Interactions of gemcitabine, carboplatin and paclitaxel in molecularly defined non-small-cell lung cancer cell lines

Porous Polymeric Microspheres With Controllable Pore Diameters for Tissue Engineered Lung Tumor Model Development

Complex cell cultures are more representative of in vivo conditions than conventionally used monolayer cultures, and are hence being investigated for predictive screening of therapeutic agents. Poly lactide co-glycolide (PLGA) polymer is frequently used in the development of porous substrates for complex cell culture. Substrates or scaffolds with highly interconnected, micrometric pores have been shown to positively impact tissue model formation by enhancing cell attachment and infiltration. We report a novel alginate microsphere (AMS)-based controlled pore formation method for the development of porous, biodegradable PLGA microspheres (PPMS), for tissue engineered lung tumor model development. The AMS porogen, non-porous PLGA microspheres (PLGAMS) and PPMS had spherical morphology (mean diameters: 10.3 ± 4, 79 ± 21.8, and 103 ± 30 μm, respectively). The PPMS had relatively uniform pores and a porosity of 45.5%. Degradation studies show that PPMS effectively maintained their structural integrity with time whereas PLGAMS showed shrunken morphology. The optimized cell seeding density on PPMS was 25 × 103 cells/mg of particles/well. Collagen coating on PPMS significantly enhanced the attachment and proliferation of co-cultures of A549 lung adenocarcinoma and MRC-5 lung fibroblast cells. Preliminary proof-of-concept drug screening studies using mono- and combination anti-cancer therapies demonstrated that the tissue-engineered lung tumor model had a significantly higher resistance to the tested drugs than the monolayer co-cultures. These studies indicate that the PPMS with controllable pore diameters may be a suitable platform for the development of complex tumor cultures for early in vitro drug screening applications.

Synergistic Chemotherapy Drug Response Is a Genetic Trait in Lymphoblastoid Cell Lines

Lymphoblastoid cell lines (LCLs) are a highly successful model for evaluating the genetic etiology of cancer drug response, but applications using this model have typically focused on single drugs. Combination therapy is quite common in modern chemotherapy treatment since drugs often work synergistically, and it is an important progression in the use of the LCL model to expand work for drug combinations. In the present work, we demonstrate that synergy occurs and can be quantified in LCLs across a range of clinically important drug combinations. Lymphoblastoid cell lines have been commonly employed in association mapping in cancer pharmacogenomics, but it is so far untested as to whether synergistic effects have a genetic etiology. Here we use cell lines from extended pedigrees to demonstrate that there is a substantial heritable component to synergistic drug response. Additionally, we perform linkage mapping in these pedigrees to identify putative regions linked to this important phenotype. This demonstration supports the premise of expanding the use of the LCL model to perform association mapping for combination therapies.

Scaffold-based lung tumor culture on porous PLGA microparticle substrates

Scaffold-based cancer cell culture techniques have been gaining prominence especially in the last two decades. These techniques can potentially overcome some of the limitations of current three-dimensional cell culture methods, such as uneven cell distribution, inadequate nutrient diffusion, and uncontrollable size of cell aggregates. Porous scaffolds can provide a convenient support for cell attachment, proliferation and migration, and also allows diffusion of oxygen, nutrients and waste. In this paper, a comparative study was done on porous poly (lactic-co-glycolic acid) (PLGA) microparticles prepared using three porogens—gelatin, sodium bicarbonate (SBC) or novel poly N-isopropylacrylamide [PNIPAAm] particles, as substrates for lung cancer cell culture. These fibronectin-coated, stable particles (19–42 μm) supported A549 cell attachment at an optimal cell seeding density of 250,000 cells/ mg of particles. PLGA-SBC porous particles had comparatively larger, more interconnected pores, and favored greater cell proliferation up to 9 days than their counterparts. This indicates that pore diameters and interconnectivity have direct implications on scaffold-based cell culture compared to substrates with minimally interconnected pores (PLGA-gelatin) or pores of uniform sizes (PLGA-PMPs). Therefore, PLGA-SBC-based tumor models were chosen for preliminary drug screening studies. The greater drug resistance observed in the lung cancer cells grown on porous particles compared to conventional cell monolayers agrees with previous literature, and indicates that the PLGA-SBC porous microparticle substrates are promising for in vitro tumor or tissue development.

Gemcitabine and Carboplatin Treatment in Advanced NSCLC: A Retrospective Evaluation Including Elderly Patients

Background

Carboplatin-containing regimens are sometimes preferred for patients with advanced non-small cell lung cancer.

Methods

Eighty-three patients with stage III-IV non-small cell lung cancer received 3 to 4 cycles of carboplatin AUC 5 on day 2 and gemcitabine 1250 mg/m2 on days 1 and 8 every 21 days.

Results

The overall response rate was 43.4%. Results obtained from elderly and non-elderly groups were compared using the logrank method. Median overall survival and progression-free survival were 11 and 7 months, respectively (12 and 7 months, non-elderly group; 6.5 and 5 months, elderly group, P = 0.28 and 0.25 respectively). Grade 3–4 toxicity included neutropenia, thrombocytopenia, anemia, nausea/vomiting, and diarrhea. Incidences of grade 3–4 toxicity were similar for elderly and non-elderly patients.

Conclusions

Data confirm that carboplatin-gemcitabine is an active and well-tolerated regimen in advanced non-small cell lung cancer and could be investigated in elderly patients.

New in vitro system to predict chemotherapeutic efficacy of drug combinations in fresh tumor samples

Background

To find the best individual chemotherapy for cancer patients, the efficacy of different chemotherapeutic drugs can be predicted by pretesting tumor samples in vitro via the chemotherapy-resistance (CTR)-Test^®. Although drug combinations are widely used among cancer therapy, so far only single drugs are tested by this and other tests. However, several first line chemotherapies are combining two or more chemotherapeutics, leading to the necessity of drug combination testing methods.

Methods

We established a system to measure and predict the efficacy of chemotherapeutic drug combinations with the help of the Loewe additivity concept in combination with the CTR-test. A combination is measured by using half of the monotherapy’s concentration of both drugs simultaneously. With this method, the efficacy of a combination can also be calculated based on single drug measurements.

Results

The established system was tested on a data set of ovarian carcinoma samples using the combination carboplatin and paclitaxel and confirmed by using other tumor species and chemotherapeutics. Comparing the measured and the calculated values of the combination testings revealed a high correlation. Additionally, in 70% of the cases the measured and the calculated values lead to the same chemotherapeutic resistance category of the tumor.

