New therapies, new directions: advances in the systemic treatment of metastatic colorectal cancer

Gαi2 Protein Inhibition Blocks Chemotherapy- and Anti-Androgen-Induced Prostate Cancer Cell Migration

We have previously shown that heterotrimeric G-protein subunit alphai2 (Gαi2) is essential for cell migration and invasion in prostate, ovarian and breast cancer cells, and novel small molecule inhibitors targeting Gαi2 block its effects on migratory and invasive behavior. In this study, we have identified potent, metabolically stable, second generation Gαi2 inhibitors which inhibit cell migration in prostate cancer cells. Recent studies have shown that chemotherapy can induce the cancer cells to migrate to distant sites to form metastases. In the present study, we determined the effects of taxanes (docetaxel), anti-androgens (enzalutamide and bicalutamide) and histone deacetylase (HDAC) inhibitors (SAHA and SBI-I-19) on cell migration in prostate cancer cells. All treatments induced cell migration, and simultaneous treatments with new Gαi2 inhibitors blocked their effects on cell migration. We concluded that a combination treatment of Gαi2 inhibitors and chemotherapy could blunt the capability of cancer cells to migrate and form metastases.

BI 2536 induces gasdermin E-dependent pyroptosis in ovarian cancer

Background

The frequent emergence of drug resistance to chemotherapy is a major obstacle for the treatment of ovarian cancer. There is a need for novel drugs to fulfill this challenge. Pyroptosis-inducing drugs can inhibit tumor growth. However, their roles in ovarian cancer have not been demonstrated.

Methods

We tested the effectiveness of a novel drug, BI 2536, which we found in colorectal cancer. Cell proliferation, cell cycle, and drug-induced apoptosis and pyroptosis were tested. In vivo treatments were performed using a cell-derived xenograft model.

Results

BI 2536 significantly inhibited the proliferation of ovarian cancer cells and induced cell cycle arrest at the G2/M phases. After BI 2536 treatment, DNA fragmentation and PS exposure on the outside of apoptotic cells were detected. Moreover, the pyroptotic phenotype of ovarian cancer cells along with the release of LDH and HMGB1 were observed, indicating the leakage of cells. Western blot analysis verified that BI 2536 induced GSDME-mediated pyroptosis. Pyroptosis was abolished after additional treatment with Z-DEVD-FMK, a caspase-3 inhibitor. Thus, BI 2536 induced pyroptosis in ovarian cancer through the caspase-3/GSDME pathway. In vivo experiments further demonstrated the antitumoral effect and ability of BI 2536 to accumulate CD8⁺ T cells in ovarian cancer.

Conclusion

In this study, we identified BI 2536 as an effective anti-ovarian cancer drug that inhibits proliferation, arrests the cell cycle, induces apoptosis and pyroptosis, and leads to the accumulation of CD8⁺ T cells in tumor sites. Drug-induced pyroptosis may have promising prospects for reducing side effects and activating immune responses.

The Anti-Tumor Efficacy of Verbascoside on Ovarian Cancer via Facilitating CCN1-AKT/NF-κB Pathway-Mediated M1 Macrophage Polarization

Background

Ovarian cancer (OC) is the leading cause of gynecological cancer-related mortality. Verbascoside (VB) is a phenylpropanoid glycoside from Chinese herbs, with anti-tumour activities. This study aimed to investigate the effects and mechanism of VB on OC.

Methods

OC cell lines SKOV3 and A2780 were used in this study. Cell viability, proliferation, and migration were measured using CCK-8, clonogenic, and transwell assays, respectively. Apoptosis and M1/M2 macrophages were detected using flow cytometry. The interaction between VB and CCN1 was predicted by molecular docking. The mRNA expression of CCN1 was detected by RT-qPCR. The protein levels of CCN1, AKT, p-AKT, p65, and p-p65 were determined by western blotting. A xenograft mice model was established for in vivo validation.

