Vitamin B12 produced by gut bacteria modulates cholinergic signalling

A growing body of evidence indicates that gut microbiota influence brain function and behaviour. However, the molecular basis of how gut bacteria modulate host nervous system function is largely unknown. Here we show that vitamin B12-producing bacteria that colonize the intestine can modulate excitatory cholinergic signalling and behaviour in the host Caenorhabditis elegans. Here we demonstrate that vitamin B12 reduces cholinergic signalling in the nervous system through rewiring of the methionine (Met)/S-adenosylmethionine cycle in the intestine. We identify a conserved metabolic crosstalk between the methionine/S-adenosylmethionine cycle and the choline-oxidation pathway. In addition, we show that metabolic rewiring of these pathways by vitamin B12 reduces cholinergic signalling by limiting the availability of free choline required by neurons to synthesize acetylcholine. Our study reveals a gut-brain communication pathway by which enteric bacteria modulate host behaviour and may affect neurological health.

A randomized phase III trial comparing adjuvant single-agent S1, S-1 with oxaliplatin, and postoperative chemoradiation with S-1 and oxaliplatin in patients with node-positive gastric cancer after D2 resection: the ARTIST 2 trial☆

BACKGROUND

Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC.

PATIENTS AND METHODS

The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m² every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146).

RESULTS

A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable.

CONCLUSIONS

In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.

TORC1 signaling regulates cytoplasmic pH through Sir2 in yeast

Glucose controls the phosphorylation of silent information regulator 2 (Sir2), a NAD⁺‐dependent protein deacetylase, which regulates the expression of the ATP‐dependent proton pump Pma1 and replicative lifespan (RLS) in yeast. TORC1 signaling, which is a central regulator of cell growth and lifespan, is regulated by glucose as well as nitrogen sources. In this study, we demonstrate that TORC1 signaling controls Sir2 phosphorylation through casein kinase 2 (CK2) to regulate PMA1 expression and cytoplasmic pH (pHc) in yeast. Inhibition of TORC1 signaling by either TOR1 deletion or rapamycin treatment decreased PMA1 expression, pHc, and vacuolar pH, whereas activation of TORC1 signaling by expressing constitutively active GTR1 (GTR1Q65L) resulted in the opposite phenotypes. Deletion of SIR2 or expression of a phospho‐mutant form of SIR2 increased PMA1 expression, pHc, and vacuolar pH in the tor1Δ mutant, suggesting a functional interaction between Sir2 and TORC1 signaling. Furthermore, deletion of TOR1 or KNS1 encoding a LAMMER kinase decreased the phosphorylation level of Sir2, suggesting that TORC1 signaling controls Sir2 phosphorylation. It was also found that Sit4, a protein phosphatase 2A (PP2A)‐like phosphatase, and Kns1 are required for TORC1 signaling to regulate PMA1 expression and that TORC1 signaling and the cyclic AMP (cAMP)/protein kinase A (PKA) pathway converge on CK2 to regulate PMA1 expression through Sir2. Taken together, these findings suggest that TORC1 signaling regulates PMA1 expression and pHc through the CK2–Sir2 axis, which is also controlled by cAMP/PKA signaling in yeast.

Xanthohumol Inhibits the Growth of Keratin 18-Overexpressed Esophageal Squamous Cell Carcinoma in vitro and in vivo

Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related death worldwide. Xanthohumol is a prenylated flavonoid isolated from hops. Although xanthohumol has been reported to exert anti-obesity, hypoglycemic, anti-hyperlipidemia and anti-cancer activities, the mechanisms underlying its chemotherapeutic activity are yet to be elucidated. In the present study, we found that xanthohumol inhibited ESCC cell proliferation in vitro and in vivo by targeting keratin (KRT)-18. Xanthohumol suppressed the proliferation, foci formation, and anchorage-independent colony growth of KYSE30 cells. Using xanthohumol-sepharose conjugated bead pull-down and mass/mass analysis, we found that KRT18 is a novel target of xanthohumol in KYSE30 cells. KRT18 protein was highly expressed in patient ESCC tissues compared to adjunct tissues. Anti-proliferative activity of xanthohumol was abrogated or enhanced according to the knockdown or overexpression of KRT18 protein, respectively. Xanthohumol also induced apoptosis and cell cycle arrest at G1 phase which was associated with the modulation of expression of related makers including cyclin D1, cyclin D3, and cleaved-PARP, Bcl-2, cytochrome c and Bax. While xanthohumol attenuated KRT18 protein expression, it failed to cause any change in the KRT18 mRNA level. Furthermore, oral administration of xanthohumol decreased tumor volume and weight in patient-derived xenografts (PDXs) tumors having overexpressed KRT18. Overall these results suggest that xanthohumol acts as a KRT18 regulator to suppress the growth of ESCC.

Epigenomic promoter alterations predict for benefit from immune checkpoint inhibition in metastatic gastric cancer

BACKGROUND

Utilization of alternative transcription start sites through alterations in epigenetic promoter regions causes reduced expression of immunogenic N-terminal peptides, which may facilitate immune evasion in early gastric cancer. We hypothesized that tumors with high alternate promoter utilization would be resistant to immune checkpoint inhibition in metastatic gastric cancer.

PATIENTS AND METHODS

Two cohorts of patients with metastatic gastric cancer treated with immunotherapy were analyzed. The first cohort (N = 24) included patients treated with either nivolumab or pembrolizumab. Alternate promoter utilization was measured using the NanoString® (NanoString Technologies, Seattle, WA, USA) platform on archival tissue samples. The second cohort was a phase II clinical trial of patients uniformly treated with pembrolizumab (N = 37). Fresh tumor biopsies were obtained, and transcriptomic analysis was carried out on RNAseq data. Alternate promoter utilization was correlated to T-cell cytolytic activity, objective response rate and survival.

RESULTS

In the first cohort 8 of 24 (33%) tumors were identified to have high alternate promoter utilization (APhigh), and this was used to define the APhigh tertile of the second cohort (13 APhigh of 37). APhigh tumors exhibited decreased markers of T-cell cytolytic activity and lower response rates (8% versus 42%, P = 0.03). Median progression-free survival was lower in the APhigh group (55 versus 180 days, P = 0.0076). In multivariate analysis, alternative promoter utilization was an independent predictor of immunotherapy survival [hazard ratio 0.29, 95% confidence interval 0.099-0.85, P = 0.024). Analyzing tumoral evolution through paired pre-treatment and post-treatment biopsies, we observed consistent shifts in alternative promoter utilization rate associated with clinical response.

CONCLUSION

A substantial proportion of metastatic gastric cancers utilize alternate promoters as a mechanism of immune evasion, and these tumors may be resistant to anti-PD1 immune checkpoint inhibition. Alternate promoter utilization is thus a potential mechanism of resistance to immune checkpoint inhibition, and a novel predictive biomarker for immunotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT#02589496.

Impact of genomic alterations on lapatinib treatment outcome and cell-free genomic landscape during HER2 therapy in HER2+ gastric cancer patients

Background

To identify predictive markers for responders in lapatinib-treated patients and to demonstrate molecular changes during lapatinib treatment via cell-free genomics.

Patients and methods

We prospectively evaluated the efficacy of combining lapatinib with capecitabine and oxaliplatin as first line neoadjuvant therapy in patients with previously untreated, HER2-overexpressing advanced gastric cancer. A parallel biomarker study was conducted by simultaneously performing immunohistochemistry and next-generation sequencing (NGS) with tumor and blood samples.

Results

Complete response was confirmed in 7/32 patients (21.8%), 2 of whom received radical surgery with pathologic-confirmed complete response. Fifteen partial responses (46.8%) were observed, resulting in a 68.6% overall response rate. NGS of the 16 tumor specimens demonstrated that the most common co-occurring copy number alteration was CCNE1 amplification, which was present in 40% of HER2+ tumors. The relationship between CCNE1 amplification and lack of response to HER2-targeted therapy trended toward statistical significance (66.7% of non-responders versus 22.2% of responders harbored CCNE1 amplification; P = 0.08). Patients with high level ERBB2 amplification by NGS were more likely to respond to therapy, compared with patients with low level ERBB2 amplification (P = 0.02). Analysis of cfDNA showed that detectable ERBB2 copy number amplification in plasma was predictive to the response (100%, response rate) and changes in plasma-detected genomic alterations were associated with lapatinib sensitivity and/or resistance. The follow-up cfDNA genomics at disease progression demonstrated that there are emergences of other genomic aberrations such as MYC, EGFR, FGFR2 and MET amplifications.

Conclusions

The present study showed that HER2+ GC patients respond differently according to concomitant genomic aberrations beyond ERBB2, high ERBB2 amplification by NGS or cfDNA can be a positive predictor for patient selection, and tumor genomic alterations change significantly during targeted agent therapy.

