New systemic frontline treatment for metastatic colorectal carcinoma

Low expression of exosomal miR-150 predicts poor prognosis in colorectal cancer patients after surgical resections

Liver metastasis is a leading indicator of poor prognosis in patients with colorectal cancer (CRC). Exosomal intercellular communication has been reported to play an important role in cancer invasion and metastasis. Here, we characterized exosomal miRNAs underlying liver metastasis in CRC patients (Cohort 1, n = 30) using miRNA arrays. Exosomal miR-150 was found to be downregulated in CRC patients with liver metastases compared to those without (P = 0.025, fold change [FC] = 2.01). These results were then validated using another independent cohort of CRC patients (Cohort 2, n = 64). Patients with low expression of exosomal miR-150 had significantly shorter overall survival (OS) time (33.3 months versus 43.3 months, P = 0.002). In addition, the low expression of exosomal miR-150 was significantly correlated with advanced tumor node metastasis staging (P = 0.013), higher CA199 level (P = 0.018), and the presence of liver metastasis (P = 0.048). Multivariate analysis showed that low expression of exosomal miR-150 (P = 0.035) and liver metastasis (P < 0.001) were independent prognostic factors for overall survival. In vivo and in vitro studies showed that the viability and invasion of CRC cells were both significantly suppressed by ExomiR-150. Target-prediction assessment and dual-luciferase reporter assay indicated that FTO (the fat mass and obesity-associated gene) was a direct target for miR-150. This study first demonstrated that exosomal miR-150 may be a potential prognostic factor and treatment target for CRC.

Overexpression of sortilin is associated with 5-FU resistance and poor prognosis in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Even if 5-fluorouracil (5-FU) is used as the first-line chemotherapeutic drug, responsiveness is only 20-30%. Acquired resistance to 5-FU contributes to both poor patient prognosis and relapse, emphasizing the need to identify biomarkers. Sortilin, a vacuolar protein sorting 10 protein (Vps10p), implicated in protein trafficking, is over expressed in CRC cell lines cultured 72 hours in presence of 5-FU. This overexpression was also observed in 5-FU-resistant cells derived from these cell lines as well as in CRC primary cultures (or patients derived cell lines). A significantly higher expression of sortilin was observed in vivo, in 5-FU-treated tumours engrafted in Nude mice, as compared with non-treated tumour. A study of transcriptional regulation allowed identifying a decrease in ATF3 expression, as an explanation of sortilin overexpression following 5-FU treatment. In silico analysis revealed SORT1 expression correlation with poor prognosis. Moreover, sortilin expression was found to be positively correlated with CRC tumour grades. Collectively, our findings identify sortilin as a potential biomarker of 5-FU resistance associated with poor clinical outcomes and aggressiveness in CRC. As a new prognostic factor, sortilin expression could be used to fight against CRC.

Ferritin Light Chain (FTL) competes with long noncoding RNA Linc00467 for miR-133b binding site to regulate chemoresistance and metastasis of colorectal cancer

Although the colorectal cancer (CRC) mortality rates are decreasing in virtue of CRC screening and improved therapeutic methods, CRC is still a leading cause of cancer deaths. One of the main causes is chemoresistance occurrence in CRC. Understanding of the molecular mechanisms of chemoresistance benefits to CRC diagnosis and treatment. In this study, gene expression was determined by western blot and qRT-PCR. The biological functions of genes in CRC cells were studied by knocking down or overexpressing the gene in CRC cells and then analyzing cell sensitivity to 5-Fu by the MTT assay and the flow cytometry, and analyzing cell migration and invasion by transwell assays. The luciferase reporter assay was used to examine microRNA regulation of target gene expression, and biotin pull-down assay was performed to detect interaction between RNA molecules. This study found that ferritin light chain (FTL) and long intergenic noncoding RNA Linc00467 were both upregulated in CRC tissues and cell lines, and inversely correlated to CRC patient survival. FTL and Linc00467 promoted CRC cells abilities to resistance against 5-fluor-ouracil (5-Fu), migration and invasion. These effects were compromised by miR-133b which targeted both FTL and Linc00467. miR-133b interacted with Linc00467 and miR-133b inhibitor prevented Linc00467 knockdown-induced alternations of FTL expression and biological functions. Both FTL and Linc00467 are oncogenes in CRC. FTL expression upregulated in CRC via Linc00467/ miR-133b axis, and leads to CRC cell resistance against 5-FU treatment and promotes CRC metastasis. FTL expression upregulated in CRC via Linc00467/miR-133b axis, and leads to CRC cell resistance to 5-FU treatment and promotes CRC metastasis.

Targeting mTOR suppressed colon cancer growth through 4EBP1/eIF4E/PUMA pathway

Colorectal cancer is the third most frequently diagnosed malignancies among both men and women, which has an increased mortality but a poor prognosis. Targeting mTOR becomes an effective approach that shows promising antitumor activities in various cancers including colonic carcinoma. However, the potential mechanism against colon cancer remains incompletely understood. Here, we demonstrated that the anti-cancer effect of AZD8055 and OSI-027 is at least in part modulated by the gradual process of apoptosis initiation, progressing from mTOR suppression, 4EBP1 dephosphorylation, or EZH2 suppression, thereby leading to PUMA-dependent apoptosis via the intrinsic mitochondrial pathway. Furthermore, AZD8055 inhibited colorectal cancer tumor growth in mice significantly. PUMA deletion caused resistance of dual mTOR inhibitors, suggesting PUMA mediated carcinogenesis in vitro and in vivo. Collectively, these findings established a vital status of PUMA in driving the antineoplastic efficacy of targeting mTOR by AZD8055 and OSI-027 and offered the rationales for the current clinical assessment.

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.

Dihydroartemisinin potentiates antitumor activity of 5-fluorouracil against a resistant colorectal cancer cell line

Although the combination of chemotherapy and surgical resection has effectively increased the survival rate of colorectal cancer patients in recent decades, acquired drug resistance is still a problem that leads to treatment failure. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has recently been reported to show anticancer effects against numerous types of cancer, including colorectal cancer. This study showed that DHA exerted a strong anticancer effect against several colorectal cancer cell lines. We also found that p53 knockout colorectal cancer HCT116 cells (HCT116 TP53^-/-) were not sensitive to 5-fluorouracil (5-FU) treatment, unlike wild-type HCT116 cells. Interestingly, co-treatment with DHA could effectively restore the anticancer effect of 5-FU against HCT116 TP53^-/- cells, which manifested as the inhibition of proliferation and induction of reactive oxygen species (ROS)-mediated apoptosis and was accompanied by the upregulation of B-cell lymphoma 2 (BCL-2) and downregulation of the BCL-2-associated X protein (BAX). These findings suggested that DHA could effectively sensitize cells to 5-FU through ROS-mediated apoptosis and the alteration of the BCL-2/BAX expression ratio, which indicated that this may be one of the mechanisms of the DHA-promoted 5-FU anticancer effect.

