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Tomohide Tamura

Publications and source records attributed to Tomohide Tamura.

At least 19 recordsLinked to original sources
PubMed2006

Phase 1 clinical study of pegylated liposomal doxorubicin (JNS002) in Japanese patients with solid tumors.

BACKGROUND: Pegylated liposomal doxorubicin (PLD, JNS002) is a formulation of doxorubicin encapsulated polyethylene-glycol coated liposomes with prolonged circulation time and unique toxicity profile. This phase 1 study was aimed at investigating the maximum tolerated dose (MTD), recommended dose, toxicity, pharmacokinetics, and antitumor activity in Japanese patients with solid tumors. METHODS: Patients with solid tumors not amenable to standard forms of treatment were eligible. PLD was administered as an intravenous infusion every 4 weeks. Dose escalation of PLD was planned from 30 to 60 mg/m(2) in 10 mg/m(2) increments. The pharmacokinetics of total doxorubicin (encapsulated plus non-encapsulated) in plasma were examined for the first cycle of treatment. RESULTS: Fifteen patients, aged 49-69 (median; 56) years with advanced solid tumors were enrolled. The major non-hematological toxicities were hand-foot syndrome (HFS), rash and stomatitis. Myelosuppression, especially leukopenia and neutropenia were major hematological toxicities. Although HFS was not severe, a delay of doses for subsequent cycles was required with multiple dosing. The peak plasma concentration and the area under the concentration time curve of PLD increased proportionally to the dose. Objective response was observed in one patient and the normalization of tumor marker values in another. These two patients had been diagnosed with ovarian cancer. CONCLUSION: The recommended dose for phase 2 clinical studies of PLD in Japanese patients was 50 mg/m(2) every 4 weeks. The encouraging results prompted us to plan a subsequent clinical study of PLD against ovarian cancer.

Aged↗
PubMed2006

Pharmacokinetics and pharmacodynamics of weekly epoetin beta in lung cancer patients.

BACKGROUND: To assess the pharmacokinetic profile and time-course of trough concentrations and hemoglobin levels associated with subcutaneous weekly administration of epoetin beta in lung cancer patients with chemotherapy-induced anemia. METHODS: Epoetin beta was subcutaneously administered to 15 anemic lung cancer patients once weekly for 8 weeks at doses of 9000, 18,000 and 36,000 IU. Pharmacokinetic parameters (C(max), AUC(inf) and T(1/2)) were determined after the first single dose administration on a model-independent basis, and the relationship between the dose and these parameters was examined for linearity. RESULTS: Weekly administration of epoetin beta at 9000, 18,000 and 36,000 IU produced C(max) values of 308 +/- 117 (mean +/- standard deviation), 678 +/- 86.7 and 1316 +/- 766 mIU/ml, and AUC(inf) values of 15,300 +/- 9524, 54,574 +/- 16,265 and 88,501 +/- 55,687 hr mIU/ml, respectively, showing dose-proportional increases. Trough concentrations tended to increase in the presence of severe bone marrow suppression induced by chemotherapy or other factors. Extremely high values were seen in three patients, but there was no apparent trend toward an increase with repeated doses. After 8 weeks' administration at 9000, 18,000 and 36,000 IU, hemoglobin levels were changed by -0.37 +/- 1.26, 2.15 +/- 1.36 and 2.82 +/- 2.17 g/dl, respectively. CONCLUSIONS: Epoetin beta exhibited linear pharmacokinetics when administered to anemic cancer patients at weekly doses of 9000-36,000 IU and did not cause drug accumulation. Hemoglobin levels increased with weekly doses of 18,000 or 36,000 IU.

Adenocarcinoma↗
PubMed2006

In-frame deletion in the EGF receptor alters kinase inhibition by gefitinib.

