Risk Factors for Infusion Reactions in Patients with Breast Cancer Administered Trastuzumab Therapy.

Trastuzumab is a humanized monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2) that is indicated for the treatment of HER2-positive breast cancer. The administration of biologics, such as trastuzumab, frequently causes infusion reactions (IRs) with fever and chills. This study aimed to clarify the risk factors for IRs in trastuzumab therapy. Between March 2013 and July 2022, 227 patients with breast cancer who started trastuzumab therapy were included in this study. The severity of IRs was graded according to the Common Terminology Criteria for Adverse Events, Version 5.0. The incidence of IRs in trastuzumab therapy was 27.3% (62/227). Dexamethasone administration was significantly different between the IR and non-IR groups in patients receiving trastuzumab therapy (univariate analysis, p < 0.001; multivariate analysis, p = 0.0002). Without dexamethasone, the severity of IRs in the pertuzumab combination group (Grade 1, 8/65; Grade 2, 23/65) was significantly higher than that in the non-pertuzumab group (Grade 1, 9/37; Grade 2, 3/37; p < 0.05). Our findings suggest that the risk of IRs is significantly higher in patients not premedicated with dexamethasone in trastuzumab therapy and that the concomitant use of pertuzumab without dexamethasone increases the severity of IRs caused by trastuzumab.

Optimal Sampling Strategy and Threshold of Serum Vancomycin Concentration in Elderly Japanese Patients Undergoing High-Flux Hemodialysis.

BACKGROUND: The optimal sampling points and thresholds for initial serum vancomycin (VCM) concentrations have not been determined in hemodialysis (HD) patients. To clarify this, multiple blood tests were performed, and the correlations between VCM concentrations at several sampling points and the area under the concentration-time curve for 24 hours (AUC24h) were analyzed. METHODS: A single-center, prospective observational study was conducted. Patients with end-stage renal failure who received VCM treatment while undergoing chronic maintenance HD were enrolled in this study. HD was performed using a high-flux membrane as the dialyzer. After VCM administration, 7 points were sampled between the first and second HD. The AUC24h after the end of the first HD (AUC0-24) and that before the end of the second HD (AUC24-48) were calculated using the linear trapezoidal method. Correlation analysis and simple regression analysis between AUC24h and serum concentrations were performed at each sampling point. RESULTS: Nine patients were evaluated. Strong correlations were found between AUC24-48 and serum concentrations at 24 hours after the initiation of VCM treatment following the first HD (C24h, R = 0.983 and P < 0.001), between AUC0-24 and C24h (R = 0.967 and P < 0.001), and between AUC24-48 and serum concentration just before the second HD (Cpre(HD2), R = 0.965 and P < 0.001). Regression equations with high coefficients of determination (R2 > 0.9) were obtained, and a C24h of ≥18.0 mg/L and a Cpre(HD2) of ≥16.5 mg/L were required to achieve an AUC24-48 value of ≥400 mg·h/L. In addition, a C24h of ≤23.3 mg/L was estimated to satisfy the AUC0-24 range of ≤600 mg·h/L. CONCLUSIONS: C24h and Cpre(HD2) are optimal sampling points for predicting VCM-AUC24h in HD patients.

In Vitro Evidence of Potential Interactions between CYP2C8 and Candesartan Acyl-ß-D-glucuronide in the Liver.

