The Combination of the Selective Cyclooxygenase-2 Inhibitor Celecoxib with Weekly Paclitaxel Is a Safe and Active Second-Line Therapy for Non-Small Cell Lung Cancer

Cancer and inflammation

The relationship between inflammation and cancer has been recognized since the 17^th century,¹ and we now know much about the cells, cytokines and physiological processes that are central to both inflammation and cancer.^2-9 Chronic inflammation can induce certain cancers,^10-17 and solid tumors, in turn, can initiate and perpetuate local inflammatory processes that foster tumor growth and dissemination.⁵ ,^18-20 Consequently, inflammatory pathways have been targeted in attempts to control cancer.^21-23 Inflammation is a central aspect of the innate immune system's response to tissue damage or infection, and also facilitates the recruitment of circulating cells and antibodies of the adaptive immune response to the tissue. Components of the innate immune response carry out a robust, but sometimes overly-conservative response, sacrificing specificity for the sake of preservation. Thus, when innate immunity goes awry, it can have profound implications. How the innate and adaptive immune systems cooperate to neutralize pathogens and repair damaged tissues is still an area of intense investigation. Further, how these systems can respond to cancer, which arises from normal 'self' cells that undergo an oncogenic transformation, has profound implications for cancer therapy. Recently, immunotherapies that activate adaptive immunity have shown unprecedented promise in the clinic, producing durable responses and dramatic increases in survival rate in patients with advanced stage melanoma.^24-26 Consequently, the relationship between cancer and inflammation has now returned to the forefront of clinical oncology. WIREs Syst Biol Med 2017, 9:e1370. doi: 10.1002/wsbm.1370 For further resources related to this article, please visit the WIREs website.

Anti-tumor enhancement of Fei-Liu-Ping ointment in combination with celecoxib via cyclooxygenase-2-mediated lung metastatic inflammatory microenvironment in Lewis lung carcinoma xenograft mouse model

Background

Fei-Liu-Ping (FLP) ointment is an oral prescription medication that has been widely applied to treat lung cancer patients in China. Regulation of the metastatic microenvironment is an important therapeutic approach for prevention and treatment of tumor recurrence and metastasis. The advantage of Traditional Chinese Medicine management of lung cancer lies in the prevention of recurrence and metastasis. Our previous study has demonstrated that FLP ointment could regulate lung inflammatory microenvironment in vitro. However, the effects of FLP on the tumor microenvironment in vivo are still poorly understood. The objective of this study is to investigate the effect of FLP alone or in combination with celecoxib in the prevention of lung cancer progression by Cyclooxygenase (Cox)-2 mediated tumor inflammatory microenvironment in vivo.

Methods

120 Lewis lung carcinoma xenograft mice were divided equally into four groups: vehicle, FLP, celecoxib, and FLP plus celecoxib. The dynamic growth of the xenografted tumors was observed using an in vivo fluorescence imaging system. Mice were sacrificed on day 14, day 21, and day 28, and tumor specimens and lung tissues were harvested to detect the metastasis-associated protein expression.

Results

Tumor inhibition rate was 15.4, 44.2, 47.4 % at day 14, 37.3, 34.7, 61.5 % at day 21, and 15.5, 10.3, 32.5 % at day 28 after treatment of FLP, celecoxib, and FLP plus celecoxib, respectively. Upon treatment of FLP and celecoxib together, lung metastasis rate was 30 % (8 metastatic nodules) lower than other groups. FLP inhibited Cox-2 expression in a time-dependent manner. Moreover, FLP inhibited N-cadherin, matrix metalloproteinases (MMP)-9, and Vimentin expression. Treatment of FLP in combination with celecoxib was more effective than FLP or celecoxib alone in inhibiting vascular endothelial growth factor, platelet-derived growth factor receptors β, microsomal Prostaglandin E synthase-1, MMP-2, MMP-9, N-cadherin, and Vimentin expression, but increased E-cadherin expression.

Conclusions

FLP inhibited tumor growth and metastasis in a Lewis lung xenograft mice model through the Cox-2 pathway. FLP in combination with celecoxib enhanced the antitumor growth and anti-metastasis effects. Traditional Chinese herbs combined with anti-inflammatory drugs might offer a promising strategy to prevent tumor metastasis.

