The Role of Intestinal Cytochrome P450s in Vitamin D Metabolism.

Vitamin D hydroxylation in the liver/kidney results in conversion to its physiologically active form of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. 1,25(OH)2D3 controls gene expression through the nuclear vitamin D receptor (VDR) mainly expressed in intestinal epithelial cells. Cytochrome P450 (CYP) 24A1 is a catabolic enzyme expressed in the kidneys. Interestingly, a recently identified mutation in another CYP enzyme, CYP3A4 (gain-of-function), caused type III vitamin D-dependent rickets. CYP3A are also expressed in the intestine, but their hydroxylation activities towards vitamin D substrates are unknown. We evaluated CYP3A or CYP24A1 activities on vitamin D action in cultured cells. In addition, we examined the expression level and regulation of CYP enzymes in intestines from mice. The expression of CYP3A or CYP24A1 significantly reduced 1,25(OH)2D3-VDRE activity. Moreover, in mice, Cyp24a1 mRNA was significantly induced by 1,25(OH)2D3 in the intestine, but a mature form (approximately 55 kDa protein) was also expressed in mitochondria and induced by 1,25(OH)2D3, and this mitochondrial enzyme appears to hydroxylate 25OHD3 to 24,25(OH)2D3. Thus, CYP3A or CYP24A1 could locally attenuate 25OHD3 or 1,25(OH)2D3 action, and we suggest the small intestine is both a vitamin D target tissue, as well as a newly recognized vitamin D-metabolizing tissue.

Involvement of α-klotho in growth hormone (GH) signaling.

Growth hormone (GH) exerts multiple effects on different organs directly or via its main mediator, insulin-like growth factor1 (IGF1). In this study, we focused on the novel relationship between GH action and the antiaging hormone α-klotho. Immunofluorescent staining of α-klotho was observed in the renal distal tubules and pituitary glands of somatostatin- and GH-positive cells in wild-type (WT) mice. Treatment of 4-week-old WT mice with GH increased IGF1 mRNA expression in the pituitary gland, liver, heart, kidney, and bone but increased α-klotho mRNA expression only in the pituitary gland, kidney, and bone. Increased α-klotho protein levels were observed in the kidney but not in the pituitary gland. No induction of α-klotho RNA expression by GH was observed in juvenile mice with kidney disease, indicating GH resistance. Furthermore, GH and α-klotho supplementation in HEK293 cells transfected with GHR increased Janus kinase 2 mRNA (a GH downstream signal) expression compared to supplementation with GH alone. In conclusion, we suggest that 1) the kidney is the main source of secreted α-klotho, which is detected in blood by the downstream action of GH, 2) α-klotho induction by GH is resistant in kidney disease, and 3) α-klotho might be an enhanced regulator of GH signaling.

Effects of EOS789, a novel pan-phosphate transporter inhibitor, on phosphate metabolism : Comparison with a conventional phosphate binder.

BACKGROUND: Inorganic phosphate (Pi) binders are the only pharmacologic treatment approved for hyperphosphatemia. However, Pi binders induce the expression of intestinal Pi transporters and have limited effects on the inhibition of Pi transport. EOS789, a novel pan-Pi transporter inhibitor, reportedly has potent efficacy in treating hyperphosphatemia. We investigated the properties of EOS789 with comparison to a conventional Pi binder. METHODS: Protein and mRNA expression levels of Pi transporters were measured in intestinal and kidney tissues from male Wistar rats fed diets supplemented with EOS789 or lanthanum carbonate (LC). 32Pi permeability was measured in intestinal tissues from normal rats using a chamber. RESULTS: Increased protein levels of NaPi-2b, an intestinal Pi transporter, and luminal Pi removal were observed in rats treated with LC but not in rats treated with EOS789. EOS789 but not LC suppressed intestinal protein levels of the Pi transporter Pit-1 and sodium/hydrogen exchanger isoform 3. 32Pi flux experiments using small intestine tissues from rats demonstrated that EOS789 may affect transcellular Pi transport in addition to paracellular Pi transport. CONCLUSION: EOS789 has differing regulatory effects on Pi metabolism compared to LC. The properties of EOS789 may compensate for the limitations of LC therapy. The combined or selective use of EOS789 and conventional Pi binders may allow tighter control of hyperphosphatemia. J. Med. Invest. 70 : 260-270, February, 2023.