The existence of an in-frame deletion mutant correlates with the sensitivity of lung cancers to EGFR (epidermal growth factor receptor)-targeted tyrosine kinase inhibitors. We reported previously that the in-frame 15-bp deletional mutation (delE746-A750 type deletion) was constitutively active in cells. Kinetic parameters are important for characterizing an enzyme; however, it remains unclear whether the kinetic parameters of deletion mutant EGFR are similar to those of wild-type EGFR. We analysed autophosphorylation in response to ATP and inhibition of gefitinib for deletion mutant EGFR and wild-type EGFR. Kinetic studies, examining autophosphorylation, were carried out using EGFR fractions extracted from 293-pDelta15 and 293-pEGFR cells transfected with deletion mutant EGFR and wild-type EGFR respectively. We demonstrated the difference in activities between unstimulated wild-type (K(m) for ATP=4.0+/-0.3 microM) and mutant EGFR (K(m) for ATP=2.5+/-0.2 microM). There was no difference in K(m) values between EGF-stimulated wild-type EGFR (K(m) for ATP=1.9+/-0.1 microM) and deletion mutant EGFR (K(m) for ATP=2.2+/-0.2 microM). These results suggest that mutant EGFR is active without ligand stimulation. The K(i) value for gefitinib of the deletion mutant EGFR was much lower than that of wild-type EGFR. These results suggest that the deletion mutant EGFR has a higher affinity for gefitinib than wild-type EGFR.

Antineoplastic Agents↗
PubMed2006

Impact of the haplotype CYP3A4*16B harboring the Thr185Ser substitution on paclitaxel metabolism in Japanese patients with cancer.

OBJECTIVE: Paclitaxel is one of the most important anticancer drugs for the treatment of various tumors such as non-small cell lung cancer. We investigated the association between CYP3A4 haplotypes and pharmacokinetic parameters of paclitaxel metabolism. METHODS: This study enrolled 235 Japanese patients with cancer who were receiving paclitaxel. These patients were screened for CYP3A4 gene polymorphisms by either direct sequencing or pyrosequencing. Plasma concentrations of paclitaxel and its 3 metabolites were determined by HPLC in 229 patients. RESULTS: Median values of paclitaxel clearance, normalized for body surface area, were lower in the high-dose group (>or=175 mg/m2, n = 199) than in the low-dose group (<or=100 mg/m2, n = 30), suggesting nonlinearity of pharmacokinetics caused by Cremophor EL. Therefore we mainly used the patients in the high-dose group for further analysis. The median value of the area under the curve (AUC) ratio of 3'-p-hydroxypaclitaxel to paclitaxel was 20% greater (95% confidence interval, 2.4% to 41.7%) in the women than in the men (P = .01). Although no significant difference in paclitaxel clearance was observed among the CYP3A4 haplotypes, 16B-bearing (1/16B) patients (n = 8) showed a 20% lower (95% confidence interval, -58.5 to -11.5%) median AUC ratio of 3'-p-hydroxypaclitaxel to paclitaxel (P = .04) and a 2.4-fold higher median AUC ratio of 6alpha-hydroxypaclitaxel to paclitaxel (P < .001) compaed with those in the wild-type (1/1) patients (n = 180). In contrast, no significant differences were seen between 1/1 and 18B/1 (n = 10) patients for the pharmacokinetic parameters examined. CONCLUSIONS: Our results suggest that CYP3A416B is associated with both reduced 3'-p-hydroxylation of paclitaxel and probably increased levels of 6alpha-hydroxypaclitaxel.

Adult↗
PubMed2006

Retrospective analysis of steroid therapy for radiation-induced lung injury in lung cancer patients.

PURPOSE: To disclose characteristics of lung cancer patients developing radiation-induced lung injury treated with or without corticosteroid therapy. METHODS AND MATERIALS: Radiographic changes, symptoms, history of corticosteroid prescription, and clinical course after 50-70 Gy of thoracic radiotherapy were retrospectively evaluated in 385 lung cancer patients. RESULTS: Radiation-induced lung injury was stable without corticosteroid in 307 patients (Group 1), stable with corticosteroid in 64 patients (Group 2), and progressive to death despite corticosteroid in 14 patients (Group 3). Fever and dyspnea were noted in 11%, 50% and 86% (p<0.001), and in 13%, 44% and 57% (p<0.001) patients in Groups 1-3, respectively. Median weeks between the end of radiotherapy and the first radiographic change were 9.9, 6.7 and 2.4 for Groups 1-3, respectively (p<0.001). The initial prednisolone equivalent dose was 30-40 mg daily in 52 (67%) patients. A total of 16 (4.2%) patients died of radiation pneumonitis or steroid complication with a median survival of 45 (range, 8-107) days. CONCLUSION: Development of fever and dyspnea, and short interval between the end of radiotherapy and the first radiographic change were associated with fatal radiation-induced lung injury. Prednisolone 30-40 mg daily was selected for the treatment in many patients.

