Association between albumin-bilirubin grade and plasma trough concentrations of regorafenib and its metabolites M-2 and M-5 at steady-state in Japanese patients.

The aim of the present study was to determine whether the trough plasma concentrations (C0) of regorafenib and its metabolites, the N-oxide metabolite (M-2) and the desmethyl N-oxide metabolite (M-5), in 21 patients receiving regorafenib therapy were affected by albumin-bilirubin (ALBI) grade. Regorafenib was administered at dosages ranging from 40 to 160 mg once daily on a 3-week-on, 1-week-off cycle. C0 values of regorafenib and its major metabolites were measured by high-performance liquid chromatography on day 8 after treatment initiation. The C0 values of regorafenib and metabolites M-2 and M-5 were significantly lower in patients with ALBI grade 2 as compared with grade 1 (P = 0.023, 0.003 and 0.017, respectively). The total C0 of regorafenib and its metabolites was significantly higher in ALBI grade 1 patients relative to grade 2 (3.489 µg/mL vs. 1.48 µg/mL; P = 0.009). The median relative dose intensity (RDI) of patients categorized as ALBI grade 2 was significantly lower than that of grade 1 patients (21.9% vs. 62.9%; P = 0.006). In 15 colorectal cancer patients among the total 21 patients, patients with ALBI grade 2 (n = 9) had a significantly shorter median overall survival time than patients with grade 1 (n = 6; P = 0.013). Administering a low dose of regorafenib to patients with ALBI grade 2 reduces the RDI of regorafenib and lowers treatment efficacy, as an appropriate C0 of regorafenib is not maintained. Monitoring the C0 of regorafenib regularly is necessary to guide dose adjustment.

Circulating IL-6 and not its circulating signaling components sIL-6R and sgp130 demonstrate clinical significance in NSCLC patients treated with immune checkpoint inhibitors.

Introduction: Clinical roles of plasma IL-6 levels have been reported in patients with various cancers, including non-small cell lung cancer (NSCLC), treated with immune checkpoint inhibitors (ICIs). However, the roles of other IL-6 signaling components, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130), in the plasma have not been elucidated. Methods: Blood was collected from 106 patients with NSCLC before initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Plasma levels of IL-6, sIL-6R, sgp130, and their complexes were assessed by Cox regression hazard model to evaluate their clinical significance. The clinical role of IL-6 or IL-6R genetic polymorphisms was also analyzed. Results: Cox regression analysis showed that higher plasma IL-6 levels significantly predicted unfavorable overall survival (OS; hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.05-1.68, p = 0.012) in NSCLC patients treated with ICIs. However, plasma sIL-6R and sgp130 levels showed no prognostic significance (p = 0.882 and p = 0.934, respectively). In addition, the estimated concentrations of binary IL-6:sIL-6R and ternary IL-6:sIL-6R:sgp130 complexes and their ratios (binary/ternary complex) were not significantly associated with OS (p = 0.647, p = 0.727, and p = 0.273, respectively). Furthermore, the genetic polymorphisms of IL-6 (-634G>C) and IL-6R (48892A>C) showed no clinical role by Kaplan-Meier survival analysis (p = 0.908 and p = 0.639, respectively). Discussion: These findings demonstrated the clinical significance of plasma levels of IL-6, but not of other IL-6 signaling components, sIL-6R and sgp130, suggesting that classical IL-6 signaling, but not trans-signaling, may be related to anti-tumor immune responses in cancer patients treated with ICIs.

A Multi-institutional Study to Diagnose the Risk of Lymph Node Metastasis Using a CRP Genetic Polymorphism Test Kit in pT1, cN0 Thoracic Esophageal Squamous Cell Carcinoma.