Safety and efficacy of nivolumab in combination with S-1/capecitabine plus oxaliplatin in patients with previously untreated, unresectable, advanced, or recurrent gastric/gastroesophageal junction cancer: interim results of a randomized, phase II trial (ATTRACTION-4)

BACKGROUND

Nivolumab is approved as an option for third- or later-line treatment of advanced gastric/gastroesophageal junction (G/GEJ) cancer in several countries after ATTRACTION-2. To further improve the therapeutic efficacy of first-line therapy, exploration of a nivolumab-chemotherapy combination is warranted. In part 1 (phase II) of ATTRACTION-4, the safety and efficacy of nivolumab combined with S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (CapeOX) as first-line therapy for unresectable advanced or recurrent human epidermal growth factor receptor 2 (HER2)-negative G/GEJ cancer were evaluated.

PATIENTS AND METHODS

Patients were randomized (1 : 1) to receive nivolumab (360 mg intravenously every 3 weeks) plus SOX (S-1, 40 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) or CapeOX (capecitabine, 1000 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) until disease progression, unacceptable toxicity, or consent withdrawal.

RESULTS

Of 40 randomized patients, 39 (nivolumab plus SOX, 21; nivolumab plus CapeOX, 18) and 38 (21 and 17, respectively) comprised the safety and efficacy populations, respectively. Most frequent (>10%) grade 3/4 treatment-related adverse events were neutropenia (14.3%) in the nivolumab plus SOX group, and neutropenia (16.7%), anemia, peripheral sensory neuropathy, decreased appetite, type 1 diabetes mellitus, and nausea (11.1% each) in the nivolumab plus CapeOX group. No treatment-related death occurred. Objective response rate was 57.1% (95% confidence interval 34.0-78.2) with nivolumab plus SOX and 76.5% (50.1-93.2) with nivolumab plus CapeOX. Median overall survival was not reached (NR) in both groups. Median progression-free survival was 9.7 months (5.8-NR) and 10.6 months (5.6-12.5), respectively.

CONCLUSION

Nivolumab combined with SOX/CapeOX was well tolerated and demonstrated encouraging efficacy for unresectable advanced or recurrent HER2-negative G/GEJ cancer. ATTRACTION-4 has proceeded to part 2 (phase III) to compare nivolumab plus SOX/CapeOX versus placebo plus SOX/CapeOX.

CLINICALTRIALS.GOV ID

NCT02746796.

PD-L1 and immune infiltrates are differentially expressed in distinct subgroups of gastric cancer

This study investigates the association of PD-L1 expression and immune cell infiltrates and their impact on clinical outcome, in addition to their overlap with microsatellite instability (MSI), HER2 and ATM molecular subgroups of gastric cancer (GC). PD-L1 membrane expression on tumour cells (TC) and infiltrating immune cells (IC), CD3 + T-lymphocytes, CD8+ cytotoxic T-cells, ATM and HER2 were assessed by immunohistochemistry (IHC) in the ACRG (Asian Cancer Research Group) GC cohort (N = 380). EBV status was determined using in situ hybridization and MSI status was performed using PCR and MLH1 IHC. The PD-L1 segment was associated with increased T-cell infiltrates, while the MSI-high segment was enriched for PD-L1, CD3, and CD8. Multivariate analysis confirmed PD-L1 positivity, high CD3 and high CD8 as independent prognostic factors for both disease-free survival and overall survival (all p < 0.05). Patients with MSI-high tumours had better overall survival by both univariate and multivariate analysis. The ATM-low and HER2-high subgroups differed markedly in their immune profile; the ATM-low subgroups enriched for MSI, PD-L1 positivity and CD8 + T-cells, while the HER2 segment was enriched for MSS, with no enrichment for immune markers. Hence, we demonstrate a molecular profiling approach that can divide GC into four molecular subgroups, namely ATM-low, HER2-high, PD-L1 positive and MSI-high with differing levels of immune infiltrates and prognostic significance which may help to stratify patients for response to targeted therapies.

Rapamycin-insensitive companion of mTOR (RICTOR) amplification defines a subset of advanced gastric cancer and is sensitive to AZD2014-mediated mTORC1/2 inhibition

Background

Targeting oncogenic genomic aberrations is an established therapeutic strategy in multiple tumor types. Molecular classification has uncovered a number of novel targets, and rapamycin-insensitive companion of mTOR (RICTOR) amplification has been identified in lung cancer. Further investigation assessing the therapeutic potential of RICTOR amplification as a novel target across advanced cancers is needed.

Patients and methods

Tumor samples from 640 patients with metastatic solid tumors, primarily gastrointestinal and lung cancers were prospectively subjected to a next-generation sequencing (NGS) assay to identify molecular targets. Samples with NGS-detected RICTOR amplification were confirmed with FISH. A RICTOR-amplified patient-derived cell (PDC) line was generated and used to investigate the effectiveness of selective AKT, mTORC1, and mTORC1/2 inhibition.

Results

NGS identified 13 (2%) of 640 patients with RICTOR-amplified tumors (6 gastric, 3 NSCLC, 1 SCLC, 1 CRC, 1 sarcoma, 1 MUO). Of the 13 patients, seven patients had RICTOR protein overexpression by IHC. The prevalence of RICTOR amplification in gastric cancer by NGS was 3.8% (6/160). FISH testing confirmed amplification (RICTOR/control >2) in 5/13 (38%) of samples, including four gastric cancers and one lung cancer. Treatment of a RICTOR amplified PDC with a selective AKT (AZD5363), selective mTORC1 (everolimus), dual mTORC1/2 (AZD2014), and the multi-target kinase inhibitor pazopanib demonstrated preferential sensitivity to the mTORC1/2 inhibitor (AZD2014). Knockdown of RICTOR reversed PDC sensitivity to AZD2014, validating the importance of RICTOR amplification to the PDC line.

Conclusions

RICTOR amplification is a rare but therapeutically relevant genomic alteration across solid tumors. Our results support further pre-clinical and clinical investigation with AZD2014 in RICTOR amplified gastric cancer and highlights the importance of genomic profiling.

MAP2K1 Mutation in Colorectal Cancer Patients: Therapeutic Challenge Using Patient-Derived Tumor Cell Lines

BACKGROUND: The MAP2K1 K57T mutation is known to be a potential mechanism of primary and secondary resistance to EGFR inhibitors in metastatic colorectal cancer (CRC) and has also been reported to promote resistance to BRAF and MEK inhibitors. It is important to overcome therapeutic resistance to EGFR inhibitors to improve the treatment outcomes of metastatic CRC. METHODS: We established patient-derived tumor cells (PDCs) from metastatic lesions that newly appeared during treatment with a BRAF inhibitor (LGX-818) plus an EGFR inhibitor (cetuximab) in a patient with BRAF-mutant CRC. To investigate therapeutic options to overcome acquired resistance due to MAP2K1 mutation in BRAF-mutant CRC, we performed cell viability assays using the PDCs. RESULTS: We tested whether the PDCs were resistant to an EGFR inhibitor (cetuximab) and a BRAF inhibitor (sorafenib) as these cells were established at the time of resistance to the EGFR plus BRAF inhibitors. Moreover, the anti-tumor effect of AZD6244 (MEK inhibitor) was evaluated because PDCs harbored a MAP2K1 mutation at the time of resistance to the EGFR plus BRAF inhibitors. MTT proliferation assays showed that monotherapy with cetuximab, sorafenib, or AZD6244 did not suppress cell viability. We next tested viability of the PDCs to combination treatment with cetuximab plus AZD6244 and sorafenib plus AZD6244. Proliferation of PDCs was significantly inhibited by sorafenib and AZD6244, but not by cetuximab plus AZD6244. Investigation of the combined effect of sorafenib and AZD6244 using the calculated combination index (CI) showed synergistic effects of sorafenib and AZD6244 in combination therapy applied to PDCs with the MAP2K1 K57T mutation. CONCLUSION: Our results suggest that combination treatment with BRAF and MEK inhibitors might be a novel treatment strategy for MAP2K1 K57T-mutant CRC. This finding will be helpful to guide treatment of patients with CRC that is resistant to EGFR inhibitors.

A randomised, double-blind, placebo-controlled multi-centre phase III trial of XELIRI/FOLFIRI plus simvastatin for patients with metastatic colorectal cancer

Background:

The purpose of this randomised phase III trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3methyglutaryl coenzyme A reductase inhibitor, to XELIRI/FOLFIRI chemotherapy regimens confers a clinical benefit to patients with previously treated metastatic colorectal cancer.

Methods:

We undertook a double-blind, placebo-controlled phase III trial of 269 patients previously treated for metastatic colorectal cancer and enrolled in 5 centres in South Korea. Patients were randomly assigned (1 : 1) to one of the following groups: FOLFIRI/XELIRI plus simvastatin (40 mg) or FOLFIRI/XELIRI plus placebo. The FOLFIRI regimen consisted of irinotecan at 180 mg m⁻² as a 90-min infusion, leucovorin at 200 mg m⁻² as a 2-h infusion, and a bolus injection of 5-FU 400 mg m⁻² followed by a 46-h continuous infusion of 5-FU at 2400 mg m⁻². The XELIRI regimen consisted of irinotecan at 250 mg m⁻² as a 90-min infusion with capecitabine 1000 mg m⁻² twice daily for 14 days. The primary end point was progression-free survival (PFS). Secondary end points included response rate, duration of response, overall survival (OS), time to progression, and toxicity.

