Secondary chromosome changes in mantle cell lymphoma: cytogenetic and fluorescence in situ hybridization studies.

To better define the incidence and nature of secondary chromosome anomalies in mantle cell lymphoma (MCL) carrying the t(11:14)/BCL1 rearrangement, cytogenetic and fluorescence in situ hybridization studies (FISH) were performed in 42 patients (39 classical histology, 3 blastoid variant), using 6q21, 9p21/p16, 13q14, 17p13/p53 and chromosome-12-specific probes. Karyotypes from 89 cases published in 5 recent series including patients diagnosed in a homogeneous fashion were reviewed. In our series, FISH confirmed the interpretation of the karyotype in all cases and disclosed cryptic chromosome deletions in a sizeable fraction of cases. One patient (2.4% of total) was found with a cryptic 9p21 deletion by FISH. Two cases (4.8%) had a 6q21 deletion at CCA and at FISH; +12 was found in three cases by CCA plus nine by FISH (28.6%); 13q14 deletion was found in six cases by CCA plus 16 by FISH (52.4%), 17p13 deletion in three cases by CCA plus 8 by FISH (26.2%). In 131 patients (42 present series plus 89 in the literature) secondary chromosome aberrations seen by conventional cytogenetic analysis in more than 5 cases included deletions/translocations (del/t) 6q15-23 [15 cases]; -13 [14 cases]; del/t 1p21-31 [12 cases]; +3q [11 cases]; del/t 17p [9 cases]; 8p translocations and del(Y) [8 cases each]; -20 [7 cases]; 13q14 deletion, del/t 11q22-23, del/t 9q, del(10)(q22q24), -20, -21, -22 and -X [6 cases each]. We arrived at the following conclusions: i) though no secondary anomaly is specific for MCL, there is a distinct profile of recurrent chromosome lesions in MCL with 1p21-31 deletions, 8p translocations, 11q22-23 anomalies having a strong association with CD5+ B-cell lymphomas of low-to-intermediate grade histology; ii) FISH enabled the detection of cryptic chromosome 12, 13q and 17p rearrangements in a sizeable fraction of cases; iii) 9p21/p16 deletions did not occur at a high incidence in this series, possibly because of the low number of cases with blastoid variant.     

Bortezomib therapy response is independent of cytogenetic abnormalities in relapsed/refractory multiple myeloma

Myeloma patients with unfavorable molecular cytogenetics have a poor prognosis irrespective of treatment with conventional chemotherapy or autologous stem cell transplant. To investigate whether bortezomib, a new proteasome inhibitor, is active in relapsed/refractory myeloma patients with genetic risk factors, we evaluated the outcome of 65 patients and correlated the clinical response with 13q deletion, translocations t(11;14) and t(4;14) and CKS1B amplification as detected by interphase cytoplasmic fluorescence in situ hybridization (cIg-FISH). Thirty-seven of 61 (61%) evaluable patients had an objective response to bortezomib with median progression free (PFS) and overall survivals (OS) of 9.5 and 15.1 months, respectively. Of 43 cases with evaluable bone marrows, cIg-FISH determination of del(13q), t(4;14), t(11;14) and CKS1B amplification was done on 40, 41, 41 and 37 cases and the frequency of their detection was 35%, 15%, 15%, and 32%, respectively. There was no statistically significant difference in response to bortezomib for patients with or without 13q deletion (77% versus 50%), t(4;14) (67% versus 56%), t(11;4) (33% versus 62%), or CKS1B amplification (67% versus 57%). Furthermore, there was no statistically significant difference in PFS or OS following bortezomib therapy between patients with or without these molecular cytogenetic abnormalities. Our data suggest that, in this pilot study, bortezomib is an effective salvage therapy for refractory/relapsed myeloma, irrespective of genetic risk factors.     