Results

VB inhibited OC cell proliferation and migration in a dose-dependent manner, and promoted apoptosis and M1 macrophage polarization. VB downregulated CCN1 and inhibited the AKT/NF-κB pathway. LY294002, an AKT inhibitor, potentiated the anti-tumour effects of VB. CCN1 overexpression weakened the anti-tumour effects of VB and VB + LY294002. In vivo experiments verified that VB inhibited tumour growth and promoted M1 polarization, which is regulated by the CCN1-mediated AKT/NF-κB pathway.

Conclusion

VB triggers the CCN1-AKT/NF-κB pathway-mediated M1 macrophage polarization for protecting against OC.

CUDC-101 enhances the chemosensitivity of gemcitabine-treated lymphoma cells

BACKGROUND

The metastasis and recurrence of Non-Hodgkin's lymphoma (NHL) is a major cause of morbidity and mortality. Recent work suggests that drugs capable of targeting epigenetic regulatory mechanisms may be well suited to the treatment of such disease progression.

METHODS

This study was thus designed to evaluate the ability of the novel histone deacetylase (HDAC) inhibitor CUDC-101 to synergize with gemcitabine in order to kill human HUT78 and Pfeiffer NHL cells. To that end, we analyzed the viability of these NHL cells via CCK-8 assay, while the incidence of apoptosis among treated cells was evaluated via Annexin V-FITC/PI staining and by the Western blotting-mediated evaluation of proteins associate with apoptosis and related signaling pathways.

RESULTS

We found that CUDC-101 and gemcitabine interacted synergistically to reduce NHL cell viability and to induce the apoptotic death of these cells via the EGFR/ PI3K/Akt and Erk pathways, which were regulated by HDAC signaling pathways.

CONCLUSION

Together, our results highlight the anti-cancer properties of CUDC-101 alone or in combination with gemcitabine as an approach to inducing the apoptotic death of lymphoma cells in vitro, while also offering insight into the underlying molecular mechanisms governing this activity.

Embolotherapy for Hepatic Oncology: Current Perspectives and Future Directions

Primary and secondary liver cancers are a major cause of mortality worldwide. Transarterial liver-directed therapy, or embolotherapy, represents an important locoregional treatment strategy for primary and secondary liver tumors. Embolotherapeutic modalities include bland embolization (transarterial embolization), chemoembolization (transarterial chemoembolization), and radioembolization or selective internal radiotherapy. A brief technical overview of embolotherapeutic modalities as well as supportive evidence for the treatment of most common primary and secondary liver tumors will be discussed in this review. Several potential future applications, including synergy with systemic therapy, interventional theranostics, and artificial intelligence will also be reviewed briefly.

Regulation of IL-6 signaling by miR-125a and let-7e in endothelial cells controls vasculogenic mimicry formation of breast cancer cells

The role of tumor-proximal factors in tumor plasticity during chemoresistance and metastasis following chemotherapy is well studied. However, the role of endothelial cell (EC) derived paracrine factors in tumor plasticity, their effect on chemotherapeutic outcome, and the mechanism by which these paracrine factors modulate the tumor microenvironment are not well understood. In this study, we report a novel mechanism by which endothelial miR-125a and let-7e-mediated regulation of interleukin-6 (IL-6) signaling can manipulate vasculogenic mimicry (VM) formation of MDA-MB-231 breast cancer cells. We found that endothelial IL-6 levels were significantly higher in response to cisplatin treatment, whereas levels of IL-6 upon cisplatin exposure remained unchanged in MDA-MB-231 breast cancer cells. We additionally found an inverse correlation between IL-6 and miR-125a/let-7e expression levels in cisplatin treated ECs. Interestingly, IL-6, IL-6 receptor (IL-6R), and signal transducer and activator of transcription 3 (STAT3) genes in the IL-6 pathway are closely regulated by miR-125a and let-7e, which directly target its 3′ untranslated region. Functional analyses revealed that endothelial miR-125a and let-7e inhibit IL-6-induced adhesion of monocytes to ECs. Furthermore, conditioned medium from cisplatin treated ECs induced a significantly higher formation of VM in MDA-MB-231 breast cancer cells as compared to that from intact ECs; this effect of cisplatin treatment was abrogated by concurrent overexpression of miR-125a and let-7e. Overall, this study reveals a novel EC-tumor cell crosstalk mediated by the endothelial miR-125a/let-7e-IL-6 signaling axis, which might improve chemosensitivity and provide potential therapeutic targets for the treatment of cancer.

