOLFOX so that neurotoxicity and not tumor progression could become the dominating treatment-limiting issue in the first-line therapy of advanced colorectal cancer.

Second-line therapy for advanced colorectal carcinoma

The past decade has witnessed considerable advances in the treatment of colorectal cancer (CRC). The emergence and integration into clinical practice of new cytotoxic agents, such as irinotecan and oxaliplatin, has had a significant impact on outcomes from advanced CRC with median survivals of 18 to 21 months now achievable. Improvements in survival as a consequence of using these drugs as salvage therapies ultimately led to demonstration of efficacy for both in the first-line treatment of CRC. As the importance of second-line therapy is increasingly recognized, key issues, such as optimal schedules, chemotherapy combinations, and sequential therapy, need to be addressed. The integration of newer biologic agents, such as cetuximab and bevacizumab, for which recent data have emerged, has further added to the complexities of delivering therapy to patients with advanced CRC, heralding a new treatment era for this disease.