Knockdown of Hypoxia-Inducible Factor 1α Improved the Efficacy of Low-Dose Metronomic Chemotherapy of Paclitaxel in Human Colon Cancer Xenografts

Low-dose metronomic chemotherapy represents a new strategy for solid tumor treatments with a strong antiangiogenic activity and few side effects. However, low-dose metronomic therapy alone is not always as effective as traditional chemotherapy on eradication of tumor. On the contrary, low-dose metronomic in some cases could stimulate tumor growth due to hypoxia of tumor cells induced during therapy. Our study aimed to investigate whether knockdown of hypoxia-inducible factor-1α expression in tumor cell could facilitate low-dose metronomic therapy with paclitaxel for human colon cancer. Human colon cancer cell line (HT-29) stably transfected with specific short hairpin RNAs silencing hypoxia-inducible factor-1α exhibited marked attenuation of hypoxia-induced expression of the target genes such as vascular endothelial growth factor, glucose transporter 1, and P-glycoprotein. Compared with HT-29-c xenograft tumor model established by subcutaneous injection of HT-29 cells stably transfected with scrambled control short hairpin RNA, HT-29-ih xenograft tumor model showed more significant and long-lasting antitumor responses of empirical metronomic paclitaxel regimens, accompanied by drastic angiogenesis decrease and neglectable toxicity. All these data indicated that the combination of paclitaxel low-dose metronomic therapy with hypoxia-inducible factor-1α knockdown might provide a potent battle against colon cancer.

Identification of metabolites of the novel anti-tumor drug candidate MDH-7 in rat urine by liquid chromatography coupled with triple quadrupole linear ion trap mass spectrometry

RATIONALE

Our previous preliminary pharmacokinetic study demonstrated that the novel double pyrimidine tricyclic nucleoside MDH-7 in rats had a very short half-life (<30 min) after oral administration. As a result, the in vivo metabolic profile of MDH-7 should be investigated during early stages of drug development to better select drug candidates.

METHODS

In this study, a rapid method was developed to identify the metabolites of MDH-7 in rat urine by means of ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization mass spectrometry (ESI-MS) using a triple quadrupole linear ion trap instrument. MDH-7 and its metabolites were detected and characterized by the combined use of the multiple reaction monitoring-information-dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode and the precursor scan information-dependent acquisition-enhanced product ion (PREC-IDA-EPI) mode.

RESULTS

Ten novel metabolites of MDH-7 were identified and characterized in rat urine by LC/ESI-MS and collision-induced dissociation tandem mass spectrometry (CID-MS/MS) analyses. M1 was identified as 5-fluoro-N(4) -[(pentyloxy)carbonyl]cytosine; M2 and M3 were formed by hydroxylation products of M1. Metabolites M4-M10 were formed by a series of degradation reactions such as: deacetylation, hydroxylation, loss of the defluorocytosine base, oxidative-deamination, loss of the defluorouracil base, N-dealkylation and amide hydrolysis.

CONCLUSIONS

Based on the profiles of the metabolites, possible metabolic pathways of MDH-7 in rats were proposed for the first time. This study provides new and available information on the metabolism of MDH-7 which is very useful to further understand its in vivo metabolic fate. Copyright © 2016 John Wiley & Sons, Ltd.

Triptolide abrogates growth of colon cancer and induces cell cycle arrest by inhibiting transcriptional activation of E2F

Despite significant progress in diagnostics and therapeutics, over 50 thousand patients die from colorectal cancer annually. Hence, there is urgent need for new lines of treatment. Triptolide, a natural compound isolated from the Chinese herb Tripterygium wilfordii, is effective against multiple cancers. We have synthesized a water soluble analog of triptolide, named Minnelide, which is currently in phase I trial against pancreatic cancer. The aims of the current study were to evaluate whether triptolide/Minnelide is effective against colorectal cancer and to elucidate the mechanism by which triptolide induces cell death in colorectal cancer. Efficacy of Minnelide was evaluated in subcutaneous xenograft and liver metastasis model of colorectal cancer. For mechanistic studies, colon cancer cell lines HCT116 and HT29 were treated with triptolide and the effect on viability, caspase activation, annexin positivity, lactate dehydrogenase release, and cell cycle progression was evaluated. Effect of triptolide on E2F transcriptional activity, mRNA levels of E2F-dependent genes, E2F1- retinoblastoma protein (Rb) binding, and proteins levels of regulator of G1-S transition was also measured. DNA binding of E2F1 was evaluated by chromatin immunoprecipitation assay. Triptolide decreased colon cancer cell viability in a dose- and time-dependent fashion. Minnelide markedly inhibited the growth of colon cancer in the xenograft and liver metastasis model of colon cancer and more than doubles the median survival of animals with liver metastases from colon cancer. Mechanistically, we demonstrate that at low concentrations triptolide induces apoptotic cell death but at higher concentrations it induces cell cycle arrest. Our data suggest that triptolide is able to induce G1 cell cycle arrest by inhibiting transcriptional activation of E2F1. Our data also show that triptolide downregulates E2F activity by potentially modulating events downstream of DNA binding. Therefore, we conclude that Triptolide and Minnelide are effective against colon cancer in multiple pre-clinical models.

Comparative effectiveness of chemotherapy in elderly patients with metastatic colorectal cancer

PURPOSE

Treatment advances have improved outcomes in clinical trials of patients with metastatic colorectal cancer (mCRC). Less is known about these effects for patients in real-world settings. This study evaluated treatment patterns and survival in older, demographically diverse patients with mCRC.

METHODS

A retrospective cohort analysis was performed for 4,250 patients from January 1, 2000 to December 31, 2007 using linked Surveillance, Epidemiology, and End Results-Medicare database. Patients were ≥ 66 years, enrolled in Medicare parts A and B, and received first-line treatment with fluorouracil and leucovorin (5-FU/LV), capecitabine (CAP), 5-FU/LV plus oxaliplatin (FOLFOX), or CAP and oxaliplatin (CAPOX). Cox regression with backward elimination and propensity score-weighted Cox regression estimated relative risk of death. Date of last follow-up was December 2009. Statistical comparisons were made between 5-FU/LV vs. CAP and FOLFOX vs. CAPOX.

RESULTS

Compared to 5-FU/LV, patients treated with CAP were older (mean age 78 vs. 76; P<0.0001) and more likely female (61 vs. 54 %; P=0.0017), while patients receiving CAPOX and FOLFOX were similar in age (mean age 74 vs. 73; P=0.0924). Complications requiring medical resource utilization following initiation of therapy were significantly higher among patients administered with 5-FU/LV (54 %) vs. CAP (17 %; P<0.0001) and FOLFOX (75 %) vs. CAPOX (57 %; P<0.0001). The multivariate analysis revealed no significant differences in survival between 5-FU/LV and CAP and between FOLFOX and CAPOX.

CONCLUSIONS

Overall survival was comparable between CAP and 5-FU/LV and between CAPOX and FOLFOX with fewer complications requiring medical resource utilization associated with CAP and CAPOX, thus confirming clinical trial results.