Stress-inducible gene Atf3 in the noncancer host cells contributes to chemotherapy-exacerbated breast cancer metastasis

Chemotherapy is a double-edged sword. It is anticancer because of its cytotoxicity. Paradoxically, by increasing chemoresistance and cancer metastasis, it is also procancer. However, the underlying mechanisms for chemotherapy-induced procancer activities are not well understood. Here we describe the ability of paclitaxel (PTX), a frontline chemotherapeutic agent, to exacerbate metastasis in mouse models of breast cancer. We demonstrate that, despite the apparent benefit of reducing tumor size, PTX increased the circulating tumor cells in the blood and enhanced the metastatic burden at the lung. At the primary tumor, PTX increased the abundance of the tumor microenvironment of metastasis, a landmark microanatomical structure at the microvasculature where cancer cells enter the blood stream. At the metastatic lung, PTX improved the tissue microenvironment (the "soil") for cancer cells (the "seeds") to thrive; these changes include increased inflammatory monocytes and reduced cytotoxicity. Importantly, these changes in the primary tumor and the metastatic lung were all dependent on Atf3, a stress-inducible gene, in the noncancer host cells. Together, our data provide mechanistic insights into the procancer effect of chemotherapy, explaining its paradox in the context of the seed-and-soil theory. Analyses of public datasets suggest that our data may have relevance to human cancers. Thus, ATF3 in the host cells links a chemotherapeutic agent-a stressor-to immune modulation and cancer metastasis. Dampening the effect of ATF3 may improve the efficacy of chemotherapy.

Comparative Effectiveness of Hepatic Artery Based Therapies for Unresectable Colorectal Liver Metastases: A Meta-Analysis

Background

Patients with unresectable Colorectal Liver Metastases (CRLM) are increasingly being managed using Hepatic Artery Based Therapies (HAT), including Hepatic Arterial Infusion (HAI), Radioembolization (RE), and Transcatheter Arterial Chemoembolization (TACE). Limited data is available on the comparative effectiveness of these options. We hypothesized that outcomes in terms of survival and toxicity were equivalent across the three strategies.

Methods

A meta-analysis was performed using a prospectively registered search strategy at PROSPERO (CRD42013003861) that utilized studies from PubMed (2003–2013). Primary outcome was median overall survival (OS). Secondary outcomes were treatment toxicity, tumor response, and conversion of the tumor to resectable. Additional covariates included prior or concurrent systemic therapy.

Results

Of 491 studies screened, 90 were selected for analyses—52 (n = 3,000 patients) HAI, 24 (n = 1,268) RE, 14 (n = 1,038) TACE. The median OS (95% CI) for patients receiving HAT in the first-line were RE 29.4 vs. HAI 21.4 vs. TACE 15.2 months (p = 0.97, 0.69 respectively). For patients failing at least one line of prior systemic therapy, the survival outcomes were TACE 21.3 (20.6–22.4) months vs. HAI 13.2 (12.2–14.2) months vs. RE 10.7 (9.5–12.0). Grade 3–4 toxicity for HAT alone was 40% in the HAI group, 19% in the RE group, and 18% in the TACE groups, which was increased with the addition of systemic chemotherapy. Level 1 evidence was available in 5 studies for HAI, 2 studies for RE and 1 for TACE.

Conclusion

HAI, RE, and TACE are equally effective in patients with unresectable CRLM with marginal differences in survival.

Non-Hodgkin's B-cell lymphoma: advances in molecular strategies targeting drug resistance