Conclusion

Our data suggest that the best drug combination consists of the most efficient single drugs and the worst drug combination of the least efficient single drugs. Our results showed that single measurements are sufficient to predict combinations in specific cases but there are exceptions in which it is necessary to measure combinations, which is possible with the presented system.

A Phase II Study of Weekly Paclitaxel Plus Gemcitabine as a Second-Line Therapy in Patients with Metastatic or Recurrent Small Cell Lung Cancer

Purpose

Paclitaxel (P) and gemcitabine (G) are clinically synergistic in small cell lung cancer (SCLC). We evaluated the efficacy of PG as a salvage treatment for SCLC patients whose disease progressed after a platinum-containing regimen.

Materials and Methods

Eligibility included histologically confirmed SCLC, one dimensionally measurable disease, Eastern Cooperative Oncology Group performance status 0-2, and progressive disease after platinum-based chemotherapy. Treatment consisted of P (80 mg/m²) and G (1,000 mg/m²) on days 1 and 8 of each cycle of 21 days until disease progression.

Results

Thirty-three patients seen between December 2005 and February 2009 were selected into this study. Thirty patients (91%) had received irinotecan-platinum, and three had received etoposide-platinum. Sixteen patients (49%) had a treatment-free interval of less than 3 months. The overall response rate was 30.3% (29.4% in sensitive relapse and 31.3% in refractory relapse). The median time to progression was 12.0 weeks and median overall survival (OS) 31.0 weeks, with a 1-year OS rate of 30.3%. Toxicities were moderate and manageable with 18.2% grade (G) 4 neutropenia, 24.2% G3 thrombocytopenia, 6.1% G3 sensory neuropathy, and 3% G3 asthenia. One patient developed febrile neutropenia.

Conclusion

Second-line paclitaxel and gemcitabine were well-tolerated and moderately active in SCLC patients previously treated with platinum-based chemotherapy.

Concurrent chemo-radiation with or without induction gemcitabine, Carboplatin, and Paclitaxel: a randomized, phase 2/3 trial in locally advanced nasopharyngeal carcinoma

PURPOSE

To compare survival, tumor control, toxicities, and quality of life of patients with locally advanced nasopharyngeal carcinoma (NPC) treated with induction chemotherapy and concurrent chemo-radiation (CCRT), against CCRT alone.

PATIENTS AND METHODS

Patients were stratified by N stage and randomized to induction GCP (3 cycles of gemcitabine 1000 mg/m(2), carboplatin area under the concentration-time-curve 2.5, and paclitaxel 70 mg/m(2) given days 1 and 8 every 21 days) followed by CCRT (radiation therapy 69.96 Gy with weekly cisplatin 40 mg/m(2)), or CCRT alone. The accrual of 172 was planned to detect a 15% difference in 5-year overall survival (OS) with a 5% significance level and 80% power.

RESULTS

Between September 2004 and August 2012, 180 patients were accrued, and 172 (GCP 86, control 86) were analyzed by intention to treat. There was no significant difference in OS (3-year OS 94.3% [GCP] vs 92.3% [control]; hazard ratio 1.05; 1-sided P=.494]), disease-free survival (hazard ratio 0.77, 95% confidence interval 0.44-1.35, P=.362), and distant metastases-free survival (hazard ratio 0.80, 95% confidence interval 0.38-1.67, P=.547) between the 2 arms. Treatment compliance in the induction phase was good, but the relative dose intensity for concurrent cisplatin was significantly lower in the GCP arm. Overall, the GCP arm had higher rates of grades 3 and 4 leukopenia (52% vs 37%) and neutropenia (24% vs 12%), but grade 3 and 4 acute radiation toxicities were not statistically different between the 2 arms. The global quality of life scores were comparable in both arms.

CONCLUSION

Induction chemotherapy with GCP before concurrent chemo-irradiation did not improve survival in locally advanced NPC.

Role of adenovirus-mediated retinoblastoma 94 in the treatment of human non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality despite the fact that great advances have been made in therapeutic treatment methods. Therefore, in the present study, the role of adenovirus-mediated retinoblastoma 94 (Ad-RB94) gene therapy in NSCLC was investigated. Following treatment with Ad-RB94, the proportion of A549 cells in the G2/M phase was increased. In the mouse xenograft model, the overexpression of RB94 inhibited the tumor growth compared with the control group and the Ad-LacZ-treated group. In the transplanted tumors, the overexpression of RB94 induced the apoptosis of tumors as well as an increase in the mRNA levels of cyclinB1. In conclusion, the results of the present study suggested that RB94 may effectively inhibit NSCLC tumor cell growth by inducing G2/M cell cycle arrest and apoptosis, indicating that RB94 may be a promising candidate for adjuvant therapy with radiation or chemotherapy in NSCLC.

Low-dose etoposide-treatment induces endoreplication and cell death accompanied by cytoskeletal alterations in A549 cells: Does the response involve senescence? The possible role of vimentin

Background

Senescence in the population of cells is often described as a program of restricted proliferative capacity, which is manifested by broad morphological and biochemical changes including a metabolic shift towards an autophagic-like response and a genotoxic-stress related induction of polyploidy. Concomitantly, the cell cycle progression of a senescent cell is believed to be irreversibly arrested. Recent reports suggest that this phenomenon may have an influence on the therapeutic outcome of anticancer treatment. The aim of this study was to verify the possible involvement of this program in the response to the treatment of the A549 cell population with low doses of etoposide, as well as to describe accompanying cytoskeletal alterations.

Methods

After treatment with etoposide, selected biochemical and morphological parameters were examined, including: the activity of senescence-associated ß-galactosidase, SAHF formation, cell cycle progression, the induction of p21^{Cip1/Waf1/Sdi1} and cyclin D1, DNA strand breaks, the disruption of cell membrane asymmetry/integrity and ultrastructural alterations. Vimentin and G-actin cytoskeleton was evaluated both cytometrically and microscopically.

Results and conclusions

Etoposide induced a senescence-like phenotype in the population of A549 cells. Morphological alterations were nevertheless not directly coupled with other senescence markers including a stable cell cycle arrest, SAHF formation or p21^{Cip1/Waf1/Sdi1} induction. Instead, a polyploid, TUNEL-positive fraction of cells visibly grew in number. Also upregulation of cyclin D1 was observed. Here we present preliminary evidence, based on microscopic analyses, that suggest a possible role of vimentin in nuclear alterations accompanying polyploidization-depolyploidization events following genotoxic insults.