Possibility of sandwiched liver surgery with molecular targeting drugs, cetuximab and bevacizumab on colon cancer liver metastases: a case report

A 31-year-old man with sigmoid colon cancer with concomitant simultaneous multiple liver metastases had received FOLFIRI (leucovorin, fluorouracil and irinotecan) and FOLFOX6 (leucovorin, fluorouracil and oxaliplatin) after an ordinary sigmoidectomy. However, his serum carcinoembryonic antigen (CEA) level increased rapidly during the fifteen months after the operation while he was on FOLFOX6. Abdominal computed tomography revealed expanding multiple liver tumors. As the third line chemotherapy, a combination therapy of cetuximab with irinotecan was given, which markedly reduced his levels of serum CEA, and the size and number of liver tumors. He underwent lateral segmentectomy of the liver and microwave coagulation of the liver metastases in the remnant liver. Thereafter, a good quality of life with tumor dormancy was obtained for 6 months. However, his serum CEA started to rise again in the absence of liver tumors. Therefore, FOLFOX6 with bevacizumab was chosen as the fourth line chemotherapy, and the serum CEA was reduced with tumor dormancy. A good quality of life was obtained again at 3 years after the first surgery. This report indicates the effectiveness of sandwiched liver surgery with the molecular targeting drugs cetuximab and bevacizumab on multiple liver metastases of colon cancer, and suggests the possibility of a regimen consisting of bevacizumab following cetuximab.

Complete Response of Isolated Para-aortic Lymph Node Recurrence from Rectosigmoid Cancer Treated by Chemoradiation Therapy with Capecitabine/Oxaliplatin plus Bevacizumab: A Case Report

Para-aortic lymph node recurrence is a rare type of metastasis from colorectal cancer, and no treatment has yet been established. Here, we report on a case of isolated para-aortic lymph node metastasis from rectosigmoid cancer that showed complete response to chemoradiation therapy with capecitabine/oxaliplatin plus bevacizumab. A 58-year-old woman underwent high anterior resection for rectosigmoid cancer in 2009. Para-aortic lymph node recurrence occurred in 2011. She underwent radiation therapy (50 Gy) and 8 courses of capecitabine/oxaliplatin plus bevacizumab. Abdominal computed tomography and positron emission tomography with 18-fluorodeoxyglucose did not reveal any para-aortic lymph node recurrence after chemoradiation therapy. Hence, this case was interpreted as a complete response. No recurrence was noted 6 months after the complete response. Chemoradiation therapy with capecitabine/oxaliplatin plus bevacizumab is likely to be effective in treating patients with para-aortic lymph node recurrence.

The plasma and cerebrospinal fluid pharmacokinetics of the platinum analog satraplatin after intravenous administration in non-human primates

BACKGROUND

Satraplatin is an orally bioavailable platinum analog with preclinical activity in cisplatin resistant models and clinical activity in adults with refractory cancers. The cerebrospinal fluid (CSF) penetration of cisplatin and carboplatin in non-human primates (NHP) is limited (3.7 and 2.6%, respectively). We evaluated the plasma and CSF pharmacokinetics (PK) of satraplatin after an intravenous (IV) dose in NHP.

METHODS

Satraplatin (120 mg/m(2)) was administered as 1 h IV infusion in DMSO (5%) and normal saline to 5 NHP. Serial blood and CSF samples were obtained over 48 h. Plasma ultrafiltrate (UF) was immediately prepared by centrifugation. Platinum was quantified in plasma UF and CSF using a validated atomic absorption spectroscopy assay with lower limit of quantification (LLQ) of 0.025 μM in UF and 0.006 μM after concentration in CSF. Pharmacokinetic parameters were estimated using non-compartmental analyses. CSF penetration was calculated from the CSF AUC(0-48h) : plasma UF AUC(0-48h).

RESULTS

Satraplatin was well tolerated. Median (range) PK parameters in plasma UF were: maximum concentration (C (max)) 8.3 μM (5.7-10.6), area under the curve (AUC(0-48h)) 29.2 μM h (22.6-33.2), clearance 0.36 l/h/kg (0.31-0.37), and t (1/2) 18.8 h (13.4-25). Satraplatin was detected in the CSF of all NHP. Median (range) PK parameters in CSF were: C (max) 0.07 μM (0.02-0.12), AUC(0-48h) 1.2 μM h (0.49-2.43). The median (range) CSF penetration of satraplatin was 4.3% (2.2-7.4).

CONCLUSIONS

Satraplatin penetration into CSF is similar to that of carboplatin and cisplatin, despite its greater lipophilicity. The development of a phase I trial of satraplatin for refractory childhood solid tumors including brain tumors is in progress.

A new, validated HPLC-MS/MS method for the simultaneous determination of the anti-cancer agent capecitabine and its metabolites: 5'-deoxy-5-fluorocytidine, 5'-deoxy-5-fluorouridine, 5-fluorouracil and 5-fluorodihydrouracil, in human plasma

A rapid and selective liquid chromatography/tandem mass spectrometric method was developed for the simultaneous determination of capecitabine and its metabolites 5'-deoxy-5-fluorocytidine (5'-DFCR), 5'-deoxy-5-fluorouracil (5'-DFUR), 5-fluorouracil (5-FU) and dihydro-5-fluorouracil (FUH(2)) in human plasma. A 200 microL human plasma aliquot was spiked with a mixture of internal standards fludarabine and 5-chlorouracil. A single-step protein precipitation method was employed using 10% (v/v) trichloroacetic acid in water to separate analytes from bio-matrices. Volumes of 20 microL of the supernatant were directly injected onto the HPLC system. Separation was achieved on a 30 x 2.1 mm Hypercarb (porous graphitic carbon) column using a gradient by mixing 10 mm ammonium acetate and acetonitrile-2-propanol-tetrahydrofuran (1 : 3 : 2.25, v/v/v). The detection was performed using a Finnigan TSQ Quantum Ultra equipped with the electrospray ion source operated in positive and negative mode. The assay quantifies a range from 10 to 1000 ng/mL for capecitabine, from 10 to 5000 ng/mL for 5'-DFCR and 5'-DFUR, and from 50 to 5000 ng/mL for 5-FU and FUH(2) using a plasma sample of 200 microL. Correlation coefficients (r(2)) of the calibration curves in human plasma were better than 0.99 for all compounds. At all concentration levels, deviations of measured concentrations from nominal concentration were between -4.41 and 3.65% with CV values less than 12.0% for capecitabine, between -7.00 and 6.59% with CV values less than 13.0 for 5'-DFUR, between -3.25 and 4.11% with CV values less than 9.34% for 5'-DFCR, between -5.54 and 5.91% with CV values less than 9.69% for 5-FU and between -4.26 and 6.86% with CV values less than 14.9% for FUH(2). The described method was successfully applied for the evaluation of the pharmacokinetic profile of capecitabine and its metabolites in plasma of treated cancer patients.