Non-Hodgkin's lymphoma (NHL) is a heterogeneous class of cancers displaying a diverse range of biological phenotypes, clinical behaviours and prognoses. Standard treatments for B-cell NHL are anthracycline-based combinatorial chemotherapy regimens composed of cyclophosphamide, doxorubicin, vincristine and prednisolone. Even though complete response rates of 40-50% with chemotherapy can be attained, a substantial proportion of patients relapse, resulting in 3-year overall survival rates of about 30%. Relapsed lymphomas are refractory to subsequent treatments with the initial chemotherapy regimen and can exhibit cross-resistance to a wide variety of anticancer drugs. The emergence of acquired chemoresistance thus poses a challenge in the clinic preventing the successful treatment and cure of disseminated B-cell lymphomas. Gene-expression analyses have increased our understanding of the molecular basis of chemotherapy resistance and identified rational targets for drug interventions to prevent and treat relapsed/refractory diffuse large B-cell lymphoma. Acquisition of drug resistance in lymphoma is in part driven by the inherent genetic heterogeneity and instability of the tumour cells. Due to the genetic heterogeneity of B-cell NHL, many different pathways leading to drug resistance have been identified. Successful treatment of chemoresistant NHL will thus require the rational design of combinatorial drugs targeting multiple pathways specific to different subtypes of B-cell NHL as well as the development of personalized approaches to address patient-to-patient genetic heterogeneity. This review highlights the new insights into the molecular basis of chemorefractory B-cell NHL that are facilitating the rational design of novel strategies to overcome drug resistance.

Advances in regional chemotherapy of the liver

INTRODUCTION

Primary and secondary liver tumors resemble some of the most common causes of cancer and represent a major clinical problem owing to the poor prognosis. First-line therapeutic concepts are mainly based on surgical resection and/or systemic chemotherapy (SCT). However, many patients are not suitable for surgery or have failed SCT, although the total tumor load is still limited, which makes a regional therapy approach appealing.

AREAS COVERED

This review focuses on different types of transarterial instillation of chemotherapy, which encompasses conventional and drug-eluting transarterial chemoembolization (TACE), hepatic arterial infusion (HAI) chemotherapy and isolated hepatic perfusion (ILP).

EXPERT OPINION

TACE can be regarded as the treatment of choice in patients with multinodular hepatocellular carcinoma, but it should still be performed as a lipiodol-based regimen, while the value of doxorubicin-eluting beads needs to be exploited in further randomized controlled trials (RCTs). For patients with colorectal liver metastases, HAI chemotherapy has been challenged by the advent of more effective SCT, but encouraging results have been observed for the combination of the most recent, active drugs given by means of HAI with SCT. Nevertheless, data from RCTs comparing SCT with this transarterial regional therapy approach, as well as with TACE and ILP, are urgently needed.

DNA damage-mediated induction of a chemoresistant niche

While numerous cell-intrinsic processes are known to play decisive roles in chemotherapeutic response, relatively little is known about the impact of the tumor microenvironment on therapeutic outcome. Here, we use a well-established mouse model of Burkitt's lymphoma to show that paracrine factors in the tumor microenvironment modulate lymphoma cell survival following the administration of genotoxic chemotherapy. Specifically, IL-6 and Timp-1 are released in the thymus in response to DNA damage, creating a "chemo-resistant niche" that promotes the survival of a minimal residual tumor burden and serves as a reservoir for eventual tumor relapse. Notably, IL-6 is released acutely from thymic endothelial cells in a p38-dependent manner following genotoxic stress, and this acute secretory response precedes the gradual induction of senescence in tumor-associated stromal cells. Thus, conventional chemotherapies can induce tumor regression while simultaneously eliciting stress responses that protect subsets of tumor cells in select anatomical locations from drug action.

Gene signature is associated with early stage rectal cancer recurrence

BACKGROUND

Despite expected excellent outcomes of surgical resection for early stage rectal cancers, 20% of stage I and II rectal cancers recur. Identifying biologic factors that predict the subset prone to recur could allow more directed therapy. This study identifies a tumor gene expression profile that accurately predicts disease recurrence.

STUDY DESIGN

Stage I/II rectal cancer patients treated by surgery alone at a single institution were included and classified as having recurrent or nonrecurrent cancer. Tumor mRNA was isolated from frozen tissue and evaluated for total genome gene expression by microarray analysis. Background-corrected and normalized microarray data were analyzed using BAMarray software. Selected genes were further analyzed using unsupervised clustering and nearest-centroid classification. A balanced K-fold scoring-pair algorithm using 1,000 independent replications was used for gene signature development.