Effects of combining Taxol and cyclooxygenase inhibitors on the angiogenesis and apoptosis in human ovarian cancer xenografts

The present study aimed to investigate the combined effects of Taxol and cyclooxygenase (COX) inhibitors on angiogenesis and cell apoptosis of SKOV-3 human ovarian carcinoma cell xenograft-bearing mice. The experiments were continued for 28 days. Animals were treated with 3 mg/kg SC-560 (a COX-1-selective inhibitor) alone, 100 mg/kg celecoxib (a COX-2-selective inhibitor) alone or SC-560/celecoxib by gavage twice a day, 20 mg/kg Taxol alone intraperitoneally once a week or in combination with SC-560 or celecoxib or SC-560/celecoxib/Taxol for three weeks. The mRNA levels of vascular endothelial growth factor (VEGF) was determined by reverse transcription-polymerase chain reaction (RT-PCR). The microvessel density (MVD) of ovarian carcinoma was determined by immunohistochemistry with anti-CD₃₄ as the label. The apoptotic index was detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. The MVD value and apoptotic index in the SC-560/Taxol group were notably inhibited compared with the Taxol group (P<0.001). Moreover, the VEGF mRNA levels, MVD value and apoptotic index in the SC-560/Taxol group were significantly different from the celecoxib/Taxol group (P<0.05, P<0.05 and P<0.001, respectively). The present study demonstrated that SC-560 enhances the anti-angiogenic and pro-apoptotic effects of Taxol and these effects are better than with celecoxib.

Effects of cyclooxygenase inhibitors in combination with taxol on expression of cyclin D1 and Ki-67 in a xenograft model of ovarian carcinoma

The present study was designed to investigate the effects of cyclooxygenase (COX) inhibitors in combination with taxol on the expression of cyclin D1 and Ki-67 in human ovarian SKOV-3 carcinoma cells xenograft-bearing mice. The animals were treated with 100 mg/kg celecoxib (a COX-2 selective inhibitor) alone, 3 mg/kg SC-560 (a COX-1 selective inhibitor) alone by gavage twice a day, 20 mg/kg taxol alone by intraperitoneally (i.p.) once a week, or celecoxib/taxol, SC-560/celecoxib, SC-560/taxol or SC-560/celecoxib/taxol, for three weeks. To test the mechanism of the combination treatment, the index of cell proliferation and expression of cyclin D1 in tumor tissues were determined by immunohistochemistry. The mean tumor volume in the treated groups was significantly lower than control (p < 0.05), and in the three-drug combination group, tumor volume was reduced by 58.27% (p < 0.01); downregulated cell proliferation and cyclin D1 expression were statistically significant compared with those of the control group (both p < 0.01). This study suggests that the effects of COX selective inhibitors on the growth of tumors and decreased cell proliferation in a SKOV-3 cells mouse xenograft model were similar to taxol. The three-drug combination showing a better decreasing tendency in growth-inhibitory effect during the experiment may have been caused by suppressing cyclin D1 expression.

Tumor and host factors that may limit efficacy of chemotherapy in non-small cell and small cell lung cancer

While chemotherapy provides useful palliation, advanced lung cancer remains incurable since those tumors that are initially sensitive to therapy rapidly develop acquired resistance. Resistance may arise from impaired drug delivery, extracellular factors, decreased drug uptake into tumor cells, increased drug efflux, drug inactivation by detoxifying factors, decreased drug activation or binding to target, altered target, increased damage repair, tolerance of damage, decreased proapoptotic factors, increased antiapoptotic factors, or altered cell cycling or transcription factors. Factors for which there is now substantial clinical evidence of a link to small cell lung cancer (SCLC) resistance to chemotherapy include MRP (for platinum-based combination chemotherapy) and MDR1/P-gp (for non-platinum agents). SPECT MIBI and Tc-TF scanning appears to predict chemotherapy benefit in SCLC. In non-small cell lung cancer (NSCLC), the strongest clinical evidence is for taxane resistance with elevated expression or mutation of class III beta-tubulin (and possibly alpha tubulin), platinum resistance and expression of ERCC1 or BCRP, gemcitabine resistance and RRM1 expression, and resistance to several agents and COX-2 expression (although COX-2 inhibitors have had minimal impact on drug efficacy clinically). Tumors expressing high BRCA1 may have increased resistance to platinums but increased sensitivity to taxanes. Limited early clinical data suggest that chemotherapy resistance in NSCLC may also be increased with decreased expression of cyclin B1 or of Eg5, or with increased expression of ICAM, matrilysin, osteopontin, DDH, survivin, PCDGF, caveolin-1, p21WAF1/CIP1, or 14-3-3sigma, and that IGF-1R inhibitors may increase efficacy of chemotherapy, particularly in squamous cell carcinomas. Equivocal data (with some positive studies but other negative studies) suggest that NSCLC tumors with some EGFR mutations may have increased sensitivity to chemotherapy, while K-ras mutations and expression of GST-pi, RB or p27kip1 may possibly confer resistance. While limited clinical data suggest that p53 mutations are associated with resistance to platinum-based therapies in NSCLC, data on p53 IHC positivity are equivocal. To date, resistance-modulating strategies have generally not proven clinically useful in lung cancer, although small randomized trials suggest a modest benefit of verapamil and related agents in NSCLC.