Results:

Between April 2010 and July 2013, 269 patients were enrolled and assigned to treatment groups (134 simvastatin, 135 placebo). The median PFS was 5.9 months (95% CI, 4.5–7.3) in the XELIRI/FOLFIRI plus simvastatin group and 7.0 months (95% CI, 5.4–8.6) in the XELIRI/FOLFIRI plus placebo group (P=0.937). No significant difference was observed between the two groups with respect to OS (median, 15.9 months (simvastatin) vs 19.9 months (placebo), P=0.826). Grade ⩾3 nausea and anorexia were noted slightly more often in patients in the simvastatin arm compared with with the placebo arm (4.5% vs 0.7%, 3.0% vs 0%, respectively).

Conclusions:

The addition of 40 mg simvastatin to the XELIRI/FOLFIRI regimens did not improve PFS in patients with previously treated metastatic colorectal cancer nor did it increase toxicity.

Sir2 phosphorylation through cAMP-PKA and CK2 signaling inhibits the lifespan extension activity of Sir2 in yeast

Silent information regulator 2 (Sir2), an NAD⁺-dependent protein deacetylase, has been proposed to be a longevity factor that plays important roles in dietary restriction (DR)-mediated lifespan extension. In this study, we show that the Sir2's role for DR-mediated lifespan extension depends on cAMP-PKA and casein kinase 2 (CK2) signaling in yeast. Sir2 partially represses the transcription of lifespan-associated genes, such as PMA1 (encoding an H⁺-ATPase) and many ribosomal protein genes, through deacetylation of Lys 16 of histone H4 in the promoter regions of these genes. This repression is relieved by Sir2 S473 phosphorylation, which is mediated by active cAMP-PKA and CK2 signaling. Moderate DR increases the replicative lifespan of wild-type yeast but has no effect on that of yeast expressing the Sir2-S473E or S473A allele, suggesting that the effect of Sir2 on DR-mediated lifespan extension is negatively regulated by S473 phosphorylation. Our results demonstrate a mechanism by which Sir2 contributes to lifespan extension.

DOI:http://dx.doi.org/10.7554/eLife.09709.001

We know that cutting calorie intake through a restricted diet can slow down the aging process and prolong the lives of many organisms ranging from yeast to mammals. Calorie restriction also has protective effects on various age-related diseases including neurodegenerative disorders, cardiovascular disease, and cancer. Many studies suggest that we may mimic the beneficial effects of calorie restriction by controlling the activities of some proteins involved in the aging process.

An enzyme called Sir2 is required for calorie restriction to be able to increase lifespan. This enzyme modifies proteins called histones, which are used to package DNA inside cells. In yeast, Sir2 modifies the histones in such a way that the genes contained in that section of DNA are inactivated (or ‘silenced’). As the yeast cells age, the activity of Sir2 declines, which allows these genes to become active and contribute to the aging process. However, when yeast cells are grown in the presence of little sugar—which mimics caloric restriction—Sir2 is activated and this restores gene silencing.

It is not clear how Sir2's ability to silence these genes contributes to prolonged lifespan. Kang et al. studied the role of Sir2 in yeast and observed that one of the genes that Sir2 inactivates is called PMA1. This gene encodes a protein that is known to restrict the lifespan of yeast cells. Further experiments show that other proteins attach or remove molecules called phosphate groups from Sir2 to regulate its activity. Sir2 is inactivated when a phosphate group is attached, and active in the absence of phosphate. Under a reduced diet, the proteins that add phosphate to Sir2 are inactive, which allows Sir2 to become active and reduce the expression of the PMA1 gene.

These results show that Sir2 fine-tunes the expression of PMA1 and other age-related genes and that the attachment of phosphate groups to Sir2 by other proteins interferes with this regulation. The next challenges will be to identify the proteins responsible for attaching phosphate groups to Sir2, and to find out how they work.

DOI:http://dx.doi.org/10.7554/eLife.09709.002

Comparison of two different S-1 plus cisplatin dosing schedules as first-line chemotherapy for metastatic and/or recurrent gastric cancer: a multicenter, randomized phase III trial (SOS)

BACKGROUND

Five-weekly S-1 plus cisplatin (SP5) is one of the standard first-line regimens for advanced gastric cancer (GC), proven in a Japanese phase III study. To enhance the dose intensity of cisplatin, 3-weekly S-1 plus cisplatin (SP3) was developed.

PATIENTS AND METHODS

This multicenter, randomized, open-label, phase III study evaluated whether SP3 (S-1 80 mg/m(2)/day on days 1-14 and cisplatin 60 mg/m(2) on day 1) was noninferior/superior to SP5 (S-1 80-120 mg/day on days 1-21 and cisplatin 60 mg/m(2) on day 1 or 8) in terms of progression-free survival (PFS). Chemotherapy-naive patients with metastatic, recurrent gastric or gastroesophageal junction adenocarcinoma were randomized 1 : 1 to receive either SP3 or SP5. The trial is registered at ClinicalTrials.gov (NCT00915382).

RESULTS

Between February 2009 and January 2012, 625 patients were randomized at 42 sites in Korea and Japan. With a median follow-up duration of 32.4 months (range, 13.3-48.6 months) in surviving patients, SP3 was not only noninferior but also superior to SP5 in terms of PFS [median 5.5 versus 4.9 months; hazard ratio (HR) = 0.82; 95% confidence interval (CI) 0.68-0.99; P = 0.0418 for superiority). There was no difference in overall survival (OS) between the groups (median 14.1 versus 13.9 months; HR = 0.99; 95% CI 0.81-1.21; P = 0.9068). In patients with measurable disease, the response rates were 60% in the SP3 arm and 50% in the SP5 arm (P = 0.065). Both regimens were generally well tolerated, but grade 3 or higher anemia (19% versus 9%) and neutropenia (39% versus 9%) were more frequent in SP3.

CONCLUSIONS

SP3 is superior to SP5 in terms of PFS. However, since the improvement in PFS was only slight and there was no difference in OS, both SP3 and SP5 can be recommended as first-line treatments for patients with advanced GC.

Growth phase-dependent roles of Sir2 in oxidative stress resistance and chronological lifespan in yeast

Silent Information Regulator 2 (Sir2), a conserved NAD(+)-dependent histone deacetylase, has been implicated as one of the key factors in regulating stress response and longevity. Here, we report that the role of Sir2 in oxidative stress resistance and chronological lifespan is dependent on growth phase in yeast. In exponential phase, sir2Δ cells were more resistant to H2O2 stress and had a longer chronological lifespan than wild type. By contrast, in post-diauxic phase, sir2Δ cells were less resistant to H2O2 stress and had a shorter chronological lifespan than wild type cells. Similarly, the expression of antioxidant genes, which are essential to cope with oxidative stress, was regulated by Sir2 in a growth phase-dependent manner. Collectively, our findings highlight the importance of the metabolic state of the cell in determining whether Sir2 can protect against or accelerate cellular aging of yeast.

Innovative personalized medicine in gastric cancer: time to move forward

Globally, gastric cancer (GC) is the second leading cancer cause of death. To date, only one targeted therapy trial generated positive survival outcomes in a selected population among many targeted therapy trials. This trial showed the addition of trastuzumab to fluoropyrimidine/platinum chemotherapy as first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)-positive GC that resulted in an overall survival (OS) benefit. The increasing use of next generation sequencing approach to genomically profile GC patients allows the identification of many more GC patients who could benefit from specific targeted agents. Here we provide a comprehensive review of targeted therapy trials in GC and discuss future potential actionable driver mutations in GC.

Enhanced secretion of biologically active, non-glycosylated VEGF from Saccharomyces cerevisiae

Vascular endothelial growth factor (VEGF) mediates angiogenesis, which plays a critical role in the development and differentiation of the vascular system. VEGF is a homodimeric glycoprotein that contains one N-glycosylation site. In this study, we evaluated Saccharomyces cerevisiae expression systems producing glycosylated and non-glycosylated splice variants of human VEGF, VEGF121, and VEGF165. The pre region of the mating factor α1 (MFα1) signal sequence was found to perform better than the entire MFα1 prepro signal sequence in secreting glycosylated VEGF. Secretion of non-glycosylated VEGF165 was completely blocked, indicating the importance of glycosylation in VEGF165 secretion. Interestingly, non-glycosylated VEGF165 was secreted when guided by the MFα1 prepro signal sequence, albeit to a lesser degree, compared to glycosylated VEGF165. N-glycosylation in the pro region was required for the prepro sequence to promote VEGF secretion. Furthermore, substitution of asparagine at the VEGF glycosylation site with lysine or glutamic acid increased secretion of non-glycosylated VEGF, a finding not previously reported. Our findings suggest that S. cerevisiae could be a suitable host for secreting biologically active, non-glycosylated VEGF for clinical use.

