Oxaliplatin as single agent in previously untreated colorectal carcinoma patients: a phase II multicentric study

Beta-Hydroxybutyrate Augments Oxaliplatin-Induced Cytotoxicity by Altering Energy Metabolism in Colorectal Cancer Organoids

Deregulation of cellular metabolism has recently emerged as a notable cancer characteristic. This reprogramming of key metabolic pathways supports tumor growth. Targeting cancer metabolism demonstrates the potential for managing colorectal cancer. Beta-hydroxybutyrate (BOHB) acts as an acetyl-CoA source for the tricarboxylic acid (TCA) cycle, possibly redirecting energy metabolic pathways towards the TCA cycle that could enhance sensitivity to oxaliplatin, through the generation of reactive oxygen species (ROS). This study explores the potential of BOHB to enhance oxaliplatin's cytotoxic effect by altering the energy metabolism in colorectal cancer. The study employed advanced in vitro organoid technology, which successfully emulates in vivo physiology. The combination treatment efficacy of BOHB and oxaliplatin was evaluated via cell viability assay. The levels of key proteins involved in energy metabolism, apoptotic pathways, DNA damage markers, and histone acetylation were analyzed via Western Blot. ROS levels were evaluated via flow cytometer. Non-toxic doses of BOHB with oxaliplatin significantly amplified cytotoxicity in colorectal cancer organoids. Treatment with BOHB and/or melatonin resulted in significantly decreased lactate dehydrogenase A and increased mitochondrial carrier protein 2 levels, indicating inhibited aerobic glycolysis and an increased oxidative phosphorylation rate. This metabolic shift induced apoptotic cell death mediated by oxaliplatin, owing to high levels of ROS. Melatonin counteracted this effect by protecting cancer cells from high oxidative stress conditions. BOHB may enhance the efficacy of chemotherapeutics with a similar mechanism of action to oxaliplatin in colorectal cancer treatment. These innovative combinations could improve treatment outcomes for colorectal cancer patients.

Oxaliplatin-induced peripheral neurotoxicity in colorectal cancer patients: mechanisms, pharmacokinetics and strategies

Oxaliplatin-based chemotherapy is a standard treatment approach for colorectal cancer (CRC). However, oxaliplatin-induced peripheral neurotoxicity (OIPN) is a severe dose-limiting clinical problem that might lead to treatment interruption. This neuropathy may be reversible after treatment discontinuation. Its complicated mechanisms are related to DNA damage, dysfunction of voltage-gated ion channels, neuroinflammation, transporters, oxidative stress, and mitochondrial dysfunction, etc. Several strategies have been proposed to diminish OIPN without compromising the efficacy of adjuvant therapy, namely, combination with chemoprotectants (such as glutathione, Ca/Mg, ibudilast, duloxetine, etc.), chronomodulated infusion, dose reduction, reintroduction of oxaliplatin and topical administration [hepatic arterial infusion chemotherapy (HAIC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and hyperthermic intraperitoneal chemotherapy (HIPEC)]. This article provides recent updates related to the potential mechanisms, therapeutic strategies in treatment of OIPN, and pharmacokinetics of several methods of oxaliplatin administration in clinical trials.

Curcumin, calebin A and chemosensitization: How are they linked to colorectal cancer?

Colorectal cancer (CRC) is one of the leading malignant diseases worldwide with a high rate of metastasis and poor prognosis. Treatment options include surgery, which is usually followed by chemotherapy in advanced CRC. With treatment, cancer cells could become resistant to classical cytostatic drugs such as 5-fluorouracil (5-FU), oxaliplatin, cisplatin, and irinotecan, resulting in chemotherapeutic failure. For this reason, there is a high demand for health-preserving re-sensitization mechanisms including the complementary use of natural plant compounds. Calebin A and curcumin, two polyphenolic turmeric ingredients derived from the Asian Curcuma longa plant, demonstrate versatile anti-inflammatory and cancer-reducing abilities, including CRC-combating capacity. After an insight into their epigenetics-modifying holistic health-promoting effects, this review compares functional anti-CRC mechanisms of multi-targeting turmeric-derived compounds with mono-target classical chemotherapeutic agents. Furthermore, the reversal of resistance to chemotherapeutic drugs was presented by focusing on calebin A's and curcumin's capabilities to chemosensitize or re-sensitize CRC cells to 5-FU, oxaliplatin, cisplatin, and irinotecan. Both polyphenols enhance the receptiveness of CRC cells to standard cytostatic drugs converting them from chemoresistant into non-chemoresistant CRC cells by modulating inflammation, proliferation, cell cycle, cancer stem cells, and apoptotic signaling. Therefore, calebin A and curcumin can be tested for their ability to overcome cancer chemoresistance in preclinical and clinical trials. The future perspective of involving turmeric-ingredients curcumin or calebin A as an additive treatment to chemotherapy for patients with advanced metastasized CRC is explained.

Tumor growth rate during re-challenge chemotherapy with previously used agents as salvage treatment for metastatic colorectal cancer: A retrospective study

BACKGROUND

In clinical practice, the same chemotherapeutic agents are occasionally reused (re-challenge) after failure of all available standard chemotherapy options for metastatic colorectal cancer (mCRC). However, the benefits of re-challenge chemotherapy (Re-Cx) are unclear. This retrospective study evaluated the efficacy of Re-Cx, focusing on the tumor growth rate (TGR).

METHODS

The study included mCRC patients with measurable lesions who received Re-Cx from November 2011 to October 2018 at National Cancer Center Hospital. Re-Cx was defined as re-administration of agents which had been used in prior lines of chemotherapy and discontinued due to disease progression. We compared the TGR immediately after initiating Re-Cx regimens with that observed at the time of disease progression during prior chemotherapy (Prior-Cx) immediately before Re-Cx.

RESULTS

Of the 25 patients who received Re-Cx, five patients received two Re-Cx regimens. Therefore, a total of 30 cases of Re-Cx were analyzed in this study. The regimens of Re-Cx were oxaliplatin based (19 cases), irinotecan based (8 cases), and others (3 cases). Although the objective response rate to Re-Cx was 0%, the disease control rate was 60% (18 cases), and 40% (12 cases) showed some tumor shrinkage. We compared the effects of Re-Cx and Prior-Cx by the TGR and found that the TGR of Re-Cx was slower than that recorded in Prior-Cx in 26 of 30 cases (87%). In particular, the ratio of% TGR <0, which indicates tumor shrinkage, was obtained in 13 of 30 cases (43.3%). The median progression-free survival and overall survival after Re-Cx were 3.8 and 6.57 months, respectively.

CONCLUSION

We found that Re-Cx may have some anti-tumor efficacy as salvage treatment for mCRC and these results also suggested the clinical benefits of Re-Cx.

Localized and triggered release of oxaliplatin for the treatment of colorectal liver metastasis

Purpose: The aim of this study was to develop and evaluate a liposome formulation that deliver oxaliplatin under magnetic field stimulus in high concentration to alleviate the off-target effects in a rat model of colorectal liver metastases (CRLM).