Phenethyl isothiocyanate-induced cytoskeletal changes and cell death in lung cancer cells

Isothiocyanates are known for their anticarcinogenic and antitumor potential, however, the exact mechanism of their action has not been fully elucidated. The present study was designed to investigate and compare the effects of phenethyl isothiocyanate on cell morphology, the cytoskeleton and induction of cell death in human non-small cell lung cancer cell lines A549 and H1299 differing in p53 status. Cell viability tests (MTT assay, xCELLigence system) showed that PEITC exhibits lower cytotoxicity to A549 cells containing wild-type p53. The observed growth-inhibitory effect of PEITC was dose-dependent, but time-dependence was observed only at higher concentrations. The results of flow-cytometric and fluorescence-microscopic analyses indicate that PEITC induced disassembly of actin stress fibers and degradation of tubulin which, most likely, contributed to the induction of cell death. Although, 24-h incubation caused G2/M cell cycle arrest, the fraction of G2/M cells decreased in a dose- and time-dependent manner in favor of cells with sub-G1 DNA content. Further experiments (Annexin V staining, electron microscopic observations) confirmed that the apoptosis-inducing potency of PEITC is probably the main factor responsible for cell growth inhibition. However, PEITC treatment also resulted in the appearance of an increased proportion of H1299 cells exhibiting morphological features of mitotic catastrophe.

WITHDRAWN: Second or third additional chemotherapy drug for non-small cell lung cancer in patients with advanced disease

BACKGROUND

Randomized trials have demonstrated that adding a drug to a single-agent or to a two-agent regimen increased the tumor response rate in patients with advanced non-small cell lung cancer (NSCLC), although its impact on survival remains controversial.

OBJECTIVES

To evaluate the clinical benefit of adding a drug to a single-agent or two-agent chemotherapy regimen in terms of tumor response rate, survival, and toxicity in patients with advanced NSCLC.

SEARCH METHODS

There were no language restrictions. Searches of MEDLINE and EMBASE were performed using the search terms non-small cell lung carcinoma/drug therapy, adenocarcinoma, large-cell carcinoma, squamous-cell carcinoma, lung, neoplasms, clinical trial phase III, and randomized trial. Manual searches were also performed to find conference proceedings published between January 1982 and June 2006.

SELECTION CRITERIA

Data from all randomized controlled trials performed between 1980 and 2006 (published between January 1980 and June 2006) comparing a doublet regimen with a single-agent regimen or comparing a triplet regimen with a doublet regimen in patients with advanced NSCLC.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed the publications and extracted the data. Pooled odds ratios (ORs) for the objective tumor response rate, one-year survival rate, and toxicity rate were calculated using the fixed-effect model. Pooled median ratios (MRs) for median survival also were calculated using the fixed-effect model. ORs and MRs lower than unity (< 1.0) indicate a benefit of a doublet regimen compared with a single-agent regimen (or a triplet regimen compared with a doublet regimen).

MAIN RESULTS

Sixty-five trials (13601 patients) were eligible. In the trials comparing a doublet regimen with a single-agent regimen, a significant increase was observed in tumor response (OR 0.42, 95% confidence interval [CI] 0.37 to 0.47, P < 0.001) and one-year survival (OR 0.80, 95% CI 0.70 to 0.91, P < 0.001) in favor of the doublet regimen. The median survival ratio was 0.83 (95% CI 0.79 to 0.89, P < 0.001). An increase also was observed in the tumor response rate (OR 0.66, 95% CI 0.58 to 0.75, P < 0.001) in favor of the triplet regimen, but not for one-year survival (OR 1.01, 95% CI 0.85 to 1.21, P = 0.88). The median survival ratio was 1.00 (95% CI 0.94 to 1.06, P = 0.97).

AUTHORS' CONCLUSIONS

Adding a second drug improved tumor response and survival rate. Adding a third drug had a weaker effect on tumor response and no effect on survival.

111In-BnDTPA-F3: an Auger electron-emitting radiotherapeutic agent that targets nucleolin

INTRODUCTION

The F3 peptide (KDEPQRRSARLSAKPAPPKPEPKPKKAPAKK), a fragment of the human high mobility group protein 2, binds nucleolin. Nucleolin is expressed in the nuclei of normal cells but is also expressed on the membrane of some cancer cells. The goal was to investigate the use of 111In-labeled F3 peptide for Auger electron-targeted radiotherapy.

METHODS

F3 was labeled with fluorescein isothiocyanate (FITC) for confocal microscopy and conjugated to p-SCN-benzyl-diethylenetriaminepentaacetic acid (BnDTPA) for labeling with 111In to form 111In-BnDTPA-F3. MDA-MB-231-H2N (231-H2N) human breast cancer cells were exposed to 111In-BnDTPA-F3 and used in cell fractionation, γH2AX immunostaining (a marker of DNA double-strand breaks), and clonogenic assays. In vivo, biodistribution studies of 111In-BnDTPA-F3 were performed in 231-H2N xenograft-bearing mice. In tumor growth delay studies, 111In-BnDTPA-F3 (3 μg, 6 MBq/μg) was administered intravenously to 231-H2N xenograft-bearing mice once weekly for 3 weeks.

RESULTS

Membrane-binding of FITC-F3 was observed in 231-H2N cells, and there was co-localization of FITC-F3 with nucleolin in the nuclei. After exposure of 231-H2N cells to 111In-BnDTPA-F3 for 2 h, 1.7% of 111In added to the medium was membrane-bound. Of the bound 111In, 15% was internalized, and of this, 37% was localized in the nucleus. Exposure of 231-H2N cells to 111In-BnDTPA-F3 (1 μM, 6 MBq/μg) resulted in a dose-dependent increase in γH2AX foci and in a significant reduction of clonogenic survival compared to untreated cells or cells exposed to unlabeled BnDTPA-F3 (46 ± 4.1%, 100 ± 1.8%, and 132 ± 7.7%, respectively). In vivo, tumor uptake of 111In-BnDTPA-F3 (3 μg, 6 MBq/μg) at 3-h post-injection was 1% of the injected dose per gram (%ID/g), and muscle uptake was 0.5%ID/g. In tumor growth delay studies, tumor growth rate was reduced 19-fold compared to untreated or unlabeled BnDTPA-F3-treated mice (p = 0.023).

CONCLUSION

111In-BnDTPA-F3 is internalized into 231-H2N cells and translocates to the nucleus. 111In-BnDTPA-F3 has a potent cytotoxic effect in vitro and an anti-tumor effect in mice bearing 231-H2N xenografts despite modest total tumor accumulation.