RESULTS

Sixty-nine patients with disease-free survival and 31 patients with recurrent disease were included at a median follow-up of 105 months (interquartile range 114 months) and 32 months (interquartile range 25 months), respectively. Demographics and tumor characteristics between groups were similar. Fifty-two genes from 43,148 probes were differentially expressed, and a 36-gene signature was found to be statistically associated with recurrence using a scoring-pair algorithm. Accuracy to identify recurrence as measured by area under the receiver operating characteristic curve was 0.803.

CONCLUSIONS

Differential gene expression within rectal cancers is associated with recurrence of early stage disease. A 36-gene signature correlates with an increased risk of more or less aggressive tumor behavior. This information obtainable at biopsy may assist in determining treatment decisions.

Oxaliplatin Added to Simplified Bimonthly Low-Dose Leucovorin and 5-FU for Pretreated Advanced Colorectal Cancer Is Effective and Not Affected by Different Previous 5-FU Regimens

This phase II study examined bimonthly oxaliplatin (85 mg/m2) added to a continuous infusion of fluorouracil (3000 mg/m2 for 46 h following a 400 mg/m2 bolus), with leucovorin (LV) (150 mg/m2) administrated in a simplified way to patients with metastatic colorectal cancers (CRC) refractory or resistant to 5-fluorouracil (5-FU). Sixty patients were registered. Of the 52 evaluable patients, 3 (5.8%) achieved a complete response (CR) and 18 (34.6%) achieved a partial response (PR). The overall response rate (CR + PR) was 40.4% (95% confidence interval [CI]: 26.6%-54.2%) for evaluable patients and 35% (95% CI: 22.6%-47.4%) by intention to treat. The median progression-free survival (PFS) was 5.2 months, and the median survival was 14.2 months. No significant differences were seen in response rates and PFS of patient groups pretreated either with high-dose 5-FU/LV by continuous infusion or with intravenous 5-FU/LV by a weekly bolus. From the 421 cycles analyzed, dose-limiting toxicities included cumulative sensory neuropathy and leukopenia, accounting for 11.6% and 10.0%, National Cancer Institute-Common Toxicity Criteria grade 3/4 toxicities per patient, respectively. Two (3.3%) patients experienced hepatic encephalopathy related to high-dose 5-FU. With necessary caution, this regimen was effective for 5-FU-pretreated CRC, regardless of ethnic differences, and it had the advantage of LV being administrated at a low dose in a simplified way.

Graft-versus-tumor effect after reduced-intensity allogeneic hematopoietic stem cell transplantation in a patient with advanced colon cancer

A 27-year-old man with advanced colon cancer that was resistant to conventional chemoradiotherapies was treated with reduced-intensity allogeneic peripheral blood stem cell transplantation (PBSCT). After obtaining complete donor-type chimerism, there was an apparent graft-versus-tumor effect accompanied by severe hepatic graft-versus-host disease (GVHD) showing hyperbilirubinemia, resulting in a stable disease condition that lasted for 18 months, which had not been seen previously in his previous disease history. The antitumor effect observed in this patient was insufficient for the patient to achieve complete remission, because the disease was at an already widespread and treatment-resistant stage. He finally died of hepatic failure due to extensive liver GVHD 65 months after the diagnosis of the advanced colon cancer and 29 months after the allogeneic PBSCT. Prospective studies are necessary to achieve better clinical results in patients with advanced colon cancer.

A pharmacokinetic and pharmacodynamic study on metronomic irinotecan in metastatic colorectal cancer patients