Capecitabine for locally advanced and metastatic colorectal cancer: A review

Capecitabine (Xeloda^®) is an oral fluoropyrimidine which is produced as a pro-drug of fluorouracil, and shows improved tolerability and intratumor drug concentrations following its tumor-specific conversion to the active drug. We have searched the Pubmed and Cochrane databases from 1980 to 2009 with the purpose of reviewing all available information on Capecitabine, focusing on its clinical effectiveness against colorectal cancer. Special attention has been paid to trials that compared Capecitabine with standard folinic acid (leucovorin, LV)-modulated intravenous 5-fluorouracil (5-FU) bolus regimens in patients with metastatic colorectal cancer. Moreover the efficacy of Capecitabine on metastatic colorectal cancer, either alone or in various combinations with other active drugs such as Irinotecan and Oxaliplatin was also assessed. Finally, neoadjuvant therapy consisting of Capecitabine plus radiation therapy, for locally advanced rectal cancer was analysed. This combination of chemotherapy and radiotherapy has a special role in tumor down staging and in sphincter preservation for lower rectal tumors. Comparative trials have shown that Capecitabine is at least equivalent to the standard LV-5-FU combination in relation to progression-free and overall survival whilst showing a better tolerability profile with a much lower incidence of stomatitis. It is now known that Capecitabine can be combined with other active drugs such as Irinotecan and Oxaliplatin. The combination of Oxaliplatin with Capecitabine represents a new standard of care for metastatic colorectal cancer. Combinating the Capecitabine-Oxaliplatin regimen with promising new biological drugs such as Bevacizumab seems to give a realistic prospect of further improvement in time to progression of metastatic disease. Moreover, preoperative chemo-radiation using oral capecitabine is better tolerated than bolus 5-FU and is more effective in the promotion of both down-staging and sphincter preservation in patients with locally advanced rectal cancer. Finally, the outcomes of recently published trials suggest that capecitabine seems to be more cost effective than other standard treatments for the management of patients with colorectal cancer.

Meta-analysis: the efficacy and safety of monoclonal antibody targeted to epidermal growth factor receptor in the treatment of patients with metastatic colorectal cancer

OBJECTIVE

To evaluate systematically the efficacy and safety of anti-epidermal growth factor receptor (EGFR) monoclonal antibody added to a chemotherapeutic regimen in the treatment of patients with metastatic colorectal cancer (mCRC).

METHODS

Eligible articles were identified by searching electronic databases. All randomized trials comparing the arm with an anti-EGFR monoclonal antibody to the arm without an anti-EGFR monoclonal antibody during the treatment of mCRC were included. A statistical analysis was performed with Review Manager 4.2.8.

RESULTS

Seven randomized trials (n = 4186) were identified. The pooled response rates were 25.4% and 17.6% by intention-to-treat analyses for patients with or without an anti-EGFR monoclonal antibody, respectively, the OR was 3.36 (95% CI 1.42-7.95); the incidence of grades 3-4 adverse events were 71.2% and 54.3% for two groups, respectively, the OR was 2.23 (95% CI 1.74-2.86). The incidence of diarrhea, skin toxicity, hypomagnesemia was 62.3% versus 55.7%; 79.3% versus 19.7%; 27.2% versus 5.6%; and the summary OR was 1.36 (95% CI 1.03-1.80); 33.47 (95% CI 14.81-75.61); 6.73 (95% CI 3.84-11.82), respectively.

CONCLUSION

Our results confirmed that monoclonal antibody targeted to EGFR could be effective in increasing response rates and could be a key therapeutic agent in the optimal treatment of mCRC, despite a moderate increase in grades 3-4 adverse events.

Low-dose metronomic chemotherapy of paclitaxel synergizes with cetuximab to suppress human colon cancer xenografts

Low-dose metronomic (LDM) chemotherapy represents a new strategy to treat solid tumors by stronger antiangiogenic activity and lower side effects, especially in combination with other antiangiogenic agents. This study aims to investigate whether LDM chemotherapy of paclitaxel could synergize with cetuximab, an antiangiogenic agent to suppress HT-29 human colon tumors in BALB/c nude mice. To explore its possible mechanism, the tumor vascular status was detected by staining with anti-CD31 Ab and the tumoral expression of thrombospondin-1 was examined by immunohistochemistry, western blot analysis, and real-time PCR. Our results showed that empirical metronomic paclitaxel regimens in combination with cetuximab induces significant and durable antitumor responses without overt toxicity. Paclitaxel LDM chemotherapy displayed stronger antiangiogenic activity than maximum tolerable dose (MTD) chemotherapy, whereas MTD chemotherapy induced more apoptotic cells. The combinational therapy with LDM and cetuximab showed the strongest antiangiogenic activity among all the groups. Paclitaxel LDM chemotherapy also dramatically upregulated the expression of thrombospondin-1, but MTD chemotherapy did not. These results suggest that the combination of paclitaxel LDM chemotherapy and cetuximab represents a potent strategy to combat colon cancers.

Benefits and risks of palliative capecitabine based therapy to elderly patients with advanced colorectal cancer: Danish single centre experiences

This study aimed to compare efficacy and toxicity of palliative chemotherapy for elderly and younger colorectal cancer patients. Patients aged 24-69 (n = 203) and 70-82 years (n = 57) with advanced colorectal cancer were consequetively treated with first line capecitabine monotherapy or combined with oxaliplatin (XELOX). The response rates were 37% and 33% (P = 0.61), the median times to progression were 5.5 and 6.0 months (P = 0.84, hazard ratio (HR) 1.09; 95% confidence interval: 0.71-1.68), and median overall survival times were 8.4 and 12.5 months (P = 0.07, HR 1.48; 1.04-2.38) for elderly and younger patients, respectively. Elderly patients had similar frequencies of Common Toxicity Criteria (CTC) grade 3 or 4 toxicity (P > 0.05) and number of treatment courses (P = 0.44), and maintained performance status as well as younger patients (P = 0.68). Palliative capecitabine based therapy for advanced colorectal cancer should be considered also for elderly who are in good performance without major comorbidities.

[N,N'-Bis(salicylidene)-1,2-phenylenediamine]metal complexes with cell death promoting properties

We developed N,N'-bis(salicylidene)-1,2-phenylenediamine (salophene, 1) as a chelating agent for metal ions such as Mn(II/III), Fe(II/III), Co(II), Ni(II), Cu(II), and Zn(II). The resulting complexes, from which owing to the carrier ligand a selective mode of action is assumed, were tested for antiproliferative effects on the MCF-7 breast cancer cell line. The cytotoxicity in this assay depended on the nature of the transition metal used. Iron complexes in oxidation states +II and +III (3, 4) strongly reduced cell proliferation in a concentration-dependent manner, whereas, e.g., the manganese analogues 5 and 6 were only marginally active. Therefore, the [N,N'-bis(salicylidene)-1,2-phenylenediamine]iron(II/III) complexes 3 and 4 were selected for studies on the mode of action. Both complexes possessed high activity against various tumor cells, for instance, MDA-MB-231 mammary carcinoma cells as well as HT-29 colon carcinoma cells. They were able to generate reactive oxygen species, showed DNA binding, and induced apoptosis. Exchange of 1 by N,N'-bis(salicylidene)-1,2-cyclohexanediamine (saldach, 2) yielding complexes 7 and 8 reduced the in vitro effects drastically. An unequivocal mode of action cannot be deduced from these results, but it seems to be very likely that cell death is caused by interference with more than one intracellular target.