Dietary polyphosphate has a greater effect on renal damage and FGF23 secretion than dietary monophosphate.

Phosphate (Pi)-containing food additives are used in several forms. Polyphosphate (PPi) salt has more harmful effects than monophosphate (MPi) salt on bone physiology and renal function. This study aimed to analyze the levels of parathyroid hormone PTH and fibroblast growth factor 23 (FGF23) and the expression of renal / intestinal Pi transport-related molecules in mice fed with an MPi or PPi diet. There were no significant differences in plasma Pi concentration and fecal Pi excretion levels between mice fed with the high-MPi and PPi diet. However, more severe tubular dilatation, interstitial fibrosis, and calcification were observed in the kidneys of mice fed with the high PPi diet versus the MPi diet. Furthermore, there was a significant increase in serum FGF23 levels and a decrease in renal phosphate transporter protein expression in mice fed with the PPi diet versus the MPi diet. Furthermore, the high MPi diet was associated with significantly suppressed expression and activity of intestinal alkaline phosphatase protein. In summary, PPi has a more severe effect on renal damage than MPi, as well as induces more FGF23 secretion. Excess FGF23 may be more involved in inflammation, fibrosis, and calcification in the kidney. J. Med. Invest. 69 : 173-179, August, 2022.

Tmem174, a regulator of phosphate transporter prevents hyperphosphatemia.

Renal type II sodium-dependent inorganic phosphate (Pi) transporters NaPi2a and NaPi2c cooperate with other organs to strictly regulate the plasma Pi concentration. A high Pi load induces expression and secretion of the phosphaturic hormones parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) that enhance urinary Pi excretion and prevent the onset of hyperphosphatemia. How FGF23 secretion from bone is increased by a high Pi load and the setpoint of the plasma Pi concentration, however, are unclear. Here, we investigated the role of Transmembrane protein 174 (Tmem174) and observed evidence for gene co-expression networks in NaPi2a and NaPi2c function. Tmem174 is localized in the renal proximal tubules and interacts with NaPi2a, but not NaPi2c. In Tmem174-knockout (KO) mice, the serum FGF23 concentration was markedly increased but increased Pi excretion and hypophosphatemia were not observed. In addition, Tmem174-KO mice exhibit reduced NaPi2a responsiveness to FGF23 and PTH administration. Furthermore, a dietary Pi load causes marked hyperphosphatemia and abnormal NaPi2a regulation in Tmem174-KO mice. Thus, Tmem174 is thought to be associated with FGF23 induction in bones and the regulation of NaPi2a to prevent an increase in the plasma Pi concentration due to a high Pi load and kidney injury.

Generation of a BAC transgenic mouse strain that expresses CreERT and a fluorescent protein under the transcriptional control of the Fzd5 locus.

BACKGROUND: The expression of FZD5 distinguishes immature human mesenchymal stem/stromal cells (MSC) in cultures, and the function of FZD5 is crucial for maintaining the proliferation and multilineage differentiation capacity of human MSC. We herein investigated whether Fzd5 expression also marks undifferentiated MSC in animals. METHODS: We generated a transgenic mouse strain (Fzd5-CreERT-tFP635) that expresses CreERT and the fluorescent protein, TurboFP635 (tFP635), under the transcriptional control of the Fzd5 gene using the BAC transgenic technique, and identified cells expressing tFP635 by flow cytometry. We also conducted lineage tracing with this strain. RESULTS: In the bone marrow of transgenic mice, tFP635 was preferentially expressed in MSC, Leptin receptor-expressing MSC (LepR+MSCs), and some Pdgfrα+ Sca1+ MSC (PαS). Inducible lineage tracing using the Fzd5-CreERT-tFP635; CAG-CAT-EGFP strain at the adult stage showed that Fzd5-expressing cells and their descendants labeled with GFP were progressively dominant in LepR+MSC and PαS, and GFP+ cells persisted for 1 year after the activation of CreERT. Adipocyte progenitor cells (APCs), osteoblast progenitor cells (OPCs), and Cd51+ stromal cells were also labeled with GFP. CONCLUSIONS: Our transgenic mouse marks two different types of MSC, LepR+MSC and PαS.