Growing evidence suggests that certain glucuronides function as potent inhibitors of CYP2C8. We previously reported the possibility of drug-drug interactions between candesartan cilexetil and paclitaxel. In this study, we evaluated the effects of candesartan N2-glucuronide and candesartan acyl-ß-D-glucuronide on pathways associated with the elimination of paclitaxel, including those involving organic anion-transporting polypeptide (OATP) 1B1, OATP1B3, CYP2C8, and CYP3A4. UDP-glucuronosyltransferase (UGT) 1A10 and UGT2B7 were found to increase candesartan N2-glucuronide and candesartan acyl-ß-D-glucuronide formation in a candesartan concentration-dependent manner. Additionally, the uptake of candesartan N2-glucuronide and candesartan acyl-ß-D-glucuronide by cells stably expressing OATPs is a saturable process with K m of 5.11 and 12.1 µM for OATP1B1 and 28.8 and 15.7 µM for OATP1B3, respectively; both glucuronides exhibit moderate inhibition of OATP1B1/1B3. Moreover, the hydroxylation of paclitaxel was evaluated using recombinant CYP3A4 and CYP3A5. Results show that candesartan, candesartan N2-glucuronide, and candesartan acyl-ß-D-glucuronide inhibit the CYP2C8-mediated metabolism of paclitaxel, with candesartan acyl-ß-D-glucuronide exhibiting the strongest inhibition (IC50 is 18.9 µM for candesartan acyl-ß-D-glucuronide, 150 µM for candesartan, and 166 µM for candesartan N2-glucuronide). However, time-dependent inhibition of CYP2C8 by candesartan acyl-ß-D-glucuronide was not observed. Conversely, the IC50 values of all the compounds are comparable for CYP3A4. Taken together, these data suggest that candesartan acyl-ß-D-glucuronide is actively transported by OATPs into hepatocytes, and drug-drug interactions may occur with coadministration of candesartan and CYP2C8 substrates, including paclitaxel, as a result of the inhibition of CYP2C8 function. SIGNIFICANCE STATEMENT: This study demonstrates that the acyl glucuronidation of candesartan to form candesartan acyl-ß-D-glucuronide enhances CYP2C8 inhibition while exerting minimal effects on CYP3A4, organic anion-transporting polypeptide (OATP) 1B1, and OATP1B3. Thus, candesartan acyl-ß-D-glucuronide might represent a potential mediator of drug-drug interactions between candesartan and CYP2C8 substrates, such as paclitaxel, in clinical settings. This work adds to the growing knowledge regarding the inhibitory effects of glucuronides on CYP2C8.

Factors Associated with Dose Modification of Lenalidomide Plus Dexamethasone Therapy in Multiple Myeloma.

Long-term combination treatment with lenalidomide and low-dose dexamethasone is important to achieve a curative effect in patients with multiple myeloma (MM). In this study, the plasma concentration of lenalidomide was measured at 3 h after oral administration, when the drug is in the elimination phase and can be easily measured in outpatients, to identify factors that may lead to the discontinuation of this combination therapy. Patients were assigned to continuation or discontinuation of therapy groups, and the baseline characteristics of patients, lenalidomide concentration, and concentration/dose (C/D) ratios reflecting oral clearance were compared between the two groups. The efficacy and severity of adverse events were also compared. The results showed that patients who discontinued or modified treatment had low plasma concentrations of lenalidomide and C/D ratios, indicating high oral clearance of lenalidomide. The estimated creatinine clearance rate was negatively correlated with the C/D ratio. The plasma concentrations of lenalidomide were independent from kidney function and differed significantly among patients. Taken together, the results indicate that low plasma concentrations of lenalidomide and low C/D ratios may lead to discontinuation of combination therapy in patients with MM. This suggests that early measurement of lenalidomide plasma continuation would help to prevent discontinuation of therapy or a delay in modifying the dose of lenalidomide.

A case of idiosyncratic liver injury after oxaliplatin-induced thrombocytopenia.

WHAT IS KNOWN AND OBJECTIVE: Oxaliplatin is a platinum drug used for treating digestive cancers that can lead to drug-induced thrombocytopenia (DITP). We report a case of oxaliplatin-induced anaphylaxis and DITP, complicated by idiosyncratic drug-induced liver injury (IDILI). CASE SUMMARY: A 46-year-old woman with rectal cancer developed anaphylaxis shortly after oxaliplatin administration (post-operative CapeOX), presenting with low platelet count (0.2 × 104 /µL) and elevated aspartate aminotransferase (1091 IU/L) and alanine aminotransferase (1010 IU/L) by day 10. Following 50 mg/d prednisolone administration from day 9, she left the hospital on day 36 after recovering. WHAT IS NEW AND CONCLUSION: This is the first case report of oxaliplatin-induced IDILI and its effective treatment with steroids.

