Yukiko Tsunematsu

Six Months of Maintenance Chemotherapy After Intensified Treatment for Acute Lymphoblastic Leukemia of Childhood

PURPOSE We postulated that intensification of chemotherapy immediately after remission induction might reduce the leukemic cell burden sufficiently to allow an abbreviated period of antimetabolite therapy. PATIENTS AND METHODS Three hundred forty-seven children (ages 1 to 15 years) with previously untreated acute lymphoblastic leukemia (ALL) were enrolled onto the Tokyo L92-13 study, which excluded patients with mature B-cell ALL and patients less than 1 year old. One hundred twenty-four patients were classified as standard risk, 122 as high risk, and 101 as extremely high risk, according to age, peripheral-blood leukocyte count, selected genetic abnormalities, and immunophenotype. All subjects received four drugs for remission induction, followed by a risk-directed multidrug intensification phase and therapy for presymptomatic leukemia in the CNS. Maintenance chemotherapy with oral mercaptopurine and methotrexate was administered for 6 months, with all treatment stopped by 1 year after diagnosis. RESULTS The mean (+/- SD) event-free survival (EFS) and overall survival rates for all patients were 59.5% +/- 3.4% and 81.5% +/- 2.2%, respectively, at 5. 5 years after diagnosis. EFS rates by risk category were similar (60. 2% +/- 6.0% for standard risk, 57.7% +/- 5.6% for high risk, and 62. 5% +/- 5.7% for extremely high risk), whereas overall survival rates differed significantly (91.2% +/- 2.7%, 80.0% +/- 4.1%, and 72.1% +/- 4.5%, respectively, P <.0001 by the log-rank test). There were 107 relapses. Eighty-five (79.4%) of these 107 patients achieved second complete remissions, with subsequent EFS rates of 61.5% +/- 7. 9% (standard risk), 42.6% +/- 8.1% (high risk), and 9.6% +/- 6.4% (extremely high risk). Of the five risk factors analyzed, only the response to prednisolone monotherapy among extremely high-risk patients proved important. CONCLUSION Early treatment intensification did not compensate for a truncated phase of maintenance chemotherapy in children with standard- or high-risk ALL. However, 6 months of antimetabolite treatment seemed adequate for extremely high-risk patients who were good responders to prednisolone and received intensified chemotherapy that included high-dose cytarabine early in the clinical course.

Improved outcome in the treatment of pediatric multifocal Langerhans cell histiocytosis: Results from the Japan Langerhans Cell Histiocytosis Study Group-96 protocol study.

The treatment outcome of multifocal childhood Langerhans cell histiocytosis (LCH) has not been satisfactory and has resulted in poor therapeutic responses with high mortality and a high incidence of reactivation with late sequelae. To overcome these issues, the Japan LCH Study Group‐96 (JLSG‐96) protocol was conducted prospectively from 1996 to 2001 in Japan.

11p15 translocations involving the NUP98 gene in childhood therapy-related acute myeloid leukemia/myelodysplastic syndrome

In a survey of childhood therapy‐related acute myeloid leukemia/myelodysplastic syndrome (t‐AML/MDS) in Japan, we found 11p15 translocations in 5 (6%) of 81 children with t‐AML/MDS. t(11;17)(p15;q21), t(11;12)(p15;q13), t(7;11)(p15;p15), inv(11)(p15q22), and add(11)(p15) were each found in one patient. Southern blotting and/or RT‐PCR analyses revealed rearrangements of the NUP98 gene in tumor samples of all five patients. Rearrangements of DDX10 were detected in t‐AML/MDS cells with inv(11), and rearrangements of HOXA9 were detected in t‐AML cells with t(7;11). The 17q21 breakpoint of t(11;17) and the 12q13 breakpoint of t(11;12)(p15;q13) coincided with the loci of the HOXB and HOXC gene families, respectively. Therefore, it is reasonable to speculate that one of the HOXB genes and one of the HOXC genes were fused to NUP98 by t(11;17) and t(11;12), respectively, in t‐AML/MDS cells. We propose that NUP98 may be a target gene for t‐AML/MDS, and that t‐AML/MDS with a fusion of NUP98 and HOX or DDX10 genes may be more frequent in children than in patients of other age groups. Genes Chromosomes Cancer 26:215–220, 1999.