Common Dietary Sources of Natural and Artificial Phosphate in Food.

The Recommended Dietary Allowance (RDA) for phosphate in the U.S. is around 700 mg/day for adults. The majority of healthy adults consume almost double the amount of phosphate than the RDA. Lack of awareness, and easy access to phosphate-rich, inexpensive processed food may lead to dietary phosphate overload with adverse health effects, including cardiovascular diseases, kidney diseases and tumor formation. Nutritional education and better guidelines for reporting phosphate content on ingredient labels are necessary, so that consumers are able to make more informed choices about their diets and minimize phosphate consumption. Without regulatory measures, dietary phosphate toxicity is rapidly becoming a global health concern, and likely to put enormous physical and financial burden to the society.

HLA genotyping in Japanese patients with multiple myeloma receiving bortezomib: An exploratory biomarker study of JCOG1105 (JCOG1105A1).

Bortezomib (Btz) shows robust efficacy in patients with multiple myeloma (MM); however, some patients experience suboptimal responses and show specific toxicities. Therefore, we attempted to identify specific HLA alleles associated with Btz-related toxicities and response to treatment. Eighty-two transplant-ineligible patients with newly diagnosed MM enrolled in a phase II study (JCOG1105) comparing two less intensive melphalan, prednisolone, plus Btz (MPB) regimens were subjected to HLA typing. The frequency of each allele was compared between the groups, categorized based on toxicity grades and responses to MPB therapy. Among 82 patients, the numbers of patients with severe peripheral neuropathy (PN; grade 2 or higher), skin disorders (SD; grade 2 or higher), and pneumonitis were 16 (19.5%), 15 (18.3%), and 6 (7.3%), respectively. Complete response was achieved in 10 (12.2%) patients. Although no significant HLA allele was identified by multiple comparisons, several candidates were identified. HLA-B*40:06 was more prevalent in patients with severe PN than in those with less severe PN (odds ratio [OR] = 6.76). HLA-B*40:06 and HLA-DRB1*12:01 were more prevalent in patients with SD than in those with less severe SD (OR = 7.47 and OR = 5.55, respectively). HLA-DRB1*08:02 clustered in the group of patients with pneumonitis (OR = 11.34). Complete response was achieved in patients carrying HLA-DQB1*03:02, HLA-DQB1*05:01, and HLA-DRB1*01:01 class II alleles. HLA genotyping could help predict Btz-induced toxicity and treatment efficacy in patients with MM, although this needs further validation.

Stage III disease of ovarian, tubal and peritoneal cancers can be accurately diagnosed with pre-operative CT. Japan Clinical Oncology Group Study JCOG0602.

PURPOSE: Computed tomography of the abdomen and pelvis is a useful imaging modality for identifying origin and extent of ovarian cancer before primary debulking surgery. However, the International Federation of Gynecology and Obstetrics staging for ovarian cancer is determined based on surgico-pathological findings. The purpose of this study is to determine whether computed tomography staging can be the surrogate for surgico-pathological International Federation of Gynecology and Obstetrics staging in advanced ovarian cancer undergoing neoadjuvant chemotherapy. METHODS: Computed tomography staging was compared with surgico-pathological International Federation of Gynecology and Obstetrics staging in primary debulking surgery arm patients in a randomized controlled trial comparing primary debulking surgery and neoadjuvant chemotherapy (JCOG0602). The cancer of primary debulking surgery arm was identically diagnosed regarding the origin and extent with the cancer of neoadjuvant chemotherapy arm before accrual, using imaging studies (computed tomography and/or magnetic resonance imaging), cytological examination (ascites, pleural effusion or tumor contents fluid) and tumor marker (CA125 > 200 U/mL and CEA < 20 ng/mL). Institutional computed tomography staging was also compared with computed tomography staging by central review. RESULTS: Among 149 primary debulking surgery arm patients, 147 patients who underwent primary debulking surgery immediately were analyzed. Positive predictive values and sensitivity of computed tomography staging for surgical stage III disease (extra-pelvic peritoneal disease and/or retroperitoneal lymph node metastasis) were 99%. Meanwhile, positive predictive values for the presence of small (≤2 cm) extra-pelvic peritoneal disease were low; <20% in omentum. Accuracy of institutional computed tomography staging was comparable with computed tomography staging by central review. CONCLUSIONS: Preoperative computed tomography staging in each institution can be the surrogate for surgico-pathological diagnosis in stage III disease of ovarian cancer patients undergoing neoadjuvant chemotherapy without diagnostic surgery, but reliability of diagnosis of stage IIIB disease is inadequate.Clinical trial registration: UMIN000000523(UMIN-CTR).