Adrenal Cortex Hormones↗
PubMed2006

Detection of epidermal growth factor receptor mutations in serum as a predictor of the response to gefitinib in patients with non-small-cell lung cancer.

Cases of non-small-cell lung cancer (NSCLC) carrying the somatic mutation of epidermal growth factor receptor (EGFR) have been shown to be hyperresponsive to the EGFR tyrosine kinase inhibitor gefitinib (IRESSA). If EGFR mutations can be observed in serum DNA, this could serve as a noninvasive source of information on the genotype of the original tumor cells that could influence treatment and the ability to predict patient response to gefitinib. Serum genomic DNA was obtained from Japanese patients with NSCLC before first-line gefitinib monotherapy. Scorpion Amplified Refractory Mutation System technology was used to detect EGFR mutations. Wild-type EGFR was detected in all of the 27 serum samples. EGFR mutations were detected in 13 of 27 (48.1%) patients and two major EGFR mutations were identified (E746_A750del and L858R). The EGFR mutations were seen significantly more frequently in patients with a partial response than in patients with stable disease or progressive disease (P = 0.046, Fisher's exact test). The median progression-free survival was significantly longer in patients with EGFR mutations than in patients without EGFR mutations (200 versus 46 days; P = 0.005, log-rank test). The median survival was 611 days in patients with EGFR mutations and 232 days in patients without EGFR mutations (P > 0.05). In pairs of tumor and serum samples obtained from 11 patients, the EGFR mutation status in the tumors was consistent with those in the serum of 8 of 11 (72.7%) of the paired samples. Thus, EGFR mutations were detectable using Scorpion Amplified Refractory Mutation System technology in serum DNA from patients with NSCLC. These results suggest that patients with EGFR mutations seem to have better outcomes with gefitinib treatment, in terms of progression-free survival, overall survival, and response, than those patients without EGFR mutations.

Adult↗
PubMed2006

Common arm analysis: one approach to develop the basis for global standardization in clinical trials of non-small cell lung cancer.

The global development of new anticancer treatments is desirable. However, whether results of clinical trials performed in one population can be fully extrapolated to another population remains in question. We retrospectively compared "common arms" of platinum-based doublet phase III trials among Japanese, European, and American patients with non-small cell lung cancer to develop the basis for global standardization in clinical trials. Patient demographics were very similar through all studies, indicating that extrinsic ethnic factors including socioeconomic factors, medical service background, and patient selection process for clinical trials may be consistent between geographically different oncology groups. The doses of docetaxel, gemcitabine, and vinorelbine were lower in Japanese studies. The toxicity profile was generally acceptable and similar among many studies. Thus, the dose and schedule of anticancer agents established in prior phase I and II studies conducted in each country were appropriate and applicable to large patient populations in these countries. Response rates seemed to be distributed randomly from one study to another, whereas patient survival might be better in Japanese studies. In conclusion, geographical differences in the dose of anticancer agents, response, survival and toxicity of lung cancer chemotherapy were actually observed. However, extrapolation of clinical data obtained in one country to another population and global clinical trials were considered possible with adequate dose adjustment based on dose finding studies using a carefully projected protocol.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Geographic variation in the second-line treatment of non-small cell lung cancer.