Leukemia and other malignancies among GH users.

The number of reported cases of leukemia developing in growth hormone (GH) users worldwide has reached 31. Twelve Japanese cases are briefly reviewed; five each of AML and ALL, and one each of CML and malignant histiocytosis. The underlying diseases of these patients consisted of 8 idiopathic disease, 3 tumors and one Fanconis anemia. Leukemia occurred during GH treatment in 9 cases and after cessation of GH in 3. The longest interval from the cessation of GH therapy was 10 years. GH administration from a younger age tended to be linked to myeloid type. Risk factors and possible mechanisms of leukemogenesis by growth hormone are discussed, and proposals for the future have been made by the Foundation for Growth Science in Japan.

The FANCA gene in Japanese Fanconi anemia : Reports of eight novel mutations and analysis of sequence variability

Fanconi anemia (FA), an autosomal recessive disorder characterized by a progressive pancytopenia associated with congenital anomalies and high predisposition to malignancies, is a genetically and clinically heterogeneous disease. At least eight complementation groups (FA‐A to FA‐H) have been identified with their relative prevalence varying among the ethnical backgrounds. Recently, responsible genes, FANCA and FANCC, have been cloned. This report describes mutations of the FANCA gene, which we studied by direct sequencing of cDNA with confirmation on genomic DNA in 15 unclassified Japanese FA patients. A total of 19 sequence alterations were identified, of which 10 (six missense and four silent alterations) were likely to be nonpathogenic polymorphism. The remaining nine alterations, of which eight were novel mutations, were assumed to be pathogenic and consisted of two missense mutations and seven mutations resulting in truncation of gene product, demonstrating a wide allelic heterogeniety. The pathogenic mutations were found in 12 patients (80%); they were either homozygous or compound heterozygous in 10 patients, apparently heterozygous in two patients and none in three patients. We conclude that the sequence variability is intrinsic to the FANCA gene and that the relative prevalence of the FA‐A subtype is unusually high in Japanese FA patients. Hum Mutat 13:237–244, 1999.

Minimal residual disease with TEL-AML1 fusion transcript in childhood acute lymphoblastic leukaemia with t(12;21).

We analysed the TEL‐AML1 transcript using reverse transcription‐polymerase chain reaction (RT‐PCR) in order to detect minimal residual disease (MRD) in seven children with t(12;21)‐associated B‐lineage ALL. Leukaemic cells with the TEL‐AML1 transcript appear to be very sensitive to chemotherapy, and may be eradicated in most patients if adequate chemotherapy is given. However, a small number of patients with t(12;21) ALL may relapse under the currently used chemotherapy, and we believe that RT‐PCR for detecting MRD with the transcript is a suitable tool for monitoring the efficacy of chemotherapy or impending relapse in these patients. We analysed the TEL‐AML1 transcript using reverse transcription‐polymerase chain reaction (RT‐PCR) in order to detect minimal residual disease (MRD) in seven children with t(12;21)‐associated B‐lineage ALL. Two sets of primers, TEL exon 5 and AML1 exon 3 or 4, detected two types of transcript in four patients and two other types in two other patients. The two different translocation breakpoints in the AML1 gene with or without splicing out of AML1 exon 3 seemed to result in these four types of transcript in leukaemia samples.

Promoter hypermethylation of the RASSF1A gene predicts the poor outcome of patients with hepatoblastoma

Despite the progress of therapy, about 25% of patients with hepatoblastoma succumb to the disease. Prognostic factors, as well as improved therapies, are needed for these patients. We investigated the incidence and clinical significance of genetic and epigenetic aberrations in hepatoblastoma.