Feasibility of Application of the Newly Developed Nano-Biomaterial, ß-TCP/PDLLA, in Maxillofacial Reconstructive Surgery: A Pilot Rat Study.

This study was performed to examine the applicability of the newly developed nano-biocomposite, ß-tricalcium phosphate (ß-TCP)/u-HA/poly-d/l-lactide (PDLLA), to bone defects in the oral and maxillofacial area. This novel nano-biocomposite showed several advantages, including biocompatibility, biodegradability, and osteoconductivity. In addition, its optimal plasticity also allowed its utilization in irregular critical bone defect reconstructive surgery. Here, three different nano-biomaterials, i.e., ß-TCP/PDLLA, ß-TCP, and PDLLA, were implanted into critical bone defects in the right lateral mandible of 10-week-old Sprague-Dawley (SD) rats as bone graft substitutes. Micro-computed tomography (Micro-CT) and immunohistochemical staining for the osteogenesis biomarkers, Runx2, osteocalcin, and the leptin receptor, were performed to investigate and compare bone regeneration between the groups. Although the micro-CT results showed the highest bone mineral density (BMD) and bone volume to total volume (BV/TV) with ß-TCP, immunohistochemical analysis indicated better osteogenesis-promoting ability of ß-TCP/PDLLA, especially at an early stage of the bone healing process. These results confirmed that the novel nano-biocomposite, ß-TCP/PDLLA, which has excellent biocompatibility, bioresorbability and bioactive/osteoconductivity, has the potential to become a next-generation biomaterial for use as a bone graft substitute in maxillofacial reconstructive surgery.

Comparison of the Bone Regenerative Capacity of Three-Dimensional Uncalcined and Unsintered Hydroxyapatite/Poly-d/l-Lactide and Beta-Tricalcium Phosphate Used as Bone Graft Substitutes.

This study compared the in vivo applicability of three-dimensional uncalcined and unsintered hydroxyapatite/poly-d/l-lactide (3D-HA/PDLLA) with beta-tricalcium phosphate (ß-TCP). 3D-HA/PDLLA is a newly developed bioactive, osteoconductive, bioresorbable bone regenerative composite. We performed critical-defect surgery on the mandible body of rats; the defects were filled with one of two bone graft substitutes. After a 4-week follow-up period, the mandibular specimens were examined using hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC) staining and micro-computed tomography (micro-CT). The H&E staining showed an increase in newly formed bone in both groups from week 1 to 4. The difference in the Runx2 IHC optical density (OD) scores of 3D-HA/PDLLA and ß-TCP was not statistically significant (p > 0.05); however, the osteocalcin IHC OD scores of the groups differed significantly (p < 0.05). Micro-CT demonstrated a similar trabecular thickness, trabecular spacing, and bone volume per total volume in the two groups (p > 0.05), indicating that bone formation in the two groups was nearly the same from a macro-perspective of bone regeneration. These results demonstrated that a different bone regeneration pattern and earlier osteoblast differentiation occurred in 3D-HA/PDLLA compared with ß-TCP. In conclusion, our study demonstrates that 3D-HA/PDLLA is feasible for clinical application as a new bioactive, osteoconductive/bioresorbable bone graft substitute for maxillofacial surgery.

Evidence of an intestinal phosphate transporter alternative to type IIb sodium-dependent phosphate transporter in rats with chronic kidney disease.