Capecitabine: an overview of the side effects and their management

Xeloda (capecitabine), a thymidine phosphorylase activated fluoropyrimidine carbamate, is currently the only universally approved orally administered 5-fluorouracil (5-FU) prodrug. It belongs to a newer generation of orally administered fluoropyrimidines. It has been developed because of the clinical need for efficient, tolerable and convenient agents, which do not require continuous infusion. Capecitabine is not a cytotoxic drug in itself, but via a three-step enzymatic cascade, it is converted to 5-FU mainly within human cancer cells. While the drug compares favorably with 5-FU in patients with advanced or metastatic colorectal cancer and pretreated breast cancer, it also has an improved toxicity profile, mainly of gastrointestinal and dermatologic effects with a significantly lower incidence of grade 3/4 myelotoxicity compared with infusional 5-FU-based chemotherapy. Capecitabine's selective activation within the tumor allows for less systemic toxicity events. A gradient of fluoropyrimidine toxicity is observed: high in the US and low in East Asia. In addition, there is a discrepancy in tolerance of dose among patients treated in the US vs. Europe. Although patients can take the drug orally in the convenience of their own home, the key to successful management of capecitabine is the clinician's awareness of its severe, but low in incidence, adverse effects, and the patients' education, emphasizing compliance with the treatment plan, prevention and timely recognition of its toxicities.

Efficacy of the oral fluorouracil pro-drug capecitabine in cancer treatment: a review

Capecitabine (Xeloda) was developed as a pro-drug of fluorouracil (FU), with the aim of improving tolerability and intratumor drug concentrations through its tumorspecific conversion to the active drug. The purpose of this paper is to review the available information on capecitabine, focusing on its clinical effectiveness against various carcinomas. Identification of all eligible English trails was made by searching the PubMed and Cochrane databases from 1980 to 2007. Search terms included capecitabine, Xeloda and cancer treatment. Nowadays, FDA has approved the use of capecitabine as a first line therapy in patients with metastatic colorectal cancer when single-agent fluoropyrimidine is preferred. The drug is also approved for use as a single agent in metastatic breast cancer patients who are resistant to both anthracycline and paclitaxel-based regimens or when further anthracycline treatment is contraindicated. It is also approved in combination with docetaxel after failure of prior anthracycline-based chemotherapy. In patients with prostate, pancreatic, renal cell and ovarian carcinomas, capecitabine as a single-agent or in combination with other drugs has also shown benefits. Improved tolerability and comparable efficacy, compared with the intravenous FU/LV combination, in addition to its oral administration, make capecitabine an attractive option for the treatment of several types of carcinomas.

Salvage radioembolization of liver-dominant metastases with a resin-based microsphere: initial outcomes

PURPOSE

The use of radioembolization of hepatic metastases with yttrium-90 ((90)Y) microspheres is increasing. The present report describes the outcomes in a cohort of patients with metastatic liver tumors treated with a resin-based microsphere agent.

MATERIALS AND METHODS

Thirty patients with colon (n = 13), breast (n = 7), and other primary cancers (n = 10) were treated after the failure of first- and second-line therapy. Overall survival (OS), time to progression (TTP), and time to treatment failure (TTTF) were calculated from the first treatment. Response was measured according to Response Evaluation Criteria In Solid Tumors at interval follow-up imaging.

RESULTS

Thirty patients underwent 56 infusions of (90)Y, and 18 remained alive at the end of the study. Fourteen patients (47%) had a partial response or stable disease. OS (604 vs 251 days), TTP (223 vs 87 days), and TTTF (363 vs 87 days) were all significantly longer for patients who had a partial response or stable disease (P < .05). Median OS, TTP, and TTTF for patients with colorectal carcinoma were 357, 112, and 107 days, respectively, versus 638, 118, and 363 days in patients with other metastatic sources. Median survival was not reached for patients with breast carcinoma, and the TTP and TTTF were each 282 days. One patient (3%) experienced grade 3 toxicity (gastrointestinal ulceration).

CONCLUSIONS

(90)Y microsphere therapy produced promising survival rates compared with systemic salvage options, with minimal toxicity.

Pharmacogenetic approach for capecitabine or 5-fluorouracil selection to be combined with oxaliplatin as first-line chemotherapy in advanced colorectal cancer

We studied the role of TS (5'VNTR, 5'SNP and 3'UTR), XRCC1-399, XPD-751, ERCC1-118 and XRCC3-241 genetic polymorphisms in tailoring fluroropyrimidine/oxaliplatin treatment. For this purpose, 110 XELOX (capecitabine/oxaliplatin)- or FUOX (fluorouracil/oxaliplatin)-treated metastatic colorectal cancer patients were selected prospectively for genotyping. In the FUOX group, TS-3'UTR +6bp/+6bp (hazards ratio, HR=2.62, p=0.007) and ERCC1-118C/T or C/C (HR=1.96, p=0.050) genotypes correlated with a shorter progression-free survival (PFS). When analysed jointly, the higher the number of favourable genotypes (FG) the longer the PFS (6.8m, 9.6m and 25.8m for 0, 1 or 2 FG; p=0.005). Disease-control rate was 100% in patients with 2 FG (87% and 38.5% for 1 or 0 FG; p=0.001). In the multivariate analysis, ERCC1-118 (HR=2.12, p=0.0037) and TS-3'UTR (HR=2.68, p=0.006) were strong independent prognostic factors. According to this, patients harbouring TS-3'UTR +6bp/+6bp and ERCC1-118C/T or C/C genotypes may better receive capecitabine instead of 5FU in an oxaliplatin-based first-line treatment.

Anticancer activity of a peptide combination in gastrointestinal cancers targeting multiple neuropeptide receptors

A novel peptide combination consisting of four synthetic neuropeptide analogs of Vasoactive Intestinal Peptide (VIP), Bombesin, Substance P and Somatostatin has been found to have potent anticancer activity in vitro and in vivo. The receptors of these four neuropeptides are known to be over expressed in various cancers. We have found the presence of native neuropeptides in the culture supernatant of the primary tumor cells of human colon adenocarcinomas. It was further demonstrated by receptor-ligand assays that not only do these tumor cells synthesize and secrete four peptide hormones but also possess specific high affinity receptors on their surface. Screening a large panel of analogs to the four peptide hormones on tumor cell proliferation led to the identification of four cytotoxic analogs, the combination of which was code-named DRF7295. The design and synthesis of the peptide analogs have been described in this paper. In vitro anticancer activity of DRF7295 was studied in a large panel of human tumor cells. Gastrointestinal tumor cells of the colon, pancreas and duodenum were found to be most sensitive to DRF7295 with moderate activity seen in glioblastoma, prostate, leukemia and those of oral cancer cells. Efficacy studies in xenograft models of colon and duodenum resulted in T/C% of less than 40%, which is indicative of strong tumor regressing potential of DRF7295 in gastrointestinal cancers. Acute and long-term toxicity studies as well as safety pharmacology studies conducted indicate the safety of the drug upon systemic administration with no significant adverse pharmacological effects.