Materials and Methods: Hybrid liposome-magnetic nanoparticles loaded with Cy5.5 dye and oxaliplatin (L-NIR- Fe₃O₄/OX) were synthesized by using thermal decomposition method. CRLM (CC-531) cell viability was assessed and rats orthotopically implanted with CC-531 cells were treated with L-NIR-Fe₃O₄/OX or by drug alone via different routes, up to 3 cycles of alternating magnetic field (AMF). Optical and MR imaging was performed to assess the targeted delivery. Biodistribution and histology was performed to determine the distribution of oxaliplatin.

Results: L-NIR-Fe₃O₄/OX presented a significant increase of oxaliplatin release (~18%) and lower cell viability after AMF exposure (p<0.001). Optical imaging showed a significant release of oxaliplatin among mesenteric vein injected (MV) group of animals. MR imaging on MV injected animals showed R2* changes in the tumor regions at the same regions immediately after infusion compared to the surrounding liver (p<0.001). Biodistribution analysis showed significantly higher levels of oxaliplatin in liver tissues compared to lungs (p<0.001) and intestines (p<0.001) in the MV animals that received AMF after L-NIR- Fe₃O₄/OX administration. Large tumor necrotic zones and significant improvement in the survival rates were noted in the MV animals treated with AMF.

Conclusion: AMF triggers site selective delivery of oxaliplatin at high concentrations and improves survival outcomes in colorectal liver metastasis tumor bearing rats.

Genetically Encoded Stealth Nanoparticles of a Zwitterionic Polypeptide-Paclitaxel Conjugate Have a Wider Therapeutic Window than Abraxane in Multiple Tumor Models

Small-molecule therapeutics demonstrate suboptimal pharmacokinetics and bioavailability due to their hydrophobicity and size. One way to overcome these limitations-and improve their efficacy-is to use "stealth" macromolecular carriers that evade uptake by the reticuloendothelial system. Although unstructured polypeptides are of increasing interest as macromolecular drug carriers, current recombinant polypeptides in the clinical pipeline typically lack stealth properties. We address this challenge by developing new unstructured polypeptides, called zwitterionic polypeptides (ZIPPs), that exhibit "stealth" behavior in vivo. We show that conjugating paclitaxel to a ZIPP imparts amphiphilicity to the polypeptide chain that is sufficient to drive its self-assembly into micelles. This in turn increases the half-life of paclitaxel by 17-fold compared to free paclitaxel, and by 1.6-fold compared to the nonstealth control, i.e., ELP-paclitaxel. Treatment of mice bearing highly aggressive prostate or colon cancer with a single dose of ZIPP-paclitaxel nanoparticles leads to near-complete eradication of the tumor, and these nanoparticles have a wider therapeutic window than Abraxane, an FDA-approved taxane nanoformulation.

Acute chemotherapy-induced peripheral neuropathy due to oxaliplatin administration without cold stimulation

PURPOSE

The incidence and time of onset of acute chemotherapy-induced peripheral neuropathy (ACIPN) caused by oxaliplatin remain unclarified. Hence, we investigated the prevalence, onset time, and location of ACIPN symptoms in patients with colorectal cancer (CRC) receiving oxaliplatin without cold stimulation.

METHODS

The study cohort comprised patients receiving oxaliplatin for CRC at our hospital between April 2017 and August 2018. Patients were instructed not to touch and/or drink cold things and were monitored for ACIPN symptoms in the hospital for 24 h after chemotherapy. ACIPN symptoms that appeared > 24 h after chemotherapy were recorded at the next visit. Symptom appearance time was defined as the duration from the administration of chemotherapy until the appearance of paresthesia classified as grade 1 using the Common Terminology Criteria for Adverse Events.

RESULTS

Forty-five patients received chemotherapy, comprising 23 men and 22 women, aged 67 years (29-88 years). The location of ACIPN was the fingers in 55.6% of cases, pharynx in 26.7%, perioral region in 24.4%, and feet in 6.7%. The average duration from oxaliplatin administration to symptom development was 182 min (range 62-443 min) for the fingers, 291 min (176-432 min) for the pharynx, 311 min (127-494 min) for the perioral region, and 297 min (234-355 min) for the feet. Pharyngeal symptoms were more common in patients older than 65 years than in those younger than 65 years.

CONCLUSIONS

The incidence and time of the onset of ACIPN caused by oxaliplatin varies between the body and regions.

Molecular mechanisms of cold pain

The sensation of cooling is essential for survival. Extreme cold is a noxious stimulus that drives protective behaviour and that we thus perceive as pain. However, chronic pain patients suffering from cold allodynia paradoxically experience innocuous cooling as excruciating pain. Peripheral sensory neurons that detect decreasing temperature express numerous cold-sensitive and voltage-gated ion channels that govern their response to cooling in health and disease. In this review, we discuss how these ion channels control the sense of cooling and cold pain under physiological conditions, before focusing on the molecular mechanisms by which ion channels can trigger pathological cold pain. With the ever-rising number of patients burdened by chronic pain, we end by highlighting the pressing need to define the cells and molecules involved in cold allodynia and so identify new, rational drug targets for the analgesic treatment of cold pain.

Ex vivo tissue slice culture system to measure drug-response rates of hepatic metastatic colorectal cancer

Background

The lack of predictive biomarkers or test systems contributes to high failure rates of systemic therapy in metastasized colorectal carcinoma, accounting for a still unfavorable prognosis. Here, we present an ex vivo functional assay to measure drug-response based on a tissue slice culture approach.

Methods

Tumor tissue slices of hepatic metastases of nine patients suffering from colorectal carcinoma were cultivated for 72 h and treated with different concentrations of the clinically relevant drugs Oxaliplatin, Cetuximab and Pembrolizumab. Easy to use, objective and automated analysis routines based on the Halo platform were developed to measure changes in proliferative activity and the morphometric make-up of the tumor. Apoptotic indices were assessed semiquantitatively.

Results

Untreated tumor tissue slices showed high morphological comparability with the original “in vivo”-tumor, preserving proliferation and stromal-tumor interactions. All but one patients showed a dosage dependent susceptibility to treatment with Oxaliplatin, whereas only two patients showed responses to Cetuximab and Pembrolizumab, respectively. Furthermore, we identified possible non-responders to Cetuximab therapy in absence of RAS-mutations.

Conclusions

This is the first time to demonstrate feasibility of the tissue slice culture approach for metastatic tissue of colorectal carcinoma. An automated readout of proliferation and tumor-morphometry allows for quantification of drug susceptibility. This strongly indicates a potential value of this technique as a patient-specific test-system of targeted therapy in metastatic colorectal cancer. Co-clinical trials are needed to customize for clinical application and to define adequate read-out cut-off values.

Bifunctional liposomes reduce the chemotherapy resistance of doxorubicin induced by reactive oxygen species

Doxorubicin (DOX) liposome is a widely used nano-medicine for colorectal cancer treatment. However, doxorubicin therapy increases the level of reactive oxygen species (ROS) in tumor cells, such as hydrogen peroxide (H₂O₂), which can stabilize hypoxia-inducible-factor-1α (HIF-1α). In a tumor hypoxic microenvironment, HIF-1 can up-regulate tumor-resistance related proteins, including P-glycoprotein (P-gp), glucose transporter 1 (GLUT-1), and matrix metalloproteinase 9 (MMP-9), leading to tumor tolerance to chemotherapy. The functional inhibition of HIF-1 can overcome this resistance and enhance the efficacy of tumor therapy. Here, we encapsulated one of the most effective HIF-1 inhibitors, acriflavine (ACF), and DOX in liposomes (DOX-ACF@Lipo) to construct bifunctional liposomes. ACF and DOX, released from DOX-ACF@Lipo, could effectively suppress the function of HIF-1 and the process of DNA replication, respectively. Consequently, the bifunctional liposome has great potential to be applied in clinics to overcome chemotherapy resistance induced by hypoxia.