Substrate-dependent effects of molecular-targeted anticancer agents on activity of organic anion transporting polypeptide 1B1.

1. Organic anion-transporting polypeptide 1B1 (OATP1B1) plays an important role in the hepatic uptake of a broad range of substrate drugs. In vitro experiments show that molecular-targeted agents do not always have similar effects on OATP1B1 activity. 2. The purpose of this study was to clarify whether the effects of molecular-targeted agents on OATP1B1 are substrate-dependent. We used OATP1B1-transfected cells to compare the effects of molecular-targeted agents on OATP1B1-mediated uptake of fluorescein (FL), 2',7'-dichlorofluorescein (DCF), atorvastatin, SN-38 and valsartan. 3. Cabozantinib, cediranib, neratinib, pazopanib, regorafenib, sorafenib and tivantinib did not affect or only slightly affected OATP1B1-mediated substrate uptake. Nilotinib and lenvatinib moderately and strongly inhibited OATP1B1-mediated substrate uptake, respectively. In contrast, afatinib stimulated OATP1B1-mediated uptake of FL and SN-38, ceritinib stimulated that of valsartan, and nintedanib stimulated that of FL and valsartan. In addition, the effects of afatinib, ceritinib and nintedanib on OATP1B1 activity differed markedly depending on the type of substrate. Afatinib, ceritinib and nintedanib had a substrate-dependent effect on OATP1B1 activity. 4. We conclude that the evaluation of OATP1B1 activity using only a single probe substrate for some molecular-targeted agents may lead to a faulty understanding of their mechanisms of drug interactions.

Concomitant administration of candesartan cilexetil in patients on paclitaxel and carboplatin combination therapy increases risk of severe neutropenia
.

OBJECTIVE: Angiotensin receptor blockers (ARBs) are often used in patients on paclitaxel (PTX) and carboplatin combination (TC) therapy to treat hypertension caused by the co-administration of bevacizumab. The aim of this retrospective study was to analyze the association between co-administration of ARBs and the development of severe neutropenia in patients on TC therapy. MATERIALS AND METHODS: In this study, 211 concomitant medications were prescribed to 173 patients on TC therapy. 24 of those patients received ARBs. The incidences of neutropenia among those on various ARBs were compared. RESULTS: Patients on candesartan cilexetil had the highest incidence of neutropenia compared to those on other concomitant medications, including other ARBs. Of 173 patients, 6 received candesartan cilexetil during the first cycle of TC therapy, and all 6 of them developed severe neutropenia. We noted that prior to TC therapy, there were no significant differences in age, serum albumin levels, neutrophil counts, liver injury marker, and renal function between the patients on candesartan cilexetil and those on other ARBs. CONCLUSION: Our data suggest that a drug-drug interaction between candesartan cilexetil and TC therapy is probable. Unlike with other ARBs, the possible increased risk for development of severe neutropenia should be taken into account when prescribing candesartan cilexetil in combination with TC therapy.
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Inhibitory Effects of Juices Prepared from Individual Vegetables on CYP3A4 Activity in Recombinant CYP3A4 and LS180 Cells.