Although there is broad agreement on management options for treating different stages of non-small cell lung cancer (ie, surgery for stage I and II disease, combined treatment modalities for stage III disease, and platinum-based chemotherapy as initial treatment for appropriate patients with stage IV disease), there is considerable geographic variation in practice patterns. These variations reflect a number of factors, including health care economics, the influence of national and regional regulatory bodies, the nature of physician and patient interaction, and probable biological differences between different populations in terms of drug metabolism and inherent susceptibility to both drug activity and toxicity. The approaches taken by three different geographic regions, the United States, European Union, and Japan, are evaluated. Clinically, the most striking differences in activity and toxicity between different regions have been seen with the epidermal growth factor receptor inhibitors gefitinib and erlotinib. Japanese patients experience significantly greater response and a greater degree of interstitial lung disease than patients in the European Union and North America (ie, US and Canada). Similar differences in efficacy and toxicity have also been noted with cytotoxic chemotherapy agents in the first-line setting. These geographic and ethnic differences in toxicity and efficacy will need to be considered in the design and comparison of future clinical trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

High sensitivity detection of epidermal growth factor receptor mutations in the pleural effusion of non-small cell lung cancer patients.

Epidermal growth factor receptor (EGFR) mutations are a strong determinant of tumor response to gefitinib in non-small cell lung cancer (NSCLC). We attempted to elucidate the feasibility of EGFR mutation detection in cells of pleural effusion fluid. We obtained 24 samples of pleural effusion fluid from NSCLC patients. The pleural effusion fluid was centrifuged, and the cellular components obtained were used for detection. EGFR mutation status was determined by a direct sequencing method (exons 18-21) and by the Scorpion Amplified Refractory Mutation System (ARMS) method. EGFR mutations were detected in eight cases. Three mutations were detected by both methods, and the other five mutations were detected by Scorpion ARMS alone. The mutations were detected by both methods in all four partial responders among the seven patients who received gefitinib therapy. Direct sequencing detected the mutations in only two of four cases with partial response. These results suggest that the DNA in pleural effusion fluid can be used to detect EGFR mutations. The Scorpion ARMS method appears to be more sensitive for detecting EGFR mutations than the direct sequencing method.

Adult↗
PubMed2006

Genetic variation and haplotype structure of the ABC transporter gene ABCG2 in a Japanese population.

The ATP-binding cassette transporter, ABCG2, which is expressed at high levels in the intestine and liver, functions as an efflux transporter for many drugs, including clinically used anticancer agents such as topotecan and the active metabolite of irinotecan (SN-38). In this study, to elucidate the linkage disequilibrium (LD) profiles and haplotype structures of ABCG2, we have comprehensively searched for genetic variations in the putative promoter region, all the exons, and their flanking introns of ABCG2 from 177 Japanese cancer patients treated with irinotecan. Forty-three genetic variations, including 11 novel ones, were found: 5 in the 5'-flanking region, 13 in the coding exons, and 25 in the introns. In addition to 9 previously reported nonsynonymous single nucleotide polymorphisms (SNPs), 2 novel nonsynonymous SNPs, 38C>T (Ser13Leu) and 1060G>A (Gly354Arg), were found with minor allele frequencies of 0.3%. Based on the LD profiles between the SNPs and the estimated past recombination events, the region analyzed was divided into three blocks (Block -1, 1, and 2), each of which spans at least 0.2 kb, 46 kb, and 13 kb and contains 2, 24, and 17 variations, respectively. The two, eight, and five common haplotypes detected in 10 or more patients accounted for most (>90%) of the haplotypes inferred in Block -1, Block 1, and Block 2, respectively. The SNP and haplotype distributions in Japanese were different from those reported previously in Caucasians. This study provides fundamental information for the pharmacogenetic studies investigating the relationship between the genetic variations in ABCG2 and pharmacokinetic/pharmacodynamic parameters.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2005

Dimerization and the signal transduction pathway of a small in-frame deletion in the epidermal growth factor receptor.

