Development of DNA aptamers universally bound to single-chain fragment variables and their applications in bioprocess monitoring.

Single-chain fragment variables (scFvs), composed of variable heavy and light chains joined together by a peptide linker, can be produced using a cost-effective bacterial expression system, making them promising candidates for pharmaceutical applications. However, a versatile method for monitoring recombinant-protein production has not yet been developed. Herein, we report a novel anti-scFv aptamer-based biosensing system with high specificity and versatility. First, anti-scFv aptamers were screened using the competitive systematic evolution of ligands by exponential enrichment, focusing on a unique scFv-specific peptide linker. We selected two aptamers, P1-12 and P2-63, with KD = 2.1 µM or KD = 1.6 µM toward anti-human epidermal growth factor receptor (EGFR) scFv, respectively. These two aptamers can selectively bind to scFv but not to anti-EGFR Fv. Furthermore, the selected aptamers recognized various scFvs with different CDRs, such as anti-4-1BB and anti-hemoglobin scFv, indicating that they recognized a unique peptide linker region. An electrochemical sensor for anti-EGFR scFv was developed using anti-scFv aptamers based on square wave voltammetry. Thus, the constructed sensor could monitor anti-EGFR scFv concentrations in the range of 10-500 nM in a diluted medium for bacterial cultivation, which covered the expected concentration range for the recombinant production of scFvs. These achievements promise the realization of continuous monitoring sensors for pharmaceutical scFv, which will enable the real-time and versatile monitoring of large-scale scFv production.

Acute Liver Failure Due to Hypereosinophilic Syndrome Accompanied by Duodenal Perforation.

A 78-year-old woman presenting with severe acute liver failure was admitted to our hospital. On screening for the etiology of acute liver failure, it was diagnosed as being due to idiopathic hypereosinophilic syndrome (eosinophil count reported as 4766/µL; 33.8% of the white blood cells). Her medical history included marked eosinophilia, as observed six months prior to this admission. Corticosteroid therapy was initiated. During the clinical course, duodenal perforation occurred but was managed promptly by appropriate surgery. A liver biopsy, following the initiation of corticosteroid therapy, revealed degenerating hepatic cells with mild eosinophilic infiltration. With corticosteroid therapy, the liver function improved.

Evaluation of chemical chaperones based on the monitoring of Bip promoter activity and visualization of extracellular vesicles by real-time bioluminescence imaging.

It is known that endoplasmic reticulum (ER) stress in cells and extracellular vesicles (EVs) plays a significant role in cancer cells, therefore the evaluation of compounds that can regulate ER stress and EV secretion would be a suitable system for further screening and development of new drugs. In this study, we evaluated chemical chaperones derived from natural products based on monitoring Bip/GRP78 promoter activity during cancer cell growth, at the level of the single cell, by a bioluminescence microscopy system that had several advantages compared with fluorescence imaging. It was found that several chemical chaperones, such as ferulic acid (FA), silybin, and rutin, affected the activity. We visualized EVs from cancer cells using bioluminescence imaging and showed that several EVs could be observed when using CD63 fused with NanoLuc luciferase, which has a much smaller molecular weight and higher intensity than conventional firefly luciferase. We then examined the effects of the chemical chaperones on EVs from cancer cells by bioluminescence imaging and quantified the expression of CD63 in these EVs. It was found that the chemical chaperones examined in this study affected CD63 levels in EVs. These results showed that imaging at the level of the single cell using bioluminescence is a powerful tool and could be used to evaluate chemical chaperones and EVs from cancer cells. This approach may produce new information in this field when taken together with conventional and classical methods.

Etiology and long-term rebleeding of endoscopic ulcerative lesions in the small bowel in patients with obscure gastrointestinal bleeding: A multicenter cohort study.