Human intestinal absorption and drug metabolism vary to a large extent among individuals. For example, CYP3A4 activity has large individual variation that cannot be attributed to only genetic differences. Various flavonoids in vegetables, such as kaempferol and quercetin, possess inhibitory effects, and some vegetable and fruit juices have also been found to inhibit CYP3A4 activity. Therefore, differences in daily intake of flavonoid-containing vegetables may induce individual variation in intestinal bioavailability. To identify a vegetable that strongly inhibits CYP3A4, we investigated the effects of juices, prepared from individual vegetables, on CYP3A4 activity using recombinant CYP3A4 and LS180 cells in this study. Nine vegetable juices (cabbage, Japanese radish, onion, tomato, eggplant, carrot, Chinese cabbage, green pepper, and lettuce), were prepared and recombinant CYP3A4 and LS180 cells were used for evaluation of CYP3A4 activity. Metabolism to 6ß-hydroxytestosterone by recombinant CYP3A4 was strongly inhibited by cabbage, onion, and green pepper juices, and cabbage and green pepper juices significantly inhibited CYP3A4 activity in a preincubation time-dependent manner. In addition, CYP3A4 activity in LS180 cells was significantly inhibited by cabbage and onion juices. In conclusion, this study showed that juices prepared from some individual vegetables could significantly inhibit CYP3A4 activity. Therefore, variation in the daily intake of vegetables such as cabbage and onion may be one of the factors responsible for individual differences in intestinal bioavailability.

Previous Dosage of Allopurinol Is a Strong Determinant of Febuxostat Efficacy.

Febuxostat has currently played pivotal role in the treatment of hyperuricemia, but there is little comprehensive information for the determinants of individual difference in efficacy of febuxostat. Therefore, the present study, a retrospective investigation, was carried out to analyze the effects of patient characteristics on the efficacy of febuxostat. A total of 225 patients who were continuously prescribed the same dose of febuxostat for 8-12 weeks from the initial therapy were enrolled in the present study. The data, including patient information and laboratory data, were collected from electronic medical records. Serum urate lowering effects of febuxostat were evaluated by calculating the change in serum urate level at baseline and at 8-12 weeks after starting febuxostat. The multiple regression analysis showed the change in serum urate level was significantly lower in male patients and in those with a lower baseline serum urate level, higher previous dose of allopurinol, lower dose of febuxostat and lower body surface area-unadjusted estimated glomerular filtration rate. Concomitantly administered drugs did not show a significantly influence on the efficacy of febuxostat. In conclusion, it should be noted that the serum urate lowering efficacy of febuxostat may decrease in patients with a higher previous dose of allopurinol, renal impairment or male patients. The basic findings of the present study are believed to contribute to the proper use of febuxostat.

Inhibitory Effects of Vegetable Juices on CYP3A4 Activity in Recombinant CYP3A4 and LS180 Cells.

It is thought that eating habits induces individual variation in intestinal absorption and metabolism of drugs. The objective of this research was to clarify the influence of vegetables juices on CYP3A4 activity, which is an important enzyme in intestine. Five vegetables juices (VJ-o, Kagome Original(®); VJ-g, Kagome 30 kinds of vegetables and fruits(®); VJ-p, Kagome Purple vegetables(®); VJ-r, Kagome Sweet Tomato(®); and VJ-y, Kagome Fruity Salada(®); KAGOME Co., Ltd., Aichi, Japan) were centrifuged (1630×g, 10 min) and filtered using filter paper and 0.45-µm membrane filters. In this study, recombinant CYP3A4 and LS180 cells were used for the evaluation of CYP3A4 activity. The metabolisms to 6ß-hydroxytestosterone by recombinant CYP3A4 were significantly inhibited by VJ-o, VJ-g, and VJ-y in a preincubation time-dependent manner, and CYP3A4 activity in LS180 cells were significantly inhibited by VJ-o and VJ-y. These results show that the difference in ingestion volume of vegetable juices and vegetables might partially induce individual difference in intestinal drug metabolism.

Genetic polymorphisms in SLC23A2 as predictive biomarkers of severe acute toxicities after treatment with a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma.