A short, in-frame deletional mutant (E746-A750del) is one of the major mutant forms of epidermal growth factor receptor (EGFR) and has been reported to be a determinant of response to EGFR tyrosine kinase inhibitors such as gefitinib and erlotinib. However, the biological and pharmacological functions of mutational EGFR remain unclear. To clarify these biological functions of deletional EGFR, we examined the cellular response to EGF ligand stimulation. Dimerization and phosphorylation of EGFR were observed without any ligand stimulation in the 293(D) cells transfected with deletional EGFR as compared with those transfected with wild-type EGFR (293(W) cells). When the 293(D) cells were exposed to gefitinib, an immunoblotting analysis revealed remarkable inhibition of AKT phosphorylation but not phospho-p44/42 MAPK. To examine the cellular response in a lung cancer cell line intrinsically expressing deletional EGFR, phospho-EGFR, and downstream reactions were monitored under EGF stimulation with a beads-based mulitiplex assay. EGFR and its downstream proteins were constitutively phosphorylated in the PC-9 cells without any ligand stimulation as compared with A549 lung cancer cells expressing wild-type EGFR. In conclusion, deletional EGFR is constitutively active and phosphorylates p44/42 MAPK and AKT in the cells, although the fact that the EGFR phosphorylation in the PC-9 cells is still modulated by EGF stimulation cannot be ignored. Gefitinib-inhibited phospho-AKT predominantly in deletional EGFR expressing cells.

Cell Line↗
PubMed2005

Phase I and pharmacokinetic study of edotecarin, a novel topoisomerase I inhibitor, administered once every 3 weeks in patients with solid tumors.

PURPOSE: Edotecarin (J-107088) is a potent indolocarbazole topoisomerase I inhibitor which is structurally distinct from the camptothecins. This study aimed to determine the maximum tolerated dose (MTD), the recommended dose for future Phase II studies and the safety, pharmacokinetic profile, and preliminary antitumor activity of edotecarin in a population of patients with advanced solid tumors. EXPERIMENTAL DESIGN: Edotecarin was administered as a single dose by IV infusion over 2 h every 21 days (with 1 week permitted for recovery from toxicities, if needed) in patients with advanced solid tumors. Doses ranged from 8 to 15 mg/m(2). Pharmacokinetic assessments were performed during and after the first administration. RESULTS: Twenty-four patients received 61 cycles of therapy. Dose-limiting toxicities (infection, febrile neutropenia, constipation, ileus, and prolonged grade 4 granulocytopenia) were observed in 3 of 5 evaluable patients at the 15 mg/m(2) dose, defining the MTD. The most commonly reported non-hematologic toxicities were anorexia, nausea, malaise, and constipation. Diarrhea was neither frequent nor severe. Neutropenia was the most common hematologic toxicity (grade 3-4 in 21/23 patients during cycle 1). Plasma concentrations of edotecarin rose rapidly following the start of the 2-hour infusion, reaching C (max) values of 103+/-17 ng/ml at the 13 mg/m(2) dose, and decreased steeply after the end of the infusion. Plasma concentrations declined to approximately 1-2 ng/ml at 26 h post start of infusion, the last PK sampling time point. The mean apparent plasma half-life of the drug was 20 h, which should be considered a preliminary estimate until results from studies with a longer duration of plasma sampling are available. A mean of 1.4-3.6% of the dose was recovered as unchanged drug in the urine over 48 h. Unconfirmed tumor regression > or =50% was observed in 2 patients, 1 with metastatic gastric carcinoma and 1 with esophageal cancer. CONCLUSIONS: The MTD of edotecarin administered IV over 2 h every 21 days was 15 mg/m(2). The recommended dose for Phase II studies with a 3-week schedule (with 1 week permitted for recovery from toxicities, if needed) is 13 mg/m(2). The observed safety profile and preliminary evidence of antitumor activity warrant further investigation of this drug in solid tumors.

Adult↗
PubMed2005

Plasma MIP-1beta levels and skin toxicity in Japanese non-small cell lung cancer patients treated with the EGFR-targeted tyrosine kinase inhibitor, gefitinib.