BACKGROUND: Among patients with obscure gastrointestinal bleeding (OGIB), endoscopic ulcerative lesions in the small bowel have diverse etiologies and often cause rebleeding. Certain characteristics of patients or ulcerations may be reasonable indications for diagnostic balloon-assisted endoscopy (BAE) to assess etiology and may be risks of rebleeding; however, these characteristics are unclear. We aimed to elucidate appropriate indications for diagnostic BAE and predictors of long-term rebleeding in patients with small bowel ulcerative lesions. METHODS: We conducted a multicenter retrospective cohort study of 68 patients with OGIB, in whom small bowel ulcerative lesions were detected by capsule endoscopy (n = 60) and/or BAE (n = 43). Patients' characteristics, including medications and endoscopic findings, were evaluated. Predictors of the need for diagnostic BAE to determine ulceration etiology were identified by logistic regression analysis. Rebleeding risks were evaluated using Cox proportional hazards analysis. RESULTS: Single ulcerations were diagnosed in 26 patients, and multiple ulcerations were diagnosed in 42 patients. Among 43 patients who underwent BAE, ulceration etiology was identified in 12 (28%) patients. In the etiology identification, BAE was more useful for a single ulceration than for multiple ulcerations (P < 0.001). Among the 68 patients, rebleeding occurred in 14 (21%) patients during a mean follow-up period of 17 months. Aspirin use and multiple ulcerations were significant predictors of rebleeding (P < 0.05). CONCLUSIONS: When we manage small bowel ulcerative lesions in OGIB patients, a single ulceration is a reasonable indication for the diagnostic BAE. The rebleeding rate was lower for single ulcerations than for multiple ulcerations.

Combining Fluorescence and Bioluminescence Microscopy to Study the Series of Events from Cellular Signal Transduction to Gene Expression.

The molecular interactions and translocation of signal transduction factors in individual cells can be imaged by fluorescence microscopy. Alternatively, downstream promoter activity in single cells can be imaged by bioluminescence microscopy. However, the same stimuli can lead to different gene expression responses in individual cells. For this reason, it is desirable to simultaneously image signal transduction and gene expression events in the same cells. Here, we describe a method that combines fluorescence and bioluminescence microscopy to image protein kinase C (PKC) translocation from the cytosol to the plasma membrane and the expression of nuclear factor kappa-light polypeptide B (NF-κB)-regulated genes. © 2017 by John Wiley & Sons, Inc.

Colonoscopy reduces colorectal cancer mortality: A multicenter, long-term, colonoscopy-based cohort study.

BACKGROUND: There are limited colonoscopy-based cohort data concerning the effectiveness of colonoscopy in reducing colorectal cancer deaths. The aim of this study was to clarify whether colonoscopy reduces colorectal cancer mortality. METHODS: A cohort of 18,816 patients who underwent colonoscopy without a diagnosis of colorectal cancer between 2001 and 2010 at high colonoscopy procedure volume centers was selected. Patient characteristics and colonoscopy findings were assessed. The main endpoint was colorectal cancer death (all, right-sided, and left-sided cancers), and data were censored at the time of the final visit or the final colonoscopy. The standardized all colorectal, colon, and rectal cancer mortality rates were estimated with reference to those of the general Japanese population. Additional outcome was all- cause death and the standardized all-cause mortality rate was also estimated. RESULTS: The total observed person-year mortality for colorectal cancer was 67,119. Of these, 4, 3, and 1 patients died from colorectal, colon, and rectal cancers, respectively; these values were significantly lower than the number of expected deaths in the general population, estimated to be 53.1, 34.0, and 19.1, respectively. The standardized mortalities for all colorectal, colon, and rectal cancers were 0.08 (95% confidence interval (CI), 0.02-0.17), 0.09 (95% CI, 0.02-0.22), and 0.05 (95% CI, 0.0002-0.21), respectively. There were 586 all-cause deaths (3.11%) during the observation period. The standardized all-cause mortality ratios were 0.22 (95% CI, 0.206-0.23). CONCLUSIONS: The colorectal cancer mortality of patients who received colonoscopy without colorectal cancer diagnosis decreased significantly compared with that of individuals in the general population. These results were compatible even in patients with right-sided colon cancer.

Genetic deletion of GPR52 enhances the locomotor-stimulating effect of an adenosine A2A receptor antagonist in mice: A potential role of GPR52 in the function of striatopallidal neurons.

