Studies of chronic lymphocytic leukemia (CLL) have yielded substantial progress, however a lack of immortalized cell lines representative of the primary disease has hampered a full understanding of disease pathogenesis and development of new treatments. Here we describe a novel CLL cell line (OSU-CLL) generated by EBV transformation, which displays a similar cytogenetic and immunophenotype observed in the patient’s CLL (CD5 positive with trisomy 12 and 19). A companion cell line was also generated from the same patient (OSU-NB). This cell line lacked typical CLL characteristics, and is likely derived from the patient’s normal B cells. In vitro migration assays demonstrated that OSU-CLL exhibits migratory properties similar to primary CLL cells whereas OSU-NB has significantly reduced ability to migrate spontaneously or towards chemokine. Microarray analysis demonstrated distinct gene expression patterns in the two cell lines, including genes on chromosomes 12 and 19, which is consistent with the cytogenetic profile in this cell line. Finally, OSU-CLL was readily transplantable into NOG mice, producing uniform engraftment by three weeks with leukemic cells detectable in the peripheral blood spleen and bone marrow. These studies describe a new CLL cell line that extends currently available models to study gene function in this disease.
Autologous stem cell transplant (ASCT) is an effective treatment for multiple myeloma (MM). However the timing of ASCT in the era of novel agents (lenalidomide, thalidomide, bortezomib) is unknown. We retrospectively reviewed the outcome of MM patients who received novel agent based induction treatment and received first ASCT within 12 months of diagnosis (early ASCT, N = 102), or at a later date (late ASCT, N = 65). Median time to ASCT was 7.9 months vs. 17.7 months in the early vs. late ASCT. The 3 and 5 yr overall Survival (OS) from diagnosis was 90 and 63% versus 82 and 63% in early and late ASCT respectively (P=0.45). Forty-one and 36 patients in the early and late ASCT have relapsed or progressed with median time to relapse of 28 and 23 mos (p=0.055). On multivariable analysis, factors predictive of increased risk for progression were ISS stage III (p=0.007), and < VGPR post-ASCT (p<0.001). Factor predictive of worst outcomes for OS was being on hemodialysis (p=0.037). No superiority of one agent was seen. In summary, early or late ASCT is a viable option for MM patients receiving induction treatment with novel targeted therapies.
Multiple Myeloma; Transplantation; Bortezomib; Lenalidomide
Five laboratories in the Chronic Lymphocytic Leukemia (CLL) Research Consortium (CRC) investigated standardizing and pooling of fluorescence in situ hybridization (FISH) results as a collaborative research project. This investigation used fixed bone marrow and blood cells available from previous conventional cytogenetic or FISH studies in two pilot studies, a one-day workshop, and proficiency test. Multiple FISH probe strategies were used to detect 6q-, 11q-, +12, 13q-, 17p-, and IGH rearrangements. Ten specimens were studied by participants who used their own probes (pilot study 1). Of 312 FISH interpretations, 224 (72%) were true-negative, 74 (24%) true-positive, 6 (2%) false-negative, and 8 (3%) false-positive. In pilot study no. 2, each participant studied two specimens using identical FISH probe sets to control for variation due to probe sets and probe strategies. Of 80 FISH interpretations, no false interpretations were identified. At a subsequent workshop, discussions produced agreement on scoring criteria. The proficiency test that followed produced no false-negative results and 4% (3/68) false-positive interpretations. Interpretation disagreements among laboratories were primarily attributable to inadequate normal cutoffs, inconsistent scoring criteria, and the use of different FISH probe strategies. Collaborative organizations that use pooled FISH results may wish to impose more conservative empiric normal cutoff values or use an equivocal range between the normal cutoff and the abnormal reference range to eliminate false-positive interpretations. False-negative results will still occur, and would be expected in low-percentage positive cases; these would likely have less clinical significance than false positive results. Individual laboratories can help by closely following rigorous quality assurance guidelines to ensure accurate and consistent FISH studies in their clinical practice and research.