Role of Dicer in regulating oxaliplatin resistance of colon cancer cells

Colorectal cancer (CRC) is a major health problem due to its high mortality rate. The incidence of CRC is increasing in young individuals. Oxaliplatin (OXA) is an approved third-generation drug and is used for first-line chemotherapy in CRC. Although current standard chemotherapy improves the overall survival of CRC patients, an increasing number of reports of OXA resistance in CRC therapy indicates that resistance has become an urgent problem in clinical applications. Dicer is a critical enzyme involved in miRNA maturation. The expression of Dicer has been reported to be involved in the resistance to various drugs in cancer. In the present study, we aimed to investigate the role of Dicer in OXA resistance in CRC. We found that OXA treatment inhibited Dicer expression through decreasing the protein stability. OXA-induced Dicer protein degradation occurred through both proteasomal and lysosomal proteolysis, while the CHIP E3 ligase was involved in OXA-mediated Dicer ubiquitination and degradation. We established stable OXA-resistant clones from CRC cells, and observed that the CHIP E3 ligase was decreased, along with the increased Dicer expression in OXA-resistant cells. Knockdown of Dicer resensitized CRC cells to OXA treatment. In this study, we have revealed the role of miRNA biogenesis factors in OXA resistance in CRC cells.

Safety and antitumor activity of arsenic trioxide plus infusional 5-fluorouracil, leucovorin, and irinotecan as second-line chemotherapy for refractory metastatic colorectal cancer: A pilot study from South India

BACKGROUND

After failing oxaliplatin-based first-line chemotherapy (CT), approximately 4%-21% of patients with metastatic colorectal cancer (mCRC) respond to irinotecan-based second-line treatment. Earlier studies have demonstrated that arsenic trioxide (ATO) can significantly resensitize resistant colon cancer to 5-fluorouracil (5-FU) by downregulating thymidylate synthase (TS). We hypothesized that a combination of ATO with infusional 5-FU, leucovorin, and irinotecan (FOLFIRI) regimen in mCRC patients refractory to first-line FOLFOX/CAPOX could further improve the outcome of second-line CT.

MATERIALS AND METHODS

Patients were administered ATO 0.15 mg/kg/day on days 1-2 along with FOLFIRI regimen at standard doses every 2 weeks, until disease progression, unacceptable toxicity, or patients' refusal. Responses to CT were reported according to RECIST 1.1. Adverse events were classified based on CTCAE version 4.0.

RESULTS

Between September 2016 and July 2017, 17 patients with refractory mCRC were treated with this investigational combination. The median age was 49 years; 13 males and 4 females; ECOG PS 0-1/2, 14/3. The most common site of metastases was liver (n = 11) followed by peritoneum (n = 7) and number of involved metastatic sites 1-2/≥3, 9/8. After 6 cycles of CT, overall response rate and disease control rate were 17.6% and 82.4%, respectively (complete remission = 0, partial remission = 3 patients, stable disease = 11 patients). Median progression-free survival was 5.3 months (95% confidence interval [CI]: 4.3-7.0) and median overall survival was 9 months (95% CI: 7.4-10.5) from the initiation of ATO plus FOLFIRI. The toxicities were as follows: Grade 1/2 toxicity: fatigue (7 patients), constipation (2), and nausea and vomiting (2); Grade 3 toxicity: fatigue (3), neutropenia (2), febrile neutropenia (1), diarrhea (2), and QTc prolongation (1). No patient experienced Grade 4 toxicities.

CONCLUSIONS

The addition of ATO to FOLFIRI regimen as second-line CT in patients with refractory mCRC offered an encouraging antitumor effect at the cost of manageable toxicity.

The Value of Oxaliplatin in Combination with Continuous infusion ± Bolus 5-Fluorouracil and Levo-Folinic Acid in Metastatic Colorectal Cancer Progressing after 5FU-Based Chemotherapy: A Giscad (Italian Group for the Study of Digestive Tract) Cancer Phase II Trial

Aims and background

The phase II trial was designed to evaluate the activity of combined oxaliplatin (L-OHP), continuous infusion (CI) ± bolus 5-fluorouracil (5FU) and levo-folinic acid (IFA) in patients with metastatic colorectal cancer progressing after one or more lines of 5FU-based chemotherapy.

Patients and methods

We designed two contemporary studies: in the former we enrolled patients previously treated with 1 line of chemotherapy, and in the latter, patients previously treated with 2, 3 and 4 lines. Seventy-six consecutive patients were enrolled: 45 received L-OHP (85 mg/m2 iv 2 h on day 1) + I-FA (100 mg/m2 iv 2 h on days 1 and 2) + 5FU iv bolus (400 mg/m2 days 1 and 2) + 5FU (600 mg/m2 CI 22 h days 1 and 2 (FOLFOX 4); 31 received L-OHP (100 mg/m2 iv 2 h on day 1) + I-FA (250 mg/m2 iv 2 h on days 1 and 2), followed by 5FU (1500 mg/m2 CI 24 h days 1 and 2 (FOLFOX 2). The treatment was recycled every 2 weeks and continued until progression and/or unacceptable toxicity or patient preference. The primary end point was activity (tumor growth control [TGC]: partial response [PR] + stable disease [SD]); the secondary end points were time to progression (TTP), overall survival (OS) and toxicity.

Results

Forty-five patients in 2nd line (22 FOLFOX 4, 23 FOLFOX 2), 23 (17 FOLFOX 4, 6 FOLFOX 2) in 3rd, 4 in 4th and 1 in 5th line were assessable; 3 were lost to follow-up. In 15 patients (11 FOLFOX 4, 4 FOLFOX 2), disease involved the liver only. A total of 533 courses were administered with a range of 1-14 in FOLFOX4 and 1-12 in FOLFOX2; dose intensity was 92.85%, and the total dose of the administered L-OHP was 98.29%. As a 2nd line treatment, FOLFOX 4 achieved TGC in 72.8% of the patients (PR, 18.2%; SD, 54.6%), with a median TTP of 6 months and a median OS of 7 months, whereas in the FOLFOX 2 group these figures were 78.3% (PR 21.8%, SD 56.5%), and 5 and 9 months. As a 3rd line treatment, FOLFOX 4 produced TGC in 41.1% of patients (PR 23.5%, SD 17.6%), with a median TTP of 5 months and median OS of 7+ months, whereas FOLFOX 2 obtained respective values of 50% (PR 16.7%, SD 33.3%), 7 and 9 months. As a 4th line of treatment, TGC was achieved in 2 patients (1 PR, 1 SD); the patient in 5th line therapy obtained a SD. With “de Gramont” as the first-line regimen, patients assessable were 24 in FOLFOX 4 and 18 in FOLFOX 2. In the former population, TGC was 70.8% (PR 37.5%, SD 33.3%), with a TTP of 6 months and OS of 10 months, whereas with FOLFOX2 these values were 61.1% (PR 5.6%, SD 55.5), 5 and 7 months. In patients with liver involvement only, FOLFOX 4 obtained TGC in 63.6% of cases (with a TTP of 7 months and OS of 6+ months), FOLFOX 2 in 100% (with a TTP of 9.5 months and OS of 13.5+ months). Both schedules exhibited an acceptable toxicity: neurologic, hematologic and hepatic grade 3 side effects occurred in a limited number of patients, with a higher frequency in the FOLFOX 2 group.