BACKGROUND/AIM: For patients with T1a muscularis mucosae (MM) esophageal squamous cell carcinoma (ESCC) with lymphovascular invasion (LVI) or T1b submucosal (SM) ESCC, endoscopic resection is non-curative, and adjuvant treatment entailing esophagectomy or definitive chemoradiotherapy is necessary. This is because about 30% of these cases have lymph node (LN) metastasis. The purpose of this study was to test the utility of a CRP genetic polymorphism test kit for determining the risk of LN metastasis with the aim of eliminating additional invasive adjuvant therapy. PATIENTS AND METHODS: This is a retrospective, multi-institutional, observational study. The CRP 1846C>T genetic polymorphisms were identified using a fully automated genotyping system. The primary end points were an 85% negative predictive value (NPV) for diagnosis of LN metastasis in pT1a (MM) and 80% NPV in pT1b (SM1) patients. RESULTS: A total of 742 ESCC (105 pMM, 166 pSM1 and 471 pSM2-3) patients who had received esophagectomy with 2- or 3-field LN dissection at 65 institutions were enrolled. According to this test, patients with the C/C and C/T genotypes were considered to be low risk. The NPVs using this test were 82.8% in pMM and 71.7% in pSM1 patients. CONCLUSION: CRP 1846C>T genetic polymorphism is not a useful diagnostic indicator for determining the risk of LN metastasis; however, the possibility that CRP gene polymorphisms are involved in the mechanism of lymph node metastasis in solid tumors still remains.

Association between ABCC2 polymorphism and hematological toxicity in patients with esophageal cancer receiving platinum plus 5-fluorouracil therapy.

BACKGROUND: Platinum agents are taken up into cells by copper transporter (CTR) 1 (gene code: SLC31A1) and are excreted from cells by copper-transporting P-type adenosine triphosphatase (ATP7B) and multidrug resistance-associated protein (MRP) 2 (gene code: ABCC2). In addition, glutathione S transferase (GST) P1 is involved in the metabolism of platinum agents. The present study aimed to determine whether the rate of grade 3-4 hematological toxicity associated with platinum plus 5-fluorouracil (5-FU) therapy in 239 patients with esophageal cancer was affected by the SLC31A1 rs10981694A>C and rs12686377G>T, ATP7B rs9535828A>G, GSTP1 rs1695A>G, and ABCC2 -24C>T polymorphisms. METHODS: Chemotherapy consisted of protracted infusion of 5-FU (800 mg/m2/day) on days 1-5 and cisplatin or nedaplatin (80 mg/m2/day) on day 1. RESULTS: A total of 82 of 239 patients developed grade 3-4 hematological toxicity after chemotherapy. Univariate analysis showed that ABCC2 -24C/T + T/T genotypes (P = 0.038), radiation therapy (P = 0.013), baseline white blood cell count < 6000/µL (P = 0.003), and baseline neutrophil count < 3900/µL (P = 0.021) were statistically significant predictors of grade 3-4 hematological toxicity. Multivariate analysis revealed that ABCC2 -24C/T + T/T genotypes (P = 0.036), radiation therapy (P = 0.005), and baseline white blood cell count < 6000/µL (P < 0.001) were significant risk factors. CONCLUSIONS: We determined that ABCC2 -24C>T is significantly associated with grade 3-4 hematological toxicity after platinum plus 5-FU therapy. These findings might contribute to improved treatment strategies for patients with esophageal cancer.

Effects of SLC31A1 and ATP7B polymorphisms on platinum resistance in patients with esophageal squamous cell carcinoma receiving neoadjuvant chemoradiotherapy.

The relationship between the SLC31A1 (protein: copper transporter 1) rs10981694 A > C and ATP7B (protein: P-type adenosine triphosphatase 7B) rs9535828 A > G polymorphisms on the overall survival and disease-free survival of 104 Japanese patients with esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant chemoradiotherapy (CRT) was investigated. Chemotherapy consisted of protracted infusion of 5-fluoracil (800 mg/m2/day) on days 1-5 and cisplatin or nedaplatin (80 mg/m2/day) on day 1. The median (range) follow-up was 47 (6-127) months. The 5-year overall and disease-free survival rates were 71.2% and 60.6%, respectively. The 5-year overall survival rate was significantly higher in patients with the SLC31A1 rs10981694 C allele compared with the rs10981694 A/A genotype (91.7% vs. 65.0%, P = 0.018). The 5-year disease-free survival rate was significantly higher in patients with the SLC31A1 rs10981694 C allele compared with the rs10981694 A/A genotype (79.2% vs. 55.0%, P = 0.043). In addition, univariate and multivariate analyses showed the SLC31A1 rs10981694 A > C polymorphism to be a significant prognostic factor affecting 5-year overall survival after neoadjuvant CRT. However, the overall and disease-free survival rates after surgery did not differ significantly among the ATP7B rs9535828 genotypes. In conclusion, only the SLC31A1 rs10981694 A/A genotype was an independent predictor of a poorer 5-year overall survival. Therefore, in neoadjuvant CRT for ESCC patients, the effect of platinum was affected by the SLC31A1 rs10981694 A > C polymorphism. The presence of this polymorphism should be considered when devising neoadjuvant CRT regimens or treatment strategies for ESCC.