Brain metastases from colorectal cancer: the role of surgical resection in selected patients

AIM

Brain metastasis is infrequent in colorectal cancer patients, and the prognosis is poor. In this retrospective study survival and prognostic factors were determined in patients with brain metastasis from colorectal cancer.

METHOD

Between 1997 and 2006, 39 patients with brain metastasis from colorectal cancer who survived more than 1 month were identified. Data were collected with regard to patient characteristics, location and stage of the primary tumour, extent and location of metastatic disease, and treatment modalities used.

RESULTS

Most (79.5%) patients had pulmonary metastases before brain metastasis, and the brain was the site of solitary metastasis in only one patient. The most frequent symptom was weakness [18 (43.6%) patients]. Overall median survival was 5.0 months and the 1- and 2-year survival rates were 21.8 and 9.1%, respectively. Univariate analysis revealed uncontrolled extracranial metastases (P = 0.019), multiple brain lesions (P = 0.026), bilateral brain metastases (P = 0.032) and serum carcinoembryonic antigen levels greater than 5 ng/ml (P = 0.008) to be poor prognostic factors. The median survival after the diagnosis of brain metastasis was significantly longer in patients who underwent surgical resection (15.2 ± 8.0 months) than in those treated by other modalities (P = 0.001). Treatment modality was the only independent prognostic factor for overall survival in patients with brain metastases from colorectal cancers (P = 0.015).

CONCLUSION

Aggressive surgical resection in selected patients with brain metastases from colorectal cancer may prolong survival, even in the presence of extracranial metastatic lesions.

Randomised phase II trial of docetaxel and sunitinib in patients with metastatic gastric cancer who were previously treated with fluoropyrimidine and platinum

BACKGROUND

Docetaxel is widely used as a chemotherapeutic agent for gastric cancer treatment. A combined regimen with sunitinib demonstrated a synergistic antitumour effect in a preclinical model. The aim of this study was to evaluate the efficacy and safety of this combination in patients with unresectable or metastatic advanced gastric cancer following failure of treatment with a fluoropyrimidine and platinum combination.

METHODS

This open-label, phase II, randomised trial enrolled patients with unresectable or metastatic gastric cancer. Patients were assigned to either a docetaxel monotherapy arm (D only arm: 60 mg m(-2), every 3 weeks) or a combination arm (DS arm: docetaxel+sunitinib 37.5 mg every day). The primary end point of the study was time to progression and the secondary end points were overall response rate, disease control rate, overall survival, and toxicity profile. A pharmacokinetic study was also performed.

RESULTS

A total of 107 patients were entered into the study. The TTP was not significantly prolonged in the DS arm when compared with the D only arm (DS vs D only arm: 3.9 months (95% confidence interval (CI) 2.9-4.9) vs 2.6 months (95% CI 1.8-3.5) (P=0.206). The hazard ratio for TTP was 0.77 (95% CI 0.52-1.16). However, the objective response rate was significantly higher in the DS arm (41.1% vs 14.3%, P=0.002). Patients in the DS arm experienced stomatitis, diarrhoea, and hand-foot syndrome more frequently.

CONCLUSION

The addition of sunitinib to docetaxel did not significantly prolong TTP, although it significantly increased response.

Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

Lag1p and Lac1p catalyse ceramide synthesis in Saccharomyces cerevisiae. This study shows that Lag1 family proteins are generally required for polarized growth in hemiascomycetous yeast. However, in contrast to S. cerevisiae where these proteins are functionally redundant, C. albicans Lag1p (CaLag1p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal growth in this organism under non-hypha-inducing conditions, suggesting that CaLag1p is necessary for relaying signals to induce hypha-specific gene expression. Analysis of ceramide and sphingolipid composition revealed that CaLag1p predominantly synthesizes ceramides with C24:0/C26:0 fatty acid moieties, which are involved in generating inositol-containing sphingolipids, whereas CaLac1p produces ceramides with C18:0 fatty acid moieties, which are precursors for glucosylsphingolipids. Thus, our study demonstrates that CaLag1p and CaLac1p have distinct substrate specificities and physiological roles in C. albicans.

Outcomes after repeated resection for recurrent pulmonary metastases from colorectal cancer

BACKGROUND

It remains controversial whether metastasectomy is still feasible in patients with pulmonary recurrence from colorectal cancer, after initial metastasectomy. The aim of this study was to evaluate outcomes of repeated metastasectomy in these patients.

MATERIALS AND METHODS

From 1995 to 2007, 202 patients had received a pulmonary metastasectomy from colorectal cancer at our institution. Over a median follow-up of 28.9 months, 48 patients received second metastasectomy (29 wedge resections, 5 segmentectomies, 13 lobectomies, and 1 completion pneumonectomy). The median disease-free interval was 9.6 months. Among these 48 patients, 28 showed pulmonary recurrence again and of those, 10 patients received third metastasectomy (two wedge resections, two segmentectomies, four lobectomies, and two completion pneumonectomies).

RESULTS

There was no postoperative mortality. Of the 48 patients who underwent second metastasectomy, overall and disease-free 5-year survivals were 79% and 49%, respectively, after second operation. Of the 10 patients who received third metastasectomy, overall survival was 78% at 5 years after last operation.

CONCLUSIONS

Repeated resection after initial metastasectomy can be carried out safely and provides long-term survival in patients with recurrent pulmonary metastasis from colorectal cancer. Our findings indicate that close follow-up for the early detection of recurrence and parenchyma-saving resection can improve the results after repeated resection.

A comparative study on the short-term clinicopathologic outcomes of laparoscopic surgery versus conventional open surgery for transverse colon cancer

BACKGROUND

The long-term oncologic stability of laparoscopic surgery for colon cancer was established, and laparoscopic surgery was accepted as an alternative to conventional open surgery for colon cancer. However, transverse colon cancer was excluded from the majority of the previous prospective studies. As a result, debate on laparoscopic surgery for transverse colon cancer continues. This study aimed to compare the clinicopathologic outcome of laparoscopic surgery with that of conventional open surgery for transverse colon cancer.

METHODS

From August 2004 to December 2007, 106 cases of transverse colon cancer were managed by resection at our institution, and 89 of these cases were included in this study. Age, sex, body mass index (BMI), operation time, blood loss, time to first flatus, time to start of diet, hospital stay, complications, tumor size, distal resection margin, proximal resection margin, and number of nodes harvested were compared between the two groups.

RESULTS

No significant differences were found between the laparoscopic and conventional groups in terms of age, sex, BMI, operation time, or hospital stay. The mean blood loss during the operations was significantly less in the laparoscopic group (113.8 +/- 128.9 ml) than in the conventional group (278.8 +/- 268.7 ml; p < 0.05). Moreover, the time to the first flatus was shorter (2.8 +/- 0.9 days vs. 4.4 +/- 2.0 days; p < 0.00) and the diet was started earlier (3.9 +/- 1.7 days vs. 5.4 +/- 1.9 days; p < 0.00) in the laparoscopic group. No intergroup differences in tumor size, proximal resection margin, or number of lymph nodes were observed. The mean distal resection margin was longer in the laparoscopic group (12.5 +/- 4.1 cm vs. 9.2 +/- 6.2 cm; p < 0.05).

CONCLUSION

Laparoscopic and conventional open surgeries were found to have similar clinical outcomes in transverse colon cancer, and the oncologic quality of laparoscopic surgery was found to be acceptable compared with conventional open surgery.

IMVP-16/Pd followed by high-dose chemotherapy and autologous stem cell transplantation as a salvage therapy for refractory or relapsed peripheral T-cell lymphomas

The present study aimed to analyse the treatment outcome of IMVP-16/Pd (ifosfamide, methotrexate, etoposide and prednisone) followed by high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with peripheral T-cell lymphomas (PTCLs) who were previously treated with CHOP. Since 1995, 32 PTCL patients were treated with IMPV-16/Pd. Nine of 32 patients achieved a response (5 demonstrating complete response (CR) and 4 partial response), with an overall response rate of 28.1% (95% onfidence interval 0.12-0.45). Considering histopathologic subtypes, 3 of 4 relapsed natural killer (NK)/T-cell lymphoma patients (75%) achieved CR, but only 1 of 6 in non-NK/T-cell lymphoma patients (16.7%) achieved CR (P = 0.19). Six of 9 IMVP-16/Pd sensitive patients underwent HDC/ASCT. Three of them relapsed after 3, 4 and 15 months, respectively, of HDC/ASCT. Estimated 3-year overall survival and progression-free survival rates were 14.2% and 12.2%, respectively. Multivariate analysis revealed that responsiveness to first-line CHOP was a significant prognostic factor (P < 0.05). These results indicate that IMVP-16/Pd followed by HDC/ASCT appears to be an effective salvage regimen, especially for NK/T-cell lymphoma.