ErbB-2 blockade and prenyltransferase inhibition alter epidermal growth factor and epidermal growth factor receptor trafficking and enhance (111)In-DTPA-hEGF Auger electron radiation therapy

The intracellular distribution of Auger electron-emitting radiopharmaceuticals is a determinant of cytotoxicity. However, the mechanisms by which these agents are routed through the cell are ill understood. The aim of this study was to investigate how trafficking of (111)In-labeled human epidermal growth factor ((111)In-DTPA-hEGF) relates to that of the EGF receptor (EGFR) and whether coadministration of agents that modulate EGFR signaling alters the efficacy of (111)In-DTPA-hEGF.

METHODS

The spatiotemporal interaction between AlexaFluor488-EGF (AF488-EGF) and Cy3-conjugated anti-EGFR antibody (Cy3-anti-EGFR) was studied in the breast cancer cell line MDA-MB-468 using fluorescence resonance energy transfer and 2-photon fluorescence lifetime imaging. (111)In internalization and nuclear fractionation assays were performed to investigate the effect of the ErbB-2-blocking antibody trastuzumab and a prenyltransferase inhibitor, L-778,123, on the subcellular localization of (111)In-DTPA-hEGF in MDA-MB-468 (1.3 × 10(6) EGFR per cell; ErbB-2 negative) and 231-H2N (0.2 × 10(6) EGFR per cell; 0.4 × 10(5) ErbB-2 per cell) cell lines. The cytotoxicity of (111)In-DTPA-hEGF (0-64 nM) plus trastuzumab (0-50 μg/mL) or L-778,123 (0-22.5 μM) was measured using clonogenic assays in a panel of breast cancer cell lines that express different levels of EGFR and ErB-2. Clonogenic survival data were used to calculate combination indices. Tumor growth inhibition was measured in vivo in 231-H2N xenograft-bearing mice treated with (111)In-DTPA-hEGF plus trastuzumab or L-788,123.

RESULTS

Using fluorescence resonance energy transfer, we showed that EGF interacts with EGFR in the cytoplasm and nucleus after internalization of the ligand-receptor complex in MDA-MB-468 cells. Nuclear localization of (111)In-DTPA-hEGF is enhanced by trastuzumab and L-788,123. Trastuzumab and L-788,123 sensitized 231-H2N cells to (111)In-DTPA-hEGF. Nuclear localization and cytotoxicity of (111)In-DTPA-hEGF were significantly increased in 231-H2N xenografts by cotreatment with L-788,123 (P < 0.0001).

CONCLUSION

The therapeutic efficacy of (111)In-DTPA-hEGF is increased through the coadministration of selected molecularly targeted drugs that modulate EGFR signaling and trafficking.

Adjuvant carboplatin and gemcitabine combination chemotherapy postamputation in canine appendicular osteosarcoma

BACKGROUND

Appendicular osteosarcoma (OSA), the most common bone tumor in dogs, is typically treated by amputation and adjuvant chemotherapy. Despite numerous efforts, the median survival time (MST) for dogs receiving a platinum compound, doxorubicin, or a combination of these remains at 8-12 months. Evidence from studies in mice suggests that gemcitabine has activity against OSA in vivo. Our preliminary work demonstrated that the addition of low-dosage (10 mM) gemcitabine to carboplatin resulted in synergistic inhibition of OSA cell viability in vitro.

OBJECTIVE

The purpose of the following study was to determine whether the addition of low-dosage (2 mg/kg) gemcitabine to carboplatin chemotherapy in dogs with OSA after amputation would improve MST over carboplatin monotherapy.

ANIMALS

Fifty dogs with histologically confirmed appendicular OSA.

METHODS

Dogs were treated prospectively with amputation and up to 4 dosages of carboplatin and gemcitabine in combination every 3 weeks.

RESULTS

The chemotherapeutic regimen was well tolerated with only 5 episodes of grade 3 or 4 hematologic toxicity. The median disease-free interval (DFI) was 203 days and the MST was 279 for all dogs in this study. The 1- and 2-year survival rates were 29.5 and 11.3%, respectively. Dogs with proximal humeral OSA had a shorter median DFI (P = .04) compared with dogs with OSA in other locations.

CONCLUSIONS AND CLINICAL IMPORTANCE

These results are comparable to those reported for carboplatin monotherapy indicating that the addition of gemcitabine to carboplatin in dogs with appendicular OSA does not appear to improve outcome.

A phase II study of gemcitabine plus paclitaxel in patients with metastatic breast cancer and prior anthracycline treatment

AIM

To investigate the efficacy and safety of gemcitabine-paclitaxel in Chinese patients with metastatic breast cancer following anthracycline failure in a multicenter, open-label, single-arm, phase II clinical trial.

METHODS

Chinese female patients with unresectable, locally recurrent or metastatic breast cancer who had relapsed after neo-adjuvant anthracycline-based chemotherapy were included. All patients had measurable disease and an Eastern Cooperative Oncology Group performance status of 0 or 1 at baseline. Gemcitabine (1250 mg/m(2) )-paclitaxel (175 mg/m(2) ) was administered on a 3-weekly schedule until disease progression, and patients were followed up for 12 months (post-enrollment). The primary end point was objective response rate; secondary end points included duration of response, progression-free survival and overall survival.

RESULTS

Overall 60 patients were enrolled. Their mean age was 46.9 (SD ± 9.0) years and 90% of patients had metastatic disease. All patients had previously received chemotherapy. A total of 48 patients (80%) completed the 12-month follow up, and 40 patients (67%) completed at least six cycles of study therapy. The objective response rate (complete response + partial response) was 50% (95% CI: 36.6-63.4). Median duration of response was 5.6 months (95% CI: 4.4-7.6) and median progression-free survival was 7.6 months (95% CI: 5.8-8.8). Overall survival at 12 months was 87% (95% CI: 77.9-95.2). Laboratory toxicities were primarily hematologic, including Grade 3 and 4 neutropenia (n = 27 [45%]) and leukopenia (n = 18 [30%]). Eight patient deaths (13%) were not treatment-related.

CONCLUSION

Gemcitabine-paclitaxel combination therapy is an active and well-tolerated chemotherapy regimen, with expected and manageable toxicity in Chinese patients with metastatic breast cancer.

