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Purpose. To assess the efficacy of imatinib for different tumor genotypes in Korean patients with advanced gastrointestinal stromal tumors (GIST). Material and methods. Clinical data were collected from 370 consecutive patients with locally advanced unresectable, metastatic, or recurrent GIST treated with imatinib 400 mg/day between August 2001 and December 2007 at 20 Korean institutions. Tumor genotypes were determined for 290 patients by direct DNA sequencing of KIT exons 9, 11, 13, and 17, and PDGFRA exons 12, 14, and 18. Results. Of 290 patients assessed for genotype, 261 (90.0%) had mutations in KIT: 222 (76.6%) in exon 11, 35 (12.1%) in exon 9 and two each (0.7%) for exons 13 and 17. Four patients (1.4%) had mutations in the PDGFRA gene: one in exon 12, and three in exon 18. Twenty-five patients (8.6%) had no detectable mutations. The best responses of the 235 patients with measurable lesions were: 15 complete response (6.4%), 126 partial response (53.5%), 86 stable disease (36.6%), and eight progressive disease (3.4%). Patients with KIT exon 9 mutations, compared with patients with KIT exon 11 mutations, had a lower objective response rate (36.7% vs. 63.6%, p == 0.007) and a shorter progression-free survival (median 28.7 months vs. 49.4 months, p == 0.001). No statistical difference in overall survival was observed between these genotypes. Conclusion. This study confirms that imatinib efficacy is dependent on genotype in Korean GIST patients, consistent with results demonstrated by Western patients with GIST. [ABSTRACT FROM AUTHOR]

The proteasome inhibitor bortezomib has demonstrated clinical activity in patients with multiple myeloma (MM). Adverse events, including thrombocytopenia and peripheral neuropathy, have affected 30% to 60% of patients overall, and interrupted therapy in 10% to 20%. No prior toxicity data are available for Asian patients who have used bortezomib for MM. We used National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, to review the clinical records of patients with an MM diagnosis from 25 centers in Korea. The included patients were treated with bortezomib alone or in combination with other agents, including thalidomide. Ninety-five MM patients were treated. The patients had a median age of 60 years (range, 42-77 years). The median number of previous treatments was 3 (range, 0-10), and 39% of the patients had been treated with 4 or more major classes of agents, including thalidomide (67%), and autologous stem cell transplantation (51%). Regimens included bortezomib only in 38 patients (40%), bortezomib plus dexamethasone in 34 patients (36%), and bortezomib plus a thalidomide-containing regimen in 23 patients (24%). The analysis of patient response to therapy revealed a complete response (CR) or a near-CR in 31 patients (33%) and a partial response in 30 patients (32%), for an objective response rate of 65% in 93 patients. The most common adverse events reported were thrombocytopenia (47%), sensory neuropathy (42%), anemia (31%), and leukopenia (31%). Thirteen patients (14%) stopped therapy because of adverse events (neuropathy, 8; infection, 4; diarrhea, 1). Neuropathy greater than grade 2 was more frequent in patients who received 4 or more prior therapy regimens (17/37) than in those who received 3 or fewer (14/58). In addition, therapy including thalidomide was significantly correlated with neuropathy of grades 1 to 3 (P = .001). We identified 6 therapy-related deaths (6%) within 20 days after the last dose of bortezomib. The causes of death were infection in 3 patients, disease progression in 2 patients, and suicide in 1 patient. The incidences of thrombocytopenia and neurotoxicity were similar; however, gastrointestinal toxicities were relatively low in Korean patients compared with those reported in Western studies. Significant neuropathy was associated with the number of prior regimens and combination with thalidomide. These findings provide useful information for clinicians and patients using bortezomib. [ABSTRACT FROM AUTHOR]

The purpose of our study was to determine the most accurate analytic method to define in vitro chemosensitivity, using clinical response as reference standard in prospective clinical trial, and to assess accuracy of adenosine triphosphate-based chemotherapy response assay (ATP-CRA). Forty-eight patients with chemo-naïve, histologically confirmed, locally advanced or metastatic gastric cancer were enrolled for the study and were treated with combination chemotherapy of paclitaxel 175 mg/m(2) and cisplatin 75 mg/m(2) for maximum of six cycles after obtaining specimen for ATP-CRA. We performed the receiver operator characteristic curve analysis using patient responses by WHO criteria and ATP-CRA results to define the method with the highest accuracy. Median progression free survival was 4.2 months (95% confidence interval [CI]: 3.4-5.0) and median overall survival was 11.8 months (95% CI: 9.7-13.8) for all enrolled patients. Chemosensitivity index method yielded highest accuracy of 77.8% by ROC curve analysis, and the specificity, sensitivity, positive and negative predictive values were 95.7%, 46.2%, 85.7%, and 75.9%. In vitro chemosensitive group showed higher response rate (85.7% vs. 24.1%) (P=0.005) compared to chemoresistant group. ATP-CRA could predict clinical response to paclitaxel and cisplatin chemotherapy with high accuracy in advanced gastric cancer patients. Our study supports the use of ATP-CRA in further validation studies.