The pharmacokinetics (PK) and pharmacodynamics (PD) of metronomic irinotecan have not been studied in cancer patients. The aim of the study is to investigate the PK/PD profile of irinotecan/SN-38 administered by metronomic schedule. Twenty chemotherapy-refractory or chemotherapy-resistant patients with metastatic colorectal carcinoma were enrolled. Irinotecan was infused continuously as follows: irinotecan 1.4 mg m⁻² day⁻¹ (n=7), 2.8 mg m⁻² day⁻¹ (n=5) and 4.2 mg m⁻² day⁻¹ (n=8). Drug levels were examined by HPLC, whereas ELISAs and real-time RT-PCR were used, respectively, for the measurement of plasma levels and gene expression in peripheral blood mononuclear cells of vascular endothelial growth factor/thrombospondin-1. Pharmacokinetic analysis demonstrated that the steady-state levels (C_ss) of SN-38 were between 1 and 3.3 ng ml⁻¹. From a PD point of view, higher thrombospondin-1 (TSP-1) plasma levels (153.4±30.1 and 130.4±9.2% at day 49 vs pretreatment values at 1.4 and 2.8 mg m⁻² day⁻¹ dose levels, respectively) and increased gene expression in PBMC were found during the metronomic irinotecan infusion, especially at the lower doses. Four patients (20%) obtained a stable disease (median 3.9 months) despite progressing during previous standard irinotecan schedule. Toxicities >grade 1 were not observed. Metronomic irinotecan administration is very well tolerated and induces an increase of gene expression and plasma concentration of TSP-1 at low plasma SN-38 concentrations.

Meta-analysis of hepatic arterial infusion for unresectable liver metastases from colorectal cancer: the end of an era?

PURPOSE

The treatment of unresectable liver-confined metastatic disease from colorectal cancer (CRC) is a challenging issue. Although locoregional treatments such as hepatic arterial infusion (HAI) claim the advantage of delivering higher doses of anticancer agents directly into the affected organ, the benefit in terms of overall survival (OS) is unclear. We quantitatively summarized the results of randomized controlled trials (RCT) comparing HAI with systemic chemotherapy (SCT).

METHODS

To date, 10 RCTs have been published, for a total of 1,277 patients enrolled. For tumor response rates, relative risks (RR) and their 95% CIs were obtained from raw data; for OS, hazard ratios (HRs) and their 95% CIs were extrapolated from the Kaplan-Meier survival curves.

RESULTS

HAI regimens were based on floxuridine (FUDR) in nine of 10 RCTs, whereas in one RCT, fluorouracil (FU) + leucovorin was used. SCT consisted of FUDR, FU, FU + leucovorin, or a miscellany of FU and best supportive care in three, one, four, and two studies, respectively. Pooling the data, tumor response rate was 42.9% and 18.4% for HAI and SCT, respectively (RR = 2.26; 95% CI, 1.80 to 2.84; P < .0001). Mean weighted median OS times were 15.9 and 12.4 months for HAI and SCT, respectively; the meta-risk of death was not statistically different between the two study groups (HR = 0.90; 95% CI, 0.76 to 1.07; P = .24).

CONCLUSION

Currently available evidence does not support the clinical or investigational use of fluoropyrimidine-based HAI alone for the treatment of patients with unresectable CRC liver metastases, at least as a first-line therapy.

Rapidly Reversible Hydrophobization: An Approach to High First-Pass Drug Extraction

We have investigated a rapidly reversible hydrophobization of therapeutic agents for improving first-pass uptake in locoregional drug therapy. This approach involves the attachment of a hydrophobic moiety to the drug by highly labile chemical linkages that rapidly hydrolyze upon injection. Hydrophobization drastically enhances cell-membrane association of the prodrug and, consequently, drug uptake, while the rapid lability protects nontargeted tissues from exposure to the highly active agent. Using the membrane-impermeable DNA intercalator propidium iodide, and melphalan, we report results from in vitro cellular internalization and toxicity studies. Additionally, we report in vivo results after a single liver arterial bolus injection, demonstrating both tumor targeting and increased survival in a mouse tumor model.

Mass Spectrometry-Based Study of the Plasma Proteome in a Mouse Intestinal Tumor Model