IR spectroscopy reveals effect of non-cytotoxic doses of anti-tumour drug on cancer cells

Identifying early cellular events in response to a chemotherapy drug treatment, in particular at low doses that will destroy the highest possible number of cancer cells, is an important issue in patient management. In this study, we employed Fourier transform infrared spectroscopy as a potential tool to access such information. We used as model the non-small cell lung cancer cell line, Calu-1. They were exposed to cytostatic doses (0.1 to 100 nM for 24, 48 and 72 h) of gemcitabine, an anti-tumour drug, currently used in treatment of lung cancer patients. In these conditions, inhibition of cell proliferation ranges from weak (< or = 5%), to moderate (approximately 23%), to high (82-95%) without affecting cell viability. Following drug treatment as a function of doses and incubation times, the spectra of cell populations and of individual cells were acquired using a bench-top IR source and a synchrotron infrared microscope. It is demonstrated that spectral cell response to gemcitabine is detectable at sublethal doses and that effects observed on cell populations are similar to those from single cells. Using cluster analysis, spectra could be classified in two main groups: a first group that contains spectra of cells exhibiting a weak or moderate proliferation rate and a second group with spectra from cells presenting a high growth inhibition. These results are promising since they show that effects of subtoxic doses can also be monitored at the single-cell level with the clinical implications that this may have in terms of patient benefit and response to chemotherapy.

Second or third additional chemotherapy drug for non-small cell lung cancer in patients with advanced disease

BACKGROUND

Randomized trials have demonstrated that adding a drug to a single-agent or to a two-agent regimen increased the tumor response rate in patients with advanced non-small cell lung cancer (NSCLC), although its impact on survival remains controversial.

OBJECTIVES

To evaluate the clinical benefit of adding a drug to a single-agent or two-agent chemotherapy regimen in terms of tumor response rate, survival, and toxicity in patients with advanced NSCLC.

SEARCH STRATEGY

There were no language restrictions. Searches of MEDLINE and EMBASE were performed using the search terms non-small cell lung carcinoma/drug therapy, adenocarcinoma, large-cell carcinoma, squamous-cell carcinoma, lung, neoplasms, clinical trial phase III, and randomized trial. Manual searches were also performed to find conference proceedings published between January 1982 and June 2006.

SELECTION CRITERIA

Data from all randomized controlled trials performed between 1980 and 2006 (published between January 1980 and June 2006) comparing a doublet regimen with a single-agent regimen or comparing a triplet regimen with a doublet regimen in patients with advanced NSCLC.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed the publications and extracted the data. Pooled odds ratios (ORs) for the objective tumor response rate, one-year survival rate, and toxicity rate were calculated using the fixed-effect model. Pooled median ratios (MRs) for median survival also were calculated using the fixed-effect model. ORs and MRs lower than unity (< 1.0) indicate a benefit of a doublet regimen compared with a single-agent regimen (or a triplet regimen compared with a doublet regimen).

MAIN RESULTS

Sixty-five trials (13601 patients) were eligible. In the trials comparing a doublet regimen with a single-agent regimen, a significant increase was observed in tumor response (OR 0.42, 95% confidence interval [CI] 0.37 to 0.47, P < 0.001) and one-year survival (OR 0.80, 95% CI 0.70 to 0.91, P < 0.001) in favor of the doublet regimen. The median survival ratio was 0.83 (95% CI 0.79 to 0.89, P < 0.001). An increase also was observed in the tumor response rate (OR 0.66, 95% CI 0.58 to 0.75, P < 0.001) in favor of the triplet regimen, but not for one-year survival (OR 1.01, 95% CI 0.85 to 1.21, P = 0.88). The median survival ratio was 1.00 (95% CI 0.94 to 1.06, P = 0.97).

AUTHORS' CONCLUSIONS

Adding a second drug improved tumor response and survival rate. Adding a third drug had a weaker effect on tumor response and no effect on survival.

A preclinical evaluation of pemetrexed and irinotecan combination as second-line chemotherapy in pancreatic cancer

Gemcitabine (GEM)-based chemotherapy is regarded as the standard treatment of pancreatic adenocarcinoma, but yields a very limited disease control. Very few studies have investigated salvage chemotherapy after failure of GEM or GEM-containing chemotherapy and preclinical studies attempting to widen the therapeutic armamentarium, not including GEM, are warranted. MIA PaCa2, CFPAC-1 and Capan-1 pancreatic cancer cell lines were treated with GEM, fluouracil (5-FU), docetaxel (DCT), oxaliplatin (OXP), irinotecan (CPT-11), pemetrexed (PMX) and raltitrexed (RTX) as single agent. Pemetrexed, inducing apoptosis with IC50s under the Cmax in the three lines tested, appeared the most effective drug as single agent. Based on these results, schedule- and concentration-dependent drug interactions (assessed using the combination index) of PMX/GEM, PMX/DCT and PMX-CPT-11 were evaluated. The combinatory study clearly indicated the PMX and CPT-11 combination as the most active against pancreatic cancer. To confirm the efficacy of PMX-CPT-11 combination, we extended the study to a panel of 10 pancreatic cancer cell lines using clinically relevant concentrations (PMX 10 microM; CPT-11 1 microm). In eight of 10 lines, the PMX-CPT-11 treatment significantly reduced cell recovery and increased both the subG1 and caspase 3/7 fraction. After a 5-day wash out period, an increased fraction of subG1 and caspase3/7 persisted in PMX-CPT-11-pretreated cell lines and a significant reduction in the clonogenicity capacity was evident. Finally, in vivo, the PMX/CPT-11 combination showed the ability to inhibit xenograft tumours growth as second-line therapy after GEM treatment. The PMX and CPT-11 combination displays a strong schedule-independent synergistic cytotoxic activity against pancreatic cancer, providing experimental basis for its clinical testing as salvage chemotherapy in pancreatic cancer patients.

Pharmacogenetics in the Management of Breast Cancer – Prospects for Individualised Treatment

Increased understanding of how variants in genes encoding metabolising enzymes, transporters and receptors affect drug efficacy and toxicity, in parallel with advances in genotyping technology means that clinical pharmacogenetics is drawing tantalisingly close to reality. This review considers some of the pharmacogenetic variants that have been described that are relevant to the management of women with breast cancer and how these may soon translate into clinical practice.

Adding Gemcitabine to Paclitaxel/Carboplatin Combination Increases Survival in Advanced Non–Small-Cell Lung Cancer: Results of a Phase II-III Study

Purpose

Paclitaxel/carboplatin (PC) is one of the reference combinations in the treatment of non–small-cell lung cancer (NSCLC). No triplet novel agent combination has until now shown superiority over a two-drug combination for advanced NSCLC. We therefore conducted a clinical trial to test if paclitaxel/carboplatin/gemcitabine (PCG) increases overall survival (OS) and response rate (RR) over PC.

Methods

Stage IIIB patients not suitable for radical radiation treatment and stage IV chemotherapy-naive patients with measurable disease and performance status of 0 to 2 were randomly assigned to PC arm (paclitaxel 200 mg/m2 and carboplatin area under the concentration-time curve 6 day 1/q21 days) or the PCG arm (paclitaxel 200 mg/m2 and carboplatin area under the concentration-time curve 6 day 1, and gemcitabine 1,000 mg/m2 days 1 and 8 every 21 days).