Objective: This prospective multicenter study conducted by the Korean Cancer Study Group evaluated the efficacy and safety of pemetrexed in Korean patients with advanced non-small cell lung cancer (NSCLC) who had prior chemotherapy., Patients and Methods: Patients with stage IIIB or IV NSCLC in whom prior chemotherapy failed received pemetrexed 500 mg/m(2) every 3 weeks with folic acid and vitamin B12 supplementation until disease progression or the development of intolerable toxicity. Eighty-one patients were enrolled., Results: The overall response rate for 78 evaluable patients was 5.1% [95% confidence interval (CI) 1.4-12.6; partial response 4/78, no complete response]. The disease control rate including complete, partial response and stable disease was 46.2% (36/78, 95% CI 34.8-57.8). With a median 8.7 months follow-up, the median time to progression was 3.1 months (95% CI 1.17-5.03) and the median overall survival (OS) was 7.8 months (95% CI 5.19-10.35). The median OS for patients with adenocarcinoma histology was 18.7 months compared to 6.1 months for non-adenocarcinoma. In a multivariate analysis, Eastern Cooperative Oncology Group performance status 0-1 [hazards ratio (HR)=0.331, 95% CI 0.135-0.814] and adenocarcinoma (HR=0.504, 95% CI 0.283-0.899) were independent factors for prolongation of overall survival., Conclusions: Pemetrexed monotherapy has promising efficacy in patients with advanced NSCLC as a second-line therapy with less hematologic and non-hematologic toxicity, especially in those with adenocarcinoma histology.

Background: Ticlopidine is an antiplatelet agent used for the prevention of vascular accidents. In clinical practice in Korea, ginkgo extract may be administered along with ticlopidine to enhance the inhibition of platelet aggregation., Objective: To meet the requirements for marketing a combined fixed-dose formulation in Korea, the investigators compared the pharmacokinetic characteristics of ticlopidine in a combined fixed-dose tablet of ticlopidine/ginkgo extract with the concomitant administration of ticlopidine and ginkgo extract tablets., Methods: An open-label, 2-period, 2-treatment, single-dose, randomized-sequence crossover study was conducted in healthy Korean male volunteers. Subjects were randomly allocated to 2 sequence groups. In one period, a combined ticlopidine 250 mg/ ginkgo extract 80-mg fixed-dose tablet was administered and, in the other period, ticlopidine 250-mg and ginkgo extract 80-mg tablets were concomitantly administered. A 7-day washout separated the 2 periods. For analysis of pharmacokinetic properties, including C(max), T(max), t((1/2)), AUC(0-infinity), and AUC(0-last), serial blood sampling was performed up to 48 hours after study drug administration during each period. Ticlopidine concentrations in plasma were determined by a validated method using LC-MS/MS. In order for the 2 treatments to be considered bioequivalent, the 90% CI of the geometric means ratios for C(max) and AUC needed to be between 80% and 125%. Bleeding time was determined before dosing (0 hour) and at 5 and 24 hours after dosing. Adverse events (AEs) were identified through patient interview, recording of blood pressure, heart rate, and body temperature, physical examination, 12-lead ECG, and laboratory assessments., Results: Twenty-four healthy Korean male subjects (mean [range] age, 23.9 [22-38] years; height, 174.0 [162-184] cm; weight, 67.4 [56-80] kg) completed the study. Median (range) T(max) of ticlopidine was 1.5 (0.5-2.0) hours in both groups. The mean (SD) t((1/2)) of ticlopidine in the combined fixed-dose formulation and the concomitant administration groups was 19.5 (3.4) and 19.0 (3.3) hours after study drug administration, respectively. The geometric means ratios of ticlopidine AUC(0-last), AUC(0-infinity), and C(max) between the combined fixed-dose formulation and concomitant administration were 1.04 (90% CI, 0.96-1.13), 1.04 (90% CI, 0.96-1.13), and 1.09 (90% CI, 0.96-1.23), respectively. The mean (SD) bleeding time at predose (0), and 5 and 24 hours after dose administration was 4.5 (1.6) to 5.4 (1.7) minutes in the combined fixed-dose formulation group and 4.4 (1.6) to 5.1 (1.1) minutes in the concomitant administration group. Five subjects (3 in the combined fixed-dose formulation group and 2 in the concomitant administration group) had bleeding times >8 minutes, but this was not considered to be clinically significant. A total of 24 AEs were reported in 13 of 24 subjects: nausea (3 cases), diarrhea (3), dizziness (3), epigastric discomfort (2), headache (2), rhinorrhea (2), purulent sputum (2), dyspepsia (1), upper abdominal pain (1), cough (1), pharyngolaryngeal pain (1), oropharyngeal swelling (1), dysphonia (1), and dysphagia (1). All were considered mild or moderate in nature. There was no statistically significant difference between the 2 treatments in the number of AEs or in the number of subjects who reported an AE., Conclusion: Administration of a single dose of a combined fixed-dose formulation of ticlopidine 250 mg/ ginkgo extract 80-mg tablets and concomitant administration of ticlopidine and ginkgo extract tablets did not result in statistically significant differences in the pharmacokinetics of ticlopidine in these healthy Korean male volunteers.