Early detection of cancer can greatly improve prognosis. Identification of proteins or peptides in the circulation, at different stages of cancer, would greatly enhance treatment decisions. Mass spectrometry (MS) is emerging as a powerful tool to identify proteins from complex mixtures such as plasma that may help identify novel sets of markers that may be associated with the presence of tumors. To examine this feature we have used a genetically modified mouse model, Apc(Min), which develops intestinal tumors with 100% penetrance. Utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified total plasma proteome (TPP) and plasma glycoproteome (PGP) profiles in tumor-bearing mice. Principal component analysis (PCA) and agglomerative hierarchial clustering analysis revealed that these protein profiles can be used to distinguish between tumor-bearing Apc(Min) and wild-type control mice. Leave-one-out cross-validation analysis established that global TPP and global PGP profiles can be used to correctly predict tumor-bearing animals in 17/19 (89%) and 19/19 (100%) of cases, respectively. Furthermore, leave-one-out cross-validation analysis confirmed that the significant differentially expressed proteins from both the TPP and the PGP were able to correctly predict tumor-bearing animals in 19/19 (100%) of cases. A subset of these proteins was independently validated by antibody microarrays using detection by two color rolling circle amplification (TC-RCA). Analysis of the significant differentially expressed proteins indicated that some might derive from the stroma or the host response. These studies suggest that mass spectrometry-based approaches to examine the plasma proteome may prove to be a valuable method for determining the presence of intestinal tumors.

The future development of bevacizumab in colorectal cancer

Bevacizumab (Avastin), the first approved therapy designed to inhibit tumor angiogenesis, has significant clinical benefits in the management of colorectal cancer (CRC). When bevacizumab is added to IFL (5-fluorouracil [5-FU]/leucovorin [LV]/irinotecan [Camptosar)]) as first-line therapy for metastatic CRC, significant overall and progression-free survival benefits are obtained. Similar survival benefits may be achieved when bevacizumab is added to 5-FU/LV alone. In addition, additive and synergistic effects with a range of chemotherapeutic agents illustrate that bevacizumab has considerable potential in combination with existing therapeutic options. Clinical data indicate that bevacizumab is the only agent in addition to chemotherapy that has demonstrated survival benefit in the first- and second-line settings. In addition, bevacizumab is expected to produce clinical benefit in the adjuvant setting: inhibition of vascular endothelial growth factor should prevent the angiogenic switch in micrometastases, which is a key factor in malignancy. The clinical program is examining the activity of bevacizumab in combination with the likely future standard of care in both the metastatic and adjuvant treatment settings. Phase III trials (NO16966C, CONcePT and TREE-2) are studying the benefit of combining bevacizumab with oxaliplatin (Eloxatin)-based regimens. Similarly, in the adjuvant setting, phase III trials are assessing the efficacy and tolerability of bevacizumab in combination with oxaliplatin-based chemotherapy (AVANT, NSABP C-08).

Geraniol, a component of plant essential oils, modulates DNA synthesis and potentiates 5-fluorouracil efficacy on human colon tumor xenografts

We investigated on colon cancer cells the effect of geraniol on thymidylate synthase and thymidine kinase expression, two enzymes related to 5-fluorouracil cytotoxicity. The anti-tumoral efficacy of geraniol and 5-fluorouracil were also evaluated on TC-118 human tumors transplanted in Swiss nu/nu mice. Geraniol (150 microM) but not 5-fluorouracil caused a 2-fold reduction of thymidylate synthase and thymidine kinase expression in cancer cells. In nude mice, the combined administration of 5-fluorouracil (20 mg/kg) and geraniol (150 mg/kg) caused a 53% reduction of the tumor volume, whereas a 26% reduction was obtained with geraniol alone, 5-fluorouracil alone showed no effect.

Whole-body hyperthermia in the scope of von Ardenne's systemic cancer multistep therapy (sCMT) combined with chemotherapy in patients with metastatic colorectal cancer: a phase I/II study