The prognostic significance of cytogenetics and molecular profiling in multiple myeloma

Multiple myeloma (MM) is a plasma cell malignancy characterized by very complex cytogenetic and molecular genetic aberrations. In newly diagnosed symptomatic patients, the modal chromosome number is usually either hyperdiploid with multiple trisomies or hypodiploid with one of several types of immunoglobulin heavy chain (Ig) translocations. The chromosome ploidy status and Ig rearrangements are two genetic criteria that are used to help stratify patients into prognostic groups based on the findings of conventional cytogenetics and fluorescence in situ hybridization (FISH). In general, the hypodiploid group with t(4;14)(p16;q32) or t(14;16)(q32;q23) is considered a high-risk group, while the hyperdiploid patients with t(11;14)(q13;q32) are considered a better prognostic group. As the disease progresses, it becomes more proliferative and develops a number of secondary chromosome aberrations. These secondary aberrations commonly involve MYC rearrangements, del(13q), del(17p), and the deletion of 1p and/or amplification of 1q. Of the secondary aberrations, del(17p) is consistently associated with poor prognosis. All of these cytogenetic aberrations and many additional ones are now identified by means of high resolution molecular profiling. Gene expression profiling (GEP), array comparative genomic hybridization (aCGH), and single-nucleotide polymorphism (SNP) arrays have been able to identify novel genetic aberration patterns that have previously gone unrecognized. With the integration of data from these profiling techniques, new subclassifications of MM have been proposed which define distinct molecular genetic subgroups. In this review, the findings from conventional cytogenetics, interphase FISH, GEP, aCGH, and SNP profiles are described to provide the conceptual framework for defining the emerging molecular genetic subgroups with prognostic significance.     

Molecular Cytogenetic Analysis of RB-1 Deletions in Chronic B-Cell Leukemias

Deletions or translocations of 13q, most commonly involving band 13q14, belong to the most frequent structural chromosome abnormalities in B-cell chronic lymphocytic leukemia (B-CLL). In a combined metaphase and interphase cytogenetic study using conventional G-banding analysis and fluorescence in situ hybridization (ISH) we previously analysed the retinoblastoma susceptibility gene (RB-1) and its chromosomal locus 13q14 in 35 patients with chronic B-cell leukemias. We report here on the interphase cytogenetic analysis of 109 cases with chronic B-cell leukemias [B-CLL = 90; B-prolymphocytic leukemia (B-PLL) = 6, hairy cell leukemia (HCL) = 13]; a subset of 49 patients (B-CLL = 45; B-PLL = 4) was studied by conventional G-banding analysis. By G-banding, 5/45 (11%) patients with B-CLL had deletions or translocations affecting band 13q14; in contrast, ISH to interphase cells showed RB-1 deletion in 19/90 (21%) patients with B-CLL. No 13q14 abnormalities or RB-1 deletion were detected in patients with B-PLL and HCL. Our data confirm the high frequency of RB-I deletions in B-CLL and further emphasize the possible pathogenetic role of this genomic region.     

Clinical implications of chromosomal abnormalities in multiple myeloma

The adverse prognostic role of cytogenetic abnormalities has recently been established in plasma cell dyscrasias. Modern techniques such as fluorescence in situ hybridization and comparative genomic hybridization have revealed a higher incidence of cytogenetic abnormalities in patients with multiple myeloma (MM) compared to conventional cytogenetics. Hypodiploidy and chromosome 13 abnormalities are found in more than 50% of myeloma patients, representing well known factors with adverse prognosis. Rearrangements involving the switch regions of immunoglobulin heavy chain (IgH) gene at 14q32 with various partner genes represent the most common structural abnormalities, having an incidence of 70% in MM. Structural abnormalities of chromosomes 17 and 8 involving the p53 and c-myc genes are considered to be less frequent events, but carry a poor prognosis. New therapeutic approaches such as non-myeloablative allotransplantation and modern therapeutic agents (thalidomide, lenalidomide, and bortezomib) and their combinations give promise for an improved therapeutic management of patients with MM. The detection of t(4;14), t(14;16), deletion of chromosome 13 on metaphase analysis, or deletion of p53 by FISH will define high-risk prognostic groups that are not generally controlled with high-dose melphalan and autologous stem cell transplantation (ASCT), and should therefore be treated with more investigational therapies. Alternatively, eligible patients who do not have these poor risk factors are more likely to benefit from a high-dose, melphalan-based, regimen followed by ASCT.     

Analysis of PTEN deletions and mutations in multiple myeloma

Clonal plasma cells from patients with multiple myeloma (MM), plasma cell leukemia (PCL) and human myeloma cell lines (HMCLs) were analyzed for deletions/mutations of the tumor suppressor gene PTEN. By interphase-FISH, hemizygous PTEN deletions were detected in 4 (5.6%) of 71 MM patients, 2 (20%) of 10 PCLs, and 2 (20%) of 10 HMCLs. PTEN deletions were detected in 4 MM patients at diagnosis with stage III disease (Durie-Salmon). Of the six cases with PTEN deletions, 1 MM had a 13q deletion, 1 PCL had a t(11;14), and the other PCL had a t(14;16), a 13q deletion and a p53 deletion. Sequencing analysis did not detect PTEN mutations in 11 primary MM and 5 PCL cases. Our results indicate that alterations of PTEN are uncommon in MM patients, and PTEN deletions tend to occur in advanced disease suggesting that they are secondary, rather than primary, events in the pathogenesis of MM.     