Conclusions

Treatment with L-OHP, CI ± bolus 5FU and I-FA was well tolerated. The activity in terms of TGC was interesting and comparable with results reported in the literature for the standard treatment for 2nd line, i.e. irinotecan alone. Treatment was effective in 2nd line and in patients previously treated with more than two chemotherapy lines; in particular, treatment was active in patients with hepatic disease only. Although the two schedules seemed to achieve the same benefit with the same tolerance, we could not define from the study the better regime.

The incidence of acute oxaliplatin-induced neuropathy and its impact on treatment in the first cycle: a systematic review

BACKGROUND

Although acute oxaliplatin-induced neuropathy (OXIPN) is frequently regarded to be transient, recent studies have reported prolongation of infusion times, dose reduction and treatment cessation following the first dose of oxaliplatin in quarter of patients. Acute OXIPN is also a well-established risk factor for chronic neuropathy. However, there is underreporting of these parameters during the acute phase (≤ 14 days). This paper systematically reviews the incidence of acute OXIPN and its impact on treatment in the first cycle.

METHODS

A systematic literature search was performed using PubMed and Medline. Published original articles were included if they described details about prevalence of oxaliplatin-induced acute neuropathy.

RESULTS

Fourteen studies, comprised of 6211 patients were evaluated. The majority of patients were treated with oxaliplatin in combination with leucovorin and fluorouracil (FOLFOX). Most studies used the National Cancer Institute Common Toxicity Criteria to assess acute neuropathy. Acute neuropathy (Grades 1-4) was the most common event with prevalence ranging from 4-98%, followed by haematological (1.4-81%) and gastrointestinal (1.2-67%) toxicities, respectively. Drug regimens, starting dose of oxaliplatin and neuropathy assessment tools varied across studies. In addition, moderate to severe toxicities were common in patients that received a large dose of oxaliplatin (> 85 mg/m2) and/ or combined drugs. The majority of studies did not report the factors affecting acute neuropathy namely the range (minimal) doses required to evoke acute neuropathy, patient and clinical risk factors. In addition, there was no systematic reporting of the number of patients subjected to prolonged infusion, dose reduction, treatment delay and treatment cessation during the acute phase.

CONCLUSION

Despite the heterogeneity of studies regarding oxaliplatin starting dose, drug regimen, neuropathy assessment tools and study design, a large number of patients developed acute neuropathy. To develop a better preventive and therapeutic guideline for acute/chronic neuropathy, a prospective study should be conducted in a large cohort of patients in relation to drug regimen, starting/ranges (minimal) of doses producing acute neuropathy, treatment compliance, patient and clinical risk factors using a standardised neuropathy assessment tool.

Oxaliplatin rechallenge in metastatic colorectal cancer patients after prior oxaliplatin treatment

Because the number of cytotoxic agents available for the treatment of metastatic colorectal cancer (mCRC) is limited, rechallenge with the same chemotherapy agents can provide a continuum of treatment. This study investigated the efficacy and feasibility of oxaliplatin rechallenge in mCRC patients who had been previously exposed to oxaliplatin-based chemotherapy. Patients were included if they had mCRC and evaluable disease, had remained disease-free or progression-free for at least 6 months after the last dose of prior oxaliplatin-based therapy, and were retreated with oxaliplatin therapy. Between January 2009 and May 2014, 110 patients were retreated with oxaliplatin-based regimens; of these, 42 (38.2%) had received prior oxaliplatin as adjuvant chemotherapy and 68 (61.8%) as palliative chemotherapy. The overall response rate to oxaliplatin rechallenge was 30.9% (34/110), and the disease control rate was 68.2% (75/110), with one patient achieving complete response, 33 achieving partial response, and 41 having stable disease. Median progression-free survival and overall survival following oxaliplatin rechallenge were 5.9 months (95% confidence interval [CI], 4.4-7.4 months) and 18.5 months (95% CI, 14.0-23.0 months), respectively. Sixteen patients experienced grade 2 or 3 neuropathy. Ten patients experienced any grade hypersensitivity reaction within four cycles of treatment, including six who stopped treatment due to grade 3 or 4 hypersensitivity reactions. Rechallenge with oxaliplatin-based therapy may be an option for patients who achieve at least 6 months of disease-free or progression-free survival with prior oxaliplatin-based chemotherapy. However, neurotoxicity and hypersensitivity reactions should be carefully monitored in this setting.

Facile Deposition of Manganese Dioxide to Albumin-Bound Paclitaxel Nanoparticles for Modulation of Hypoxic Tumor Microenvironment To Improve Chemoradiation Therapy

Tumor microenvironment with hypoxia and excess hydrogen peroxide (H₂O₂) tremendously limits the effect of chemoradiation therapy of colorectal cancer. For the first time, we developed a facile method to deposit manganese dioxide (MnO₂) on the surface of albumin bound paclitaxel nanoparticles (ANPs-PTX) to obtain MnO₂-functioned ANPs-PTX (MANPs-PTX). In the tumor microenvironment, MANPs-PTX could consume excess hydrogen peroxide (H₂O₂) to produce abundant oxygen for tumor oxygenation and improve chemoradiation therapy. Meanwhile, the released Mn²⁺ from MANPs-PTX had excellent T₁ magnetic resonance imaging (MRI) performances for tumor detection. Notably, the obtained MANPs-PTX would be a promising theranostic agent and have potential clinical application prospects.

Adipose-derived stem cells decrease pain in a rat model of oxaliplatin-induced neuropathy: Role of VEGF-A modulation

Oxaliplatin therapy of colorectal cancer induces a dose-dependent neuropathic syndrome in 50% of patients. Pharmacological treatments may offer limited relief; scientific efforts are needed for new therapeutic approaches. Therefore we evaluated in a preclinical setting the pain relieving properties of mesenchymal stem cells and its secretome. Rat adipose stem cells (rASCs) were administered in a rat model of oxaliplatin-induced neuropathy. A single intravenous injection of rASCs reduced oxaliplatin-dependent mechanical hypersensitivity to noxious and non-noxious stimuli taking effect 1 h after administration, peaking 6 h thereafter and lasting 5 days. Cell-conditioned medium was ineffective. Repeated rASCs injections every 5 days relieved pain each time with a comparable effect. Labeled rASCs were detected in the bloodstream 1 and 3 h after administration and found in the liver 24 h thereafter. In oxaliplatin-treated rats, the plasma concentration of vascular endothelial growth factor (pan VEGF-A) was increased while the isoform VEGF₁₆₅b was upregulated in the spinal cord. Both alterations were reverted by rASCs. The anti-VEGF-A monoclonal antibody bevacizumab (intraperitoneally) reduced oxaliplatin-dependent pain. Studying the peripheral and central role of VEGF₁₆₅b in pain, we determined that the intraplantar and intrathecal injection of the growth factor induced a pro-algesic effect. In the oxaliplatin neuropathy model, the intrathecal infusion of bevacizumab, anti-rat VEGF₁₆₅b antibody and rASCs reduced pain. Adult adipose mesenchymal stem cells could represent a novel approach in the treatment of neuropathic pain. The regulation of VEGF-A is suggested as an effective mechanism in the complex response orchestrated by stem cells against neuropathy.