The rare translocation t(8;14)(q11.2;q32) has been described in patients with B-cell acute lymphoblastic leukemia (ALL), particularly patients with Down Syndrome (DS).
We describe patients with t(8;14)(q11.2;q32) that were identified by the Children's Oncology Group (COG) ALL cytogenetics database, expanding our previous report of 10 patients with this translocation. Twenty-two such patients were treated with COG protocols. All patients had B-cell ALL and 7 (31.8%) had DS. None of the children with DS had an event, thus these patients had a superior estimated 5-year event-free survival (EFS) compared to non-DS patients (100% vs. 50.1 ± 17.7%; p=0.04). Only one patient (4.5%) had a concomitant Philadelphia chromosome t(9;22)(q34;q11.2). The cytogenetics data of two additional patients, who were not eligible for COG protocols, are also included in this report.
In conclusion, ALL patients with the recurring translocation t(8;14)(q11.2;q32) have B-cell phenotype and a high percentage have DS. Children with DS and t(8;14)(q11.2;q34) have improved event-free survival using standard COG therapy compared to non-DS patients. We did not find an increased number of patients with a concomitant Philadelphia chromosome in this population.
Acute Lymphoblastic Leukemia; B-cell; translocation; Down Syndrome
The impact of mutation of the ATM (ataxia telangiectasia mutated) gene in chronic lymphocytic leukemia (CLL) treatment outcome has not been examined. We studied ATM mutations in 73 patients treated with fludarabine and rituximab. ATM gene mutation analysis was performed using temperature gradient capillary electrophoresis. The impact of detected variants on overall survival (OS) and progression-free survival (PFS) was tested with proportional hazards models. None of the 73 patients demonstrated truncating ATM mutations; 17 (23%, 95% confidence interval 14 – 35%) had non-silent variants (ATM-NSVs), including 13 known ATM polymorphisms and four missense variants. ATM-NSVs were not significantly associated with any baseline characteristics including immunoglobulin heavy chain variable gene (IGVH) status. In multivariable models, no significant differences in complete response (p = 0.70), PFS (p = 0.59) or OS (p = 0.13) were observed. Our data indicate that truncating ATM mutations are rare in patients with CLL. Furthermore, in this dataset, these non-silent variants had limited impact on PFS and OS.
Chronic lymphocytic leukemia; ATM mutation; prognosis; chemoimmunotherapy
Complex karyotype (CK) on metaphase cytogenetics discriminates poor outcome in chronic lymphocytic leukaemia (CLL) patients undergoing salvage treatment; we hypothesized that it might provide prognostic information for patients undergoing allogeneic stem cell transplant. Fifty-one CLL patients were analysed following transplant; 18-month overall survival (OS), event-free survival (EFS) and cumulative incidence of progression estimates were 35%, 14% and 63%, respectively, in patients with CK (n = 19) versus 83%, 68% and 29% in patients without (n = 32) (P ≤ 0.0001, P ≤ 0.0001, and P = 0.02). In patients with high-risk interphase cytogenetics, CK remained predictive of worse OS (P = 0.02) and EFS (P = 0.009). These findings support further evaluation of metaphase karyotype in transplant risk assessment.
chronic lymphocytic leukaemia; transplant; fluorescent insitu hybridization; metaphase cytogenetics; conditioning
Increased ZAP-70 expression predicts poor prognosis in chronic lymphocytic leukemia (CLL). Current methods for accurately measuring ZAP-70 expression are problematic, preventing widespread application of these tests in clinical decision making. We therefore used comprehensive DNA methylation profiling of the ZAP-70 regulatory region to identify sites important for transcriptional control.
Patients and Methods
High-resolution quantitative DNA methylation analysis of the entire ZAP-70 gene regulatory regions was conducted on 247 samples from patients with CLL from four independent clinical studies.