Cytogenetic Abnormalities in Multiple Myeloma Patients at a Tertiary Healthcare Center in India

Objective: Multiple myeloma (MM) is a clinically and genetically heterogeneous plasma cell neoplasm. Theprognosis of MM patients is dependent on several factors including the patient’s age, the stage of disease and geneticalterations. This study aimed to determine the frequency of common chromosomal abnormalities and their significance inMM patients referred to a tertiary healthcare center in India. Methods: Fluorescence in situ hybridization on interphasenuclei from bone marrow cells using seven MM-specific probes for recurrent aberrations was performed in a total of215 newly diagnosed patients. Results: Chromosomal abnormalities were detected in 161 (74.9%) MM patients inthis study. The most frequent aberration was trisomy(ies) involving only gain of chromosomes in 48 (22.3%) cases.A translocation involving the IGH gene alone or accompanied by trisomy(ies) or by monosomy 13/13q deletion or byboth was registered in 80 (37.2%) patients. Atypical patterns such as a deletion of the IGH variable segment (IGHv)on the derivative chromosome 14 or on the native (normal) chromosome 14, biallelic deletion of IGHv, deletion ofthe IGH constant segment on the rearranged chromosome14 and extra fusions were noticed in 21 (9.8%) patientswith an IGH rearrangement. Monosomy 13/deletion 13q was identified singly or as part of a complex karyotype in74 patients (34.4%). Clonal heterogeneity and additional abnormalities including TP53 deletion and monosomies ofchromosomes 4, 9, 14 and 16 were recorded in 18.6% and 16.3% of patients respectively. Patients with abnormalitiesexhibited plasmacytosis, reduced hemoglobin value and high level of ß2-microglobulin. Conclusions: A lower medianage and a low frequency of IGH translocations particularly t(11;14) and chromosome 13 abnormalities suggest ethnicdiversity. Further investigations on genetic alterations including IGH deletions will contribute to improved insightsinto the biology of myeloma disease, risk stratification and patient management.     

The pathogenesis of MALT lymphomas: where do we stand?

Mucosa-associated lymphoid tissue (MALT) lymphoma is a heterogeneous form of a B-cell non-Hodgkin's lymphoma with extranodal location. The gastrointestinal tract is the most common site of disease, but involvement of multiple other organ systems has been documented. Four translocations, t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21) and t(3;14)(p13;q32), are specifically associated with MALT lymphoma. Remarkably, the genes targeted by at least three of these translocations are involved in one and the same pathway, leading to the activation of nuclear factor-kappaB (NF-kappaB). This review presents MALT lymphoma as a model of how sustained inflammation increases the risk of genotoxic insults and how these genetic events initiate oncogenesis.     

Prognostic impact of INK4A deletion in Ewing sarcoma

BACKGROUND: The primary genetic alteration in > 95% of Ewing sarcomas (ES) is a specific fusion of EWS with FLI1 or ERG. Secondary genetic alterations possibly involved in progression of ES are not well understood. A recent study found loss of the negative cell cycle regulator gene INK4A in 8 of 27 ES samples (30%). To confirm these findings and evaluate their prognostic significance, the authors studied INK4A deletion in 41 ES samples from 39 patients. METHODS: Using Southern blot analysis with an INK4A p16 cDNA probe, the intensity of the INK4A bands in ES DNA samples was normalized to that of a control probe and compared with nondeleted control DNA; > 50% signal reduction was scored as evidence of deletion. All ES tumor DNA samples previously were confirmed to have EWS rearrangements on the same Southern blots, using a cDNA probe spanning the EWS breakpoint region. RESULTS: Tumors from 7 patients (18%) showed INK4A deletion independent of disease stage (localized or metastatic) or sample source (primary tumor or metastasis). INK4A was a strong negative factor for disease specific survival in univariate analysis (P = 0.001) and in multivariate analysis including stage (relative risk = 6; P = 0.001). CONCLUSIONS: INK4A deletions appear to be the most frequent secondary molecular genetic alteration found to date in ES. Their possible clinical usefulness in identifying a subset of ES patients with poor prognosis merits systematic prospective analysis. [See related article on pages 783-92.] Copyright 2000 American Cancer Society.     