Hypoestoxide inhibits tumor growth in the mouse CT26 colon tumor model

AIM: To evaluate the effect of the natural diterpenoid, hypoestoxide (HE) on the growth of established colon cancer in mice.

METHODS: The CT26.WT mouse colon carcinoma cell line was grown and expanded in vitro. Following the expansion, BALB/c mice were inoculated s.c. with viable tumor cells. After the tumors had established and developed to about 80-90 mm³, the mice were started on chemotherapy by oral administration of HE, 5-fluorouracil (5-FU) or combination.

RESULTS: The antiangiogenic HE has previously been shown to inhibit the growth of melanoma in the B16F₁ tumor model in C57BL/6 mice. Our results demonstrate that mean volume of tumors in mice treated with oral HE as a single agent or in combination with 5-FU, were significantly smaller (> 60%) than those in vehicle control mice (471.2 mm³vs 1542.8 mm³, P < 0.01). The significant reductions in tumor burden resulted in pronounced mean survival times (MST) and increased life spans (ILS) in the treated mice.

CONCLUSION: These results indicate that HE is an effective chemotherapeutic agent for colorectal cancer in mice and that HE may be used alone or in combination with 5-FU.

Cetuximab, a chimeric human mouse anti-epidermal growth factor receptor monoclonal antibody, in the treatment of human colorectal cancer

The recent successful development of monoclonal antibodies that target key components of biological pathways has expanded the armamentarium of treatment options for patients with colorectal cancer (CRC). In particular, the epidermal growth factor receptor (EGFR), a tyrosine kinase growth factor receptor involved in CRC development and progression, is exploited by the newest monoclonal antibody that is available for use in CRC patients. Cetuximab, the first chimeric monoclonal antibody, which has been generated against the EGFR, is currently registered in USA, Europe and worldwide, in combination with irinotecan in the treatment of metastatic CRC patients who have progressed on irinotecan containing chemotherapy. Cetuximab is well tolerated and does not exacerbate the toxicity of concomitant chemotherapy. Furthermore, a series of phase III clinical trials are currently evaluating the combination of cetuximab with standard chemotherapy regimens in the first-line treatment chemotherapy-naïve patients with metastatic CRC.

Efficacy of oncolytic herpesvirus NV1020 can be enhanced by combination with chemotherapeutics in colon carcinoma cells

NV1020, an oncolytic herpes simplex virus type 1, can destroy colon cancer cells by selectively replicating within these cells, while sparing normal cells. NV1020 is currently under investigation in a clinical phase I/II trial as an agent for the treatment of colon cancer liver metastases, in combination with conventional chemotherapeutic agents such as 5-fluorouracil (5-FU), SN38 (the active metabolite of irinotecan), and oxaliplatin. To study the synergy of NV1020 and chemotherapy, cytotoxicity and viral replication were evaluated in vitro by treating various human and murine colon carcinoma cell lines, using a colorimetric viability assay, a clonogenic assay, and a plaque-forming assay. In vivo experiments, using a subcutaneous syngeneic CT-26 tumor model in BALB/c mice, were performed to determine the efficacy of combination therapy. In vitro studies showed that the efficacy of NV1020 on human colon carcinoma cell lines HT-29, WiDr, and HCT-116 was additively or synergistically enhanced in combination with 5-FU, SN38, or oxaliplatin. The sequence of application was not important and effects were still apparent after a 21-day incubation period. Three intra-tumoral treatments with NV1020 (1 x 10(7) plaque-forming units), followed by three subcutaneous treatments with 5-FU (50 mg/kg), resulted in substantially higher inhibition of tumor growth and prolongation of survival compared with monotherapies (NV1020/5-FU vs. NV1020, p = 0.027). On WiDr cells, reduced replication of NV1020, in combination with 5-FU, indicated that additive and synergistic effects of combination therapy must be independent from viral replication. These results suggest that NV1020, in combination with chemotherapy, is a promising therapy for treating patients with metastatic colorectal cancer of the liver. We hypothesize that infection of cells with NV1020 sensitizes the infected cells for the cytotoxic effect of the chemotherapeutics.

Mitomycin C and Etoposide in Advanced Colorectal Carcinoma

BACKGROUND

Aim of this study was to evaluate the activity of a combination regimen of chemotherapy containing mitomycin C (MMC) and etoposide (ETO) in advanced colorectal carcinoma.

METHODS

Fourteen pretreated patients received MMC 2 mg/m2 and ETO 60 mg/m2, days 1-5 every 28 days. The clinical study was interrupted since no clinical response was observed in 14 patients following four courses of chemotherapy. An in vitro study was then performed on HTC-8 cell line. The cytotoxic activity of the MMC/ETO combination was tested by sulforhodamine B assay and the type of drug interaction was assessed using the method of Chou and Talalay. Cell cycle perturbations and apoptosis were evaluated by flow cytometry.

RESULTS

While MMC and ETO were singularly active, the simultaneous exposure of cells to both drugs and the sequence MMC-->ETO ensued in antagonistic interaction at all levels of killed cell fraction. Conversely, the sequence ETO-->MMC produced a synergistic interaction.

CONCLUSIONS

These results suggest that the activity of the MMC/ETO combination is highly schedule-dependent and that the experimental drug associations should be based on a preclinical rationale before clinical trials are designed.

Rapid and simultaneous determination of capecitabine and its metabolites in mouse plasma, mouse serum, and in rabbit bile by high-performance liquid chromatography

A rapid high-performance liquid chromatography method has been developed for simultaneous determination of capecitabine and its metabolites: 5'-deoxy-5-fluorocytidine (5'-DFCR), 5'-deoxy-5-fluorouridine (5'-DFUR) and 5-fluorouracil (5-FU). 5'-DFCR was synthesized by hydrolyzing capecitabine using commercially available carboxyl esterase (CES) and characterized by NMR, mass spectrometry and elemental analysis. Base-line separations between capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were found with symmetrical peak shapes on a Discovery RP-amide C16 column using 10 mM ammonium acetate at pH 4.0 and methanol as the mobile phase. The retention times of capecitabine, 5'-DFCR, 5'-DFUR and 5-FU were 8.9, 5.0, 5.3 and 3.0 min, respectively. Linear calibration curves were obtained for each compound across a range from 1 to 500 microg ml(-1). The intra- and inter-day relative standard deviations (%RSD) were <5%. A single-step protein precipitation method was employed for separation of the analytes from bio-matrices. Greater than 85% recoveries were obtained for capecitabine, 5'-DFCR, 5'-DFUR and 5-FU from bio-fluids including mouse plasma, mouse serum and rabbit bile.

How may anticancer chemotherapy with fluorouracil be individualised?