Through this comprehensive analysis, we identified a small area in the 5′ regulatory region of ZAP-70 that showed large variability in methylation in CLL samples but was universally methylated in normal B cells. High correlation with mRNA and protein expression, as well as activity in promoter reporter assays, revealed that within this differentially methylated region, a single CpG dinucleotide and neighboring nucleotides are particularly important in ZAP-70 transcriptional regulation. Furthermore, by using clustering approaches, we identified a prognostic role for this site in four independent data sets of patients with CLL using time to treatment, progression-free survival, and overall survival as clinical end points.
Comprehensive quantitative DNA methylation analysis of the ZAP-70 gene in CLL identified important regions responsible for transcriptional regulation. In addition, loss of methylation at a specific single CpG dinucleotide in the ZAP-70 5′ regulatory sequence is a highly predictive and reproducible biomarker of poor prognosis in this disease. This work demonstrates the feasibility of using quantitative specific ZAP-70 methylation analysis as a relevant clinically applicable prognostic test in CLL.
Infant leukemias have a high frequency of mixed lineage leukemia (MLL) gene rearrangements.
Using data from a large etiologic study, we evaluated the distribution of selected demographic factors among 374 infant leukemia cases by leukemic subtype, MLL status and diagnosis age.
Overall, 228 cases were MLL+. Compared to white infants, black infants were significantly less likely to have MLL+ leukemia. Further, there was a statistically significantly higher age at diagnosis for infants with t(9;11) translocations compared to all other translocation partners in both acute lymphoblastic leukemia and acute myeloid leukemia cases.
These patterns may provide important etiological insight into the biology of infant leukemia.
epidemiology; infants; leukemia; MLL
Tetraspanins are commonly believed to act only as “molecular facilitators”, with no direct role in signal transduction. We herein demonstrate that upon ligation, CD37, a tetraspanin molecule expressed on mature normal and transformed B-cells, becomes tyrosine phosphorylated, associates with proximal signaling molecules, and initiates a cascade of events leading to apoptosis. Moreover, we have identified two tyrosine residues with opposing regulatory functions, one lies in the N-terminal domain of CD37 in a predicted “ITIM-like” motif and mediates SHP1-dependent death whereas the second lies in a predicted “ITAM motif” in the C-terminal domain of CD37 and counteracts death signals by mediating phosphatidylinositol 3-kinase-dependent survival.
How inflammation causes cancer is unclear. IL-15 is a pro-inflammatory cytokine elevated in human large granular lymphocyte (LGL) leukemia. Mice overexpressing IL-15 develop LGL leukemia. Here we show that prolonged in vitro exposure of wild type (WT) LGL to IL-15 results in Myc-mediated up regulation of aurora kinases, centrosome aberrancies, and aneuploidy. Simultaneously, IL-15 represses miR-29b via induction of Myc/NF-κBp65/Hdac-1, resulting in Dnmt3b overexpression and DNA hypermethylation. All this is validated in human LGL leukemia. Strikingly, adoptive transfer of WT LGL cultured with IL-15 led to malignant transformation in vivo. Drug targeting which reverses miR-29b repression, cures otherwise fatal LGL leukemia. We show how excessive IL-15 initiates cancer and demonstrate effective drug targeting for potential therapy of human LGL leukemia.