Remarkable response to fluorouracil, leucovorin, oxaliplatin, and irinotecan therapy in urothelial cancer of the renal pelvis: a case report

Background

No standard chemotherapy regimen for advanced urothelial cancer has been established, except for cisplatin-based regimens. We report the case of a patient with double primary cancer, urothelial carcinoma of the upper urinary tract and colorectal cancer, who underwent oxaliplatin-based chemotherapies.

Case presentation

A 56-year-old Japanese man presented to our hospital with the diagnosis of a left renal pelvic tumor and rectal cancer. Several examinations including ureteroscopic biopsy and computed tomography-guided biopsy were performed; however, the diagnosis of renal pelvic cancer could not be made. Because the rectal cancer had been growing during the course of examination, he underwent five cycles of neoadjuvant chemotherapy with fluorouracil, leucovorin, oxaliplatin, and irinotecan. The volumes of both the rectal cancer and renal pelvic tumor drastically decreased. He then underwent pelvic evisceration with colostomy and ureterocutaneostomy. The histological diagnosis of the renal pelvic tumor was urothelial carcinoma. He is free of disease at 12 months after the treatment.

Conclusions

To the best of our knowledge, this is the first report describing a remarkable response to fluorouracil, leucovorin, oxaliplatin, and irinotecan therapy for renal pelvic cancer. We suggest fluorouracil, leucovorin, oxaliplatin, and irinotecan is an effective therapy for patients with advanced urothelial cancer.

The Impact of Novel Radiation Treatment Techniques on Toxicity and Clinical Outcomes In Rectal Cancer

Purpose of review

Three-dimensional conformal radiation therapy (3DCRT) has been the standard technique in the treatment of rectal cancer. The use of new radiation treatment technologies such as intensity-modulated radiation therapy (IMRT), proton therapy (PT), stereotactic body radiation therapy (SBRT) and brachytherapy (BT) has been increasing over the past 10 years. This review will highlight the advantages and drawbacks of these techniques.

Recent findings

IMRT, PT, SBRT and BT achieve a higher target coverage conformity, a higher organ at risk sparing and enable dose escalation compared to 3DCRT. Some studies suggested a reduction in gastrointestinal and hematologic toxicities and an increase in the complete pathologic response rate; however, the clinical benefit of these techniques remains controversial.

Summary

The results of these new techniques seem encouraging despite conclusive data. Further trials are required to establish their role in rectal cancer.

Pharmacodynamics of Oxaliplatin-Derived Platinum Compounds During Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Emerging Aspect Supporting the Rational Design of Treatment Protocols

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is used to treat peritoneal surface malignancies with application of cytostatic drugs such as oxaliplatin (OX) after cytoreductive surgery. Despite its increased use, evidence for optimal drug dosage, and notably duration of HIPEC, is scarce.

METHODS

In this study, OX distribution was comprehensively assessed in nine patients during HIPEC (300 mg OX/m² body surface area in Physioneal solution for 30 min). Oxaliplatin and its derivatives were measured in peritoneal perfusates over time by liquid chromatography coupled with mass spectrometry (LC-MS), and the resulting total platinum concentration in tissue was analyzed by atomic absorption spectrometry. Additionally, a novel impedance-based real-time cytotoxicity assay was used to evaluate the bioactivity of perfusates ex vivo.

RESULTS

Compared with amounts of OX expected in peritoneal perfusates by calculation, only 10-15% of the parent drug could be detected by LC-MS during HIPEC. Notably, the study additionally detected platinum compounds consistent with OX transformation, accounting for a further fraction of the applied drug. The cytotoxic properties of perfusates remained unchanged during HIPEC, with only a slight but significant attenuation evidenced after 30 min.

CONCLUSIONS

The bioactivity of peritoneal perfusates ex vivo is a useful parameter for evaluating the actual cytotoxic potential of OX and its derivatives used in HIPEC over time, overcoming important limitations and disadvantages associated with respective drug monitoring only. Ex vivo cytotoxicity assays may be a promising tool to aid guiding future standardization and harmonization of HIPEC protocols based on drug-mediated effects.

Targeting of cancer‑associated fibroblasts enhances the efficacy of cancer chemotherapy by regulating the tumor microenvironment

Cancer-associated fibroblasts (CAFs), key components of the tumor stroma, can regulate tumorigenesis by altering the tumor microenvironment in variety of ways to promote angiogenesis, recruit inflammatory immune cells and remodel the extracellular matrix. Using a murine xenograft model of colon carcinoma, the present study observed that oxaliplatin increased the accumulation of CAFs and stimulated the production of cytokines associated with CAFs. When oxaliplatin was combined with the small-molecule dipeptidyl peptidase inhibitor PT-100, which inhibits CAFs by targeting fibroblast activation protein (FAP), the accumulation of CAFs was markedly reduced, xenograft tumor growth was significantly suppressed and the survival of the mice increased, compared to those of mice treated with oxaliplatin or PT-100 alone. Furthermore, the xenograft tumor tissues of mice treated with oxaliplatin and PT-100 contained lower numbers of tumor-associated macrophages and dendritic cells, expressed lower levels of cytokines associated with CAFs and had a lower density of CD31+ endothelial cells. The present study demonstrated that pharmacological inhibition of CAFs improved the response to chemotherapy, reduced the recruitment of immune tumor-promoting cells and inhibited angiogenesis. Combining chemotherapy with agents which target CAFs may represent a novel strategy for improving the efficacy of chemotherapy and reducing chemoresistance.

Pharmacologic resistance in colorectal cancer: a review

Colorectal cancer (CRC) persists as one of the most prevalent and deadly tumor types in both men and women worldwide. This is in spite of widespread, effective measures of preventive screening, and also major advances in treatment options. Despite advances in cytotoxic and targeted therapy, resistance to chemotherapy remains one of the greatest challenges in long-term management of incurable metastatic disease and eventually contributes to death as tumors accumulate means of evading treatment. We performed a comprehensive literature search on the data available through PubMed, Medline, Scopus, and the ASCO Annual Symposium abstracts through June 2015 for the purpose of this review. We discuss the current state of knowledge of clinically relevant mechanisms of resistance to cytotoxic and targeted therapies now in use for the treatment of CRC.