Targeted therapies for non-small cell lung cancer: an evolving landscape

Over the past decade, a multitude of targeted agents have been explored in the treatment of advanced non-small cell lung cancer (NSCLC). Thus far, two broad classes of agents have been implemented in clinical practice: (a) vascular endothelial growth factor (VEGF)-directed therapies and (b) antagonists of the epidermal growth factor receptor (EGFR). In the former category, the agent bevacizumab (a monoclonal antibody) has shown landmark improvements in survival when added to cytotoxic therapy. Small molecule tyrosine kinase inhibitors (TKI) targeting the VEGF receptor (i.e., sunitinib, sorafenib, and vandetanib) show activity in phase II clinical studies. With respect to EGFR-directed therapies, the TKIs gefitinib and erlotinib have shown significant benefit, and have uncovered valuable information about the biology of lung cancer. Outside of therapies directed specifically at VEGF- and EGFR-mediated signaling, trials evaluating insulin-like growth factor-1 receptor (IGF-IR)-targeting agents, cyclooxygenase-2 (COX-2) inhibitors, c-met inhibitors, irreversible pan-HER inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and histone deacetylase (HDAC) inhibitors are ongoing. Inhibitors of ALK show great promise in patients with the relevant gene translocation. Herein, the clinical development of novel therapies for NSCLC is described, including some discussion of relevant biomarkers and determination of synergy with both cytotoxic therapy and other targeted agents.

Efficacy of plasma vascular endothelial growth factor in monitoring first-line chemotherapy in patients with advanced non-small cell lung cancer

BACKGROUND

Along with the development of new cancer therapeutics, more effective tools for the estimation of response to therapy and prediction of disease progression are required for the better management of inoperable cancer patients.

METHODS

We studied 134 newly diagnosed and primarily untreated advanced non-small cell lung cancer patients and 100 controls. Forty two patients received platinum-based chemotherapy. Plasma VEGF levels were quantified in all samples at baseline and also before second and third chemotherapy cycle in 42 patients and correlated with response to therapy as assessed by computed tomography after the third chemotherapy cycle.

RESULTS

We observed that, patients who went into remission had significantly lower baseline VEGF levels before second and third cycles of chemotherapy when compared with patients with no change and progression. Plasma VEGF levels showed a greater decrease from cycle 1 to 2 and from cycle 1 to 3 in patients who showed remission in comparison to those with no change or progression. Plasma VEGF levels before the second cycle detected poor response to therapy with a sensitivity and specificity of 76.9% and 75.0%, respectively (area under the ROC curve = 0.724). Early prediction of disease progression was achieved with a sensitivity and specificity of 71.4% for plasma VEGF before cycle 2 (area under the ROC curve = 0.805). The kinetics of VEGF form cycle 1 to 2 and cycle 1 to 3 also gave significant information for predicting disease progression as well as insufficient therapy response.

CONCLUSION

Monitoring of plasma VEGF levels during the course of first-line chemotherapy could identify patients who are likely to have insufficient response to therapy and disease progression at an early stage. This may help in individualizing treatment and could lead to better management of the advanced stage lung cancer.