Both IGH translocations and chromosome 13q deletions are early events in monoclonal gammopathy of undetermined significance and do not evolve during transition to multiple myeloma.

Molecular and genetic events associated with the transition from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) are still poorly characterized. We investigated serial bone marrow specimens from 11 patients with MGUS who eventually progressed to MM (MM post-MGUS) by interphase fluorescence in situ hybridization for immunoglobulin heavy-chain gene (IgH) translocations and chromosome 13q deletions (del(13q)). In nine patients, IgH translocations were present both in MGUS and MM post-MGUS plasma cells, including three t(11;14)(q13;q32) and one t(4;14)(p16;q32), which was observed already 92 months prior to MM. Similarly, all five MM patients with del(13q) had this aberration already at the MGUS stage. Two patients without IgH translocation and del(13q) had chromosomal gains suggesting hyperdiploidy, but IgH translocations and/or del(13q) did not emerge at MM post-MGUS. IgH translocations and del(13q) are early genetic events in monoclonal gammopathies, suggesting that additional events are required for the transition from stable MGUS to progressive MM.     

A practical guide to defining high-risk myeloma for clinical trials, patient counseling and choice of therapy.

Clinical outcomes for multiple myeloma (MM) are highly heterogeneous and it is now clear that pivotal genetic events are the primary harbingers of such variation. These findings have broad implications for counseling, choice of therapy and the design and interpretation of clinical investigation. Indeed, as in acute leukemias and non-hodgkins lymphoma, we believe it is no longer acceptable to consider MM a single disease entity. As such, the accurate diagnosis of MM subtypes and the adoption of common criteria for the identification and stratification of MM patients has become critical. Herein, we provide a consensus high-risk definition and offer practical guidelines for the adoption of routine diagnostic testing. Although acknowledging that more refined classifications will continue to be developed, we propose that the definition of high-risk disease (any of the t(4;14), t(14;16), t(14;20), deletion 17q13, aneuploidy or deletion chromosome 13 by metaphase cytogenetics, or plasma cell labeling index >3.0) be adopted. This classification will identify most of the 25% of MM patients for whom current therapies are inadequate and for whom investigational regimens should be vigorously pursued. Conversely, the 75% of patients remaining have more favorable outcomes using existing - albeit non-curative - therapeutic options.     

Final safety and efficacy of erlotinib in the phase 4 POLARSTAR surveillance study of 10 708 Japanese patients with non‐small‐cell lung cancer

Interstitial lung disease (ILD) occurrence and risk factors were investigated in the Japanese non‐small‐cell lung cancer, post‐marketing, large‐scale surveillance study, POLARSTAR. All patients with unresectable, recurrent/advanced non‐small‐cell lung cancer who were treated with erlotinib in Japan between December 2007 and October 2009 were enrolled. Primary endpoints were patterns of ILD and risk factors for onset of ILD and ILD‐related death. Overall survival, progression‐free survival, and occurrence of adverse drug reactions were secondary endpoints. Interstitial lung disease was confirmed in 429 (4.3%) patients. Concurrent/previous ILD (hazard ratio, 3.19), emphysema or chronic obstructive pulmonary disease (hazard ratio, 1.86), lung infection (hazard ratio, 1.55), smoking history (hazard ratio, 2.23), and period from initial cancer diagnosis to the start of treatment (<360 days; hazard ratio, 0.58) were identified as significant risk factors for developing ILD by Cox multivariate analysis. Logistic regression analysis identified Eastern Cooperative Oncology Group performance status 2–4 (odds ratio, 2.45 [95% confidence interval, 1.41–4.27]; P = 0.0016), ≤50% remaining normal lung area (odds ratio, 3.12 [1.48–6.58]; P = 0.0029), and concomitant honeycombing with interstitial pneumonia (odds ratio, 6.67 [1.35–32.94]; P = 0.02) as poor prognostic factors for ILD death. Median overall survival was 277 days; median progression‐free survival was 67 days. These data confirm the well‐characterized safety profile of erlotinib. Interstitial lung disease is still an adverse drug reaction of interest in this population, and these results, including ILD risk factors, give helpful information for treatment selection and monitoring. Erlotinib efficacy was additionally confirmed in this population. (POLARSTAR trial ML21590.)     