OBJECTIVE: Definitive chemoradiotherapy (CRT) with 5-fluorouracil (5-FU) and cisplatin (CDDP) is one of the standard therapies for esophageal squamous cell carcinoma (ESCC); however, inter-individual variations in clinical outcomes have yet to be investigated. In the present study, single nucleotide polymorphisms (SNPs) in SLC23A2 gene were retrospectively evaluated in 49 Japanese patients with ESCC who were treated with a definitive 5-FU/CDDP-based CRT, and the predictive values for the clinical response, severe acute toxicities, and long-term survival were assessed. METHODS: A course consisted of the continuous infusion of 5-FU at 400 mg/m(2)/day for days 1-5 and 8-12, the infusion of CDDP at 40 mg/m(2)/day on days 1 and 8, and radiation at 2 Gy/day on days 1 to 5, 8 to 12, and 15 to 19, with a second course being repeated after a 2-week interval. The SLC23A2 SNPs rs2681116, rs13037458, rs1715364, rs4987219, and rs1110277 were evaluated. RESULTS: The rs2681116 and rs13037458 had a tendency to predict the clinical response (p=0.144 and 0.085, respectively) and long-term survival (p=0.142 and 0.056, respectively). The rs4987219 and rs1110277 correlated with severe acute leukopenia (p=0.025) and stomatitis (p=0.019), respectively. CONCLUSIONS: Further investigations with a larger number of patients or an in vitro study are needed to confirm the predictive values of genetic polymorphisms in SLC23A2.

Serum lactate dehydrogenase levels as a predictive marker of oxaliplatin-induced hypersensitivity reactions in Japanese patients with advanced colorectal cancer.

OBJECTIVE: Clinical laboratory test data obtained prior to treatments were previously analyzed from the standpoint of susceptibility to hypersensitivity reactions in patients treated with the platimun anticancer agent, oxaliplatin (L-OHP). In the present study, the time course from the first to last cycle of the treatment was additionally analyzed to determine a better predictor of these reactions. METHODS: A total of 20 laboratory test data were obtained from 108 Japanese patients with advanced colorectal cancer who were treated with the L-OHP-containing regimens, FOLFOX4 and/or mFOLFOX6. The averages and variation coefficients (CV%) of the data until the last cycle of the treatment were compared between patients with hypersensitivity reactions and those without. RESULTS: The average serum lactate dehydrogenase (LDH) level was lower in patients with grade 1/2 reactions (P=0.016), whereas its CV% value was higher in patients with grade 3/4 reactions (P=0.005) than in those without reactions. An increase in serum LDH levels was observed in some patients with grade 3/4 reactions as the cycle number increased, and thereafter hypersensitivity reactions occurred. This phenomenon was not always observed, but was never detected in patients with grade 1/2 reactions. CONCLUSIONS: Serum LDH levels may be a predictive marker of hypersensitivity reactions in patients treated with L-OHP. Further extensive examinations with a larger number of patients are needed to establish a patient management strategy.

TNF-α -857C>T genotype is predictive of clinical response after treatment with definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma.

BACKGROUND: Genotypes of tumor necrosis factor alpha (TNF-α) and its surface receptors, TNFRSF1A and TNFRSF1B, have been examined in terms of the progression, metastasis, clinical efficacy, and prognosis of various cancers; however, little is known about their effects on clinical outcome in patients with esophageal squamous cell carcinoma (ESCC). In this study, TNF-α and TNFRSF1A genotypes were retrospectively evaluated in terms of predicting clinical response, long-term survival, and severe acute toxicities in 46 male Japanese ESCC patients treated with definitive 5-fluorouracil (5-FU)/cisplatin (CDDP)-based chemoradiotherapy (CRT). METHODS: A course consisted of the continuous infusion of 5-FU at 400 mg/m(2)/day for days 1-5 and 8-12, the infusion of CDDP at 40 mg/m(2)/day on days 1 and 8, and radiation at 2 Gy/day on days 1-5, 8-12, and 15-19, with a second course being repeated after a 2-week interval. The TNF-α -1031T>C (rs1799964), -863C>A (rs1800630), -857C>T (rs1799724), -308G>A (rs1800629), -238G>A (rs361525), TNFRSF1A -609G>T (rs4149570), and 36A>G (rs767455) genotypes were evaluated. RESULTS: The TNF-α -857C>T genotype was found to be predictive of clinical response, i.e., complete response or not (P = 0.010, Fisher's exact test), but had no effect on long-term survival (CC(-857) vs. CT(-857) + TT(-857), P = 0.072, Fisher's exact test, P = 0.070, Log-rank test). CONCLUSIONS: The TNF-α -857C>T genotype was found to be predictive of clinical response and was more likely to predict long-term survival in Japanese ESCC patients receiving definitive 5-FU/CDDP-based CRT. Further clinical investigations with a larger number of patients or experiments in vitro should be performed to assess the predictive value of this genotype following CRT.