G protein-coupled receptor 52 (GPR52) is largely co-expressed with dopamine D2 receptor (DRD2) in the striatum and nucleus accumbens, and this expression pattern is similar to that of adenosine A2A receptor (ADORA2A). GPR52 has been proposed as a therapeutic target for positive symptoms of schizophrenia, based on observations from pharmacological and transgenic mouse studies. However, the physiological role of GPR52 in dopaminergic functions in the basal ganglia remains unclear. Here, we used GPR52 knockout (KO) mice to examine the role of GPR52 in dopamine receptor-mediated and ADORA2A-mediated locomotor activity and dopamine receptor signaling. High expression of GPR52 protein in the striatum, nucleus accumbens, and lateral globus pallidus of wild type (WT) littermates was confirmed by immunohistochemical analysis. GPR52 KO and WT mice exhibited almost identical locomotor responses to the dopamine releaser methamphetamine and the N-methyl-d-aspartate antagonist MK-801. In contrast, the locomotor response to the ADORA2A antagonist istradefylline was significantly augmented in GPR52 KO mice compared to WT mice. Gene expression analysis revealed that striatal expression of DRD2, but not of dopamine D1 receptor and ADORA2A, was significantly decreased in GPR52 KO mice. Moreover, a significant reduction in the mRNA expression of enkephalin, a marker of the activity of striatopallidal neurons, was observed in the striatum of GPR52 KO mice, suggesting that GPR52 deletion could enhance DRD2 signaling. Taken together, these results imply the physiological relevance of GPR52 in modulating the function of striatopallidal neurons, possibly by interaction of GPR52 with ADORA2A and DRD2.

Efficacy of repeat review with flexible spectral imaging color enhancement in patients with no findings by capsule endoscopy.

BACKGROUND/AIM: The efficacy of flexible spectral imaging color enhancement (FICE) ch. 1 (F1) for the detection of ulcerative lesions and angioectasias in the small intestine with capsule endoscopy (CE) has been reported. In the present study, we evaluated whether F1 could detect incremental findings in patients with no findings in a standard review mode. PATIENTS AND METHODS: In total, 52 patients (age: 60.1 ± 15.3 years; 30 males) with obscure gastrointestinal bleeding (OGIB) who underwent CE and in whom no lesion was detected in the small intestine in the standard mode (first review) were enrolled. Two experienced endoscopists independently reviewed CE videos again by F1 (second review). The following findings were defined to be significant: Ulcers, erosions, aphthas, angioectasias, tumors, and bleeding. Incremental findings at the second review were checked at F1 and in standard mode by the two reviewers (third review). Finally, the findings were confirmed by the agreement of the two reviewers at the third review. RESULTS: F1 detected five significant lesions in three patients with overt OGIB; three erosions, one aphtha, and one angioectasia. For nonsignificant lesions, F1 detected 12 red mucosas and 16 red spots. Moreover, 29 patients with 71 findings were considered false positives. CONCLUSION: F1 detected incremental significant findings in a small percentage of patients with no findings in the standard review mode. In addition, F1 showed many false-positive findings. The incremental effect of a repeated review by F1 in patients with no findings in the first review is limited.

TAK-063, a PDE10A Inhibitor with Balanced Activation of Direct and Indirect Pathways, Provides Potent Antipsychotic-Like Effects in Multiple Paradigms.