Therapeutic drug monitoring of regorafenib and its metabolite M5 can predict treatment efficacy and the occurrence of skin toxicities.

BACKGROUND: Regorafenib is a multiple tyrosine kinase inhibitor, and the use of this drug is approved for the treatment of cancers that are resistant to chemotherapy, which include advanced colorectal cancer, gastrointestinal stromal tumor, and hepatocellular carcinoma. However, the drug causes adverse events, including skin toxicities that require dose modification in approximately 75% of cases. At present, the blood concentration of regorafenib is not assessed in clinical settings; thus, we recently developed a method that can assess the blood concentration of the drug using high-performance liquid chromatography. METHODS: We measured the trough blood concentrations (Ctrough) of regorafenib and its metabolites (M2 and M5) in 14 and 4 patients with advanced colorectal cancer and gastrointestinal stromal tumor, respectively, using high-performance liquid chromatography. Then, the correlation between the Ctrough and therapeutic outcomes of regorafenib was analyzed. RESULTS: In patients who were receiving regorafenib 40-160 mg/day, the Ctrough values of regorafenib, M2, and M5 were 318-9467, 34-3594, and 38-3796 ng/mL, respectively. The difference in the values was significant. Although the specific factors influencing this difference were not elucidated, the Ctrough of regorafenib was extremely lower in some patients, even though the drug was administered at a standard dose, which may explain the lower response rate. Moreover, the Ctrough value of M5 was significantly correlated to the incidence of skin toxicities, which is the most frequent cause of dose modification. CONCLUSIONS: The use of regorafenib may not be suitable in patients with a low Ctrough value. To prevent skin toxicities, the Ctrough value of M5 should be monitored.

Influence of CYP3A4/5 and ABC transporter polymorphisms on lenvatinib plasma trough concentrations in Japanese patients with thyroid cancer.

Lenvatinib is a substrate of cytochrome P450 (CYP) 3A and ATP-binding cassette (ABC) transporters. In this study, we aimed to evaluate how CYP3A4/5 and ABC transporter polymorphisms affected the mean steady-state dose-adjusted plasma trough concentrations (C0) of lenvatinib in a cohort of 40 Japanese patients with thyroid cancer. CYP3A4 20230G > A (*1G), CYP3A5 6986A > G (*3), ABCB1 1236C > T, ABCB1 2677G > T/A, ABCB1 3435C > T, ABCC2 -24C > T, and ABCG2 421C > A genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism. In univariate analysis, there were no significant differences in the mean dose-adjusted C0 values of lenvatinib between the ABCB1, ABCG2, and CYP3A5 genotypes. However, the mean dose-adjusted C0 values of lenvatinib in patients with the CYP3A4*1/*1 genotype and ABCC2 -24T allele were significantly higher than those in patients with the CYP3A4*1G allele and -24C/C genotype, respectively (P = 0.018 and 0.036, respectively). In multivariate analysis, CYP3A4 genotype and total bilirubin were independent factors influencing the dose-adjusted C0 of lenvatinib (P = 0.010 and 0.046, respectively). No significant differences were found in the incidence rates of hypertension, proteinuria, and hand-foot syndrome following treatment with lenvatinib between the genotypes of CYP3A4/5 and ABC transporters. Lenvatinib pharmacokinetics were significantly influenced by the CYP3A4*1G polymorphism. If the target plasma concentration of lenvatinib for efficacy or toxicity is determined, elucidation of the details of the CYP3A4*1G genotype may facilitate decision-making related to the appropriate initial lenvatinib dosage to achieve optimal plasma concentrations.

Quantitative determination of regorafenib and its two major metabolites in human plasma with high-performance liquid chromatography and ultraviolet detection.