Case report. Lipomatous haemangiopericytoma (fat-forming solitary fibrous tumour) involving the perineum: CT and MRI findings and pathological correlation

Lipomatous haemangiopericytoma (a fat-forming solitary fibrous tumour) is a rare soft-tissue tumour histologically characterized by haemangiopericytomatous vasculature and the presence of mature adipocytes. We report the CT and MRI findings of a case of lipomatous haemangiopericytoma involving the perineum. CT showed a well-circumscribed soft-tissue density mass containing a small area of fat density and a punctuate calcification. On MR images, the mass was mostly isointense to the muscle on T(1) weighted images, with heterogeneous signal intensity on T(2) weighted images, and showed strong contrast enhancement except for the fatty and dense collagenous components. This is the first case report of imaging findings of a lipomatous haemangiopericytoma in the radiological literature. Although rare, lipomatous haemangiopericytoma should be considered as a differential diagnosis of fat-containing, hypervascular soft-tissue tumours with variable signal intensity on T(2) weighted images.

A randomised multicentre phase II trial of capecitabine vs S-1 as first-line treatment in elderly patients with metastatic or recurrent unresectable gastric cancer

This randomised multicentre phase II study was conducted to investigate the activity and safety of two oral fluoropyrimidines, capecitabine or S-1, in elderly patients with advanced gastric cancer (AGC). Elderly (⩾65 years) chemo-naive patients with AGC were randomly assigned to receive capecitabine 1250 mg m⁻² two times daily on days 1–14 every 3 weeks or S-1 40–60 mg two times daily according to body surface area on days 1–28 every 6 weeks. Ninety-six patients were enrolled and 91 patients were randomised to capecitabine (N=46) or S-1 (N=45). Overall response rate, the primary end point, was 27.2% (95% CI, 14.1–40.4, 12 of 44 assessable patients) with capecitabine and 28.9% (95% CI, 15.6–42.1, 13 of 45) with S-1. Median times to progression and overall survival in the capecitabine arm (4.7 and 9.5 months, respectively) were similar to those in the S-1 arm (4.2 and 8.2 months, respectively). The incidence of grade 3–4 granulocytopenia was 6.8% with capecitabine and 4.8% with S-1. Grade 3–4 nonhaematologic toxicities were: asthenia (9.1% with capecitabine vs 7.1% with S-1), anorexia (6.8 vs 9.5%), diarrhoea (2.3 vs 0%), and hand–foot syndrome (6.8 vs 0%). Both capecitabine and S-1 monotherapies were active and tolerable as first-line treatment for elderly patients with AGC.

Functional characterization of chitinase from Cydia pomonella granulovirus

Baculovirus chitinases (V-CHIAs) play a crucial role in the terminal liquefaction of virus-infected larvae after death. Although v-chiAs from nucleopolyhedroviruses (NPVs) have been well characterized, little is known about v-chiAs from granuloviruses (GVs). We characterized the v-chiA of Cydia pomonella GV (CpGV) by constructing a recombinant Bombyx mori NPV (BmNPV) in which BmNPV v-chiA was replaced by CpGV v-chiA (103CpGV virus). CpGV v-chiA encoded an approximately 70-kDa chitinase with an exo-type substrate preference. CpGV V-CHIA lacked a C-terminal KDEL endoplasmic reticulum retention motif and was suggested to be a secretory protein. Terminal host liquefaction of B. mori larvae and proper folding of BmNPV-encoded cysteine protease (BmNPV V-CATH) were observed following infection with 103CpGV, indicating that CpGV v-chiA is able to compensate for the absence of its BmNPV counterpart. Our data suggest that the molecular interaction between V-CHIA and V-CATH may be conserved across a broad range of lepidopteran GVs and NPVs.

Gastric GIST: a single institutional retrospective experience with surgical treatment for primary disease

AIMS

Because gastric GISTs show variable clinical behavior, we reviewed our experience with primary gastric GISTs after surgical treatment and imatinib mesylate treatment for advanced disease.

METHODS

Between December 1995 and December 2005, 111 patients who underwent surgical treatment for primary gastric GISTs were enrolled in this study. Patients were grouped according to the risk assessment classification, and clinicopathological features, tumor recurrence and patient survival were assessed.

RESULTS

One patient was included in the very low risk group, 35 in the low risk group, 31 in the intermediate risk group and 44 in the high-risk group. All patients with very low, low and intermediate risk GISTs and 70% of patients with high risk GISTs underwent R0 resection. While there was no recurrence or metastasis in patients with very low, low and intermediate risk GISTs, 23% of those with high risk GISTs showed a distant metastasis at diagnosis and 35% of these patients had a recurrence after R0 resection. The overall 5-year survival rate of the high risk patients was 77.1%. Nineteen patients received imatinib mesylate therapy due to an incomplete resection or recurrence; 7 with no measurable lesion at the CT scan by a local tumor control showed no tumor progression after imatinib mesylate therapy, however, 12 patients with measurable lesions showed variable clinical courses after treatment. The overall 5-year survival rate of 19 patients with imatinib mesylate treatment was 80.0%.

CONCLUSIONS

The clinical outcome of the very low, low and intermediate risk gastric GISTs was excellent, while high risk gastric GISTs had a high rate of recurrence and therefore a less favorable outcome. A complete resection is the most important treatment for cure; however imatinib mesylate treatment may improve the clinical outcome of the patients with metastatic or recurrent gastric GISTs.

New clinical grading system for chronic GVHD predicts duration of systemic immunosuppressive treatment and GVHD-specific and overall survival

We investigated outcomes according to a new clinical grading system for chronic graft-versus-host disease (chronic GVHD) in 38 patients who developed chronic GVHD after an allogeneic hematopoietic stem cell transplantation. We categorized the patients into three grade groups, namely, grade I, grade II and grade III, according to the presence of three risk factors: extensive skin involvement, thrombocytopenia (TP) and progressive type of onset. Sixteen patients were classified into grade 1, 19 into grade II and three into grade III. The probability of withdrawal of systemic immunosuppression (IST) at 1, 2 and 3 years was 61, 76 and 87%, respectively. Patients with grades 2 or 3 chronic GVHD had prolonged duration of systemic IST compared to grade 1 (P=0.043). The probability of GVHD-specific survival (GSS) at 5 years was 52%. Twenty-two of 38 patients with chronic GVHD were still alive and the estimated 3-year overall survival (OS) rate was 60%, whereas that for the group with chronic GVHD grade I and grade II+III was 64 and 48% (P<0.05). Multivariate analysis showed that prior occurrence of acute GVHD, chronic GVHD grade, serum bilirubin over 1.5 mg/dl, date of diagnosis of chronic GVHD (<day 150 versus >day 150) and transplantation-risk factor were independent prognostic factors for GSS and OS.

Prognostic model to predict survival following first-line chemotherapy in patients with metastatic gastric adenocarcinoma

BACKGROUND

This study was to devise a prognostic model for metastatic gastric cancer patients undergoing first-line chemotherapy.

PATIENTS AND METHODS

A retrospective analysis was carried out on 1455 gastric cancer patients, who received first-line chemotherapy from September 1994 to February 2005.

RESULTS

At multivariate level, poor prognostic factors were no previous gastrectomy [P = 0.003; relative risk (RR), 1.191; 95% confidence interval (CI) 1.061-1.338], albumin < 3.6 g/dl (P = or <0.001; RR, 1.245; 95% CI 1.106-1.402), alkaline phosphatase > 85 U/l (P = or <0.001; RR, 1.224; 95% CI 1.092-1.371), Eastern Cooperative Oncology Group performance status of two or more (P = or <0.001; RR, 1.690; 95% CI 1.458-1.959), the presence of bone metastases (P = 0.001; RR, 1.460; 95% CI 1.616-1.836), and the presence of ascites (P = or < 0.001; RR, 1.452; 95% CI 1.295-1.628). Of 1434 patients, 489 patients (34.1%) were categorized as low-risk group (zero to one factors), 889 patients (62.0%) as intermediate-risk group (two to four factors), and 56 patients (3.9%) as high-risk group (five to six factors). Median survival durations for low, intermediate, and high-risk groups were 12.5 months, 7.0 months, and 2.7 months, respectively.

CONCLUSIONS

This model should facilitate the individual patient risk stratification and thus, more appropriate therapies for each metastatic gastric cancer patient.

A biologically active angiogenesis inhibitor, human serum albumin-TIMP-2 fusion protein, secreted from Saccharomyces cerevisiae

Tissue inhibitor of metalloproteinase-2 (TIMP-2) is an endogenous and bi-functional inhibitor of angiogenesis. TIMP-2 is expressed in an insoluble form in Escherichia coli and secreted at a very low level from yeast. Here, we report on a high level of secretion of TIMP-2 fused with human serum albumin (HSA) from the yeast Saccharomyces cerevisiae. The secreted HSA-TIMP-2 fusion protein (87kDa) was purified to greater than 95% homogeneity. The HSA-TIMP-2 protein inhibited approximately 81% of tube formation of human umbilical vein endothelial cells (HUVECs) when studied at a concentration of 187microM. The systemic administration of HSA-TIMP-2 at 40mg/kg to the C57B1/6 mouse inhibited the growth of B16BL6 tumors. Furthermore, a combination treatment of HSA-TIMP-2 with 5-fluorouracil (50mg/kg) showed significant effects on tumor growth in this model. The high level of secretion of the biologically active angiogenesis inhibitor from S. cerevisiae should facilitate fundamental research and application studies of HSA-TIMP-2, as an attractive candidate for therapeutic agents treating angiogenesis-related diseases.