Phosphodiesterase 10A (PDE10A) inhibitors are expected to be novel drugs for schizophrenia through activation of both direct and indirect pathway medium spiny neurons. However, excess activation of the direct pathway by a dopamine D1 receptor agonist SKF82958 canceled antipsychotic-like effects of a dopamine D2 receptor antagonist haloperidol in methamphetamine (METH)-induced hyperactivity in rats. Thus, balanced activation of these pathways may be critical for PDE10A inhibitors. Current antipsychotics and the novel PDE10A inhibitor TAK-063, but not the selective PDE10A inhibitor MP-10, produced dose-dependent antipsychotic-like effects in METH-induced hyperactivity and prepulse inhibition in rodents. TAK-063 and MP-10 activated the indirect pathway to a similar extent; however, MP-10 caused greater activation of the direct pathway than did TAK-063. Interestingly, the off-rate of TAK-063 from PDE10A in rat brain sections was faster than that of MP-10, and a slower off-rate PDE10A inhibitor with TAK-063-like chemical structure showed an MP-10-like pharmacological profile. In general, faster off-rate enzyme inhibitors are more sensitive than slower off-rate inhibitors to binding inhibition by enzyme substrates. As expected, TAK-063 was more sensitive than MP-10 to binding inhibition by cyclic nucleotides. Moreover, an immunohistochemistry study suggested that cyclic adenosine monophosphate levels in the direct pathway were higher than those in the indirect pathway. These data can explain why TAK-063 showed partial activation of the direct pathway compared with MP-10. The findings presented here suggest that TAK-063's antipsychotic-like efficacy may be attributable to its unique pharmacological properties, resulting in balanced activation of the direct and indirect striatal pathways.

Inhibition of autophagy exerts anti-colon cancer effects via apoptosis induced by p53 activation and ER stress.

BACKGROUND: Although some molecularly targeted drugs for colorectal cancer are used clinically and contribute to a better prognosis, the current median survival of advanced colorectal cancer patients is not sufficient. Autophagy, a basic cell survival mechanism mediated by recycling of cellular amino acids, plays an important role in cancer. Recently, autophagy has been highlighted as a promising new molecular target. The unfolded protein response (UPR) reportedly act in complementary fashion with autophagy in intestinal homeostasis. However, the roles of UPR in colon cancer under autophagic inhibition remain to be elucidated. We aim to clarify the inhibitory effect of autophagy on colon cancer. METHODS: We crossed K19 (CreERT) and Atg5 (flox/flox) mice to generate Atg5 (flox/flox)/K19 (CreERT) mice. Atg5 (flox/flox)/K19 (CreERT) mice were first treated with azoxymethane/dextran sodium sulfate and then injected with tamoxifen to inhibit autophagy in CK19-positive epithelial cells. To examine the anti-cancer mechanisms of autophagic inhibition, we used colon cancer cell lines harboring different p53 gene statuses, as well as small interfering RNAs (siRNAs) targeting Atg5 and immunoglobulin heavy-chain binding protein (BiP), a chaperone to aid folding of unfolded proteins. RESULTS: Colon tumors in Atg5 (flox/flox)/K19 (CreERT) mice showed loss of autophagic activity and decreased tumor size (the total tumor diameter was 28.1 mm in the control and 20.7 mm in Atg5 (flox/flox)/K19 (CreERT) mice, p = 0.036). We found that p53 and UPR/endoplasmic reticulum (ER) stress-related proteins, such as cleaved caspase 3, and CAAT/enhancer-binding protein homologous protein, are up-regulated in colon tumors of Atg5 (flox/flox)/K19 (CreERT) mice. Although Atg5 and BiP silencing, respectively, increased apoptosis in p53 wild type cells, Atg5 silencing alone did not show the same effect on apoptosis in p53 mutant cells. However, co-transfection of Atg5 and BiP siRNAs led to increased apoptosis in p53 mutant cells. CONCLUSIONS: Blocking autophagy has potential in the treatment of colon cancer by inducing apoptosis via p53 and ER stress, and suppressing the UPR pathway is a valid strategy to overcome resistance to autophagic inhibition.

Combining fluorescence and bioluminescence microscopy.