Yolk sac tumor but not seminoma or teratoma is associated with abnormal epigenetic reprogramming pathway and shows frequent hypermethylation of various tumor suppressor genes

Germ cell tumors (GCTs) are thought to arise from primordial germ cells (PGCs) that undergo epigenetic reprogramming: erasure of the somatic imprint in the genital ridge, and re‐establishment of the sex‐specific imprint at gametogenesis in the developing gonad. Previous studies suggested that GCTs show epigenetic patterns reflecting the reprogramming process of PGCs; however, epigenetic alterations of imprinted genes and their relationship with the methylation status of tumor suppressor genes (TSGs) have not been comprehensively studied. We analyzed the methylation status of the H19 and SNRPN differential methylated regions (DMRs) and the promoter region of 17 TSGs, and the expression status of H19, IGF2 and SNRPN in 45 GCTs, and found that 25 and 20 were in the normal and abnormal reprogramming pathways, respectively, defined on the basis of the methylation status of the two DMRs and the anatomical tumor site. The methylation pattern of the H19 and SNRPN DMRs was total erasure in seminomas, mostly physiological in teratomas, and various in yolk sac tumors. There were no correlations between the methylation status of the H19 DMR and mono‐ or biallelic expression of H19 or IGF2. Furthermore, we found that yolk sac tumors had a higher number of methylated TSGs than seminomas (P < 0.001) teratomas (P = 0.004) or other childhood tumors. While TSG methylation was known to have prognostic implications in various cancers, it did not affect the outcomes of patients with yolk sac tumor, suggesting that mechanisms of TSG methylation may be different between yolk sac tumor and other cancers. (Cancer Sci 2009; 100: 698–708)

Neurodegenerative central nervous system disease as late sequelae of Langerhans cell histiocytosis. Report from the Japan LCH Study Group

Langerhans’ cell histiocytosis can affect the central nervous system, where it frequently manifests as diabetes insipidus. Cerebellar ataxia and other neurological defects can represent late sequelae of this disorder. Clinical features, brain magnetic resonance imaging findings and EDSS scores of 11 patients with neurodegenerative central nervous system Langerhans cell histiocytosis were analyzed in Japan. All patients initially had multi-system-type Langerhans cell histiocytosis; 8 at 1–2 years of age and 3 at a later age. Neurodegenerative central nervous system largermans cell histiocytosis disease developed after a median time interval of 3.9 years from initial diagnosis. With a median follow-up of 4.5 years, 6 patients showed progression of disease with an EDSS score >3. This study demonstrates the importance of early detection of neurodegenerative central nervous system Langerhans cell histiocytosis by brain magnetic resonance imaging, particularly in the follow-up of patients who developed multi-system-type Langerhans cell histiocytosis in early infancy.

Frequent Increase of DNA Copy Number in the 2q24 Chromosomal Region and Its Association with a Poor Clinical Outcome in Hepatoblastoma: Cytogenetic and Comparative Genomic Hybridization Analysis

In a cytogenetic and comparative genomic hybridization (CGH) study of 38 hepatoblastomas, we found gain of Iq in 17 tumors (44.7%), that of 2/2q in 14 (36.8%), that of 20/20q in 9 (23.7%) and that of 8/8q in 8 (21.0%), loss of 4q in 4 (10.5%) and no DNA copy changes with normal karyotype or no mitotic cells in 11 (28.9%). Eleven tumors with 2/2q gain detected by CGH had a total chromosome 2 gain, a partial 2q gain, or a total chromosome 2 gain with an augmented partial 2q region; the common region for DNA copy gain was 2q24. Two‐color fluorescence in situ hybridization (FISH) analyses using probes covering the centromere of chromosome 2 or HOXD13 (2q31) confirmed the CGH findings, and showed that the common region for gain in 2q was centromeric to HOXD13. Event‐free survival (EFS)±standard error (SE) at 5 years was lowest in patients with 2q gain [37±15%], highest in those with no DNA copy changes [82±12%], and intermediate in those with DNA copy changes other than 2q gain [74±13%] (P=0.0549). Multivariate analysis showed that 2q gain was an independent factor predicting a poor outcome. These findings suggest the presence of a growth‐promoting gene or an oncogene in the 2q24 chromosome band, and a tumor suppressor gene in terminal 4q, which have important roles in the development and progression of hepatoblastoma.