Treatment of Multiple Myeloma: A Comprehensive Review

Multiple myeloma (MM) is a neoplastic plasma cell disorder that results in end-organ damage (hypercalcemia, renal insufficiency, anemia, or skeletal lesions). Patients should not be treated unless they have symptomatic (end-organ damage) MM. They should be classified as having high-risk or standard-risk disease. Patients are classified as high risk in the presence of hypodiploidy or deletion of chromosome 13 (del[13]) with conventional cytogenetics, the presence of t(4:14), t(14;16), t(14;20) translocations or del(17p) with fluorescence in situ hybridization. High-risk disease accounts for about 25% of patients with symptomatic MM. If the patient is deemed eligible for an autologous stem cell transplantation (ASCT), 3 or 4 cycles of lenalidomide and low-dose dexamethasone, or bortezomib and dexamethasone, or thalidomide and dexamethasone are reasonable choices. Stem cells should then be collected and one may proceed with an ASCT. If the patient has a complete response or a very good partial response (VGPR), the patient may be followed without maintenance therapy. If the patient has a less than VGPR, a second ASCT is encouraged. If the patient is in the high-risk group, a bortezomib-containing regimen to maximum response followed by 2 additional cycles of therapy is a reasonable approach. Lenalidomide and lowdose dexamethasone is another option for maintenance until progression. If the patient is considered ineligible for an ASCT, then melphalan, prednisone, and thalidomide is suggested for the standard-risk patient, and melphalan, prednisone, and bortezomib (MPV) for the high-risk patient. Treatment of relapsed or refractory MM is covered. The novel therapies—thalidomide, bortezomib, and lenalidomide—have resulted in improved survival rates. The complications of MM are also described. Multiple myeloma is a plasma cell neoplasm that is characterized by a single clone of plasma cells producing a monoclonal protein (M-protein). The malignant proliferation of plasma cells produces skeletal destruction that leads to bone pain and pathologic fractures. The M-protein might lead to renal failure, hyperviscosity syndrome, or through the suppression of uninvolved immunoglobulins, recurrent infections. Anemia and hypercalcemia are common complications.     

De novo acute B-cell leukemia with translocation t(14;18): an entity with a poor prognosis.

Three cases of de novo acute B-cell lymphoblastic leukemia are presented, all with an unusual phenotype, involvement of translocation t(14;18) and additional chromosomal abnormalities, including translocation t(8;14) and deletion of chromosome 9. In contrast to normal FAB-L2 or FAB-L3 acute lymphoblastic leukemia (ALL), these leukemias did not express cytoplasmatic and membranous immunoglobulin. The combination of translocation t(14;18) and additional chromosomal events on the other chromosome 14 account for the lack of immunoglobulin expression. In one case a low grade follicular lymphoma was found next to a high grade Burkitt type ALL. The translocation t(14;18) takes place as a mistake in the VDJH joining in pre-B cells in the bone marrow. It is proposed that some cases of de novo ALL may arise as a blast crisis induced by genetic events, secondary to the primary t(14;18) translocation. This type of ALL seems to have a poor prognosis.     

High incidence of thromboembolism in patients with chronic GVHD: association with severity of GVHD and donor-recipient ABO blood group

Chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic cell transplantation (HCT) is associated with systemic inflammation and endothelial dysfunction, increasing risk for thromboembolic events (TEE). In 145 adult recipients who developed cGVHD after a matched sibling or umbilical cord blood donor HCT from 2010 to 2018, 32(22%) developed at least 1 TEE event, and 14(10%) developed 2 TEE events. The 5-year cumulative incidence of TEE was 22% (95% CI, 15–29%) with a median time from cGVHD to TEE of 234 days (range, 12–2050). Median time to the development of LE DVT or PE was 107 (range, 12–1925) compared to 450 days (range, 158–1300) for UE DVT. Cumulative incidence of TEE was 9% (95% CI, 0–20%), 17% (95% CI, 9–25%), and 38% (95% CI, 22–55%) in those with mild, moderate, and severe GVHD, respectively. Higher risk for TEE was associated with cGVHD severity (hazard ratio [HR] 4.9, [95% CI, 1.1–22.0]; p = 0.03), non-O-donor to recipient ABO match compared to O-donor to O-recipient match (HR 2.7, [95% CI, 1.0–7.5]; p = 0.053), and personal history of coronary artery disease (HR 2.4, [95% CI, 1.1–5.3]; p = 0.03). TEE was not associated with 2-year non-relapse mortality or 5-year overall survival.Subject terms: Medical research, Cancer     

der(11)t(11;17): a distinct cytogenetic pathway of advanced stage neuroblastoma (NBL) - detected by spectral karyotyping (SKY)