Incidence and risk factors of infusion reactions in patients with breast cancer administered trastuzumab plus pertuzumab-based regimen.

PURPOSE: Pertuzumab (Per) is a humanized monoclonal antibody used in combination with trastuzumab (Tra) in the treatment of human epidermal growth factor receptor-2 (HER2)-positive breast cancer. The administration of biologics, such as Tra and Per, frequently causes infusion reactions (IRs) with fever and chills. This study aimed to clarify the characteristics of and risk factors for IRs in Tra + Per combination therapy. METHODS: Between March 2013 and December 2019, 64 patients with breast cancer who started Tra + Per combination therapy were included in the study. The severity of IRs was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. RESULTS: The incidence of IRs in the Tra + Per combination therapy was 48.4% (31/64). The severity of IRs in the Tra + Per combination therapy was Grade 1 (9 patients) and Grade 2 (22 patients). Lymphocyte counts were significantly different between the IR and non-IR groups in patients receiving Tra + Per combination therapy (univariate analysis, p = 0.006; multivariate analysis, p = 0.050). ROC curve analysis found the cutoff value of lymphocyte counts were 1.60 (× 103/µL). The incidence of IRs in the lymphocyte counts ≥ 1.60 group was significantly higher than that in the lymphocyte counts < 1.60 group (p < 0.001). CONCLUSION: Our study indicates that the severity of IRs in most patients is moderate or less and the risk of IRs is higher in patients with higher lymphocyte counts (≥ 1.60 × 103/µL).

VEGF -634C/G genotype is predictive of long-term survival after treatment with a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma.

BACKGROUND: Reports have been accumulating that genetic properties are predictive of clinical response after and/or toxicity during cancer chemotherapy, but little information is available concerning effects on long-term survival. In this study, 49 Japanese patients with esophageal squamous cell carcinoma (ESCC) were followed up for 5 years after treatment with a definitive 5-fluorouracil (5-FU)/cisplatin (CDDP)-based chemoradiotherapy (CRT), and the effects of genotypes of vascular endothelial growth factor (VEGF) were retrospectively revaluated in terms of prediction of long-term survival. METHODS: A course consisted of the continuous infusion of 5-FU at 400 mg/m(2)/day for days 1-5 and 8-12, the infusion of CDDP at 40 mg/m(2)/day on days 1 and 8, and radiation at 2 Gy/day on days 1 to 5, 8 to 12, and 15 to 19, with a second course repeated after a 2-week interval. The VEGF genotypes -1498T/C, -1154G/A, -634C/G, -7C/T, 936C/T, and 1612G/A were evaluated. RESULTS: The complete response (CR) rate was 46.9% (23/49). The 5-year survival rate was 42.9 % (21/49). There were 7 patients with a CR, but survival of less than 5 years. They died from myocardial infarction (N=1), sudden cardiac death after suffering from heart failure (N=1), acute myeloid leukemia that developed from myelodysplastic syndromes (N=1), factors not specified (N=2), oropharynx cancer (N=1), and tongue cancer (N=1). VEGF -634C/G had no effect on clinical response, but long-term survival depended on the genotype (p=0.033, Fisher's; p=0.038, Cochran-Armitage; p=0.079, Log-rank). The genotype frequency of 7 patients with a CR, but survival of less than 5 years was different from that for the other 42 patients (p=0.032, Fisher's). None of the other 5 genotypes evaluated affected either clinical response or survival. CONCLUSIONS: VEGF -634C/G is possibly predictive of long-term survival after treatment with a definitive 5-FU/CDDP-based CRT. Further clinical studies with a larger number of cases are needed to clarify the effects of this genotype.