Gefitinib (Iressa() is an orally active, selective EGFR tyrosine kinase inhibitor that blocks signal transduction pathways. Skin toxicity has been reported to be the major toxicity observed in patients treated with the EGFR-targeted tyrosine kinase inhibitors, such as gefitinib and erlotinib. Although the mechanisms underlying the development of the skin toxicity remain to be precisely clarified, immunological mechanisms are considered to be involved. We examined the correlations between the plasma levels of several cytokines and the risk of development of adverse events, especially skin toxicity, induced by the administration of gefitinib as first-line monotherapy in non-small cell lung cancer (NSCLC) patients. Paired plasma samples were obtained from a total 28 patients of non-small cell lung cancer; the first before the initiation of gefitinib administration (250 mg/day) (24 patients) and the second 2 or 4 weeks after the initiation of treatment (23 patients). The plasma concentrations of 17 major cytokines were measured using a bead-based multiplex assay. The median concentrations of eight of these cytokines before the start of treatment ranged from 0.06 (IL-5) to 58.26 (MIP-1beta) (microg/ml). The concentrations of the remaining nine cytokines were under the detectable limit (<0.01 microg/ml) in more than 50% of the samples. Comparisons of the levels before and after treatment showed no significant differences for any of the cytokines measured. The MIP-1beta levels were significantly lower in the patients with skin toxicity (16/24) as compared with those in the patients not showing any skin toxicity (59.1+/-10.5 versus 119.0+/-36.8; p=0.042 by the two-sample t-test). The K-Nearest Neighbor Prediction (K=3) showed the classification rate to be 75% for the prediction sets containing MIP-1beta, IL-4 and IL-8. There were no significant associations between the levels of any of the cytokines measured and any other parameters, including the tumor response to the drug. In conclusion, the plasma MIP-1beta level may be a useful predictor of the development of skin toxicity in patients receiving gefitinib treatment.

Adult↗
PubMed2005

Pilot study of concurrent etoposide and cisplatin plus accelerated hyperfractionated thoracic radiotherapy followed by irinotecan and cisplatin for limited-stage small cell lung cancer: Japan Clinical Oncology Group 9903.

PURPOSE: Irinotecan and cisplatin (IP) significantly improved survival compared with etoposide and cisplatin (EP), in patients with extensive-stage small cell lung cancer (SCLC) in a previous Japan Clinical Oncology Group (JCOG) randomized trial. JCOG9903 was conducted to evaluate the safety of sequentially given IP following concurrent EP plus twice-daily thoracic irradiation (TRT) for the treatment of limited-stage SCLC (LSCLC). EXPERIMENTAL DESIGN: Between October 1999 and July 2000, 31 patients were accrued from 10 institutions. Thirty patients were assessable for toxicity, response, and survival. Treatment consisted of etoposide 100 mg/m(2) on days 1 to 3, cisplatin 80 mg/m(2) on day 1, and concurrent twice-daily TRT of 45 Gy beginning on day 2. The IP regimen started on day 29 and consisted of irinotecan 60 mg/m(2) on days 1, 8, and 15 and cisplatin 60 mg/m(2) on day 1, with three 28-day cycles. RESULTS: There were no treatment-related deaths. The response rate was 97% (complete response, 37%; partial response, 60%). Median overall survival was 20.2 months; 1-, 2-, and 3-year survival rates were 76%, 41%, and 38%, respectively. Of the 24 patients who started the IP regimen, 22 received two or more cycles. Hematologic toxicities of grade 3 or 4 included neutropenia (67%), anemia (50%), and thrombocytopenia (4%). Nonhematologic toxicities of grade 3 or 4 included diarrhea (8%), vomiting (8%), and febrile neutropenia (8%). Of the 20 patients with recurrence, none had local recurrence alone and only two had both local and distant metastasis as the initial sites of disease progression. CONCLUSIONS: IP following concurrent EP plus twice-daily TRT is safe with acceptable toxicities. A randomized phase III trial comparing EP with IP following EP plus concurrent TRT for LSCLC is ongoing (JCOG0202).

Adult↗
PubMed2005

Epidermal growth factor receptor gene mutations and increased copy numbers predict gefitinib sensitivity in patients with recurrent non-small-cell lung cancer.