Several case–control studies have evaluated associations between maternal smoking, alcohol consumption and illicit drug use during pregnancy and risk of childhood leukaemia. Few studies have specifically focused on infants (<1 year) with leukaemia, a group that is biologically and clinically distinct from older children. We present data from a Children’s Oncology Group case–control study of 443 infants diagnosed with acute leukaemia [including acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML)] between 1996 and 2006 and 324 population controls. Mothers were queried about their cigarette, alcohol and illicit drug use 1 year before and throughout pregnancy. Odds ratios (ORs) and 95% confidence intervals [CI] were calculated using adjusted unconditional logistic regression models. Maternal smoking (>1 cigarette/day) and illicit drug use (any amount) before and/or during pregnancy were not significantly associated with infant leukaemia. Alcohol use (>1 drink/week) during pregnancy was inversely associated with infant leukaemia overall [OR = 0.64; 95% CI 0.43, 0.94], AML [OR = 0.49; 95% CI 0.28, 0.87], and leukaemia with mixed lineage leukaemia gene rearrangements (‘MLL+’) [OR = 0.59; 95% CI 0.36, 0.97]. While our results agree with the fairly consistent evidence that maternal cigarette smoking is not associated with childhood leukaemia, the data regarding alcohol and illicit drug use are not consistent with prior reports and are difficult to interpret. It is possible that unhealthy maternal behaviours during pregnancy, some of which carry potential legal consequences, may not be adequately measured using only self-report. Future case–control studies of childhood leukaemia that pursue these exposures may benefit from incorporation of validated instruments and/or biomarkers when feasible.
childhood cancer; infant leukaemia; maternal smoking; maternal alcohol; illicit drug use
The Cancer and Leukemia Group B has performed central review of karyotypes submitted by institutional cytogenetics laboratories from patients with acute myeloid (AML) and acute lymphoblastic (ALL) leukemia since 1986. We assessed the role of central karyotype review in maintaining accurate, high quality cytogenetic data for clinical and translational studies using two criteria: the proportion of karyotypes rejected (i.e. inadequate), and, among accepted (i.e. adequate) cases, the proportion of karyotypes whose interpretation was changed on central karyotype review. We compared the first four years during which central karyotype review was performed with a recent four-year period and found that the proportion of rejected samples decreased significantly for both AML and ALL. However, during the latter period, central karyotype reviews still found 8% of AML and 16% of ALL karyotypes inadequate. Among adequate cases, the karyotype was revised in 26% of both AML and ALL samples. Some revisions resulted in changing the patients’ assignment to particular World Health Organization diagnostic categories and/or moving patients from one prognostic group to another. Overall, when both data on rejection rates and data on karyotype revisions made in accepted cases were considered together, 32% of AML and 38% of ALL samples submitted were either rejected or revised on central karyotype review during the recent 4-year period. These data underscore the necessity of continued central karyotype review in multi-institutional cooperative group studies.
karyotyping; chromosome aberrations; human; correlative studies; acute leukemia
This study reports six cases of primary follicular lymphoma of the testis (PFLT) in children and adolescents correlated with clinical presentation, pathologic features, treatment and outcome. All six patients (ages 3 to 16 years, median 4 years) had PFLT grade 3 with disease limited to the testis, completely resected and treated with two courses of chemotherapy (cyclophosphamide, vincristine, prednisone, doxorubicin) (COPAD). Event-free survival was 100% (follow-up: median 73 months, mean 53 months, range 6 to 96 months). In conclusion, clinical outcome in children and adolescents with PFLT is excellent with treatment including complete surgical resection and two courses of COPAD.
lymphoma B-cell; lymphoma follicular; testis; child; adolescence
Vitamin supplements have been proposed for children with Down syndrome (DS) with claims of improving cognitive abilities, or immune or thyroid function. Several studies have shown decreased levels of zinc in this population. Because children with DS have a 50-fold increased risk of developing acute leukemia during the first 5 years of life, we explored the relation between child vitamin and herbal supplement use and the risk for leukemia in a case-control study. During the period 1997–2002, we enrolled 158 children with DS aged 0–18 years that were diagnosed with acute lymphoblastic leukemia (ALL) (n=97) or acute myeloid leukemia (AML) (n=61) at participating COG institutions. We enrolled 173 DS children without leukemia (controls), selected from the cases’ primary care clinic and frequency matched on age. Data were collected via telephone interviews with mothers of the index child regarding use of multivitamins, zinc, vitamin C, iron, and herbal supplements, including age at first use, frequency and duration. Among controls, 57% reported regular multivitamin use (≥ 3 times/week for ≥ 3 months) compared with 48% of ALL cases and 61% of AML cases. We found no evidence of an association between child’s regular multivitamin use and ALL or AML (adjusted odds ratios (ORs)=0.94 [95% confidence interval 0.52, 1.70] and 1.90 [0.73, 4.91], respectively. There was a suggestion of an increased risk for AML associated with regular multivitamin use during the first year of life or for an extended duration (ORs = 2.38 [0.94, 5.76] and 2.59 [1.02, 6.59], respectively). Despite being the largest study of DS-leukemia, our sample size was small, resulting in imprecise effect estimates. Future research should include larger sample sizes as well as a full assessment of diet including vitamin supplementation to adequately examine the relation between nutritional status and childhood leukemia.
