Sachi Morita

Genetic polymorphisms associated with oxaliplatin-induced peripheral neurotoxicity in Japanese patients with colorectal cancer.

OBJECTIVE Pharmacogenomic associations between severe oxaliplatininduced chronic peripheral neurotoxicity (OXCPN) (Grade 2 lasting for > 7 days or Grade 3) and 9 single nucleotide polymorphisms (SNPs) in 8 genes (TAC1, FOXC1, ITGA1, ACYP2, DLEU7, BTG4, CAMK2N1, and FARS2) were reported by the genomewide association study (GWAS) in Korean patients. The present study was designed to explore reliable predictors of OXCPN and thereby improve the management of metastatic colorectal cancer (CRC). METHODS We retrospectively investigated pharmacogenomic characteristics of OXCPN in 70 Japanese patients with CRC who received oxaliplatin-based chemotherapy and updated the results of our previous analysis of ERCC1 (C118T, rs11615 and C8092A, rs3212986) and GSTP1 (Ile105Val, rs1695) polymorphisms. RESULTS Univariate analysis suggested potential associations of severe OXCPN with rs843748 in ACYP2 and rs17140129 in FARS2, as well as with the absence of diabetes mellitus (DM) (p = 0.056, 0.072, and 0.029, respectively). There was no association between severe OXCPN and any of the 7 other SNPs. Multiple logistic regression analysis showed that an increased risk of severe OXCPN was related to rs17140129 and the absence of DM (p = 0.034 and 0.030, respectively). On updated analysis, polymorphisms of ERCC1 (C118T, rs11615) and rs10486003 in TAC1 were associated with time to the onset of Grade 1 OXCPN (p = 0.024 and 0.049, respectively). CONCLUSIONS Severe OXCPN is significantly related to rs17140129, found in the GWAS of Korean patients, in Japanese patients. Patients without DM are more likely to have OXCPN. The association between ERCC1 polymorphism and time to the onset of OXCPN was significant on updated analysis.

Association between severe toxicity of nilotinib and UGT1A1 polymorphisms in Japanese patients with chronic myelogenous leukemia.

BackgroundNilotinib is a BCR-ABL kinase inhibitor approved for the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia (CML). The UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphism UGT1A1*28 (*28)/*28 has been linked to an increased risk of hyperbilirubinemia in patients with CML who receive nilotinib. Beside *28, UGT1A1*6 (*6) is another important variant allele in Japanese patients because it is associated with adverse events of irinotecan, metabolized by UGT1A1. We retrospectively investigated the association between severe toxicity of nilotinib and UGT1A1 polymorphisms (*6 and*28) in Japanese patients with CML.Patients and methodsEight patients with cytogenetically confirmed CML who were receiving nilotinib were studied to explore the association of UGT1A1 polymorphisms with severe nilotinib-related toxicity. Genotyping analyses were determined for *6 and *28.ResultsAll 3 patients with the *6/*6 or *6/*28 genotype had severe toxicity, including QT interval prolongation (grade 3), elevated lipase levels (grade 3) plus hyperbilirubinemia (grade 2), and anemia (grade 3) plus hepatic cyst hemorrhage (grade 2) in 1 patient each. Among the 5 patients with the *6/*1 or *1/*1 genotype, 1 had elevated lipase levels (grade 3) and another had severe pain in the lower extremities (grade 3).ConclusionThese findings suggest that UGT1A1 polymorphisms are important determinants of severe toxicity of nilotinib in Japanese patients.

Prospective evaluation of corrected QT intervals and arrhythmias after exposure to epirubicin, cyclophosphamide, and 5-fluorouracil in women with breast cancer

BACKGROUND Corrected QT (QTc) interval prolongation can induce fatal arrhythmias such as torsade de pointes. PATIENTS AND METHODS To assess the characteristics of QTc intervals and arrhythmias in women with early breast cancer who received FEC100 adjuvant chemotherapy, electrocardiograms (ECGs) were recorded before and after each chemotherapy. Associations between QTc interval prolongation and single nucleotide polymorphisms (SNPs) of potassium channel genes were also investigated. RESULTS A total of 131 ECG records were obtained in 34 patients who received 153 cycles of FEC100. QTc intervals could be measured in 127 records. There was a significant trend toward QTc interval prolongation after each treatment, persisting through four cycles of chemotherapy (P < 0.001). Median QTc interval prolongations were 13, 11, 18, and 14 ms in the first through fourth cycles of chemotherapy, respectively. QTc intervals differed significantly between cycles 1 and 4 before treatment as well as after treatment (P < 0.05). A single supraventricular premature contraction was noted in 3 (2.3%) of the 131 cycles in 2 (5.9%) of the 34 patients. There was no significant association between QTc interval prolongation and SNPs of potassium channel genes. CONCLUSION This prospective study confirmed that FEC100 is associated with significant QTc interval prolongation in women with early breast cancer.BACKGROUND Corrected QT (QTc) interval prolongation can induce fatal arrhythmias such as torsade de pointes. PATIENTS AND METHODS To assess the characteristics of QTc intervals and arrhythmias in women with early breast cancer who received FEC100 adjuvant chemotherapy, electrocardiograms (ECGs) were recorded before and after each chemotherapy. Associations between QTc interval prolongation and single nucleotide polymorphisms (SNPs) of potassium channel genes were also investigated. RESULTS A total of 131 ECG records were obtained in 34 patients who received 153 cycles of FEC100. QTc intervals could be measured in 127 records. There was a significant trend toward QTc interval prolongation after each treatment, persisting through four cycles of chemotherapy (P < 0.001). Median QTc interval prolongations were 13, 11, 18, and 14 ms in the first through fourth cycles of chemotherapy, respectively. QTc intervals differed significantly between cycles 1 and 4 before treatment as well as after treatment (P < 0.05). A single supraventricular premature contraction was noted in 3 (2.3%) of the 131 cycles in 2 (5.9%) of the 34 patients. There was no significant association between QTc interval prolongation and SNPs of potassium channel genes. CONCLUSION This prospective study confirmed that FEC100 is associated with significant QTc interval prolongation in women with early breast cancer.

Pharmacokinetic study of S-1 in patients in whom inulin clearance was measured.

Objective: This pharmacokinetic study of S-1 was conducted in patients in whom glomerular filtration rate (GFR) was directly measured to explore the possibility of adjusting the S-1 dose on the basis of GFR in patients with normal or nearly normal renal function. Methods: S-1 was given to 12 patients twice daily for 28 consecutive days followed by 14 days of rest, repeated every 6 weeks. GFR was measured on the basis of inulin clearance (CLin) before the first day of treatment. Results: The area under the time-concentration curve (AUC) of 5-fluorouracil (5-FU) correlated with that of 5-chloro-2,4-dihydroxypyridine (CDHP, r = 0.750, p = 0.005). The AUC of CDHP correlated with the measured 24-hour creatinine clearance (CLcr) per subject (r = –0.620, p = 0.032), but not with the CLin (r = –0.356, p = 0.257). The AUC of 5-FU did not correlate with either the 24-hour CLcr per subject (r = –0.401, p = 0.187) or with the CLin (r = –0.300, p = 0.351). Conclusion: Dosage adjustment based on the GFR does not reduce individual variations in 5-FU concentrations among patients with normal or nearly normal renal function who receive S-1.