PURPOSE: To evaluate epidermal growth factor receptor (EGFR) mutations and copy number as predictors of clinical outcome in patients with non-small-cell lung cancer (NSCLC) receiving gefitinib. PATIENTS AND METHODS: Sixty-six patients with NSCLC who experienced relapse after surgery and received gefitinib were included. Direct sequencing of exons 18 to 24 of EGFR and exons 18 to 24 of ERBB2 was performed using DNA extracted from surgical specimens. Pyrosequencing and quantitative real-time polymerase chain reaction were performed to analyze the allelic pattern and copy number of EGFR. RESULTS: Thirty-nine patients (59%) had EGFR mutations; 20 patients had deletional mutations in exon 19, 17 patients had missense mutations (L858R) in exon 21, and two patients had missense mutations (G719S or G719C) in exon 18. No mutations were identified in ERBB2. Response rate (82% [32 of 39 patients] v 11% [three of 27 patients]; P < .0001), time to progression (TTP; median, 12.6 v 1.7 months; P < .0001), and overall survival (median, 20.4 v 6.9 months; P = .0001) were significantly better in patients with EGFR mutations than in patients with wild-type EGFR. Increased EGFR copy numbers (> or = 3/cell) were observed in 29 patients (44%) and were significantly associated with a higher response rate (72% [21 of 29 patients] v 38% [14 of 37 patients]; P = .005) and a longer TTP (median, 9.4 v 2.6 months; P = .038). High EGFR copy numbers (> or = 6/cell) were caused by selective amplification of mutant alleles. CONCLUSION: EGFR mutations and increased copy numbers were significantly associated with better clinical outcome in gefitinib-treated NSCLC patients.

Adult↗
PubMed2005

Functional analysis of four naturally occurring variants of human constitutive androstane receptor.

The human constitutive androstane receptor (CAR, NR1I3) is a member of the orphan nuclear receptor superfamily that plays an important role in the control of drug metabolism and disposition. In this study, we sequenced all the coding exons of the NR1I3 gene for 334 Japanese subjects. We identified three novel single nucleotide polymorphisms (SNPs) that induce non-synonymous alterations of amino acids (His246Arg, Leu308Pro, and Asn323Ser) residing in the ligand-binding domain of CAR, in addition to the Val133Gly variant, which was another CAR variant identified in our previous study. We performed functional analysis of these four naturally occurring CAR variants in COS-7 cells using a CYP3A4 promoter/enhancer reporter gene that includes the CAR responsive elements. The His246Arg variant caused marked reductions in both transactivation of the reporter gene and in the response to 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO), which is a human CAR-specific agonist. The transactivation ability of the Leu308Pro variant was also significantly decreased, but its responsiveness to CITCO was not abrogated. The transactivation ability and CITCO response of the Val133Gly and Asn323Ser variants did not change as compared to the wild-type CAR. These data suggest that the His246Arg and Leu308Pro variants, especially His246Arg, may influence the expression of drug-metabolizing enzymes and transporters that are transactivated by CAR.

Animals↗
PubMed2005

Clinical responses of large cell neuroendocrine carcinoma of the lung to cisplatin-based chemotherapy.

BACKGROUND: The efficacy of chemotherapy in patients with large cell neuroendocrine carcinoma of the lung (LCNEC) remains unclear. METHODS: Patients with LCNEC who received cisplatin-based chemotherapy were identified by reviewing 567 autopsied and 2790 surgically resected lung cancer patients. The clinical characteristics and objective responses to chemotherapy in these patients were analyzed. RESULTS: Overall, 20 cases of LCNEC were identified, including stage IIIA (n=3), stage IIIB (n=6), stage IV (n=6) and postoperative recurrence (n=5) cases. Six patients had received prior chemotherapy, and 14 were chemo-naive patients. The patients had received a combination of cisplatin and etoposide (n=9), cisplatin, vindesine and mitomycin (n=6), cisplatin and vindesine (n=4), or cisplatin alone (n=1). One patient showed complete response and nine showed partial response, yielding an objective response rate of 50%. The response rate did not differ between patients with the initial diagnosis of SCLC and those with the initial diagnosis of NSCLC, however, the response rate in chemo-naive patients (64%) was significantly different from that in previously treated patients (17%). CONCLUSIONS: Our results suggest that the response rate of LCNEC to cisplatin-based chemotherapy was comparable to that of SCLC.

Adenocarcinoma↗