Fluorouracil is used clinically against various solid tumours. Both fluorouracil toxicity and pharmacokinetics vary highly within and between individuals. The reasons why doses are not individualised routinely are difficulties in defining, predicting and achieving an optimal fluorouracil exposure or dose because of a narrow therapeutic index, nonlinear pharmacokinetics, variabilities in administration rates and metabolism, and in targets like thymidylate synthase. To individualise fluorouracil administration before the first dose, assessment of the individual dihydropyrimidine dehydrogenase (DPD) activity may be useful, because this genetically highly polymorphic enzyme controls approximately 80% of fluorouracil elimination. A complete or partial loss of DPD activity in 0.1 and 3-5% of Caucasians, respectively, leads to increased fluorouracil exposure and toxicity. Several methods to assess DPD activity in patients have been proposed (genotyping, various phenotyping methods), but each of them has limitations, as has the fluorouracil test dose approach. To adapt exposure towards fluorouracil a priori, a combination of genotyping and phenotyping may yield better prediction of toxicity than one method alone. A prerequisite for dose adaptation is the definition of fluorouracil exposure ranges with sufficient therapeutic activity, but without serious toxicity. While an increased risk of leukopenia, diarrhoea, stomatitis, and hand-foot syndrome during continuous 5-day infusions was related to fluorouracil exposures above an area under the plasma concentration-time curve (AUC) threshold of 25-30 mg.h/L, tumour response was higher when an AUC of approximately 30 mg.h/L was achieved, illustrating the extremely narrow therapeutic window of fluorouracil. Pharmacokinetic target values are less clear for other regimens, including chronomodulated regimens, which yielded a superior clinically efficacy and tolerability in several trials. However, the monitoring of fluorouracil plasma concentrations seems principally useful for individual a posteriori dose adjustment. Whether an adaptation of the fluorouracil starting dose to the results of two DPD activity tests before fluorouracil administration a priori, and the adaptation of doses to fluorouracil exposure a posteriori is a reasonable approach to better prevent toxicity and increase efficacy, remains to be evaluated in randomised clinical studies comparing these strategies to routine clinical safety monitoring.

The effects of the oral, pan-VEGF-R kinase inhibitor CEP-7055 and chemotherapy in orthotopic models of glioblastoma and colon carcinoma in mice

CEP-7055, a fully synthetic, orally active N,N-dimethylglycine ester of CEP-5214, a C3-(isopropylmethoxy)-fused pyrrolocarbazole with potent pan-vascular endothelial growth factor receptor (VEGFR) kinase inhibitory activity, has recently completed phase I clinical trials in cancer patients. These studies evaluated the antitumor efficacy of CEP-7055 using orthotopic models of glioblastoma and colon carcinoma in combination with temozolomide, and irinotecan and oxaliplatin, respectively, for their effects on primary and metastatic tumor burden and median survival. Chronic administration of CEP-7055 (23.8 mg/kg/dose) and temozolomide resulted in improvement of median survival of nude mice bearing orthotopic human glioblastoma xenografts compared with temozolomide alone (261 versus 192 days, respectively; P < or = 0.02). Reductions in neurologic dysfunction, brain edema, hemorrhage, and intratumoral microvessel density (CD34 staining) were observed in glioma-bearing mice receiving CEP-7055 alone, temozolomide alone, and the combination of CEP-7055 and temozolomide relative to vehicle and to temozolomide monotherapy. The administration of CEP-7055 in combination with irinotecan (20 mg/kg/dose i.p. x 5 days), and to a lesser degree with oxaliplatin (10 mg/kg/dose i.v.), showed reductions on primary colon carcinoma and hepatic metastatic burden in the CT-26 tumor model relative to that achieved by irinotecan and oxaliplatin monotherapy. These data show the significant efficacy and tolerability of optimal efficacious doses of CEP-7055 when given in combination with temozolomide and irinotecan relative to monotherapy with these cytotoxic agents in preclinical orthotopic glioma and colon carcinoma models and lend support for the use of these treatment regimens in a clinical setting in patients with glioblastoma and colon carcinoma.

Colorectal cancer follow-up: Useful or useless?

Follow-up of surgically treated colorectal cancer patients is not supported by objectively certain data. Despite the thousands of investigations reported in the scientific literature, only six randomized prospective studies and two meta-analysis of randomized studies provide data suggesting clear conclusions. Our review of the literature revealed that intensive colorectal follow-up should be performed even if the long-term survival benefit is small. The timing and investigations conducted in follow-ups diverge. The inconsistency of follow-ups is revealed by the fact that the leading USA and European societies propose different guidelines. One datum that the literature agrees on is that pancolonoscopy performed at 3-5 year intervals in colorectal cancer surgery patients supports diagnosis of adenomatous polyps and metachronous cancers. Cost analysis have shown that intensive follow-up would certainly exceed the cut-off point level set for every additional year of good quality of life.

Local delivery of a synthetic endostatin fragment for the treatment of experimental gliomas

OBJECTIVE

Endostatin is an anti-angiogenic agent that blocks matrix-metalloproteinase-2 and inhibits endothelial cell proliferation. Currently, endostatin is available through recombinant technology, which limits its broader use. In this study, a synthetic endostatin fragment (EF) was analyzed to determine its anti-angiogenic properties when locally delivered by controlled-release polymers and to establish its effect as a treatment for experimental gliomas.

METHODS

Cytotoxicity of EF against 9L gliosarcoma and F98 glioma was determined in vitro. EF was loaded into polyanhydride-poly-(bis-[carboxyphenoxy-propane]-sebacic-acid) (pCPP:SA) polymers at increasing concentrations. Pharmacokinetics of the EF/polymer formulations were defined in vitro. Anti-angiogenic properties of the EF/polymer formulations were evaluated in the rat-cornea micropocket assay. Toxicity and efficacy of locally delivered EF polymers either alone or combined with systemic bischloroethylnitrosourea (carmustine) were determined in rats intracranially challenged with 9L gliosarcoma.

RESULTS

EF showed scarce cytotoxicity against 9L and F98 in vitro. EF/pCPP:SA formulations showed sustained release by day 19. Mean corneal angiogenesis index 20 days after tumor implantation was 4.5 +/- 0.7 for corneas implanted with 40% EF/pCPP:SA compared with controls (8.5 +/- 1.3, P = 0.02). Intracranial efficacy studies showed that EF polymers alone did not prolong animal survival. Combination of 40% EF/pCPP:SA polymers with systemic bischloroethylnitrosourea (carmustine) prolonged survival (median survival of 44 d, P = 0.001) and generated 33% long-term survivors.

CONCLUSION

Controlled-release polymers can effectively deliver a biologically active EF in a sustained fashion. EF inhibits angiogenesis in vitro and in vivo, and even though EF does not prolong survival as a single agent, it exhibits a synergistic effect when combined with systemic bischloroethylnitrosourea (carmustine) in the intracranial 9L gliosarcoma model.

Phase II trial alternating FOLFOX-6 and FOLFIRI regimens in second-line therapy of patients with metastatic colorectal cancer (FIREFOX study)

We assessed a schedule alternating 4 FOLFOX and 4 FOLFIRI cycles in 39 patients with 5-FU resistant metastatic colorectal cancer. Patients alternatively received 4 FOLFOX-6 cycles (oxaliplatin 100 mg/m(2), leucovorin 200 mg/m(2) d1 followed by bolus 400 mg/m(2) 5-FU and by a 46-hour 2,400 mg/m(2) 5-FU infusion, every 2 weeks), and 4 FOLFIRI cycles (oxaliplatin replaced by irinotecan 180 mg/m(2) d1) until progression or limiting toxicity. Eigteen patients achieved an objective response (46.1 percent). Median progression-free and overall survivals were 8.8 and 18.7 months, respectively. Only 2 patients (5.1 percent) had Grade 3 oxaliplatin-related sensory-neuropathy. This schedule had so promising efficacy and safety.