Results

A total of 324 patients were randomly assigned to the two arms. The RR for PC arm and PCG arm were 20.2% and 46% (P < .0001). The median time to the progression was 5.1 months in the PC group and 7.6 months in the PCG group (P = .012; hazard ratio [HR] 1.34; 95% CI: 1.06 to 1.72). Median OS was 8.3 months and 10.8 months (P = .032; HR 1.309; 95% CI: 1.03 to 1.67) in favor of the PCG arm. One-year survival was 34% (PC arm) and 45% (PCG arm; P = .032). Only hematologic toxicity (neutropenia, thrombocytopenia, and anemia) was significantly increased in the PCG arm and the experimental arm required more platelet and red blood cell transfusions, and more granulocyte colony-stimulating factor usage. No toxic/early deaths were observed.

Conclusion

The PCG regimen offers a significant survival advantage over PC in advanced NSCLC, making PCG a treatment option for advanced NSCLC patients.

Gemcitabine aerosol: in vitro antitumor activity and deposition imaging for preclinical safety assessment in baboons

AIM

To characterize gemcitabine aerosol, its in vitro activity against lung cancer cells, its deposition, and tolerance in a non-human primate model.

METHODS

In vitro cytotoxicity of nebulized gemcitabine against NCI-H460 and A549 lung cancer cells was tested using a growth inhibition assay and compared with non-nebulized gemcitabine. The (99m)Tc-DTPA-radiolabeled gemcitabine aerosol was characterized by cascade impaction and the gemcitabine mass/(99m)Tc activity relationship was established for further quantitative nuclear imaging. Nine weekly inhalations at a target dose of 1 mg/kg body weight of gemcitabine were performed in three baboons using dynamic scintigraphic acquisitions for continuous monitoring of gemcitabine delivery during inhalation. Gemcitabine plasma concentrations were measured during the first inhalation.

RESULTS

Growth inhibition assays for both NCI-H460 and A549 cells did not differ between nebulized and non-nebulized gemcitabine. Aerosol characterization showed a particle mass median aerodynamic diameter of 3.7+/-0.8 microm and a linear relationship between gemcitabine mass (y) and (99m)Tc activity (x) (y=0.82x - 10(-5), R (2)=0.88). No toxicity was observed after nine weekly inhalations of a mean dose of gemcitabine of 11.1 mg (88% of the target dose) as assessed from scintigraphic data. A dose-dependent peak plasma concentration of gemcitabine (20-74 ng/ml) was observed by the tenth minute of inhalation.

CONCLUSIONS

We have characterized a gemcitabine aerosol suitable for intrathoracic airway deposition and demonstrated that jet nebulization does not alter the cytotoxic properties of the drug. In a primate model, we have developed a scintigraphic procedure for the monitoring of aerosol deposition, and we have demonstrated the safety of nine weekly aerosol administrations of gemcitabine.

Enhanced P53 and BAX gene expression and apoptosis in A549 cells by cis-Pt(II) complex of 3-aminoflavone in comparison with cis-DDP

Lung cancer remains one of the most common causes of cancer-related death worldwide. Approximately 80% is histologically non-small cell lung carcinoma (NSCLC) and in about 70% of patients it is an unresectable type. Clinical studies indicated that application of platinum derivatives caused good results and combinations of platinum with other agents could improve median survivals. In view of the central problem of sufficient efficiency of drugs in chemotherapy, efforts have focused on the development of alternative platinum-based analogues that can be more effective in cancer treatment. cis-bis(3-aminoflavone)dichloroplatinum(II) (cis-Pt(II) complex of 3-aminoflavone) represents a novel class of platinum-based potential antitumour agents. In order to evaluate the degree of apoptosis, acridine orange/ethidium bromide and Hoechst 33258/propidum iodide double staining as well as RT-PCR (P53 and BAX expression evaluation) were used in lung cancer cell line A549 after treatment with this compound in comparison with cis-diamminedichloroplatinum(II) (cis-DDP). Apoptotic cells at early and late stages and also necrotic ones were observed after usage of cis-Pt(II) complex of 3-aminoflavone and the percentage of these cells outnumbered the values obtained after cis-DDP application. The former compound induced a higher percentage of P53 and BAX expression in A549 cells in comparison with the latter one. Results indicate the beneficial properties of cis-Pt(II) complex of 3-aminoflavone as a potential antitumor drug.

Phase II study of prolonged ambulatory infusion carboplatin and oral etoposide for patients progressing through hormonal therapy for prostate cancer

AIM

To develop a well-tolerated outpatient chemotherapy regimen for hormone-insensitive prostate cancer.

METHOD

Forty patients received carboplatin 20 mg/m2 by continuous ambulatory infusion with oral etoposide 50 mg/day for 21 days repeated every 6 weeks.

RESULTS

Four patients had a partial response and 16 patients had stable disease. Two of the partial responders and three additional patients recorded falls in prostate specific antigen of 50% or more. The median freedom from progression was 24 weeks and median survival 32 weeks. Twenty-four of 31 patients had decreasing pain scores and 20 of 34 patients recorded improved quality of life with at least one cycle of treatment. The main toxicity occurred in seven patients with World Health Organization (WHO) grade 4 neutropenia and in four patients with WHO grade 3 neutropenia. Only one patient developed febrile neutropenia. Six patients had grade 3 anaemia and three patients had grade 3 thrombocytopenia. Two patients reported grade 3 lethargy whereas 11 patients had grade 2 lethargy.

CONCLUSION

This was a well-tolerated regimen that improved symptomatic control of hormone-insensitive prostate cancer.