Protein synthesis is a powerful therapeutic target in leukemias and other cancers, but few pharmacologically viable agents are available that affect this process directly. The plant-derived agent silvestrol specifically inhibits translation initiation by interfering with eIF4A/mRNA assembly with eIF4F. Silvestrol has potent in vitro and in vivo activity in multiple cancer models including acute lymphoblastic leukemia (ALL) and is under pre-clinical development by the US National Cancer Institute, but no information is available about potential mechanisms of resistance. In a separate report, we showed that intraperitoneal silvestrol is approximately 100% bioavailable systemically, although oral doses were only 1% bioavailable despite an apparent lack of metabolism. To explore mechanisms of silvestrol resistance and the possible role of efflux transporters in silvestrol disposition, we characterized multi-drug resistance transporter expression and function in a silvestrol-resistant ALL cell line generated via culture of the 697 ALL cell line in gradually increasing silvestrol concentrations. This resistant cell line, 697-R, shows significant upregulation of ABCB1 mRNA and P-glycoprotein (Pgp) as well as cross-resistance to known Pgp substrates vincristine and romidepsin. Furthermore, 697-R cells readily efflux the fluorescent Pgp substrate rhodamine 123. This effect is prevented by Pgp inhibitors verapamil and cyclosporin A, as well as siRNA to ABCB1, with concomitant re-sensitization to silvestrol. Together, these data indicate that silvestrol is a substrate of Pgp, a potential obstacle that must be considered in the development of silvestrol for oral delivery or targeting to tumors protected by Pgp overexpression.
ABCB1; leukemia; multi-drug resistance; P-glycoprotein; silvestrol
The addition of rituximab to fludarabine-based regimens in chronic lymphocytic leukemia (CLL) has been shown to produce high response rates with extended remissions. The long-term follow-up of these regimens with respect to progression, survival, risk of secondary leukemia, and impact of genomic risk factors has been limited.
We report the long-term follow-up of the chemoimmunotherapy trial CALGB 9712 from the Cancer and Leukemia Group B, for which treatment regimen was previously reported, to examine end points of progression-free survival (PFS), overall survival (OS), impact of genomic features, and risk of therapy-related myeloid neoplasm (t-MN).
A total of 104 patients were enrolled on this study and now have a median follow-up of 117 months (range, 66 to 131 months). The median OS was 85 months, and 71% of patients were alive at 5 years. The median PFS was 42 months, and 27% were progression free at 5 years. An estimated 13% remained free of progression at almost 10 years of follow-up. Multivariable models of PFS and OS showed that immunoglobulin heavy chain variable region mutational status was significant for both, whereas cytogenetic abnormalities were significant only for OS. No patient developed t-MN before relapse.
Long-term follow-up of CALGB 9712 demonstrates extended OS and PFS with fludarabine plus rituximab. Patients treated with fludarabine plus rituximab administered concurrently or sequentially have a low risk of t-MN. These long-term data support fludarabine plus rituximab as one acceptable first-line treatment for symptomatic patients with CLL.
To analyze the prevalence and clinical implications of Wilms' tumor 1 (WT1) single nucleotide polymorphism (SNP) rs16754 in the context of other prognostic markers in pediatric acute myeloid leukemia (AML).