Conventional cytogenetic, molecular cytogenic and genetic methods disclosed a broad spectrum of genetic abnormalities leading to gain and loss of chromosomal segments in advanced stage neuroblastoma (NBL). Specific correlation between the genetic findings could delineate distinct genetic pathways, of which the biology and prognostic significance is as yet undetermined. Using spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) on metaphases from 16 patients with advanced stage NBL, it was possible to explore the whole spectrum of rearrangement within complex karyotypes and to detect hidden recurrent translocations. All translocations were unbalanced. The most prevalent recurrent unbalanced translocations resulted in 17q gain in 12 patients (75%), 11q loss in nine patients (56%), and 1p deletion/imbalance in eight patients (50%). The most frequent recurrent translocation was der(11)t(11;17) in six patients. Three cytogenetic pathways could be delineated. The first, with six patients, was characterized by the unbalanced translocation der(11)t(11;17), detected only by SKY, resulting in the concomitant 17q gain and 11q loss. No MYCN amplification or 1p deletion (except one patient with 1p imbalance) were found, while 3p deletion, and complex karyotypes were common. The second subgroup, with four patients, had 17q gain and 1p deletion, and in two patients 11q loss, that was apparent only by FISH. 1p deletion occurred through der(1)t(1;17) or del(1p). The third subgroup of four patients was characterized by MYCN amplification with 17q gain and 1p deletion, very rarely with 11q loss (one patient) through a translocation with a non-17q partner. The SKY subclassifications were in accordance with the findings reported by molecular genetic techniques, and may indicate that distinct oncogenes and suppressor genes are involved in the der(11)t(11;17) pathway of advanced stage NBL.     

Prognostic and therapeutic significance of myeloma genetics and gene expression profiling.

Molecular diagnostic tools and novel therapeutics now offer the potential for accurate prognostic and personalized treatment road maps for patients with multiple myeloma (MM). We will review the evidence and provide specific recommendations for routine clinical molecular genetic testing and use of such information to guide therapeutic decision making. In particular, the negative prognostic impact of specific IgH translocations such as the t(4;14), t(14;16), chromosome 13 deletion by conventional cytogenetics and loss of 17p13 by interphase fluorescence in situ hybridization are now established. Preliminary gene expression profiling studies have also demonstrated that individual genes (CSK1-B) or groups of genes can define prognosis with greater accuracy than conventional genetic markers and can provide pharmacogenomic and biologic insight into the pathophysiology, therapeutics, and future targets of myeloma. Importantly, we recommend that all clinical trials now adopt routine genetic testing and risk stratification.     

Myeloablative megatherapy with autologous stem-cell rescue versus oral maintenance chemotherapy as consolidation treatment in patients with high-risk neuroblastoma: a randomised controlled trial

BACKGROUND: Myeloablative megatherapy is commonly used to improve the poor outlook of children with high-risk neuroblastoma, yet its role is poorly defined. We aimed to assess whether megatherapy with autologous stem-cell transplantation could increase event-free survival and overall survival compared with maintenance chemotherapy. METHODS: 295 patients with high-risk neuroblastoma (ie, patients with stage 4 disease aged older than 1 year or those with MYCN-amplified tumours and stage 1, 2, 3, or 4S disease or stage 4 disease and <1 year old) were randomly assigned to myeloablative megatherapy (melphalan, etoposide, and carboplatin) with autologous stem-cell transplantation (n=149) or to oral maintenance chemotherapy with cyclophosphamide (n=146). The primary endpoint was event-free survival. Secondary endpoints were overall survival and the number of treatment-related deaths. Analyses were done by intent to treat, as treated, and treated as randomised. FINDINGS: Intention-to-treat analysis showed that patients allocated megatherapy had increased 3-year event-free survival compared with those allocated maintenance therapy (47% [95% CI 38-55] vs 31% [95% CI 23-39]; hazard ratio 1.404 [95% CI 1.048-1.881], p=0.0221), but did not have significantly increased 3-year overall survival (62% [95% CI 54-70] vs 53% [95% CI 45-62]; 1.329 [0.958-1.843], p=0.0875). Improved 3-year event-free survival and 3-year overall survival were also recorded for patients given megatherapy in the as-treated group (n=212) and in the treated-as-randomised group (n=145). Two patients died from therapy-related complications during induction treatment. No patients given maintenance therapy died from acute treatment-related toxic effects. Five patients given megatherapy died from acute complications related to megatherapy. INTERPRETATION: Myeloablative chemotherapy with autologous stem-cell transplantation improves the outcome for children with high-risk neuroblastoma despite the raised risk of treatment-associated death.     