THRB genetic polymorphisms can predict severe myelotoxicity after definitive chemoradiotherapy in patients with esophageal squamous cell carcinoma.

OBJECTIVE: Chemotherapy-related toxicities are difficult to predict before treatment. In this study, we investigated whether thyroid hormone receptor beta (THRB) genetic polymorphisms can serve as a potential biomarker in patients with esophageal squamous cell carcinoma (ESCC). METHODS: Forty-nine Japanese patients with ESCC who received a definitive chemoradiotherapy (CRT) with 5-fluorouracil and cisplatin in conjunction with concurrent irradiation were retrospectively analyzed. Severe acute toxicities, including leukopenia, stomatitis, and cheilitis, were evaluated according to 6 single nucleotide polymorphisms (SNPs) in the gene; the intronic SNPs of rs7635707 G/T, rs6787255 A/C, rs9812034 G/T, and rs9310738 C/T and the SNPs in the 3'-untranslated region (3'-UTR) of rs844107 C/T and rs1349265 G/A. RESULTS: Distribution of the 4 intronic SNPs, but not the 2 SNPs in the 3'-UTR, showed a significant difference between patients with and without severe acute leukopenia. Stomatitis and cheilitis were not associated with any of the 6 analyzed SNPs. Frequency of haplotype of the 4 intronic SNPs reached approximately 97% with the 2 major haplotypes G-A-G-C (73.4%) and T-C-T-T (23.5%). CONCLUSIONS: THRB intronic SNPs can provide useful information on CRT-related severe myelotoxicity in patients with ESCC. Future studies will be needed to confirm these findings.

Effects of bolus injection of 5-fluorouracil on steady-state plasma concentrations of 5-fluorouracil in Japanese patients with advanced colorectal cancer.

OBJECTIVES: The irinotecan (CPT-11) + 5-fluorouracil (5-FU)/leucovorin (LV) + UFT/LV chemotherapy, in which repetitive oral administration of UFT/LV replaces the infusion of 5-FU/LV in the FOLFIRI regimen, has been proposed previously. In this study, five of 10 patients were injected with a bolus of 5-FU and the other were not injected with it in order to examine the effect of omitting it in terms of pharmacokinetics of 5-FU. METHODS: The treatment consisted of the intravenous infusions of CPT-11 at 100 mg/m(2 )and l-LV at 15 mg/m(2), and the injection of a bolus of 5-FU at 500 mg/m(2) on day 1, and the repetitive oral administration of UFT/LV (300 mg/m(2)/day as tegafur + 75 mg/day of LV) on days 1-5. A total of 13 measurements of the plasma concentrations of uracil, 5-FU and tegafur were made per patient within 48 hr after the start of chemotherapy and the value of area under the concentration-time curve (AUC(0-48)) was evaluated. The plasma concentration was also determined at 2 weeks to assess long-term exposure to 5-FU. RESULTS: The plasma concentrations of 5-FU at 24 hr after the start of treatment were 27.4 ng/mL and 9.4 ng/mL in the patients with and without the bolus injection, respectively. At 48 hr, they were 31.3 ng/mL and 10.4 ng/mL with the AUC(0-48) values of 22.16 mg h/L and 0.65 mg h/L, respectively. The 5-FU was detected in the plasma at 226 hr after the last administration of UFT/LV for the patients with the bolus injection, but not for those without. CONCLUSION: A bolus of 5-FU on day 1 provided long-term exposure to 5-FU.

Risk factors for oxaliplatin-induced hypersensitivity reactions in Japanese patients with advanced colorectal cancer.