This phase I/II study evaluated the feasibility, toxicity and response rates of von Ardenne's systemic cancer multistep therapy (sCMT) when applied as an adjunct to cytostatic therapy in patients with metastatic colorectal cancer. sCMT consists of whole-body hyperthermia (WBH) at 41.8-42.1 degrees C, hyperglycaemia and hyperoxaemia. All patients who entered the trial first received three monthly courses of chemotherapy (folinic acid, 50 mg, days 1-5; 5-fluorouracil, 425 mg/m2, days 1-5; mitomycin 8 mg/m2, day 1), followed by response evaluation according World Health Organization (WHO) criteria. Responders (partial/complete remission) were assigned to three further courses of chemotherapy, whereas non-responders (stable/progressive disease) were allocated to additional sCMT on day 1 of every subsequent chemotherapy course. The WBH procedure was administered under general anaesthesia employing the Iratherm-2000 radiant heat device. Of 28 patients enrolled, 19 received more than three treatment courses. Eight of these 19 patients had responded to chemotherapy (PR) and thus obtained three further courses of chemotherapy alone. In 10 of 19 patients who had not responded (SD, PD), three additional courses of chemotherapy were combined with sCMT (with 25 sCMT applications). One patient who did not respond to initial treatment declined sCMT and was continued with chemotherapy alone. It was found that sCMT was feasible, but associated with a specific spectrum of grade III/IV toxicity (skin 20%, pain 16%, peripheral nerves 8% of treatment courses). The fact that three patients who did not respond to initial chemotherapy achieved a PR after additional sCMT suggests that sCMT may enhance the effect of chemotherapy in patients with colorectal cancer.

Isolated hypoxic hepatic perfusion with orthograde or retrograde flow in patients with irresectable liver metastases using percutaneous balloon catheter techniques: a phase I and II study

BACKGROUND

Isolated hepatic perfusion for irresectable metastases confined to the liver has reported response rates of 50% to 75%. Magnitude, costs, and nonrepeatability of the procedure are its major drawbacks. We developed a less invasive, less costly, and potentially repeatable balloon catheter-mediated isolated hypoxic hepatic perfusion (IHHP) technique.

METHODS

In this phase I and II study, 18 consecutive patients with irresectable colorectal or ocular melanoma hepatic metastases were included. Two different perfusion methods were used, both with inflow via the hepatic artery, using melphalan 1 mg/kg. In the first eight patients, the portal vein was occluded, and outflow was via the hepatic veins into an intracaval double-balloon catheter. This orthograde IHHP had on average 56% leakage. In next 10 patients, we performed a retrograde outflow IHHP with a triple balloon blocking outflow into the caval vein and allowing outflow via the portal vein. The retrograde IHHP still had 35% leakage on average.

RESULTS

Although local drug concentrations were high with retrograde IHHP, systemic toxicity was still moderate to severe. Partial responses were seen in 12% and stable disease in 81% of patients. The median time to local progression was 4.8 months.

CONCLUSIONS

We have abandoned occlusion balloon methodology for IHHP because it failed to obtain leakage control. We are presently conducting a study using a simplified surgical retrograde IHHP method, in which leakage is fully controlled, which translates into high response rates.

Capecitabine and irinotecan as first-line chemotherapy in patients with metastatic colorectal cancer: results of an extended phase I study

BACKGROUND

To define the maximum-tolerated dose (MTD) and to evaluate the dose-limiting toxicities (DLTs) of the combination of capecitabine and irinotecan in patients with metastatic colorectal cancer.

PATIENTS AND METHODS

Thirty-seven patients with measurable metastatic colorectal cancer with no prior chemotherapy for metastatic disease were treated at three dose levels (DLs). For the first two dose levels, irinotecan (70 mg/m(2)) was administered once a week for 6 weeks in combination with 2 weeks of capecitabine at 1000 mg/m(2) (DL1) or 1250 mg/m(2) (DL2) twice daily, starting on days 1 and 22. In the last dose escalation step, the dose of irinotecan was increased to 80 mg/m(2) (DL3). One cycle lasted 7 weeks.

RESULTS

In the subsequent phase I trial, 96 cycles of capecitabine and irinotecan were administered. At DL3, three out of six patients experienced DLTs (diarrhea, neutropenia, asthenia). In order to confirm the safety of the recommended dose, DL2 was extended to 15 patients. Five patients (33%) showed DLTs at this dose level, which was considered too high to embark on further clinical studies. Subsequently, the starting dose (DL1) was extended to a total of 16 patients, with diarrhea being the main toxicity. The overall response rate was 38% [95% confidence interval (CI) 21% to 58%], with a median response duration of 8.7 months (95% CI 6.4-11.5 months).

CONCLUSIONS

The recommended doses for further studies are irinotecan 70 mg/m(2) and capecitabine 1000 mg/m(2). The combination of capecitabine and irinotecan appears to have significant therapeutic efficacy with manageable toxicity.