Cellular and pharmacogenetics foundation of synergistic interaction of pemetrexed and gemcitabine in human non-small-cell lung cancer cells

Gemcitabine and pemetrexed are effective agents in the treatment of non-small-cell lung cancer (NSCLC), and the present study investigates cellular and genetic aspects of their interaction against A549, Calu-1, and Calu-6 cells. Cells were treated with pemetrexed and gemcitabine, and their interaction was assessed using the combination index. The role of drug metabolism in gemcitabine cytotoxicity was examined with inhibitors of deoxycytidine kinase (dCK), 5'-nucleotidase, and cytidine deaminase, whereas the role of pemetrexed targets, thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT) in drug chemosensitivity was analyzed in cytotoxicity rescue studies. The effect of gemcitabine and pemetrexed on Akt phosphorylation was investigated with enzyme-linked immunosorbent assay, whereas quantitative polymerase chain reaction (PCR) was used to study target gene-expression profiles and its modulation by each drug. Synergistic cytotoxicity was demonstrated, and pemetrexed significantly decreased the amount of phosphorylated Akt, enhanced apoptosis, and increased the expression of dCK in A549 and Calu-6 cells, as well as the expression of the human nucleoside equilibrative transporter 1 (hENT1) in all cell lines. PCR demonstrated a correlation between dCK expression and gemcitabine sensitivity, whereas expression of TS, DHFR, and GARFT was predictive of pemetrexed chemosensitivity. These data demonstrated that 1) gemcitabine and pemetrexed synergistically interact against NSCLC cells through the suppression of Akt phosphorylation and induction of apoptosis; 2) the gene expression profile of critical genes may predict for drug chemosensitivity; and 3) pemetrexed enhances dCK and hENT1 expression, thus suggesting the role of gene-expression modulation for rational development of chemotherapy combinations.

Interaction between gemcitabine and topotecan in human non-small-cell lung cancer cells: effects on cell survival, cell cycle and pharmacogenetic profile

The pyrimidine analogue gemcitabine is an established effective agent in the treatment of non-small-cell lung cancer (NSCLC). The present study investigates whether gemcitabine would be synergistic with the topoisomerase I inhibitor topotecan against the NSCLC A549 and Calu-6 cells. Cells were treated with gemcitabine and topotecan for 1 h and the type of drug interaction was assessed using the combination index (CI). Cell cycle alterations were analysed by flow cytometry, while apoptosis was examined by the occurrence of DNA internucleosomal fragmentation, nuclear condensation and caspase-3 activation. Moreover, the possible involvement of the PI3K-Akt signalling pathway was investigated by the measurement of Akt phosphorylation. Finally, quantitative, real-time PCR (QRT-PCR) was used to study modulation of the gemcitabine-activating enzyme deoxycytidine kinase (dCK) and the cellular target enzyme ribonucleotide reductase (RR). In results, it was found that simultaneous and sequential topotecan → gemcitabine treatments were synergistic, while the reverse sequence was antagonistic in both cell lines. DNA fragmentation, nuclear condensation and enhanced caspase-3 activity demonstrated that the drug combination markedly increased apoptosis in comparison with either single agent, while cell cycle analysis showed that topotecan increased cells in S phase. Furthermore, topotecan treatment significantly decreased the amount of the activated form of Akt, and enhanced the expression of dCK (+155.0 and +115.3% in A549 and Calu-6 cells, respectively), potentially facilitating gemcitabine activity. In conclusion, these results indicate that the combination of gemcitabine and topotecan displays schedule-dependent activity in vitro against NSCLC cells. The gemcitabine → topotecan sequence is antagonistic while drug synergism is obtained with the simultaneous and the sequential topotecan → gemcitabine combinations, which are associated with induction of decreased Akt phosphorylation and increased dCK expression.

Extracellular signal-regulated kinase activation and Bcl-2 downregulation mediate apoptosis after gemcitabine treatment partly via a p53-independent pathway

Gemcitabine is a promising compound for the treatment of human lung cancer. Although apoptosis has been shown to play a role in certain cell types with gemcitabine, the steps leading to cell death after the drug-target interaction are not well understood. We studied the molecular mechanisms of gemcitabine-induced apoptosis and determined the role of p53 function on the cytotoxic effects of gemcitabine in human nonsmall cell lung cancer (NSCLC) H1299 and H1299/p53 cells. Here, we found that gemcitabine induced an apoptotic cell death via a Bcl-2-dependent caspase-9 activation pathway. Moreover, phosphorylated activation of extracellular signal-regulated kinase (ERK) was observed upon gemcitabine treatment. Genetical or pharmacological inhibition of ERK activation markedly blocked gemcitabine-induced cell death. Furthermore, inactivation of Akt was also involved in this event. Taken together, our observations indicate that ERK activation and Akt inactivation mediated gemcitabine-induced apoptosis independently of p53 in human NSCLC H1299 cells.

Synergistic cytotoxicity and pharmacogenetics of gemcitabine and pemetrexed combination in pancreatic cancer cell lines

PURPOSE

Gemcitabine is an inhibitor of ribonucleotide reductase (RR) and DNA synthesis and is an effective agent in the treatment of pancreas cancer. The present study investigates whether the multitargeted antifolate pemetrexed would be synergistic with gemcitabine against MIA PaCa-2, PANC-1, and Capan-1 pancreatic cancer cell lines.

EXPERIMENTAL DESIGN

Cells were treated with gemcitabine and pemetrexed, and the type of drug interaction was assessed using the combination index. Cytotoxicity of gemcitabine was examined with inhibitors of (a) deoxycytidine kinase (dCK), which activates gemcitabine by phosphorylation, and (b) 5'-nucleotidase (drug dephosphorylation) and cytidine deaminase (drug deamination), the main inactivating enzymes. The effects of gemcitabine and pemetrexed on cell cycle were analyzed by flow cytometry, and apoptosis was examined by fluorescence microscopy. Finally, quantitative, real-time PCR was used to study the pharmacogenetics of the drug combination.

RESULTS

Synergistic cytotoxicity and enhancement of apoptosis was demonstrated, mostly with the sequence pemetrexed-->gemcitabine. Pemetrexed increased cells in S phase, the most sensitive to gemcitabine, and a positive correlation was found between the expression ratio of dCK:RR and gemcitabine sensitivity. Indeed, pemetrexed significantly enhanced dCK gene expression (+227.9, +86.0, and +135.5% in MIA PaCa-2, PANC-1, and Capan-1 cells, respectively), and the crucial role of this enzyme was confirmed by impairment of gemcitabine cytotoxicity after dCK saturation with 2'-deoxycytidine.

CONCLUSIONS

These data demonstrate that the gemcitabine and pemetrexed combination displays schedule-dependent synergistic cytotoxic activity, favorably modulates cell cycle, induces apoptosis, and enhances dCK expression in pancreatic cancer cells.

Phase II trial of paclitaxel, estramustine, etoposide, and carboplatin in the treatment of patients with hormone-refractory prostate carcinoma

BACKGROUND

Preclinical data suggest that the combination of intravenous (i.v.) paclitaxel, carboplatin, oral etoposide, and oral estramustine (TEEC) has significant activity in patients with advanced, hormone-refractory prostate carcinoma. The authors conducted this clinical trial to evaluate the addition of carboplatin to the three-drug combination of paclitaxel, estramustine, and etoposide (TEE).