A simple, highly sensitive and specific high-performance liquid chromatography (HPLC) method was developed for the simultaneous quantitation of regorafenib, N-oxidemetabolite (M-2) and the desmethyl N-oxide metabolite (M-5) in human plasma. Regorafenib, M-2, M-5 and the internal standard sorafenib were separated using a mobile phase of 0.5% KH2 PO4 (pH 3.5)-acetonitrile (30:70, v/v), on a Capcell PAK MG II column at a flow rate of 0.5 mL/min and measurement at UV 260 nm. The lower limits of quantification for regorafenib, M-2 and M-5 were 10 ng/mL for each analyte. A procedure using solid-phase extraction required only a small amount of plasma (100 µL) for one analysis while providing high extraction recovery (>81% for all compounds) and good selectivity. Coefficients of variation for intra- and inter-day assays were <12.2% for regorafenib, <12.3% for M-2 and <15.1% for M-5. Accuracies for intra- and inter-day assays were <9.4% for regorafenib, <8.0% for M-2 and <12.8% for M-5 over a linear range from 10 to 10,000 ng/mL. This HPLC assay is suitable for clinical pharmacokinetic studies of regorafenib. The present HPLC method is currently in use for our observational studies of patients under treatment. Copyright © 2016 John Wiley & Sons, Ltd.

CRP 1846C>T Genetic Polymorphism Is Associated with Lymph Node Metastasis and/or Severe Lymphatic Invasion in Endometrial Cancer.

Endometrial cancer (EC) rates are rising in Japan. Lymph node (LN) metastasis is an important prognostic factor in EC, and its risk is increased with higher tumor grade, deep myometrial invasion, larger tumor size, and lymphovascular space invasion (LVSI). Current methodologies to assess these factors are unreliable. We previously showed the association between C-reactive protein (CRP) 1846C>T (rs1205) polymorphism and LN metastasis in esophageal, non-small cell lung, and breast cancers. The CRP gene is located on chromosome 1q21-q23, and the polymorphism in the noncoding region (1846C>T) of this gene decreases serum CRP levels. We investigated the relationship between CRP 1846C>T genetic polymorphism and LN metastasis or LVSI in 130 EC patients using polymerase chain reaction-restriction fragment length polymorphism. The CRP 1846C/T genotype was C/C in 11 patients, C/T in 58 patients and T/T in 61 patients. The patients were divided into two groups based on their CRP 1846 genotypes: "C/C" and "C/T + T/T". Nine (7%) and 18 (13%) patients, all with the polymorphism, had LN metastasis and moderate or prominent lymphatic invasion, respectively. LN metastasis and/or severe lymphatic invasion were observed in the C/T + T/T group, while patients with the C/C genotype had no LN metastases or severe lymphatic invasion. Univariate and multivariate logistic regression models revealed that the C/T + T/T patients had a significant likelihood of developing LN metastasis and/or severe lymphatic invasion. Our results suggest that CRP genetic polymorphism is a novel risk predictor of LN metastasis and/or lymphatic invasion in EC.

Intranuclear verrucomicrobial symbionts and evidence of lateral gene transfer to the host protist in the termite gut.

In 1944, Harold Kirby described microorganisms living within nuclei of the protists Trichonympha in guts of termites; however, their taxonomic assignment remains to be accomplished. Here, we identified intranuclear symbionts of Trichonympha agilis in the gut of the termite Reticulitermes speratus. We isolated single nuclei of T. agilis, performed whole-genome amplification, and obtained bacterial 16S rRNA genes by PCR. Unexpectedly, however, all of the analyzed clones were from pseudogenes of 16S rRNA with large deletions and numerous sequence variations even within a single-nucleus sample. Authentic 16S rRNA gene sequences were finally recovered by digesting the nuclear DNA; these pseudogenes were present on the host Trichonympha genome. The authentic sequences represented two distinct bacterial species belonging to the phylum Verrucomicrobia, and the pseudogenes have originated from each of the two species. Fluorescence in situ hybridization confirmed that both species are specifically localized, and occasionally co-localized, within nuclei of T. agilis. Transmission electron microscopy revealed that they are distorted cocci with characteristic electron-dense and lucent regions, which resemble the intranuclear symbionts illustrated by Kirby. For these symbionts, we propose a novel genus and species, 'Candidatus Nucleococcus trichonymphae' and 'Candidatus Nucleococcus kirbyi'. These formed a termite-specific cluster with database sequences, other members of which were also detected within nuclei of various gut protists, including both parabasalids and oxymonads. We suggest that this group is widely distributed as intranuclear symbionts of diverse protists in termite guts and that they might have affected the evolution of the host genome through lateral gene transfer.