BACKGROUND: Phosphate is absorbed in the small intestine via passive flow and active transport.NaPi-IIb, a type II sodium-dependent phosphate transporter, is considered to mediate active phosphate transport in rodents. To study the regulation of intestinal phosphate transport in chronic kidney disease (CKD), we analyzed the expression levels of NaPi-IIb, pituitary-specific transcription factor 1 (PiT-1) and PiT-2 and the kinetics of intestinal phosphate transport using two CKD models. METHODS: CKD was induced in rats via adenine orThy1 antibody injection. Phosphate uptake by intestinal brush border membrane vesicles (BBMV) and the messenger RNA (mRNA) expression of NaPi-IIb, PiT-1 and PiT-2 were analyzed. The protein expression level of NaPi-IIb was measured by mass spectrometry (e.g. liquid chromatography tandem mass spectrometry). RESULTS: In normal rats, phosphate uptake into BBMV consisted of a single saturable component and its Michaelis constant (Km) was comparable to that of NaPi-IIb. The maximum velocity (Vmax) correlated with mRNA and protein levels of NaPi-IIb. In the CKD models, intestinal phosphate uptake consisted of two saturable components. The Vmax of the higher-affinity transport, which is thought to be responsible for NaPi-IIb, significantly decreased and the decrease correlated with reduced NaPi-IIb expression. The Km of the lower-affinity transport was comparable to that of PiT-1 and -2. PiT-1 mRNA expression was much higher than that of PiT-2, suggesting that PiT-1 was mostly responsible for phosphate transport. CONCLUSIONS: This study suggests that the contribution of NaPi-IIb to intestinal phosphate absorption dramatically decreases in rats with CKD and that a low-affinity alternative to NaPi-IIb, in particular PiT-1, is upregulated in a compensatory manner in CKD.

Comparison of the International Workshop Criteria and the Response Evaluation Criteria in Solid Tumors for indolent B-cell lymphoma.

BACKGROUND: [18F] fluorodeoxyglucose-positron emission tomography is incorporated in response criteria currently used for lymphoma; however, the primary endpoint in earlier phase study is an overall response, which includes the partial response of 50% shrinkage in two dimensions. Therefore, the measurement of target lesions is still prerequisite to determine the destiny of new, promising agents. Since required is calculating the sum of the product of bidimensional diameters of maximal six target lesions, the International Workshop Criteria (IWC) used as response evaluation in lymphoma is more time-consuming than the Response Evaluation Criteria in Solid Tumors (RECIST). This study aimed to examine whether the RECIST could replace the IWC using data from a phase II/III study of R-CHOP-21 versus R-CHOP-14 for advanced-stage indolent B-cell lymphoma, JCOG0203. METHODS: To evaluate the degree of agreement between them, the Kappa coefficient (KC) was calculated. Excluding patients without target lesions for the RECIST following central pathological review, 269 patients were evaluable. We determined which criterion was more predictive for progression-free survival. The criterion showing the lower point estimate of the hazard ratio (HR) of a complete response (CR) vs. a non-CR was defined as more useful. RESULTS: The KC between them was 0.34 (95% confidence interval [CI] 0.26-0.42); namely, indicating poor agreement. The HR of the IWC (0.47: 95% CI 0.33-0.68, log-rank test p < 0.001) was lower than that of the RECIST (0.64: 95% CI 0.45-0.89, p = 0.0075). CONCLUSION: We conclude that unidimensional measurements cannot be substituted for the bidimensional ones for indolent lymphoma.

Cutting Edge Molecular Therapy for Acute Myeloid Leukemia.

Recently, whole exome sequencing for acute myeloid leukemia (AML) has been performed by a next-generation sequencer in several studies. It has been revealed that a few gene mutations are identified per AML patient. Some of these mutations are actionable mutations that affect the response to an approved targeted treatment that is available for off-label treatment or that is available in clinical trials. The era of precision medicine for AML has arrived, and it is extremely important to detect actionable mutations relevant to treatment decision-making. However, the percentage of actionable mutations found in AML is about 50% at present, and therapeutic development is also needed for AML patients without actionable mutations. In contrast, the newly approved drugs are less toxic than conventional intensive chemotherapy and can be combined with low-intensity treatments. These combination therapies can contribute to the improvement of prognosis, especially in elderly AML patients who account for more than half of all AML patients. Thus, the treatment strategy for leukemia is changing drastically and showing rapid progress. In this review, we present the latest information regarding the recent development of treatment for AML.