METHODS

Twenty patients with carcinoma of the prostate that was progressing despite hormone therapy were enrolled on this Phase II trial. Patients were treated with oral estramustine, 280 mg three times daily, and oral etoposide, 50 mg/m2, once daily on Days 1-7, with i.v. paclitaxel, 135 mg/m2, over 1 hour followed by carboplatin (area under the curve, 5) on Day 2 of each 21-day treatment cycle. Patients were evaluated for response after three cycles, and three additional cycles were given to responding or stable patients.

RESULTS

Nineteen patients were evaluable for response, and 12 patients had measurable disease at baseline. The measurable response rate was 58% (7 of 12 patients; 95% confidence interval [95% CI], 28-85%), and all of those were partial responses. Eleven patients had decreases >50% from their baseline prostate specific antigen levels during therapy, for a response rate of 58% (95% CI, 34-80%) by this criterion. The median time to disease progression was 5.5 months, with a median survival of 14.2 months. Major toxicities included Grade (according to version 2 of the National Cancer Institute Common Toxicity Criteria) 4 neutropenia in 4 patients, Grade 4 thrombocytopenia in 4 patients, and anemia > or = Grade 3 in 4 patients. One patient had a deep vein thrombosis.

CONCLUSIONS

The combination of TEEC was active in patients with hormone-refractory prostate carcinoma. The regimen was tolerable, with primarily hematologic toxicity. The addition of carboplatin to TEE did not appear to add to the efficacy of the three-drug combination of antimicrotubule agents.

Neoadjuvant chemotherapy and chemoradiotherapy for non-small cell lung cancer: current status and future prospects

Of the patients with non-small cell lung cancer, 60% present with localised or locally advanced disease. Although they may be considered potentially curable, the vast majority will die, usually from systemic disease. So far, adjuvant (postoperative) therapy has failed to demonstrate benefit. In contrast, chemotherapy has demonstrated clear advantages when administered prior to, or concurrently with radiotherapy in Stage III disease or prior to surgery in Stage III disease. Chemotherapy administered prior to surgery, termed neoadjuvant therapy, in Stage I and II disease has been demonstrated to be feasible. Several trials employing currently available agents have yielded promising results. Whether these regimens will result in an unequivocal benefit is the subject of several ongoing studies in the US and Europe. Current research is focusing on the role of newer drugs including novel antitubulin agents, growth factor receptor antagonists, eicosanoid modulators and various other agents.

Overview of bladder cancer trials in the Cancer and Leukemia Group B

The Cancer and Leukemia Group B (CALGB) Genitourinary Committee has developed a broad range of clinical trials across most stages of bladder cancer. Recurrence rates of superficial bladder cancer after transurethral resection range from 50-70%. Although adjuvant bacillus Calmette-Guerin reduces the risk of disease recurrence or progression, only 30% of patients have long-term disease-free survival. Because the development of novel secondline agents is needed, the CALGB is evaluating the utility of intravesicle gemcitabine as well as an oral proapoptotic agent (CP-461). In patients with locally advanced disease with an increased risk of disease recurrence after cystectomy, a randomized trial of conventional chemotherapy versus sequential dose-dense therapy is under development. The gemcitabine/cisplatin combination has become a commonly used regimen for the treatment of advanced transitional cell carcinoma (TCC). The CALGB is undertaking a Phase II study that incorporates a fixed dose rate gemcitabine infusion in this regimen, together with a selective epidermal growth factor receptor tyrosine kinase inhibitor, Iressa (Astra Zeneca, Wilmington, DE). In patients with renal insufficiency, a regimen of carboplatin, gemcitabine, and Iressa is planned. Novel agents, including arsenic trioxide and trastuzumab (Herceptin; Genentech, Inc., South San Francisco, CA), are being evaluated as secondline therapy in patients with advanced TCC who have disease progression after frontline therapy.

Pharmacogenetics of anticancer drug sensitivity in non-small cell lung cancer

In mammalian cells, the process of malignant transformation is characterized by the loss or down-regulation of tumor-suppressor genes and/or the mutation or overexpression of proto-oncogenes, whose products promote dysregulated proliferation of cells and extend their life span. Deregulation in intracellular transduction pathways generates mitogenic signals that promote abnormal cell growth and the acquisition of an undifferentiated phenotype. Genetic abnormalities in cancer have been widely studied to identify those factors predictive of tumor progression, survival, and response to chemotherapeutic agents. Pharmacogenetics has been founded as a science to examine the genetic basis of interindividual variation in drug metabolism, drug targets, and transporters, which result in differences in the efficacy and safety of many therapeutic agents. The traditional pharmacogenetic approach relies on studying sequence variations in candidate genes suspected of affecting drug response. However, these studies have yielded contradictory results because of the small number of molecular determinants of drug response examined, and in several cases this approach was revealed to be reductionistic. This limitation is now being overcome by the use of novel techniques, i.e., high-density DNA and protein arrays, which allow genome- and proteome-wide tumor profiling. Pharmacogenomics represents the natural evolution of pharmacogenetics since it addresses, on a genome-wide basis, the effect of the sum of genetic variants on drug responses of individuals. Development of pharmacogenomics as a new field has accelerated the progress in drug discovery by the identification of novel therapeutic targets by expression profiling at the genomic or proteomic levels. In addition to this, pharmacogenetics and pharmacogenomics provide an important opportunity to select patients who may benefit from the administration of specific agents that best match the genetic profile of the disease, thus allowing maximum activity.

Past, present, and future of gemcitabine and carboplatin regimens in advanced non-small cell lung cancer

Several chemotherapeutic regimens have emerged in the past 5 years with the capability to improve survival and quality of life of patients with advanced non-small cell lung cancer (NSCLC). Among these treatments, the regimen of gemcitabine (Gemzar) and carboplatin (Paraplatin) has gained increasing acceptance. The combination of these two drugs was initially hampered by unacceptable platelet toxicity. However, the use of a 21-day schedule with the administration of gemcitabine on days 1 and 15 or the use of a 28-day schedule with the omission of day-15 gemcitabine has clearly been well tolerated and active. Unlike taxane based regimens, there is no need for steroid premedication, and neurotoxicity and alopecia are absent. This regimen is well tolerated and easily administered on an outpatient basis. It therefore represents an excellent "platform regimen" for the addition of new agents, particularly those associated with minimal myelotoxicity. Three-drug regimens consisting of gemcitabine/carboplatin and a taxane have been evaluated both with concurrent and sequential administration of the drugs. Trials are under way or planned for the addition of novel agents such as C225, UCN-01, PKC-alpha antisense, bexarotene, COX-2 inhibitors and other agents.