Phase II trial of irinotecan plus oxaliplatin and 5-fluorouracil/leucovorin in patients with untreated metastatic gastric adenocarcinoma

BACKGROUND

This nonrandomized open label phase II study evaluated the efficacy and safety of FOLFOXIRI in metastatic or recurrent gastric cancer patients.

PATIENTS AND METHODS

Patients with histologically proven, metastatic gastric adenocarcinoma, aged 18-70 years, performance status zero to two, no prior chemotherapy, and with signed written informed consent were eligible. Treatment consisted of irinotecan 150 mg/m2 day 1, oxaliplatin 85 mg/m2 day 1, leucovorin 100 mg/m2 day 1, and 5-fluorouracil 2000 mg/m2 as a 48-h continuous infusion starting on day 1, which was repeated every 2 weeks.

RESULTS

From August 2004 to August 2005, 48 patients were prospectively enrolled. The median age was 54 years (24-69). In total, 386 cycles were administered with a median of nine cycles per patient (range 1-12 cycles) and 45 of 48 patients were assessable for treatment response. An independent review of tumor responses resulted in overall response rate of 66.7% (95% confidence interval=53.4% to 80.0%) by intent-to-treat analysis with one complete response and 31 partial responses. The median survival of all patients was 14.8 months and the median time to progression was 9.6 months. Most common grade 3/4 toxic effects were neutropenia (12% of all cycles) and emesis (8% of all cycles). Grade 2 peripheral neuropathy occurred in five patients. One (2%) patient had severe tumor bleeding and five (10%) patients experienced grade 3 diarrhea.

CONCLUSIONS

The modified FOLFOXIRI combination chemotherapy showed a very promising preliminary antitumor activity and was generally well tolerated as a first-line treatment of patients with metastatic gastric cancer.

Salvage chemotherapy with irinotecan, 5-fluorouracil and leucovorin for taxane- and cisplatin-refractory, metastatic gastric cancer

We performed a phase II study of combination chemotherapy with irinotecan, 5-fluorouracil (5-FU) and leucovorin in metastatic gastric cancer patients who were previously treated with taxane and cisplatin, to evaluate the antitumour activity and toxicity of the combination chemotherapy. The metastatic gastric adenocarcinoma patients who were previously treated with taxane and cisplatin combination as first line, and had at least one measurable lesion, 0-2 ECOG performance status and adequate organ functions, were considered eligible. They received irinotecan (150 mg m(-2), day 1) and leucovorin (100 mg m(-2), day 1), followed by continuous infusion of 5-FU (1000 mg m(-2) day(-1), days 1 and 2) every 2 weeks. Treatment was continued until progression of disease was observed. In all, 64 patients were treated with this combination chemotherapy. The median age of the patients was 55 years (range, 33-74 years), and the median ECOG performance status was 1 (0-1, 61 (95%)). Out of 64 patients, 57 were assessable for response. Among 57 assessable patients, no complete response and 12 partial responses were observed (overall response rate, 21%; 95% confidence interval (CI), 10-32%). Stable disease was observed in 14 patients (25%) and progressive disease in 31 patients (54%). The median time to progression was 2.5 months (95% CI, 1.6-3.4) and the median overall survival since the start of the second-line modified FOLFIRI was 7.6 months (95% CI, 6.5-8.7). Grade 3-4 haematologic toxicities included neutropenia in seven patients (11%) and thrombocytopenia in five patients (8%). Grade 3-4 nonhaematologic toxicities included diarrhoea in two patients (3%) and vomiting in two patients (3%). There were no treatment-related deaths. The combination of irinotecan, 5-FU and leucovorin showed moderate activity and favourable toxicity profile as a second-line treatment in metastatic gastric cancer patients, who were previously treated with taxane and cisplatin.

Assessing the bioequivalence of 4- and 8-mg benidipine tablets in healthy volunteers after a single oral dose

OBJECTIVE

To assess the bioequivalence of a new tablet formulation of benidipine hydrochloride with reference to a marketed product.

METHODS

Two groups, consisting of 24 healthy volunteers each, received a 4- or 8-mg (one or two tablets) reference benidipine hydrochloride tablet and one or two test tablets in a 2 x 2 cross-over study. There was a 6-day washout period between doses. The plasma benidipine concentration was monitored using LC/MS/MS for 8 h after the dose. The area under the plasma concentration-time curve from time 0 to the last sampling time (AUCt) was calculated using the linear-log trapezoidal rule. The maximum plasma drug concentration (Cmax) and the time to reach Cmax (Tmax) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUCt and Cmax, and untransformed Tmax.

RESULTS

The geometric mean AUCt was 2.23 ng/mL/h (test medication) and 2.47 ng/mL/h (reference medication) for the 4-mg tablet, and 9.57 and 9.97 ng/mL/h for the 8-mg tablet, respectively. A Cmax of 1.94 and 2.01 ng/mL was achieved for the test and reference medication for the 4-mg tablet, and 5.94 and 6.53 ng/mL for the 8-mg tablet, respectively. The 90% confidence intervals for AUCt and Cmax were 0.8441-1.0481 and 0.8739-1.2037 for the 4-mg tablet, and 0.8559-1.1273 and 0.9926-1.2176 for the 8-mg tablet, respectively, satisfying the bioequivalence criteria of the US Food and Drug Administration Guidelines, and the Korea Food and Drug Administration Guidelines. These results indicate that the 4- and 8-mg tablets of benidipine are bioequivalent to the reference formulations.

Characteristics ofSaccharomyces cerevisiae gal1? andgal1?hxk2? mutants expressing recombinant proteins from theGAL promoter

Galactose can be used not only as an inducer of the GAL promoters, but also as a carbon source by Saccharomyces cerevisiae, which makes recombinant fermentation processes that use GAL promoters complicated and expensive. To overcome this problem during the cultivation of the recombinant strain expressing human serum albumin (HSA) from the GAL10 promoter, a gal1 Delta mutant strain was constructed and its induction kinetics investigated. As expected, the gal1 Delta strain did not use galactose, and showed high levels of HSA expression, even at extremely low galactose concentrations (0.05-0.1 g/L). However, the gal1 Delta strain produced much more ethanol, in a complex medium containing glucose, than the GAL1 strain. To improve the physiological properties of the gal1 Delta mutant strain as a host for heterologous protein production, a null mutation of either MIG1 or HXK2 was introduced into the gal1 Delta mutant strain, generating gal1 Delta mig1 Delta and gal1 Delta hxk2 Delta double strains. The gal1 Delta hxk2 Delta strain showed a decreased rate of ethanol synthesis, with an accelerated rate of ethanol consumption, compared to the gal1 Delta strain, whereas the gal1 Delta mig1 Delta strain showed similar patterns to the gal1 Delta strain. Furthermore, the gal1 Delta hxk2 Delta strain secreted much more recombinant proteins (HSA and HSA fusion proteins) than the other strains. The results suggest that the gal1 Delta hxk2 Delta strain would be useful for the large-scale production of heterologous proteins from the GAL10 promoter in S. cerevisiae.

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Combination chemotherapy with epirubicin, docetaxel and cisplatin (EDP) in metastatic or recurrent, unresectable gastric cancer

Based on single agent activities and the additive or synergistic effects of three individual drugs in gastric cancer, we performed a phase II study of a new regimen combining epirubicin, docetaxel and cisplatin (EDP) for unresectable gastric cancer. The patients with histologically confirmed metastatic or recurrent, unresectable gastric cancer and no history of palliative chemotherapy were eligible for this trial. In total, 40 mg m⁻² epirubicin (reduced to 30 mg m⁻² due to high incidence of febrile neutropaenia; 75%) intravenously (i.v.) over 30 min, followed by 60 mg m⁻² docetaxel i.v. over 1 h, then 75 mg m⁻² cisplatin i.v. over 1 h was administered every 3 weeks. Between January 2002 and February 2003, 30 patients (epirubicin 40 mg m⁻², eight; 30 mg m⁻², 22) were enrolled. The median age was 52 years (range, 33–68). The patients received a median of four cycles (range, 1–8). One patient (3%) achieved a complete response, 13 (43%) showed partial responses, 13 (43%) had stable diseases and three (10%) progressed. The overall response rate was 47% (95% CI, 28–66%), and the median duration of response was 5.0 months (95% CI, 3.0–7.0). The median time to progression was 4.1 months (95% CI, 2.4–5.9), and the median overall survival was 11.0 months (95% CI, 9.5–12.4). Grade 4 neutropaenia were observed in 41%, and febrile neutropaenia in 32%, out of the patients receiving 30 mg m⁻² of epirubicin. Grade 3 nonhaematological toxicities included nausea, vomiting, anorexia and peripheral neuropathy. In conclusion, EDP is active in gastric cancer, with a manageable and predictable toxicity profile.