Background: Cathepsin D is the most abundant lysosomal and endosomal aspartyl protease; it shows beta and gamma secretase activity in vitro by cleaving the amyloid precursor protein into amyloid beta protein. In recent studies, cathepsin D was co-localized with PrP(Sc), the disease-associated form of the prion disease, and abnormal expression of cathepsin D correlated with tissue damage in brains of sporadic Creutzfeldt-Jakob disease (CJD)., Objective: To investigate whether a polymorphism at position 224, C224T, on exon 2 of the cathepsin D gene (CTSD) is associated with sporadic CJD in the Korean population., Methods: We compared the genotype and allele frequencies at this polymorphism site in 172 sporadic CJD patients with those in 197 healthy Koreans., Results and Conclusion: Our study does not show a significant difference in genotype (p = 0.901) and allele (p = 0.509) frequencies of CTSD C224T between sporadic CJD patients and normal controls. This was the first genetic association study of CTSD in a sporadic CJD population., (2009 S. Karger AG, Basel.)

We isolated nickel-resistant bacterium from soil in order to identify a novel nickel resistance determinant. Using 16S rRNA gene sequencing, an isolate was identified as Enterobacter sp. Ni15. This species showed a medium-level (resistant to up to 10 mM) nickel resistance in nutrient-rich media. Enterobacter sp. Ni15 has a novel plasmid, pNi15, and an increased nickel resistance to Escherichia coli DH5alphain trans. To isolate the nickel resistance gene from pNi15, the plasmid was digested with XbaI and its fragments were cloned into pBluescriptIISK(+). The clones were transferred into E. coli DH5alpha. The nickel resistance of the clones was then assayed. From these results, a pNi15100 isolate containing a 5,328 bp XbaI fragment of pNi15 was identified and sequenced. The E. coli DH5alpha harboring the pNi15100 showed a resistance to up to 7 mM nickel. Using a subcloning analysis, we were able to identify the novel nickel resistance determinant: the nrp gene encoding the putative proteins NrpA and NrpB.

Human prion protein gene (PRNP) is considered an important gene in determining the incidence of human transmissible spongiform encephalopathies or prion diseases. Polymorphisms of PRNP at codon 129 in Europeans and codon 219 in Japanese may play an important role in the susceptibility to sporadic Creutzfeldt-Jakob disease (CJD); data regarding codon 129 in the Japanese population have led to divergent interpretations. In order to determine which, if any, of the PRNP genotypes in Korean people are associated with sporadic CJD, we examined the genotype and allelic distributions of human PRNP polymorphisms in 150 patients with sporadic CJD. All Korean sporadic CJD patients were Met/Met at codon 129, Glu/Glu at codon 219 and undeleted at the octarepeat region of PRNP. Our study showed significant differences in genotype frequency of PRNP at codon 129 (chi 2=8.8998, P=0.0117) or 219 (chi 2=12.6945, P=0.0004) between sporadic CJD and normal controls. Furthermore, the genotype frequency of the heterozygotes for codons 129 and/or 219 showed a significant difference between the normal population and sporadic CJD patients (chi 2=21.0780, P<0.0001).

We report a Korean patient with glycogen storage disease type 1b (GSD-1b) whose diagnosis was confirmed by liver biopsy and laboratory results. The patient presented with delay of puberty and short stature on admission and had typical clinical symptoms of GSD as well as chronic neutropenia and inflammatory bowel disease. Mutation analysis of the glucose 6-phosphate translocase 6-phosphate translocase (SLC37A4) gene revealed that the patient was a compound heterozygote of two different mutations including a deletion mutation (c.1042&#95;1043delCT; L348fs) and a missense mutation (A148V). The L348fs mutation was inherited from the patient's father and has been reported in an Italian family with GSD-1b, while the A148V mutation was transmitted from the patient's mother and was a novel mutation. To the best of our knowledge, this is the first report of genetically confirmed case of GSD-1b in Korean.