Population Pharmacokinetics of Oxaliplatin (85 mg/m2) in Combination With 5-fluorouracil in Patients With Advanced Colorectal Cancer

Pharmacokinetic (PK) studies of oxaliplatin, using a dose regimen of 85 mg/m, are lacking. A PK model may be used in future studies to investigate the relationship between pharmacokinetics and dose limiting toxicity. The purpose of this study was to construct a population PK model to describe platinum (Pt) concentrations in plasma in 33 patients with colorectal cancer. The secondary objective was to determine the relationship between the amount of Pt in 24-hour urine and the amount of Pt in fractionated urine collection periods. Plasma and urine samples were collected from patients during their first oxaliplatin treatment course. Population PK analysis was performed with WinNonMix. The model that best described the Pt concentrations in plasma was a two-compartment PK model. The elimination clearance (CL) and the elimination clearance of the peripheral compartment (CL2) (median +/- SE) were 25.2 +/- 6.3 L/hr and 68 +/- 24.8 L/hr, respectively. The median volume of distribution (V1) was determined to be 41.6 +/- 9.4 L and the median volume of distribution of the peripheral compartment (V2) was 452.5 +/- 96.4 L. The relationship between the cumulative amount of Pt in urine in the first 12 hours compared with the amount of Pt in 24 hours urine was reflected by a correlation coefficient (r2) of 0.95. The cumulative Pt concentration in urine in the first 10 hours and the first 8 hours compared with 24 hours was reflected by correlation coefficients r2 = 0.93 and r2 = 0.897, respectively. This PK model could be useful in identifying predictors for PK and pharmacodynamic variability to individualize dosing. The results of this study suggest that fractionated urine samples can replace 24-hour urine collection.

Lysophosphatidic acid-induced effects in human colon carcinoma DLD1 cells are partially dependent on transactivation of epidermal growth factor receptor

BACKGROUND

Lysophosphatidic acid (LPA) is a lipid mediator of diverse effects on various cells. LPA is well known to induce phosphorylation of the epidermal growth factor receptor (EGFR), which is termed transactivation, in some cell types. In this study, we investigated the contribution of EGFR transactivation in LPA-induced responses in colon cancer DLD1 cells.

MATERIALS AND METHODS

Immunoprecipitation was performed to investigate whether LPA induced EGFR phosphorylation. Then, we investigated LPA-induced migration and IL-8 secretion in DLD1 cells. Migration was measured in a modified Boyden chamber and IL-8 secretion was measured by ELISA. In these experiments we used an EGFR inhibitor, AG1478 or matrix metalloproteinase (MMP) inhibitor, GM6001.

RESULTS

Immunoprecipitation analysis revealed that LPA induced a significant level of tyrosine phosphorylation of EGFR in DLD1 cells. The LPA-induced phosphorylation of EGFR was almost completely abrogated by either AG1478 or GM6001. LPA induced significant migration and IL-8 secretion in DLD1, both of which were significantly inhibited by AG1478 or GM6001. However, the inhibitory effects were only partial (migration; 29% +/- 2%, 32 +/- 13% inhibition, IL-8 secretion; 33% +/- 1%, 26% +/- 5% inhibition, respectively).

CONCLUSION

These results clearly indicate that LPA acts upstream of EGFR and compensates the EGF signal and antagonism of the EGF signal cannot completely block tumor progression in colon cancer cells. Blockade of the LPA signal may have clinical significance in the treatment of colon cancer.

Cost-effectiveness projections of oxaliplatin and infusional fluorouracil versus irinotecan and bolus fluorouracil in first-line therapy for metastatic colorectal carcinoma

BACKGROUND

The results of a randomized comparison study (N9741) showed that oxaliplatin and infusional fluorouracil (FU) (FOLFOX) was superior to the previous standard of care in the United States, irinotecan and bolus FU (IFL), as first-line therapy for patients with metastatic colon carcinoma. The trade-offs between costs and survival for these two regimens have not been explored.

METHODS

A post-hoc, incremental cost-effectiveness (ICE) projection using simulated cohorts of patients starting FOLFOX or IFL was tracked for major clinical events, toxicities, and survival. Recurrence and survival risks were based on clinical trial data. Resource use was projected using observed dose intensity, duration of therapy, delays in therapy, and toxicities Grade > 2 in N9741. The frequency, costs, and consequences of second-line therapy were examined. The time frame was 5 years, and the perspective was that of Medicare as a third-party payer.

RESULTS

Initial treatment with FOLFOX versus IFL had an average incremental cost of dollars 29,523, a survival benefit of 4.4 months, and an ICE of dollars 80,410 per life year (LY), dollars 111,890 per quality-adjusted LY, and dollars 89,080 per progression-free year. By using the 95% confidence interval for the time to progression observed in N9741, the ICE associated with FOLFOX ranged from dollars 121,220 to dollars 59,250 per LY. In the clinical trial, dose delays and skipped doses were frequent. If progression-free patients were treated without delay for the first year or lifetime, then the ICE for FOLFOX increased to dollars 117,910 and dollars 222,200 per LY, respectively. The ICE increased to dollars 84,780 per LY when the model incorporated a revised IFL schedule with lower early toxicity and similar rates of treatment with second-line regimens.

CONCLUSIONS

FOLFOX provided substantial benefits that incurred substantial additional costs. The ICE for FOLFOX fell into the upper range of commonly accepted oncology interventions in the context of the United States healthcare system.

Chinese herbal formula, Bing De Ling, enhances antitumor effects and ameliorates weight loss induced by 5-fluorouracil in the mouse CT26 tumor model

The use of complementary and alternative medicines-including a variety of herbal therapies-by patients undergoing cancer chemotherapy has been well documented. Despite such widespread use, however, the benefits and potential mechanisms of such herbal medicines remain largely anecdotal. In this study we examined the effects of a Chinese herbal formula, Bing De Ling, when administered as an adjunct to chemotherapeutic agent 5-fluorouracil (5-FU) in the CT26 mouse colon cancer model. 5-FU and Bing De Ling were administered to both nave and CT26 mouse colon cancer-bearing BALB/c mice. Our results indicate that although the herbal formula alone did not result in antitumor effects under experimental conditions, it significantly enhanced 5-FU-induced tumor growth inhibition. Oral administration of Bing De Ling also increased survival rates of both tumor-bearing and tumor-free mice treated with 5-FU. Furthermore, oral administration of Bing De Ling reduced weight loss in tumor-free mice receiving 5-FU when compared to tumor-free mice that received 5-FU alone. Our data further show that 5-FU upregulates serum levels of IL-6, known to contribute to weight loss, in tumor-free mice, and that this increase in IL-6 is significantly less in mice that received Bing De Ling in addition to 5-FU. These data show Bing De Ling both enhances the antitumor responses of 5-FU and ameliorates side effects.