Bevacizumab in combination with fluoropyrimidine-irinotecan- or fluoropyrimidine-oxaliplatin-based chemotherapy for first-line and maintenance treatment of metastatic colorectal cancer

Despite a slight decrease in mortality rates, recent advances in screening methods, diagnosis and overall improved therapeutic options, colorectal cancer (CRC) remains among the leading causes of cancer-related death worldwide. The major cause is the mortality related to metastatic status of CRC. Increasing clinical evidence derived from randomized trials strongly suggests that the efficacy of standard cytotoxic agents, including various combinations of 5-fluoouracil (5-FU)/leucovorin (LV), capecitabine, irinotecan and oxaliplatin, may be significantly augmented with concomitant administration of molecular agents targeting the vascular endothelial growth factor (VEGF) signaling pathways, such as bevacizumab. Herein, we critically discuss the current data on the efficacy and safety profile of bevacizumab in combination with fluoropyrimidine-based chemotherapy for first-line and maintenance treatment of metastatic CRC and briefly comment on existing controversies and future perspectives.

Is more not better?: combination therapies in colorectal cancer treatment

The treatment of colorectal cancer has evolved dramatically in recent years with the availability of new chemotherapeutic agents and inhibitors of the vascular endothelial growth factor- and epidermal growth factor-signaling pathways. The incremental benefit of each individual line of therapy for advanced disease is relatively small. Advances in our ability to select patients should improve the cost-effectiveness of our treatment strategies (avoiding unnecessary toxicity in the patients who are unlikely to benefit and accepting the potential for adverse events in the patients who stand to benefit the most from a given regimen).

Computational evidence for structural consequences of kiteplatin damage on DNA

The reaction of the potential anticancer drug kiteplatin, cis-[PtCl2(cis-1,4-DACH)], with oligomers of single- and double-stranded DNA ranging from 2 to 12 base pairs in length was performed as a model for DNA interaction. The potential for conformational flexibility of single-stranded adducts was examined with density functional theory (DFT) and compared with data from (1)H-NMR 1D and 2D spectroscopy. This indicates the presence of multiple conformations of an adduct with d(GpG), but only one form of the adduct with d(TGGT). The importance of a suitable theoretical model, and in particular basis set, in reproducing experimental data is demonstrated. The DFT theoretical model was extended to platinated base pair step (GG/CC), allowing a comparison to the related compounds cisplatin and oxaliplatin. Adducts of kiteplatin with larger fragments of double-stranded DNA, including tetramer, octamer, and dodecamer, were studied theoretically using hybrid quantum mechanics/molecular mechanics methods. Structural parameters of all the base-paired models were evaluated and binding energies calculated in gas phase and in solution; these are compared across the series and also with the related complexes cisplatin and oxaliplatin, thus revealing insights into how kiteplatin binds to DNA and similarities and differences between this and related compounds.

Phase I clinical trial of ifosfamide, oxaliplatin, and etoposide (IOE) in pediatric patients with refractory solid tumors

Oxaliplatin, although related to cisplatin and carboplatin, has a more favorable toxicity profile and may offer advantages in combination regimens. We combined oxaliplatin, ifosfamide, and etoposide (IOE) and estimated the regimen's maximum tolerated dose (MTD) in children with refractory solid tumors. Dose-limiting toxicity (DLT) and MTD were assessed at 3 dose levels in a 21-day regimen: day 1, oxaliplatin 130 mg/m (consistent dose); days 1 to 3, ifosfamide 1200 mg/m/d (level 0) or 1500 mg/m/d (levels 1 and 2) and etoposide 75 mg/m/d (levels 0 and 1) or 100 mg/m/d (level 2). Course 1 filgrastim/pegfilgrastim was permitted after initial DLT determination, if neutropenia was dose limiting. Seventeen patients received 59 courses. Without filgrastim (n=9), DLT was neutropenia in 2 patients at dose level 1. No DLT was observed after adding filgrastim (n=8). There was no ototoxicity, nephrotoxicity >grade 1, or neurotoxicity >grade 2. One patient experienced a partial response and 9 had stable disease after 2 courses. In conclusion, the IOE regimen was well tolerated. Without filgrastim, neutropenia was dose limiting with MTD at ifosfamide 1200 mg/m/d and etoposide 75 mg/m/d. The MTD with filgrastim was not defined due to early study closure. Filgrastim allowed ifosfamide and etoposide dose escalation and should be included in future studies.

Inhibition of anandamide hydrolysis attenuates nociceptor sensitization in a murine model of chemotherapy-induced peripheral neuropathy

Painful neuropathy frequently develops as a consequence of commonly used chemotherapy agents for cancer treatment and is often a dose-limiting side effect. Currently available analgesic treatments are often ineffective on pain induced by neurotoxicity. Although peripheral administration of cannabinoids, endocannabinoids, and inhibitors of endocannabinoid hydrolysis has been effective in reducing hyperalgesia in models of peripheral neuropathy, including chemotherapy-induced peripheral neuropathy (CIPN), few studies have examined cannabinoid effects on responses of nociceptors in vivo. In this study we determined whether inhibition of fatty acid amide hydrolase (FAAH), which slows the breakdown of the endocannabinoid anandamide (AEA), reduced sensitization of nociceptors produced by chemotherapy. Over the course of a week of daily treatments, mice treated with the platinum-based chemotherapy agent cisplatin developed robust mechanical allodynia that coincided with sensitization of cutaneous C-fiber nociceptors as indicated by the development of spontaneous activity and increased responses to mechanical stimulation. Administration of the FAAH inhibitor URB597 into the receptive field of sensitized C-fiber nociceptors decreased spontaneous activity, increased mechanical response thresholds, and decreased evoked responses to mechanical stimuli. Cotreatment with CB1 (AM281) or CB2 (AM630) receptor antagonists showed that the effect of URB597 was mediated primarily by CB1 receptors. These changes following URB597 were associated with an increase in the endocannabinoid anandamide in the skin. Our results suggest that enhanced signaling in the peripheral endocannabinoid system could be utilized to reduce nociceptor sensitization and pain associated with CIPN.

The timing of introduction of pharmaceutical innovations in seven European countries

RATIONALE, AIMS AND OBJECTIVES

Differences in the performance of medical care may be due to variation in the introduction and diffusion of medical innovations. The objective of this paper is to compare seven European countries (United Kingdom, the Netherlands, West Germany, France, Spain, Estonia and Sweden) with regard to the year of introduction of six specific pharmaceutical innovations (antiretroviral drugs, cimetidine, tamoxifen, cisplatin, oxalaplatin and cyclosporin) that may have had important population health impacts.

METHODS

We collected information on introduction and further diffusion of drugs using searches in the national and international literature, and questionnaires to national informants. We combined various sources of information, both official years of registration and other indicators of introduction (clinical trials, guidelines, evaluation reports, sales statistics).

RESULTS AND CONCLUSIONS

The total length of the period between first and last introduction varied between 8 years for antiretroviral drugs and 22 years for cisplatin. Introduction in Estonia was generally delayed until the 1990s. The average time lags were smallest in France (2.2 years), United Kingdom (2.8 years) and the Netherlands (3.5 years). Similar rank orders were seen for year of registration suggesting that introduction lags are not only explained by differences in the process of registration. We discuss possible reasons for these between-country differences and implications for the evaluation of medical care.

Predicting acute and persistent neuropathy associated with oxaliplatin

OBJECTIVES

We sought to predict oxaliplatin-associated peripheral neuropathy during modified FOLFOX6 (mFOLFOX6) therapy.