Targeting the eicosanoid pathway in non-small-cell lung cancer

Multiple lines of evidence suggest that cyclooxygenase-2 (COX-2) upregulation is an early event in the development of non-small-cell lung cancer. Preclinical data indicate tumors with upregulation of COX-2 synthesize high levels of prostaglandin E₂ (PGE₂), which in turn are associated with increased production of proangiogenic factors and enhanced metastatic potential. These findings indicate that an increase in COX-2 expression may play a significant role in the development and growth of lung cancers and possibly with the acquisition of an invasive and metastatic phenotype. Consequently, inhibitors of COX-2 are being studied for their chemopreventative and therapeutic effects in individuals at high risk for lung cancer and patients with established cancers.

A phase II study of celecoxib in combination with paclitaxel, carboplatin, and radiotherapy for patients with inoperable stage IIIA/B non-small cell lung cancer

PURPOSE

Cyclooxygenase (COX)-2 up-regulation plays an important role in the pathogenesis of lung cancer. Selective COX-2 inhibitors have promoted chemosensitivity and radiosensitivity of tumor cells in preclinical trials.

EXPERIMENTAL DESIGN

In a single-institution phase II study, we sought to determine the effectiveness of concurrent chemoradiation given with celecoxib and examined biomarkers to predict response to COX-2 inhibition.

RESULTS

Seventeen patients with stage IIIA or IIIB non-small cell lung cancer (NSCLC) were enrolled in the study. All received 400 mg celecoxib twice daily continuously while on trial in addition to concurrent chemoradiation therapy with paclitaxel and carboplatin. Celecoxib was continued until disease progression. The overall objective response rate was 42.9%, and the median overall survival time was 203 days. In contrast to nonresponders, those patients with complete and partial responses had a significant decrease in the level of urinary 11alpha-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (PGE-M), the major metabolite of prostaglandin E(2), after 1 week of celecoxib administration. Patients with very high levels of PGE-M before initiation of therapy also responded poorly to therapy. Serum vascular endothelial growth factor levels did not predict response or survival.

CONCLUSION

The trial was terminated because it did not meet the predetermined goal of 80% overall response rate. In unselected patients, the addition of celecoxib to concurrent chemoradiotherapy with inoperable stage IIIA/B NSCLC does not improve survival. Urinary PGE-M is a promising biomarker for predicting response to COX-2 inhibition in NSCLC.

Anti-gastric cancer effects of celecoxib, a selective COX-2 inhibitor, through inhibition of Akt signaling

BACKGROUND AND AIM

Previously, we showed that treatment with celecoxib significantly reduced the number of viable gastric cancer cells, in a dose- and time-dependent manner. However, the specific anti-cancer effects of celecoxib on gastric cancer cells have not been clarified. The present in vitro study was carried out to investigate the mechanism involved in the anti-gastric cancer effects of celecoxib.

METHODS

3-(4,5-Dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was carried out after treating AGS cells (human gastric cancer cell line, ATCC CRL 1739) with celecoxib or indomethacin, and the effect of prostaglandin E(2) or LY294002 (PI3K inhibitor) was evaluated. Western blot analysis of tAkt (total Akt), pAkt (phosphorylated Akt), pGSK3beta (phosphorylated glycogen synthase kinase-3beta), pFKHR (phosphorylated forkhead transcriptional factor), and caspase-9 was carried out at various concentrations (0, 5, 10, 25, or 50 micromol/L) of celecoxib or indomethacin-treatment for 24 or 48 h in AGS cells.

RESULTS

Celecoxib- or LY294002-induced cell death was found to occur in a dose-dependent manner in AGS cells, and these decreases were slightly recovered by the addition of PGE(2) (25 or 50 micromol/L). The expression of pAkt but not tAkt was lower in the celecoxib treated-AGS cells and the response was dose dependent (P < 0.05). The expression of pGSK3beta and pFKHR was also significantly decreased in the celecoxib treated-AGS cells. Procaspase 9 (47 kDa) was frequently cleaved into 37, 35 and 17 kDa fragments in the celecoxib-treatment group. However, these changes in cell signal transduction were not observed in the indomethacin treated-AGS cells.

CONCLUSION

The anti-cancer effects of celecoxib on gastric cancer cells might be partly mediated by downregulation of Akt, GSK3beta, FKHR, and upregulation of caspase-9, in the mitochondrial apoptotic pathway.