Capecitabine Monotherapy in Patients with Anthracycline- and Taxane-Pretreated Metastatic Breast Cancer

The selection of chemotherapeutic regimens is challenging for metastatic breast cancer (MBC) patients whose diseases have failed to respond to anthracyline and taxane. Capecitabine has advantages of oral administration and favorable toxicity profiles. This study was conducted to evaluate the efficacy of capecitabine and to identify the subgroup of patients who would potentially have benefit from capecitabine monotherapy in patients with anthracycline- and taxane-pretreated MBC. Female patients with MBC who had been previously treated with anthracycline and taxane received oral capecitabine 2500 mg/m(2) divided in two doses daily for 2 wk with 1-wk rest period. Between September, 1999, and December, 2002, a total of 38 patients were enrolled. Among the 36 evaluable patients, one patient achieved a complete response (CR), 9 patients had partial responses (PRs), and 13 patients had stable diseases (SDs). Response rate was 26% [95% confidence interval (CI), 12-40%] and the tumor control rate (TCR, CR+PR+SD) was 61% (95% CI, 45-77%). The median follow-up duration was 27.8 mo. The median duration of response was 8.9 mo, the median time to progression was 4.6 mo, and the median overall survival was 18.1 mo. The major toxicities were hand-foot syndrome, diarrhea, and emesis. There was no treatment-related death. The predictors of better overall survival were positivity of hormone receptor, disease-free survival longer than 1 yr, non-refractoriness to anthracycline, and fewer number (<or= 3) of involved organs. Capecitabine monotherapy is effective and well tolerated for MBC patients who had previously been treated with anthracycline and taxane. The TCR could predict overall survival as well as the objective response in this study, suggesting a possible role of TCR as a surrogate marker for survival in MBC patients on salvage chemotherapy. The patients who have relatively slow growing tumor and less tumor burden could have benefit from capecitabine monotherapy following anthracycline- and taxane-based chemotherapy.

Autologous peripheral blood stem cell transplantation with induction of autologous graft-versus-host disease in acute myeloid leukemia

We studied whether the induction of autologous graft-versus-host disease (GVHD) has an antileukemic effect and consequently increases the survival of patients undergoing autologous peripheral blood stem cell transplantation (PBSCT). In all, 22 acute myeloid leukemia patients with favorable and intermediate cytogenetic risk, in their first complete remission, were administered cyclosporine c.i.v. from day 0 to day +28 at a dose of 3.0 mg/kg per day and interferon-gamma (IFN-gamma) at 0.025 mg/m(2) s.c. every other day from day +14 to day +42 following autologous PBSCT. Natural-killer (NK)-cell activity assays and skin biopsies were performed. Successful engraftment was achieved in all patients at a median of 13 days without significant additional toxicity. Histologically confirmed cutaneous GVHD developed in 12 patients, and NK-cell activity was significantly augmented after autologous PBSCT in those patients (P=0.03). After a median follow-up duration of 37.7 months (range, 7.3-72.8), the 3-year disease-free survival (DFS) and overall survival (OS) rates were 64.4 and 73.1%, respectively, without significant correlation with GVHD status or augmentation of NK-cell activity. These data suggest that the administration of cyclosporine and IFN-gamma following autologous PBSCT improves OS and DFS, which may be attributable to the antileukemic effect, although no difference in survival could be demonstrated between cutaneous GVHD-positive and -negative groups.

Postoperative chemoradiotherapy for gastric cancer

BACKGROUND

We report the results of postoperative chemoradiotherapy after curative resection in gastric cancer patients.

PATIENTS AND METHODS

Patients with gastric cancer staged IB to IV(M0) were treated with chemoradiotherapy after curative resection with extensive (D2) lymph node dissection. Nodal metastases were observed in 261 (90%) patients. The chemotherapy consisted of fluorouracil 400 mg/m(2) plus leucovorin 20 mg/m(2) for 5 days, followed by 4500 cGy of radiotherapy for 5 weeks with fluorouracil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two 5-day cycles of chemotherapy were given 4 weeks after the completion of radiotherapy.

RESULTS

Of 290 patients accrued, 229 (79%) patients completed chemoradiotherapy as planned. With a median follow-up of 49 months, 114 (34%) patients have relapsed: 33 (29%) locoregional relapses, 76 (67%) peritoneal relapses and 41 (36%) distant metastases. The 5-year overall and relapse-free survivals were 60% and 57%, respectively. Tolerance was acceptable, the main toxicity being neutropenia.

CONCLUSIONS

This postoperative chemoradiotherapy after curative resection of gastric cancer was feasible, with acceptable toxicities. Whether this adjuvant therapy in gastric cancer patients that have undergone a D2 lymph node dissection impacts on survival or reduces the incidence of relapses remains to be studied.

Interaction of Bombyx mori nucleopolyhedrovirus BRO-A and host cell protein laminin

The Bombyx mori nucleopolyhedrovirus (BmNPV) contains five baculovirus repeated ORF ( bro) genes, all of which are expressed as delayed early genes. We have recently reported that BmNPV BRO proteins, specially BRO-A and BRO-C, contain a nucleic acid binding activity and are involved in nucleosome structures in nuclei of infected cells. To further understand the function of bro-a gene, we looked for factors interacting with BmNPV BRO-A using the yeast two-hybrid system. Fifteen clones obtained from a cDNA library of mock-infected cells and one from a library prepared at 2 h postinfection (p.i.) were found to comprise one distinct gene, which was identified as the Bombyx homolog (bLaminin) of Drosophila laminin beta1. A direct interaction between BRO-A and N-terminal region of bLaminin was demonstrated by in vitro pull-down experiments. Further pull-down assays using BmN cell extracts and anti-laminin antibodies also showed interaction of both proteins. In addition, two more clones were obtained from cDNA library of 12 h p.i. and were found to encode BRO-A itself, indicating that BRO-A forms an oligomer. Taken together, we propose that BRO-A may function as a laminin binding protein.

A randomized trial of heparin plus ursodiol vs. heparin alone to prevent hepatic veno-occlusive disease after hematopoietic stem cell transplantation

Hepatic veno-occlusive disease (VOD) is a common and serious regimen-related toxicity after hematopoietic stem cell transplantation (HSCT). There is no safe and proven therapy for established VOD, and focus has been on its prevention. Previous studies have shown that a continuous infusion of unfractionated heparin or ursodiol may reduce the incidence of VOD. In order to compare the efficacy of heparin plus ursodiol with that of heparin alone, we conducted a prospective, randomized study involving 165 consecutive patients who underwent HSCT for a variety of disorders. Eighty-two patients were assigned to receive heparin plus ursodiol, and 83 were assigned to receive heparin alone. Thirteen and 16 patients were diagnosed as having VOD in the heparin plus ursodiol group and the heparin alone group, respectively (15.9% vs 19.3%; P = 0.348). Eighty-nine percent of the heparin plus ursodiol group and 89.2% of the heparin alone group were surviving at day 100 post-HSCT (P = 0.298). The only independent variable associated with an increased risk of VOD was an allogeneic type of HSCT (P = 0.018). In conclusion, this study shows that there is no difference in efficacy between heparin plus ursodiol and heparin alone for the prevention of hepatic VOD.

Clinical features of peripheral T-cell lymphomas in 78 patients diagnosed according to the Revised European-American lymphoma (REAL) classification

The aim of this study was to analyse the clinical characteristics and prognostic factors of peripheral T-cell lymphomas (PTCLs) according to the Revised European-American Lymphoma (REAL) classification. From 1994 to 1999, 78 patients were diagnosed with PTCLs, excluding cutaneous T-cell lymphomas and T-cell chronic lymphocytic leukaemia. The distribution of the histological subgroups were: PTCL unspecified (PTCL-U), 40%; angiocentric lymphoma, 32%; anaplastic large cell lymphoma (ALCL), 17%; angioimmunoblastic T-cell lymphoma (AILD), 6%; intestinal T-cell lymphoma, 3%; and panniculitic T-cell lymphoma, 3%. Patients with angiocentric lymphoma presented with favourable prognostic factors, whereas those with AILD presented with unfavourable prognostic factors. Most patients were treated with doxorubicin-containing combination chemotherapy (with or without radiation therapy). The overall complete remission rate was 61.2% (95% Confidence Interval (CI): 48.5-72.8%) and the 5-year probability of failure-free survival was 33.5%. Median survival of all patients was 45 months (range 0-64+ months) and the 5-year probability of survival was 36.2%. In the multivariate analysis, only the International Prognosis Index (IPI) was an independent prognostic factor for overall survival (P<0.01). Taken together, the proportion of angiocentric lymphoma in this study was higher than that in the studies of Western countries. PTCL responds poorly to treatment with low survival rates and the IPI is a useful prognostic factor for PTCL.