METHODS

Equal numbers of male and female patients with previously untreated, primary or recurrent colorectal cancer were followed through a first course of mFOLFOX6 with 85 mg/m² oxaliplatin every 2 weeks. Accounting for correlation among a subject's cycle, logistic regression estimated per cycle risk of acute (under 14 d) and persistent (14 d or more) neuropathy. Proportional hazards regression predicted time to persistent neuropathy.

RESULTS

Among mFOLFOX6 recipients (n = 50, age 58.9 ± 10.1 y), 36% received concomitant bevacizumab. Of the total number of cycles, 94.2% (422/448) were evaluable. Most (84%) subjects reported neuropathy at least once; 74% reported acute and 48% reported persistent symptoms. On multivariate analysis, risk factors shared by acute and persistent neuropathy were body surface area >2.0, acute neuropathy in a past cycle, and lower body weight. In addition, risk of acute neuropathy decreased with age (adjusted for renal function and winter season), whereas risk of persistent neuropathy increased with cumulative dose of oxaliplatin and persistent neuropathy in a past cycle. Concomitant bevacizumab was not a risk factor when administered in stage IV disease but was associated with persistent neuropathy when administered experimentally in stage III. Females had no increased risk of either form of neuropathy. After 3 cycles, weight, body surface area, and prior acute neuropathy predicted time to persistent neuropathy.

CONCLUSIONS

Routinely available clinical factors predict acute and persistent neuropathy associated with oxaliplatin. When validated, the proposed prognostic score for persistent neuropathy can help clinicians counsel patients about chemotherapy.

A phase I study of oxaliplatin and doxorubicin in pediatric patients with relapsed or refractory extracranial non-hematopoietic solid tumors

BACKGROUND

The combination of a platinum agent and anthracycline has shown activity in pediatric solid tumors. This trial evaluated the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of oxaliplatin combined with doxorubicin in pediatric patients with recurrent solid tumors.

METHODS

Oxaliplatin was administered on day 1 and Doxorubicin on days 1-3 of each 21 day course. The study utilized a standard 3 + 3 dose escalation design. Three dose levels were evaluated: (1) oxaliplatin 105 mg/m(2) and doxorubicin 20 mg/m(2); (2) oxaliplatin 130 mg/m(2) and doxorubicin 20 mg/m(2); and (3) oxaliplatin 130 mg/m(2) and doxorubicin 25 mg/m(2). Dexrazoxane was administered at 10 times the doxorubicin dose prior to doxorubicin infusion.

RESULTS

Seventeen patients were enrolled. Dose level 1 was the determined MTD. Grade 2 cardiac DLT was seen in one of six patients on dose level 1, grade 4 thrombocytopenia in two of five patients on dose level 2, and one each of grade 2 cardiac and grade 4 thrombocytopenia in five patients on dose level 3. Cardiac DLT was only noted in patients with prior exposure to both anthracycline and chest radiation. No grade 3 or 4 neurotoxicity or mucositis was seen. Objective responses were noted in two patients with neuroblastoma and one each of mixed germ cell tumor, thymic neuroendocrine carcinoma, and nasopharyngeal carcinoma.

CONCLUSIONS

Oxaliplatin 105 mg/m(2) on day 1 combined with doxorubicin 20 mg/m(2) days 1-3 was the MTD. This combination shows sufficient activity to justify further studies in select pediatric tumors.

Oxaliplatin for colorectal cancer: recent evidence from clinical trials

SUMMARY Oxaliplatin, a second-generation platinum analog, has evolved as one of the most important therapeutic agents in the treatment of both metastatic colorectal cancer and stage II/III colon cancer. Moreover, oxaliplatin is currently being investigated in the perioperative treatment of locally advanced rectal cancer. Oxaliplatin can be safely combined with fluoropyrimidines, irinotecan, bevacizumab and EGF receptor antibodies, resulting in increased response rates and delayed progression. In combination with EGF receptor antibodies, fluoropyrimidine schedules need to be cautiously considered. Treatment strategies to limit oxaliplatin-induced neurotoxicity by discontinuous administration schedules (e.g., induction followed by maintenance, followed by reinduction or intermittent treatment) are available.

Characterization of an oxaliplatin sensitivity predictor in a preclinical murine model of colorectal cancer

Despite advances in contemporary chemotherapeutic strategies, long-term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. To validate our oxaliplatin sensitivity signature, patient-derived colorectal cancer explants (PDCCE) were developed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (sensitivity = 87.5%; specificity = 100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer.

Oxaliplatin-induced hepatocellular injury and ototoxicity: A review of the literature and report of unusual side effects of a commonly used chemotherapeutic agent

After extensive literature review utilizing PubMed and Medline searches, we present a rare case of oxaliplatin-induced grade 3/4 hepatocellular injury and ototoxicity. The patient is a 46-year-old female diagnosed with stage IIIC (pT3N2bM0) adenocarcinoma of the sigmoid colon. PET/CT prior to surgery and chemotherapy was negative for distant metastatic disease and baseline liver-associated enzymes were within normal limits. Following sigmoidectomy, patient began adjuvant chemotherapy with 5-florouracil, leucovorin, and oxaliplatin (mFOLFOX-6). Cycle 1 was complicated only by refractory nausea. However, cycle 2 was complicated by vertigo with refractory nausea, tinnitus, and marked elevation in liver enzymes in a hepatocellular pattern. Extensive workup was negative and the etiology of her symptoms and grade 3/4 hepatocellular injury was hypothesized to be the result of oxaliplatin. Aspartate aminotransferase and alanine aminotransferase decreased after two additional weeks off therapy and during cycle 3 in which oxaliplatin was held. She had no evidence of 5-florouracil toxicity. On cycle 4, oxaliplatin was restarted at 50% dose; symptoms and liver-associated enzymes remained stable. However, oxaliplatin was increased up to 75% full dose for cycle 5 with reported vertigo, tinnitus, nausea, and return of elevation in liver-associated enzymes. Oxaliplatin is a chemotherapy agent widely used in the treatment of many malignancies including colon cancer. Side effects include peripheral neuropathy, gastrointestinal toxicity, neutropenia, grade 1/2 hepatocellular injury, and hepatic vascular lesions. However, grade 3/4 hepatocellular injury and ototoxicity are extremely rare with the administration of oxaliplatin. Therefore, we present the unusual chemotherapy side effects.

Oxaliplatin as a radiosensitiser for upper and lower gastrointestinal tract malignancies: what have we learned from a decade of translational research?

Some of the greatest advances in the treatment of solid malignancies have resulted from the combination of chemotherapy and radiotherapy treatments. This article comprehensively reviews the current clinical evidence for oxaliplatin-based chemo-radiotherapy that may improve local control and survival. In order to understand how clinical studies should be designed, the pre-clinical evidence for the use of oxaliplatin chemotherapy as a radiosensitising agent is appraised. Particular focus is placed on oxaliplatin's biological mechanisms of action, including cell cycle effects, the formation of DNA adducts and interstrand cross-links and the role of DNA repair proteins. At a clinical level, there is currently no evidence to suggest that oxaliplatin provides an additional benefit to concurrent chemo-radiation regimes that utilise fluoropyrimidines; we evaluate the reasons for this observation, the limitations of clinical trial design and the opportunities that currently exist to design clinical trials which are underpinned by an understanding of the basic biology.