Bioluminescence microscopy has revealed that gene expression in individual cells can respond differently to the same stimulus. To understand this phenomenon, it is important to sequentially observe the series of events from cellular signal transduction to gene expression regulated by specific transcription factors derived from signaling cascades in individual cells. However, these processes have been separately analyzed with fluorescence and bioluminescence microscopy. Furthermore, in culture medium, the background fluorescence of luciferin-a substrate of luciferase in promoter assays of gene expression in cultured cells-confounds the simultaneous observation of fluorescence and bioluminescence. Therefore, we optimized conditions for optical filter sets based on spectral properties and the luciferin concentration based on cell permeability for fluorescence observation combined with bioluminescence microscopy. An excitation and emission filter set (492-506 nm and 524-578 nm) was suitable for green fluorescent protein and yellow fluorescent protein imaging of cells, and >100 µM luciferin was acceptable in culture medium based on kinetic constants and the estimated intracellular concentration. Using these parameters, we present an example of sequential fluorescence and bioluminescence microscopic observation of signal transduction (translocation of protein kinase C alpha from the cytoplasm to the plasma membrane) coupled with activation of gene expression by nuclear factor of kappa light polypeptide B in individual cells and show that the gene expression response is not completely concordant with upstream signaling following stimulation with phorbol-12-myristate-13-acetate. Our technique is a powerful imaging tool for analysis of heterogeneous gene expression together with upstream signaling in live single cells.

Impact of fecal occult blood on obscure gastrointestinal bleeding: observational study.

AIM: To elucidate the association between small bowel diseases (SBDs) and positive fecal occult blood test (FOBT) in patients with obscure gastrointestinal bleeding (OGIB). METHODS: Between February 2008 and August 2013, 202 patients with OGIB who performed both capsule endoscopy (CE) and FOBT were enrolled (mean age; 63.6 ± 14.0 years, 118 males, 96 previous overt bleeding, 106 with occult bleeding). All patients underwent immunochemical FOBTs twice prior to CE. Three experienced endoscopists independently reviewed CE videos. All reviews and consensus meeting were conducted without any information on FOBT results. The prevalence of SBDs was compared between patients with positive and negative FOBT. RESULTS: CE revealed SBDs in 72 patients (36%). FOBT was positive in 100 patients (50%) and negative in 102 (50%). The prevalence of SBDs was significantly higher in patients with positive FOBT than those with negative FOBT (46% vs 25%, P = 0.002). In particular, among patients with occult OGIB, the prevalence of SBDs was higher in positive FOBT group than negative FOBT group (45% vs 18%, P = 0.002). On the other hand, among patients with previous overt OGIB, there was no significant difference in the prevalence of SBDs between positive and negative FOBT group (47% vs 33%, P = 0.18). In disease specific analysis among patients with occult OGIB, the prevalence of ulcer and tumor were higher in positive FOBT group than negative FOBT group. In multivariate analysis, only positive FOBT was a predictive factors of SBDs in patients with OGIB (OR = 2.5, 95%CI: 1.4-4.6, P = 0.003). Furthermore, the trend was evident among patients with occult OGIB who underwent FOBT on the same day or a day before CE. The prevalence of SBDs in positive vs negative FOBT group were 54% vs 13% in patients with occult OGIB who underwent FOBT on the same day or the day before CE (P = 0.001), while there was no significant difference between positive and negative FOBT group in those who underwent FOBT two or more days before CE (43% vs 25%, P = 0.20). CONCLUSION: The present study suggests that positive FOBT may be useful for predicting SBDs in patients with occult OGIB. Positive FOBT indicates higher likelihood of ulcers or tumors in patients with occult OGIB. Undergoing CE within a day after FOBT achieved a higher diagnostic yield for patients with occult OGIB.

Characterization of a new small bowel adenocarcinoma cell line and screening of anti-cancer drug against small bowel adenocarcinoma.