Cytogenetics of Hispanic and White children with acute lymphoblastic leukemia in California.

Epidemiologic studies of childhood leukemia have made limited use of tumor genetic characteristics, which may be related to disease etiology. We characterized the cytogenetics of 543 childhood leukemia patients (0-14 years of age) enrolled in the Northern California Childhood Leukemia Study, an approximately population-based study comprised primarily of Hispanics (42%) and non-Hispanic Whites (41%), and compared the cytogenetic profiles between these two ethnic groups. Subjects were classified by immunophenotype, conventional cytogenetic characteristics, and fluorescence in situ hybridization findings. The ploidy levels most frequently observed among acute lymphoblastic leukemia patients were high hyperdiploidy (51-67 chromosomes) and pseudodiploidy (34% and 27%, respectively). No ethnic differences in the frequency of 11q23/MLL rearrangements were observed between Hispanics and non-Hispanic Whites. Among B-lineage acute lymphoblastic leukemia patients, the percentage of TEL-AML1 translocations was significantly lower in Hispanics (13%) than in non-Hispanic Whites (24%; P = 0.01). This is the first time that this ethnic variation has been observed in a large number of patients in a defined geographic region, which is consistent with findings from smaller international studies. The mechanistic basis for this 2-fold variation in frequency of TEL-AML1 may be due to ethnic-specific risk factors or genetics and should be explored further.     

Therapy Related Leukemias: Susceptibility, Prevention and Treatment

Acute leukemia is the most frequent therapy-related malignancy. Together with the increasing use of chemo- and radiotherapy, individual predisposing factors play a key role. Most of secondary leukemias can be divided in two well-defined groups: those secondary to the use of alkylating agents and those associated to topoisomerase inhibitors. Leukemias induced by alkylating agents usually follow a long period of latency from the primary tumour and present as myelodysplasia with unbalanced chromosomal aberrations. These frequently include deletions of chromosome 13 and loss of the entire or of part of chomosomes 5 or 7. The loss of the coding regions for tumor suppressor genes from hematopoietic progenitor cells is a particularly unfavourable event, since the remaining allele becomes susceptible to inactivating mutations leading to the leukemic transformation. The tumorigenic action of topoisomerase inhibitors is on the other hand due to the formation of multiple DNA strand breaks, resolved by chromosomal translocations. Among these, chromosome 11, band q23, where the myeloid-lymphoid leukemia (MLL) gene is located, is often involved. Frequent partners are chromosomes 9, 19 and 4 in the t(9;11), t(19;11) and t(4;11) translocations. Younger age, a mean period of latency of 2 years and monocytic subtypes are characteristic features of this type of leukemia.

Among patients at risk for secondary leukemia, those with Hodgkin's disease are the most extensively studied, with the major impact of alkylating agents included in the chemotherapy schedule. The same is true for non-Hodgkin's lymphoma, while in multiple myeloma and acute lymphoblastic leukemia determinants are the dose of melphalan and of epypodophyllotoxin, respectively. Patients with breast, ovarian and testicular neoplasms are also at risk, in particular if trated with the association of alkylating agents and topoisomerase II inhibitors. According to the EBMT registry, in patients with lymphoma treated with high-dose therapy and autologous stem cell transplantation the cumulative risk of inducing leukemia at 5 years is 2.6%.

Among treatment options, supportive therapy is indicated in older patients, while allogeneic stem cell transplantation, related or matched-unrelated, is feasible in younger patients. These data indicate the need for the identification of predisposing factors for secondary leukemia. In particular, frequent follow-up of patients at high-risk should be performed and any peripheral blood cytopenia should be considered suspicious. Whenever possible, the exclusion of drugs known to be leukemogenic from the treatment schedules should be considered, especially in young patients.