The effects of neoadjuvant anastrozole and tamoxifen on circulating vascular endothelial growth factor and soluble vascular endothelial growth factor receptor 1 in breast cancer

PURPOSE

Vascular endothelial growth factor (VEGF) is a key angiogenic factor mediating neovascularization. Soluble VEGF receptor 1 (sVEGFR-1) is an intrinsic negative counterpart of VEGF signaling and the ratio of sVEGFR-1 to VEGF has been shown to be a prognostic factor. Estrogen-bound estrogen receptor enhances VEGF expression, providing a common link between these signaling pathways that may be targeted by endocrine therapy. We investigated the effects of anastrozole and tamoxifen over time on serum VEGF and sVEGFR-1.

EXPERIMENTAL DESIGN

The Immediate Preoperative Anastrozole, Tamoxifen, or Combined with Tamoxifen (IMPACT) trial compared the preoperative use of anastrozole with tamoxifen in postmenopausal women with estrogen receptor-positive primary operable breast cancer over 12 weeks. Circulating VEGF and sVEGFR-1 were measured by ELISA in 106 patients treated with anastrozole or tamoxifen alone at baseline and after 2 and 12 weeks of treatment.

RESULTS

The increase in serum VEGF from baseline to 12 weeks was significantly different between anastrozole and tamoxifen (anastrozole versus tamoxifen, 6% versus 38%; P = 0.047). There was a significant increase in sVEGFR-1 levels after 12 weeks of anastrozole (P = 0.037). The sVEGFR-1/VEGF ratio significantly decreased in the tamoxifen arm (P = 0.013) and the change in sVEGFR-1/VEGF ratio from baseline to 12 weeks was significantly different between anastrozole and tamoxifen (anastrozole versus tamoxifen, 24% increase versus 34% decrease; P = 0.013).

CONCLUSIONS

Treatment with anastrozole and tamoxifen resulted in differential effects on serum angiogenic markers. This may be related to the relative effectiveness of the treatments. These data provide further support for cross talk between estrogen receptor and VEGF.

The anti-cancer effect of COX-2 inhibitors on gastric cancer cells

Epidemiologic studies have shown that nonsteroidal anti-inflammatory drugs could reduce the risk of cancer development including gastric cancer. This study was performed to identify the antineoplastic mechanism in gastric cancer cells affected by celecoxib, a selective COX-2 inhibitor. MTT assay, ELISA for prostaglandin E(2) (PGE(2)), cell-cycle analyses, immunofluorescent staining, and flow cytometry were performed after treating human gastric cancer cell lines (AGS and MKN-45) with celecoxib or indomethacin. The viabilities of celecoxib-treated cells decreased in a dose- and time-dependent manner compared with indomethacin. Drop of PGE(2) levels was more prominent in the presence of indomethacin than in that of celecoxib. Celecoxib arrested the cell cycle in the G(0)-G(1) phase, which reduced cell numbers in the S phase. Moreover, celecoxib increased the apoptotic cell proportions, a 4-fold increase over control cells. The anticancer effects of celecoxib on gastric cancer cells appear to be mediated by cell-cycle arrest and apoptosis, and not by COX-2 or PGE(2) suppression alone.

Factorial phase III randomised trial of rofecoxib and prolonged constant infusion of gemcitabine in advanced non-small-cell lung cancer: the GEmcitabine-COxib in NSCLC (GECO) study

BACKGROUND

The addition of cyclo-oxygenase-2 (COX-2) inhibitors and prolonged constant infusion (PCI) of gemcitabine to treatment for advanced non-small-cell lung cancer (NSCLC) might improve treatment efficacy. We aimed to assess whether the addition of rofecoxib or PCI gemcitabine could improve overall survival compared with first-line treatment with cisplatin plus gemcitabine given by standard infusion.

METHODS

Patients with stage IV or IIIb (with supraclavicular nodes or pleural effusion) NSCLC who were under 70 years of age and who had performance status 0 or 1 were eligible for this multicentre, prospective, open-label, randomised phase III trial with 2 x 2 factorial design. Patients were randomly assigned to one of four treatment groups: group A, gemcitabine 1200 mg/m(2) in a 30-min intravenous infusion on days 1 and 8 and intravenous cisplatin 80 mg/m(2) on day 1, every 21 days for six cycles; group B, the same treatments as group A plus oral rofecoxib 50 mg/day until disease progression; group C, intravenous PCI gemcitabine 1200 mg/m(2) in a 120-min infusion on days 1 and 8 and intravenous cisplatin 80 mg/m(2) on day 1, every 21 days for six cycles; group D, the same drugs as group C plus oral rofecoxib 50 mg/day until disease progression. The primary endpoint was overall survival; secondary endpoints were progression-free survival, response rate, quality of life, and toxicity. Analyses were intention-to-treat. This trial is registered on the clinical trials site of the US National Institutes of Health website http://clinicaltrials.gov/ct/show/NCT00385606.