Lovastatin-induced E2F-1 modulation and its effect on prostate cancer cell death

Lovastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, induces growth arrest in a variety of cancer cell lines. Its mechanism of action, however, has not been completely elucidated. E2F-1 is thought to act as an oncogene and a tumour suppressor, with its action probably dependent upon the cellular context. We have shown in this study that transcriptional regulation and proteasomal degradation of E2F-1 are critical regulatory events in lovastatin-induced cell death. Accompanying this is a reduction in the E2F-1-regulated expression of cell cycle genes such as c-myc, cyclin D1, cyclin A and cyclin B1. Cell cycle analysis demonstrated that the accumulation of apoptotic cells was preceded by a progressive decrease in the S-phase cell population in response to lovastatin. Although expression of E2F-1 was reduced in three prostate cancer cell lines-PC-3, LNCaP and DU-145-the p21 and p27 protein levels were not increased in all the cell lines treated, suggesting that increase in p21 and p27 protein expression per se is not responsible for lovastatin-mediated down-regulation of E2F-1. The subsequent apoptotic death of these cells in the presence of lovastatin can be prevented by forced ectopic expression of E2F-1. Taken together, these facts imply that E2F-1 is the target of an HMG-CoA inhibitor and critical cell death mediator in prostate cancer cells.

Combined Chemotherapy and Radiotherapy for Primary CNS Lymphoma

PURPOSE

This study was performed in order to evaluate the effectiveness of combined chemotherapy and radiotherapy (RT) in primary central nervous system lymphoma (PCNSL).

MATERIALS AND METHODS

From January 1995 to August 1999, 21 patients with a diagnosis of PCNSL were treated with combined chemotherapy and radiotherapy. Their median age was 47 years with range of 19 to 78 years. Twelve patients were male and nine patients were female. All patients were immunocompetent and they had no evidence of systemic lymphoma. All patients underwent placement of an Ommaya reservoir and recieved a combination regimen using pre-RT systemic and intra-Ommaya methotrexate (MTX), 40 Gy whole-brain RT with a 14.4 Gy boost, and 2 courses of post-RT high-dose cytarabine. The median follow-up period of all patients and survived patients were 22 months and 36 months, respectively.

RESULTS

The median overall survival duration was 21 months and the overall two- and four-year survival rates were 51% and 43%, respectively. Complete response (CR), partial response, stable disease, and progressive disease were achieved in 12, 3, 1, and 5 patients, respectively. All nine patients without CR expired within 1-31 months (median 6 months). Two patients among the patients with CR developed recurrence after 13 and 14 months, respectively. The location of recurrent disease was within the port of radiation boost. Survival was influenced by age, performance status, and CR. There was one episode of MTX neurotoxicity and hepatotoxicity,respectively.

CONCLUSION

Combined chemotherapy and radiotherapy was an effective treatment for PCNSL, and was associated with a minimum toxicity. However, we must pay attention to the recurrence and late toxicity, particularly within two years following treatment.

Phase II study of high-dose lovastatin in patients with advanced gastric adenocarcinoma

Lovastatin, an inhibitor of mevalonate synthesis, demonstrated in vitro antitumor activity against a variety of human cancer cells, especially in gastric adenocarcinoma cells at pharmacologically achievable concentrations. To determine the antitumor activity of this drug in advanced measurable gastric adenocarcinoma as well as to assess the toxicities and the pharmacokinetic features, we carried out a phase II study of high-dose lovastatin. Patients received lovastatin 35 mg/kg/day for 7 consecutive days, with ubiquinone (60 mg qid p.o.) to prevent rhabdomyolysis. The treatment was repeated every 28 days. From March 1996 to January 1997, 16 patients (median age, 57 years; range, 34-68) were entered into the study, 14 of whom were evaluated for response and toxicity. No patient achieved a response. A total of 28 cycles were administered. The median number of cycles was 2 (range, 1 to 4). Anorexia was the most common toxicity (64%), but decreased oral intake was observed only in 3 cycles. Two patients developed myalgia with elevated muscle enzyme. When used in this dosage and schedule, lovastatin does not appear to be effective for patients with advanced gastric adenocarcinoma.

Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents

PURPOSE

To assess the usefulness of flexible covered metallic stents in the palliation of malignant obstruction of the gastric outlet and duodenum.

MATERIALS AND METHODS

Twenty-four consecutive patients with malignant obstruction of the gastric outlet (n = 22) or duodenum (n = 2) underwent palliative treatment with self-expandable flexible covered metallic stents. Fourteen patients had advanced gastric carcinoma at the antrum and/or pylorus, and eight had obstruction at the anastomosis site of previous gastrojejunostomy. Complications and clinical status were investigated during the study period.

RESULTS

The technical success rate was 75% (18 of 24 patients). Twenty-one stents were placed in 18 patients by using an introducer 6 (n = 7) or 8 mm (n = 14) in diameter. The mean follow-up period was 3.4 months (range, 1 week to 9 months). Symptoms improved in 12 (67%) patients after the procedure. There was no change in symptoms in five and a decrease in one. Twelve patients died during the follow-up period (mean survival, 4.3 months). The complication rate was 25% (six of 24 patients), including stent migration (n = 5) and fracture (n = 3).

CONCLUSION

Flexible covered metallic stent placement can be useful for palliation in patients with malignant obstruction of the gastric outlet or duodenum.

A Phase II Trial of UFT-E and Oral Leucovorin in Advanced Colorectal Cancer

PURPOSE

To determine the efficacy and toxicity of UFT-E plus oral calcium leucovorin in the treatment of patients with advanced colorectal cancer.

MATERIALS AND METHODS

Forty-three patients with advanced, bidimensionally measurable colorectal adenocarcinoma were enrolled in the trial. No patients had received prior palliative chemotherapy. The patients that had received previous adjuvant chemotherapy were enrolled when more than 6 months had elapsed after the completion of adjuvant therapy. Patients were treated with 300 mg/m2/day of UFT-E (tegafur-based) plus 90 mg/day of leucovorin administered orally in three divided daily doses, every 8 hours for 28 days followed by a 7-day rest period. Response was evaluated after two or three courses of therapy.

RESULTS

Thirty-six of forty-three patients were evaluable for response; seven dropped out due to infection, toxicity and patients' refusal. Ten patients had partial responses and one patient complete response (response rate, 31%; 95% confidence interval, 16~46%). The median response duration for the UFT-E plus leucovorin regimen was 28 weeks. Grade III toxicity was seen in one case, with diarrhea.

CONCLUSION

This oral regimen proved effective and well tolerated. This schema also avoided inconveniences, such as hospitalization and the use of infusion pumps, which are associated with 5-FU infusion regimens. The regimen used showed minimal toxicity, especially in the upper digestive tract, with good patient compliance.

An element downstream of the transcription start site is required for activation of Bombyx mori nucleopolyhedrovirus bro-c promoter

Bombyx mori nucleopolyhedrovirus (BmNPV) contains five baculovirus repeated ORF (bro) genes. We have previously reported that all of these genes (bro-a, b, c, d and e) are transcribed as early genes and require viral factor(s) for their expression. In this study, we investigated the mechanism of promoter activation of the bro-c gene. Transient expression assays using genomic libraries of BmNPV indicated that the baculoviral trans-regulator IE-1 is responsible for activating the bro-c promoter. To identify essential site(s) for promoter activation, mutations were introduced to the promoter region of bro-c. Interestingly, it was shown that the pentanucleotide sequence CACGC located 30 nucleotides downstream of the RNA start site was essential for bro-c promoter activation. In addition, the RNA start site and the spacing between the RNA start site and CACGC were also required for promoter activation. By introducing a CACGC sequence into the corresponding region of the bro-b promoter, which is not normally trans-activated by IE-1, we demonstrated that this pentanucleotide motif has the ability to confer trans-activation by IE-1 on a promoter. Gel retardation experiments also showed a sequence-specific DNA binding protein induced by baculovirus infection interacts with the CACGC motif.

Malignant esophagogastric junction obstruction: palliative treatment with an antireflux valve stent

The authors assessed the efficacy of an antireflux valve stent in the palliation of malignant esophagogastric junction (EGJ) obstruction after in vitro testing of the stent. Seventeen patients with inoperable malignant EGJ obstruction were treated. Antireflux valves, made of three polyurethane leaflets, were attached to the distal part of the stent to prevent reflux. When the flow rate of normal saline was 100 mL/sec in the forward direction, the valve fully opened at a pressure of 10 mm Hg. When the flow rate of normal saline was 0.35 mL/sec in the backward direction, the valve nearly completely closed at a pressure of 10 mm Hg. Stent placement was successful in all patients without complications. The median dysphagia score decreased significantly, from 3.0 (dysphagia to liquids) to 1.0 (dysphagia to normal solid food) (P < .0005). No patients experienced reflux symptoms. There was one case of stent migration. A valve stent that can prevent major reflux is an effective device for the palliation of malignant EGJ obstruction.