Evaluation of the representativeness and generalizability of Japanese clinical trials for localized rectal/colon cancer: Comparing participants in the Japan Clinical Oncology Group study with patients in Japanese registries.

INTRODUCTION: It is unclear if clinical trial results including patients who meet trial eligibility criteria, are applicable to actual patients in daily practice (generalizability). Moreover, the extent to which are trial participants different from patients seen in daily practice (representativeness) is also unclear. The aim of this study was to evaluate the representativeness of the patients registered in randomized clinical trials to patients in daily practice and examine the generalizability of trial results to daily practice. METHODS: We compared the results of surgical trials conducted by the Japan Clinical Oncology Group with data from two Japanese cancer registries, representing patients seen in daily practice. We compared overall survival (OS) between trial participants and registry patients to evaluate representativeness of trial participants. We then compared the OS of registry patients who received open surgery (OP) and laparoscopic surgery (LAP) to evaluate the generalizability of trial results. RESULTS: We analyzed 3051 patients (701 in JCOG0212, 2350 registry patients) with rectal cancer and 3116 patients (1057 in JCOG0404, 2059 registry patients) with colon cancer. Trial participants tended to possess lower clinical stages. Multivariable analyses revealed registry patients with significantly worse survival compared with trial participants. The hazard ratio of LAP to OP among registry patients was 0.305 (95% CI; 0.048-2.188), which did not meet the prespecified generalizability criteria of 0.9. CONCLUSIONS: Our results failed to ensure either the representativeness or generalizability of clinical trial results, compared to daily practice. Careful considerations are required when applying trial results to patients in daily practice.

Role of sodium-dependent Pi transporter/Npt2c on Pi homeostasis in klotho knockout mice different properties between juvenile and adult stages.

SLC34A3/NPT2c/NaPi-2c/Npt2c is a growth-related NaPi cotransporter that mediates the uptake of renal sodium-dependent phosphate (Pi). Mutation of human NPT2c causes hereditary hypophosphatemic rickets with hypercalciuria. Mice with Npt2c knockout, however, exhibit normal Pi metabolism. To investigate the role of Npt2c in Pi homeostasis, we generated α-klotho-/- /Npt2c-/- (KL2cDKO) mice and analyzed Pi homeostasis. α-Klotho-/- (KLKO) mice exhibit hyperphosphatemia and markedly increased kidney Npt2c protein levels. Genetic disruption of Npt2c extended the lifespan of KLKO mice similar to that of α-Klotho-/- /Npt2a-/- mice. Adult KL2cDKO mice had hyperphosphatemia, but analysis of Pi metabolism revealed significantly decreased intestinal and renal Pi (re)absorption compared with KLKO mice. The 1,25-dihydroxy vitamin D3 concentration was not reduced in KL2cDKO mice compared with that in KLKO mice. The KL2cDKO mice had less severe soft tissue and vascular calcification compared with KLKO mice. Juvenile KL2cDKO mice had significantly reduced plasma Pi levels, but Pi metabolism was not changed. In Npt2cKO mice, plasma Pi levels began to decrease around the age of 15 days and significant hypophosphatemia developed within 21 days. The findings of the present study suggest that Npt2c contributes to regulating plasma Pi levels in the juvenile stage and affects Pi retention in the soft and vascular tissues in KLKO mice.

Efficacy of aspirin for stage III colorectal cancer: a randomized double-blind placebo-controlled trial (JCOG1503C, EPISODE-III trial).

Adjuvant chemotherapy is the current standard treatment for stage III colorectal cancer after curative resection. However, the prognosis of stage III colorectal cancer is still poor even after curative resection and adjuvant chemotherapy. Several observational studies suggested that the anti-tumor effect of aspirin. Therefore, we planned a randomized double-blind placebo-controlled phase III trial, which commenced in Japan in March 2018, to confirm the superiority of aspirin over placebo added to adjuvant chemotherapy in terms of disease-free survival (DFS) for stage III colorectal cancer patients after curative resection. A total of 880 patients will be accrued from 20 Japanese institutions within 3 years. The primary endpoint is DFS and the secondary endpoints are overall survival, relapse-free survival, relative dose intensity, adverse events, and serious adverse events. This trial has been registered at Japan Registry of Clinical Trials as jRCTs031180009 (https://jrct.niph.go.jp/detail/589).