A human polyomavirus, JC virus (JCV) is ubiquitous in humans and infects children asymptomatically. It persists in renal tissue and is excreted progeny in urine. DNAs from urine samples of 100 healthy Korean individuals were screened for the presence of JCV by polymerase chain reaction (PCR). Twenty of the samples were positive for JCV. JCV DNA was found in one individual (4%) in the 1-19-year group, two individuals (9%) in the 20-39-year group, ten individuals (38%) in the 40-59-year group, seven individuals (28%) in the over 60-year group. The prevalence of JC viral DNA was the highest in the 40-59-year-old Korean population. To investigate genotypes of JCV in Korea, the genotypes were determined by DNA sequence analysis of the regulatory region (333 bp) and the VT-intergenic region (656 bp) of DNA from the 20 JCV isolates. We have identified three distinctive JCV strains in the regulatory region and ten distinctive JCV strains in the VT-intergenic region of DNA from the 20 isolates. Based on restriction fragment length polymorphism (RFLP) analysis and phylogenetic analysis of the VT-intergenic region of JCV, two distinct subtypes, CY and type 2A (MY), were found to be prevalent in this Korean population. CY and type 2A of JCV were identified in 13 individuals (65%) and four individuals (20%), respectively. Interestingly, type 1, which was distributed mostly in Europe, was found in 3 (15%) isolates from healthy Korean individuals., (Copyright 2004 Wiley-Liss, Inc.)

Human prion protein gene (PRNP) has been considered to be involved in the susceptibility of humans to prion diseases. Polymorphisms of methionine (Met)/valine (Val) at codon 129 and of glutamic acid (Glu)/lysine (Lys) at codon 219 are thought to play an important role in susceptibility to sporadic, iatrogenic and variant Creutzfeldt-Jakob disease (CJD). Although the genotype distribution of polymorphisms in PRNP open reading frame (ORF) has been reported in many European populations, among Asian groups, it has been reported only in the Japanese population. We examined the PRNP polymorphisms in 529 healthy Koreans. We observed that genotype frequencies at codon 129 was 94.33% Met/Met, 5.48% Met/Val, and 0.19% Val/Val with an allele frequency of 0.971:0.029 Met:Val, and that genotype frequencies at codon 219 was 92.06% Glu/Glu, 7.94% Glu/Lys, and 0% Lys/Lys with an allele frequency of 0.96:0.04 Glu:Lys. The frequencies of the Glu/Glu genotype ( chi(2)=10.075, P=0.0015) and of the Glu allele ( chi(2)=9.486, P=0.0021) at codon 219 were significantly higher in the Korean population than the Japanese population. In addition, the genotype frequency of heterozygotes (12.7%) at codons 129 or/and 219 was significantly lower in Koreans than in people from Great Britain ( chi(2)=89.52, P<0.0001). The deletion rate of one octarepeat (R2 deletion) was 0.38%, with 99.62% undeleted homozygotes and 0% deleted homozygote. To our knowledge, the R2 octarepeat deletion has never been found in people from countries other than Korea. The data of PRNP polymorphism at codon 219 suggest that Koreans may be more sensitive to sporadic CJD than the Japanese population.

Substantial pain is experienced by a lot of patients with cancer, and undertreated pain significantly undermines their quality of life. Despite international and national guidelines on cancer pain management, the practical effectiveness of management is still problematic. We did a prospective cross-sectional survey on pain prevalence, pain intensity, its impact on daily activity, and adequacy of pain management in 823 patients treated by medical oncologists and radiologic oncologists. At the time of the survey, 29.7% of the patients had pain that was moderate or severe. Performance status and tumor extent were significant predictors of pain presence and its intensity. Pain severity and the proportion of the patients whose function is impaired are highly associated. Among the patients with pain, only 37% rated pain relief as satisfactory. Forty-one percent of the patients with pain received inadequate pain management. Physicians did not adjust the analgesic prescription in about 53% of the patients who reported severe pain. These results demonstrate the alarming degree of undertreatment of pain in patients with cancer in Korea, and indicate the need to improve the management of cancer-related pain. Future research should elucidate the factors that impede adequate pain management in order to overcome obstacles to adequate treatment., (Copyright 2003 S. Karger AG, Basel)