Longitudinal assessment of oxaliplatin-induced neuropathy

OBJECTIVES

To characterize the natural history of oxaliplatin-associated neuropathy (ON) and determine whether intraepidermal nerve fiber density (IENFD) is a sensitive measure of neuropathy progression. In addition, we sought to assess the potential of ON as a neuroprotection model and gain insight into the relationship between axon loss and neuropathic symptoms.

METHODS

Eight subjects receiving oxaliplatin for advanced colorectal cancer were prospectively followed prior to starting chemotherapy and at 30, 90, 180, and 360 days (180 days after completing treatment). Electrophysiology, punch biopsies, symptom assessment, and examinations with calculation of a reduced total neuropathy score (rTNS) were performed at each time point. Changes over time were assessed through Poisson regression for IENFD and a mixed effects model for rTNS and electrophysiology measures.

RESULTS

The distal leg IENFD, rTNS, peroneal, and sural amplitudes were all significantly reduced over time, while conduction velocity (peroneal and sural) and distal thigh IENFD were not. Measures of axon loss continued to worsen following discontinuation of oxaliplatin. Five of 8 subjects reported prominent symptoms associated with oxaliplatin administration.

CONCLUSIONS

This study demonstrates that oxaliplatin is associated with mild, sensory, and motor axon loss that may not be reversible. Axonal loss was detected by electrophysiology, rTNS, and distal leg IENFD. Several subjects reported prominent sensory symptoms that were not associated with axon loss, and that may or may not represent neuropathy. ON is an attractive paradigm for neuroprotection studies and the distal leg IENFD is an objective measure that requires minimal subject participation or study site expertise.

The organotelluride catalyst LAB027 prevents colon cancer growth in the mice

Organotellurides are newly described redox-catalyst molecules with original pro-oxidative properties. We have investigated the in vitro and in vivo antitumoral effects of the organotelluride catalyst LAB027 in a mouse model of colon cancer and determined its profile of toxicity in vivo. LAB027 induced an overproduction of H(2)O(2) by both human HT29 and murine CT26 colon cancer cell lines in vitro. This oxidative stress was associated with a decrease in proliferation and survival rates of the two cell lines. LAB027 triggered a caspase-independent, ROS-mediated cell death by necrosis associated with mitochondrial damages and autophagy. LAB027 also synergized with the cytotoxic drug oxaliplatin to augment its cytostatic and cytotoxic effects on colon cancer cell lines but not on normal fibroblasts. The opposite effects of LAB027 on tumor and on non-transformed cells were linked to differences in the modulation of reduced glutathione metabolism between the two types of cells. In mice grafted with CT26 tumor cells, LAB027 alone decreased tumor growth compared with untreated mice, and synergized with oxaliplatin to further decrease tumor development compared with mice treated with oxaliplatin alone. LAB027 an organotelluride catalyst compound synergized with oxaliplatin to prevent both in vitro and in vivo colon cancer cell proliferation while decreasing the in vivo toxicity of oxaliplatin. No in vivo adverse effect of LAB027 was observed in this model.

Oxaliplatin: a review in the era of molecularly targeted therapy

OBJECTIVE

To review preclinical and clinical data for oxaliplatin in the current context of molecularly targeted therapy.

METHODS OF STUDY SELECTION

We searched the PubMed and PubChem databases by combining the search terms "oxaliplatin" or "platinum" or both, with "clinical trials," "pharmacokinetics," and "pharmacodynamics."

DATA EXTRACTION AND SYNTHESIS

Oxaliplatin has a complicated pharmacokinetic profile, with activity against digestive cancers in particular. It has several mechanisms of action, but cancer cells can develop resistance. Real or potential synergism has been observed when oxaliplatin is combined with other cytotoxic agents or molecularly targeted agents. Peripheral neuropathy is a prominent toxic effect.

CONCLUSIONS

Oxaliplatin lends itself to further clinical research in combination with molecularly targeted therapy.

A phase II study of oxaliplatin, dose-intense capecitabine, and high-dose bevacizumab in the treatment of metastatic colorectal cancer

BACKGROUND

This study was designed to determine the efficacy and tolerability of a novel 2-week regimen of capecitabine, oxaliplatin (OHP), and bevacizumab in patients with chemo-naive advanced colorectal cancer.

PATIENTS AND METHODS

Nineteen patients with previously untreated advanced colorectal cancer received capecitabine at 1000 mg/m(2) twice a day on days 1-5 and days 8-12 of a 14-day cycle, and OHP at 85 mg/m(2) and bevacizumab at 10 mg/kg every 2 weeks. Because of unacceptable toxicities, the capecitabine dose was reduced to 850 mg/m(2). Thirty-one additional patients were treated at the lower capecitabine dose. Treatment continued until disease progression, persistent intolerable toxicity, or physician and/or patient discretion.

RESULTS

Overall, toxicities were better managed and tolerated at the 850 mg/-m(2) capecitabine dose. The most common treatment-related grade ≥ 3 toxicities were diarrhea and sensory neuropathy. In the first 19 subjects, the response rate was 63% (95% confidence interval [CI], 38%-84%) and 5 patients had stable disease; median progression-free survival (PFS) was 10.1 months (95% CI, 5.7-19.5 months). In the subsequent 31 patients, the response was 42% (95% CI, 25%-61%); 11 patients had stable disease and median PFS was 10.4 months (95% CI, 6.9-15.4); median overall survival was 24.8 months (95% CI, 12.9-39.7).

CONCLUSIONS

This novel regimen of capecitabine at 850 mg/m(2) twice a day on days 1-5 and days 8-12 and OHP at 85 mg/m(2)and bevacizumab at 10 mg/kg every 14 days is clinically active in advanced colorectal cancer. The toxicity profile of this regimen is consistent with the standard every-3-week dosing schedule.

Retinal vein thrombosis in a patient with metastatic colon cancer receiving XELOX chemotherapy combined with bevacizumab pre-hepatic resection

Retinal vein thrombosis is a common vascular occlusive disorder of the retina responsible for varying degrees of vision impairment. It is an adverse effect rarely associated with cancer and its treatment. We report the case of a patient with metastatic colon cancer who developed central retinal vein thrombosis (CRVT) in the right eye following two cycles of chemotherapy with capecitabine and oxaliplatin (XELOX) plus bevacizumab given prior to hepatic resection. Despite cessation of chemotherapy, vision has not improved. The etiology of the CRVT in this case is not clear due to risk factors for venous thrombotic events including colonic malignancy and previous major surgery. However, the proximity of chemotherapy administration to the initial development of symptoms suggests the possibility of a medication-related cause, with bevacizumab and capecitabine the most likely suspects.

XELOX in colorectal cancer: a convenient option for the future?

XELOX is a 3-weekly chemotherapy combination of oral capecitabine and intravenous oxaliplatin. The central hypothesis that led to its development was that it would provide a convenient and cost-effective alternative to intravenous fluorouracil-based chemotherapy doublets, without compromising on anti-tumor efficacy. Recently its role in colorectal cancer has become more established in both the metastatic and adjuvant setting. Ongoing investigation of XELOX continues in a number of directions: its combination with novel biological agents, its efficacy and safety in the elderly, and the development of biomarkers that can predict its anti-tumor effect. This article provides a comprehensive and up-to-date synopsis of all pertinent clinical studies detailing this regimen and its promise for the future.