Small bowel adenocarcinoma (SBA) is a rare, aggressive malignancy with a poor prognosis, and the mechanisms of carcinogenesis in SBA remain unclear. Our aims were to investigate the molecular mechanisms underlying SBA and to identify treatments by establishing and characterizing an SBA cell line and performing anti-cancer drug screening. SIAC1 cells, established from jejunal SBA, showed epithelial characteristics and formed organoids in 3D culture. SIAC1 cells had a heterozygous ß-catenin deletion mutation, resulting in a stable ß-catenin protein with enhanced Wnt/ß-catenin activity. SIAC1 cells lacked MLH1 and MSH6 expression, and target genes such as TGFBR2 and ACVR2 showed frameshift mutations. Among 10 clinical SBA samples, 2 (20%) had interstitial deletions in ß-catenin, expression of mismatch repair protein was aberrant in 4 (40%), and heterozygous frameshift mutations of three target genes were found in all 10 samples. On screening assay using 140 compounds, eribulin significantly inhibited SIAC1 cell growth both in vitro and in vivo by inhibition of the Wnt/ß-catenin pathway via enhanced degradation of ß-catenin. In conclusion, we established an SBA cell line with molecular characteristics similar to those of clinical SBA samples, including ß-catenin deletion and mismatch repair protein deficiency, that will be useful for SBA research. Eribulin might be a candidate for SBA treatment due to its inhibitory effect on Wnt/ß-catenin signaling.

Light-induced rapid Ca²âº response and MAPK phosphorylation in the cells heterologously expressing human OPN5.

Molecular imaging is a powerful tool for investigating intracellular signalling, but it is difficult to acquire conventional fluorescence imaging from photoreceptive cells. Here we demonstrated that human opsin5 (OPN5) photoreceptor mediates light-induced Ca(2+) response in human embryonic kidney (HEK293) and mouse neuroblastoma (Neuro2a) cell lines using a luminescence imaging system with a fluorescent indicator and a newly synthesized bioluminescent indicator. Weak light fluorescence and bioluminescence imaging revealed rapid and transient light-stimulated Ca(2+) release from thapsigargin-sensitive Ca(2+) stores, whereas long-lasting Ca(2+) elevation was observed using a conventional fluorescence imaging system. Bioluminescence imaging also demonstrated that OPN5 activation in HEK293 cells induced a decrease in pertussis toxin-sensitive cAMP, confirming previous reports. In addition, ultraviolet radiation induced the phosphorylation of mitogen-activated protein kinases when OPN5 was stimulated in Neuro2a cells. These findings suggest that the combination of these imaging approaches may provide a new means to investigate the physiological characteristics of photoreceptors.

Transfection efficiency of normal and cancer cell lines and monitoring of promoter activity by single-cell bioluminescence imaging.

The bioluminescence system (luciferase reporter assay system) is widely used to study gene expression, signal transduction and other cellular activities. Although transfection of reporter plasmid DNA to mammalian cell lines is an indispensable experimental step, the transfection efficiency of DNA varies among cell lines, and several cell lines are not suitable for this type of assay because of the low transfection efficiency. In this study, we confirm the transfection efficiency of reporter DNA to several cancer and normal cell lines after transient transfection by single-cell imaging. Luminescence images could be obtained from living single cells after transient transfection, and the calculated transfection efficiency of this method was similar to that of the conventional reporter assay using a luminometer. We attempted to measure the activity of the Bip promoter under endoplasmic reticulum stress conditions using both high and low transfection efficiency cells for plasmid DNA at the single-cell level, and observed activation of this promoter even in cells with the lowest transfection efficiency. These results show that bioluminescence imaging of single cells is a powerful tool for the analysis of gene expression based on a reporter assay using limited samples such as clinical specimens or cells from primary culture, and could provide additional information compared with the conventional assay.

Feasibility of spiral enteroscopy in Japanese patients: study in two tertiary hospitals.

BACKGROUND AND AIM: Despite recent advances in enteroscopy, such as balloon enteroscopy, accessing the small intestine remains challenging. Spiral enteroscopy is a novel technique in which an endoscope is fitted with a rotating overtube that has a soft spiral fin at the tip. Whereas spiral enteroscopy is beginning to be carried out in Western countries, it is not common in many Asian countries. The aim of the present study was to evaluate the efficacy and safety of spiral enteroscopy in Japanese patients. METHODS: We prospectively conducted spiral enteroscopy in patients with suspected or known small bowel disease. All procedures were carried out using a spiral overtube. The main outcome measurements of the study were diagnosis rate, endoscopic intervention rate, and complication rate. RESULTS: Thirty-two patients underwent spiral enteroscopy. Spiral enteroscopy diagnosed 16 patients (50%) with small intestinal lesions, including six malignant lymphomas (19%), three erosions or ulcers (9%), three polyps (9%), two angioectasias (6%), one carcinoma (3%), and one submucosal tumor (3%). Additionally, four patients underwent endoscopic interventions (13%). Mallory-Weiss syndrome occurred in one patient (3%). No perforation occurred in any patient (0%). CONCLUSIONS: Our initial experience of spiral enteroscopy suggests that it can be introduced safely, but it is relatively invasive and technically demanding. More experience is needed to conduct spiral enteroscopy easily and safely.