OBJECTIVE: Previously, we suggested that oxaliplatin (L-OHP)-related grade 3/4 hypersensitivity reactions occurred immediately after the initiation, but grade 1/2 reactions did not. This study was conducted to clarify the risk factors for L-OHP-related hypersensitivity reactions. METHODS: Clinical data from 108 Japanese patients with colorectal cancer were analyzed, who were treated with L-OHP-containing regimens, FOLFOX4 and/or mFOLFOX6. The risk factors examined included demographic data, preexisting allergies, laboratory test data, treatment regimen, treatment line of therapy, pretreatment with steroids, total number of cycles and cumulative amount of L-OHP. RESULTS: The incidence of grade 1/2 and grade 3/4 hypersensitivity reactions were found at 13.0% (14/108) and 9.3% (10/108), respectively. Female (P = 0.037), preexisting allergies (P = 0.004) and lower level of lactate dehydrogenase (P = 0.003) were risk factors for grade 1/2 hypersensitivity reactions, and higher neutrophil count (P = 0.043) and lower monocyte count (P = 0.007) were for grade 3/4 reactions. Total number of cycles were larger in the patients with grade 3/4 reactions than those without reactions (P = 0.049). CONCLUSIONS: Further extensive examination with a large number of patients is needed to establish a patient management strategy.

Effect of dose-escalation of 5-fluorouracil on circadian variability of its pharmacokinetics in Japanese patients with Stage III/IVa esophageal squamous cell carcinoma.

OBJECTIVE: The effects of dose-escalation of 5-fluorouracil (5-FU) on the clinical outcome and pharmacokinetics of 5-FU were investigated in Japanese patients with Stage III/IVa esophageal squamous cell carcinoma. METHODS: Thirty-five patients with Stage III/IVa were enrolled, who were treated with a definitive 5-FU/cisplatin-based chemoradiotherapy. A course consisted of continuous infusion of 5-FU at 400 mg/m(2)/day (the standard dose group, N=27) or 500-550 mg/m(2)/day (the high dose group, N=8) for days 1-5 and 8-12, infusion of cisplatin at 40 mg/m(2)/day on days 1 and 8, and radiation at 2 Gy/day on days 1 to 5, 8 to 12, and 15 to 19, with a second course repeated after a 2-week interval. Plasma concentrations of 5-FU were determined by high performance liquid chromatography at 5:00 PM on days 3, 10, 38 and 45, and at 5:00 AM on days 4, 11, 39 and 46. RESULTS AND CONCLUSIONS: No patient with Stage IVa achieved a complete response in the standard dose group, whereas a complete response was observed at a rate of 50% in the high dose group, and this can be explained by a higher plasma concentration of 5-FU. The circadian rhythm in the concentrations found at the standard dose was not observed for a higher dose.

Olaparib Potentiates Anticancer Drug Cytotoxicity via 53BP1 in Oesophageal Squamous Cell Carcinoma Cells.

BACKGROUND/AIM: Olaparib was previously shown to synergistically enhance the cytotoxicity of DNA synthesis inhibitors in oesophageal carcinoma (OC) cell lines. However, the mechanisms of this synergy are not fully understood. As P53 binding protein 1 (53BP1) expression was previously shown to potentiate the anticancer effect of olaparib, we investigated the involvement of 53BP1 in the synergetic cytotoxic effects of olaparib and anticancer drugs in KYSE70 cells. MATERIALS AND METHODS: Experiments included small interfering RNA transfection, growth inhibition assays, western blots, immunofluorescence, and flow cytometry. RESULTS: The toxicity of DNA synthesis-inhibiting agents plus olaparib was decreased when 53BP1 was depleted. Olaparib cotreatment significantly increased phosphorylated H2A histone family member X (γH2AX) foci as well as 53BP1/γH2AX co-localisation in anticancer drug-treated cells. Silencing of 53BP1 suppressed anticancer drug-induced apoptosis with or without olaparib. CONCLUSION: Olaparib potentiates the cytotoxicity of anticancer drugs through 53BP1 in OC cells.