FINDINGS

Between Jan 30, 2003, and May 3, 2005, 400 patients were enrolled. Median age was 60 years (range 29-71). PCI gemcitabine did not improve overall survival (median 47 weeks [95% CI 40-55] vs 44 [36-52], with standard gemcitabine infusion, hazard ratio (HR) of death 0.93 [0.74-1.17], p=0.41), progression-free survival, nor any other secondary endpoint. Vomiting and fatigue were significantly worse with PCI gemcitabine. The two rofecoxib groups were closed early (on Oct 1, 2004) due to withdrawal of the drug because of safety issues. With intention-to-treat statistical analyses limited to 240 patients (ie, those randomised before July 1, 2004) who had at least 3 months of treatment, rofecoxib did not prolong overall survival (median 44 weeks [CI 36-55] vs 44 [40-54] without rofecoxib, and HR of death 1.00 [0.75-1.34], p=0.85), or progression-free survival, but did improve response rate (41%vs 26%, p=0.02), global quality of life, physical, emotional and role functioning, fatigue, and sleeping. Rofecoxib significantly increased the incidence of diarrhoea and decreased constipation, fatigue, fever, weight loss, and pain, and analgesic consumption. Severe cardiac ischaemia was more frequent with rofecoxib than without; however, the difference was not statistically significant in the primary analysis (p=0.06) and became significant when patients who were randomised between July 1, 2004, and Sept 30, 2004, were included in the analysis (p=0.03).

INTERPRETATION

Neither PCI gemcitabine nor rofecoxib prolonged survival in the patients in this study. Rofecoxib improved response rate and several quality-of-life items, including pain-related items and global quality of life. Further studies with less cardiotoxic COX-2 inhibitors are needed in NSCLC.

Novel targeted therapies for non-small cell lung cancer

Targeted therapies will advance the treatment of NSCLC as we improve our understanding of the underlying biology of NSCLC and enhance our ability to clinically target the optimal therapy to an individual's cancer. Ongoing translational research including tissue arrays, genomic, and proteomic studies will help to identify clinically useful biomarkers that will allow further classification of NSCLC and may allow accurate prediction of response to specific chemotherapeutic regimens. Advances in targeted therapy in NSCLC are already yielding exciting results, and promises to become an increasingly important adjunct to surgical management of NSCLC.

Cyclooxygenase-2: a novel target in human solid tumors

The enzyme cyclooxygenase-2, which is involved in the conversion of arachidonic acid-to-prostanoid synthesis, plays a key role in many inflammatory and proliferative reactions. Experimental data have shown that prostaglandins have a central action in therapeutic targeting not only in the treatment of many inflammatory diseases but also in several types of human cancers. Inhibitors of cyclooxygenase activity seem to protect against carcinoma development and show promise as chemopreventive agents and possible target therapies. Data support new treatments for patients with solid cancers tailored to the molecular characteristics of the individual tumor.

Randomized phase II trial of docetaxel/irinotecan and gemcitabine/irinotecan with or without celecoxib in the second-line treatment of non-small-cell lung cancer

PURPOSE

Trials combining irinotecan/docetaxel and irinotecan/gemcitabine in second-line treatment of non-small-cell lung cancer (NSCLC) have yielded promising results. Preliminary data suggested that the selective cyclooxygenase -2 inhibitor celecoxib (CBX) might enhance efficacy of chemotherapeutic regimens. This multicenter, phase II, randomized trial investigated efficacy and safety of irinotecan and docetaxel and irinotecan and gemcitabine, with or without CBX, in second-line treatment of NSCLC.

PATIENTS AND METHODS

Patients 18 years or older were randomly assigned to receive irinotecan 60 mg/m2 and docetaxel 35 mg/m2, or irinotecan 100 mg/m2 and gemcitabine 1,000 mg/m2, with or without CBX 400 mg twice daily, for four cycles. Primary efficacy end points were median and 1-year survival probabilities. Patient-reported symptoms were assessed by the Lung Cancer Symptoms Scale (LCSS).