Study risk assessment of Japan Clinical Oncology Group (JCOG) clinical trials using the European Organisation for Research and Treatment of Cancer (EORTC) study risk calculator.

BACKGROUND: New Japanese ethical guidelines for medical researches and the Clinical Trials Act have come into effect and monitoring is mandated for intervention studies. Methods of monitoring can be modified according to a study risk, but there is no established method in Japan regarding how to assess a study risk. EORTC assesses a study risk using their own study risk calculator and classifies their trials into three categories. For each category, different levels of monitoring are applied. This project is aimed to assess the study risks of JCOG trials using the EORTC calculator. METHODS: We selected clinical trials open to patient recruitment in JCOG as of Nov 2014. Each trial was scored based on the EORTC study risk calculator and classified into three risk categories; low, medium and high. RESULTS: A total of 40 studies were included in the assessment. Twenty-seven studies (67.5%) were classified into low risk group, 12 (30%) in medium risk group, and only 1 (2.5%) in high risk group. Clinical trials evaluating multimodality therapy and/or using unapproved drugs tended to be scored higher and most of them were classified into medium or high risk group. CONCLUSIONS: JCOG conducts central monitoring and site visit audit with sampling source data verification for every trial, which are almost compatible with the way in EORTC for the medium risk group. Because most of the JCOG studies were classified into low or medium risk group, the intensity of monitoring and audit in JCOG was considered as reasonable even from the EORTC perspective.

[Hairy cell leukemia complicated by bone marrow necrosis following cladribine administration].

Classic hairy cell leukemia (classic HCL) is a rare disease associated with indolent mature B-cell lymphoma. A 50-year-old man presented with pancytopenia for 3 years and was diagnosed with classic HCL because his lymphoid cells showed a hairy morphology with oval nuclei and indistinct nucleoli both in the peripheral blood and bone marrow (BM) smears. Flow cytometric analysis revealed that these cells expressed CD11c, CD25, and CD103, and the Sanger sequence method detected BRAF V600E mutation. Cladribine (0.09 mg/kg/day) was initiated for 7 days via continuous intravenous injection. On day 13, the patient died from bloodstream infection caused by methicillin-resistant Staphylococcus epidermidis. Autopsy findings revealed BM necrosis without residual leukemia cells caused by classic HCL, severe infection, and agents, such as cladribine and granulocyte-colony stimulating factor; however, its cause remained undetermined. Both early diagnosis and immediate clinical intervention are required to improve the clinical outcomes in classic HCL. The cause of hematopoiesis disturbance should also be identified using BM biopsy or magnetic resonance imaging before initiating treatment in classic HCL with severe pancytopenia.

Precision medicine and novel molecular target therapies in acute myeloid leukemia: the background of hematologic malignancies (HM)-SCREEN-Japan 01.

The development of allogeneic hematopoietic-stem-cell transplantation has improved the prognosis of younger acute myeloid leukemia (AML) patients. However, the outcome of older AML patients remains poor. The majority of AML patients are elderly. For elderly AML patients unfit for intensive chemotherapy, less toxic single agent that targets a specific gene mutation or combination therapy with a single agent is needed. The role of chromosomal abnormalities and genetic mutations in leukemia has become more apparent, and detailed prognostic stratification based on the type of genetic mutation has been established. Next-generation sequencing (NGS) has been used for gene analysis of AML. In the future, the evaluation of biologically homogeneous population on the basis of chromosomal abnormalities and gene mutations will lead to a paradigm shift that will help in the development of optimized therapy. As rapid diagnosis of gene mutations is required by the clinical physicians to decide on induction therapy, it is important to have a swift turnaround time for comprehensive DNA sequencing to provide actionable data to clinical physicians. It is required to conduct a feasibility study to evaluate the turnaround time from sending the specimens to receiving the results while maintaining the quality of the specimens contributing to gene analysis. To detect infrequent gene mutations, investigators need to perform multicenter studies and/or cooperative-group trials with a certain sample size to examine the frequency of the gene mutations in elderly AML patients, enabling sufficient statistical power for meaningful comparisons.