Successful treatment of early-stage jejunum adenocarcinoma by endoscopic mucosal resection using double-balloon endoscopy: a case report.

Small bowel adenocarcinoma (SBA) has generally been considered to have a poor prognosis because of nonspecific presentations and difficulties in detection of the disease. The advent of capsule endoscopy (CE) and double-balloon endoscopy (DBE) makes it possible to access to the small intestine for endoscopic interventions. We describe a successful case of early jejunum adenocarcinoma completely resected by endoscopic mucosal resection (EMR) using double-balloon endoscopy (DBE). Early diagnosis and EMR using new technologies such as CE and DBE may improve the recognition of this disease that, at present, has a poor prognosis.

Single-agent gemcitabine in elderly patients with unresectable biliary tract cancer.

BACKGROUND/AIMS: This study examined the effect of systemic chemotherapy with gemcitabine (GEM) on survival in elderly patients (aged > or = 70 years) with unresectable biliary tract cancer as compared with best supportive care (BSC). METHODOLOGY: We conducted a retrospective study of consecutive patients with unresectable biliary tract cancer administered GEM (800-1,000 mg/m2) on days 1, 8 and 15 every 4 weeks as a first-line treatment. Eligibility included age 70 years and over, and bile duct carcinoma or gallbladder cancer. RESULTS: Twenty-eight patients were enrolled: 13 (46.4%) received chemotherapy with GEM and 15 (53.6%) received BSC. No cases of complete or partial response were observed. Stable and progressive disease was observed in 9 (69.2%) and 2 patients (15.4%), respectively. Disease control rate was 69.2%. The median overall survival time of patients treated with GEM and BSC was 9.1 and 2.9 months, and the 1-year survival rates were 15.4% and 6.7%, respectively. Grade 3/4 neutropenia occurred in three (23.1%), leukopenia in two (15.4%) and anemia in one patient (7.7%). Grade 3 non-hematologic toxicities were constipation (7.7%) and fatigue (7.7%). CONCLUSIONS: Chemotherapy with single-agent GEM is a safe and well tolerated regimen for elderly patients with unresectable biliary tract cancer.

Single-agent gemcitabine in elderly patients with unresectable biliary tract cancer.

BACKGROUND/AIMS: This study examines the effect of systemic chemotherapy with gemcitabine (GEM) on survival in elderly patients (aged > or =70 years) with unresectable biliary tract cancer and compares it with best supportive care (BSC). METHODOLOGY: We conducted a retrospective study of consecutive patients aged > or =70 years, with unresectable biliary tract cancer who were administered GEM (800-1000 mg/m2) on days 1, 8, and 15 every 4 weeks as a first-line treatment. RESULTS: Twenty-eight patients were enrolled: 13 (46.4%) received chemotherapy with GEM and 15 (53.6%) received BSC. No cases of complete or partial response were observed. Stable disease was observed in 9 patients (69.2%) and progressive disease in 2 patients (15.4%). Disease control rate was 69.2%. The median overall survival time of patients treated with GEM and BSC was 9.1 and 2.9 months, and the 1-year survival rates were 15.4% and 6.7% respectively. Grade 3/4 neutropenia occurred in three patients (23.1%), leukopenia in two patients (15.4%) and anemia in one patient (7.7%). Grade 3 non-hematologic toxicities were constipation (7.7%) and fatigue (7.7%). CONCLUSIONS: Chemotherapy with single-agent GEM is a safe and well tolerated regimen for elderly patients with unresectable biliary tract cancer.