RESULTS

A total of 133 patients were assessable for efficacy and safety. Median survival time was 6.31 months for patients treated with CBX and 8.99 months for those treated with chemotherapy alone. One-year survival rates were 24% and 36% respectively. The overall toxicity rates and LCSS scores were similar between patients treated or not treated with CBX. Four deaths were considered possibly treatment related.

CONCLUSION

Survival results for the second-line regimens in this study were similar to results reported for single-agent therapy in this setting. CBX did not appear to enhance efficacy or improve patient-reported symptoms. The addition of high-dose CBX to second-line chemotherapy in NSCLC cannot be recommended.

Targeting the mechanisms of tumoral immune tolerance with small-molecule inhibitors

Cancer immunotherapy has been predominantly focused on biologically based intervention strategies. However, recent advances in the understanding of tumour-host interactions at the molecular level have revealed targets that might be amenable to intervention with small-molecule inhibitors. In particular, key effectors of tumoral immune escape have been identified that contribute to a dominant toleragenic state that is suspected of limiting the successful implementation of treatment strategies that rely on boosting immune function. Within the context of the pathophysiology of cancer-associated immune tolerance, this Review delineates potential molecular targets for therapeutic intervention and the progress that has been made in developing small-molecule inhibitors.

Cyclooxygenase-2 (COX-2)-independent anticarcinogenic effects of selective COX-2 inhibitors

Nonsteroidal antiinflammatory drugs (NSAIDs) appear to reduce the risk of developing cancer. One mechanism through which NSAIDs act to reduce carcinogenesis is to inhibit the activity of cyclooxygenase-2 (COX-2), an enzyme that is overexpressed in various cancer tissues. Overexpression of COX-2 increases cell proliferation and inhibits apoptosis. However, selective COX-2 inhibitors can also act through COX-independent mechanisms. In this review, we describe the COX-2-independent molecular targets of these COX-2 inhibitors and discuss how these targets may be involved in the anticarcinogenic activities of these selective COX-2 inhibitors. We also compare the concentrations of these inhibitors used in in vitro and in vivo experiments and discuss the implications of the in vitro studies for clinical management of cancer with these drugs.

Microtubule stabilizing agents: Their molecular signaling consequences and the potential for enhancement by drug combination

Microtubule stabilization by chemotherapy is a powerful weapon in the war against cancer. Disruption of the mitotic spindle activates a number of signaling pathways, with consequences that may protect the cell or lead to its death via apoptosis. Taxol, the first microtubule stabilizing drug to be identified, has been utilized successfully in the treatment of solid tumors for two decades. Several features, however, make this drug less than ideal, and the search for next generation stabilizing drugs with increased efficacy has been intense and fruitful. Microtubule stabilizing agents (MSAs), including the taxanes, the epothilones, discodermolide, laulimalide, and eleutherobin, form an important and expanding family of chemotherapeutic agents. A strong understanding of their molecular signaling consequences is essential to their value, particularly in regard to their potential for combinatorial chemotherapy - the use of multiple agents to enhance the efficacy of cancer treatment. Here we present a critical review of research on the signaling mechanisms induced by MSAs, their relevance to apoptosis, and their potential for exploitation by combinatorial therapy.

Angiogenic inhibitors: a new therapeutic strategy in oncology

Angiogenesis is a multistep, complex and tightly regulated process that is necessary for tumor growth and metastasis. Based on data of preclinical models, several antiangiogenic compounds has been shown to modify activated tumor endothelium, which suggests that these compounds can improve cytotoxic drug delivery. Such agents have entered clinical trials as single agents or in combination with cytotoxic drugs, and have shown promising antitumor activity. The pharmacodynamic and pharmacokinetic characteristics of antiangiogenic drugs are reviewed here. Most of the early clinical testing of these agents was conducted in patients with advanced disease resistant to standard therapies. Phase III trials compared the efficacy of standard chemotherapy alone with standard chemotherapy in combination with an experimental angiogenesis inhibitor. Although some of these studies were negative or controversial, recent studies validated in large clinical trials with an anti-vascular endothelial growth factor antibody demonstrated significant clinical benefit and renewed enthusiasm for this therapeutic strategy. This review describes the clinical studies of antiangiogenic agents and highlights the challenges related to choosing appropriate strategies for the selection of patients, study design and choice of appropriate endpoints for the studies' development.