Patients and Methods
Available diagnostic marrow specimens (n = 790) from 1,328 patients enrolled in three consecutive Children's Cancer Group/Children's Oncology Group trials were analyzed for the presence of SNP rs16754. SNP status was correlated with disease characteristics, WT1 expression level, and clinical outcome.
SNP rs16754 was present in 229 (29%) of 790 patients. The SNP was significantly more common in Asian and Hispanic patients and less common in white patients (P < .001). SNP rs16754 was also less common in patients with inv(16) (P = .043) and more common in patients with −5/del(5q) (P = .047). WT1 expression levels were significantly higher in patients with rs16754 or with WT1 mutations compared with WT1 wild-type patients (P = .021). Five-year overall survival (OS) for patients with and without the SNP was 60% and 50%, respectively (P = .031). Prognostic assessment by risk group demonstrated that in patients with low-risk disease, OS for those with and without SNP rs16754 was 90% versus 64% (P < .001) with a corresponding disease-free survival of 72% versus 53% (P = .041).
The presence of SNP rs16754 was an independent predictor of improved OS; outcome differences were most pronounced in the low-risk subgroup. The high prevalence of WT1 SNP rs16754, and its correlation with improved outcome, identifies WT1 SNP rs16754 as a potentially important molecular marker of prognosis in pediatric AML.
Reproducible cytogenetic analysis in CLL has been limited by the inability to obtain reliable metaphase cells for analysis. CpG oligonucleotide and cytokine stimulation have been shown to improve metaphase analysis of CLL cytogenetic abnormalities, but is limited by variability in the cytokine receptor levels, stability and biological activity of the cytokine in culture conditions and high costs associated with these reagents. We report here use of a novel, stable CpG, GNKG168 along with pokeweed mitogen (PWM) and phorbol 12-myristate 13-acetate (PMA) for conventional cytogenetic assessment in CLL. We demonstrate that the combined use of GNKG168+PWM/PMA increased the sensitivity of detection of chromosomal abnormalities compared to PWM/PMA (n=207, odds ratio=2.2, p=0.0002) and GNKG168 (n=219, odds ratio=1.5, p=0.0452). Further, a significant increase in sensitivity to detect complexity ≥3 with GNKG168+PWM/PMA compared to GNKG168 alone (odds ratio 8.0, p=0.0022) or PWM/PMA alone (odds ratio 9.6, p=0.0007) was observed. The trend toward detection of higher complexity was significantly greater with GNKG168+PWM/PMA compared to GNKG168 alone (p=0.0412). The increased sensitivity was mainly attributed to the addition of PWM/PMA with GNKG168 because GNKG168 alone showed no difference in sensitivity for detection of complex abnormalities (p=0.17). Comparison of fluorescence in situ hybridization (FISH) results with karyotypic results showed a high degree of consistency, although some complex karyotypes were present in cases with no adverse FISH abnormality. These studies provide evidence for potential use of GNKG168 in combination with PWM and PMA in karyotypic analysis of CLL patient samples to better identify chromosomal abnormalities for risk stratification.
Although the majority of children with acute lymphoblastic leukemia (ALL) are cured with current therapy, the event-free survival (EFS) of infants with ALL, particularly those with mixed lineage leukemia (MLL) gene rearrangements, is only 30% to 40%. Relapse has been the major source of treatment failure for these patients. The parallel Children's Cancer Group (CCG) 1953 and Pediatric Oncology Group (POG) 9407 studies were designed to test the hypothesis that more intensive therapy, including dose intensification of chemotherapy, and hematopoietic stem-cell transplantation (HSCT) would improve the outcome for this group of patients.
Patients and Methods
One hundred eighty-nine infants (CCG 1953, n = 115; POG 9407, n = 74) were enrolled between October 1996 and August 2000. For infants with the MLL gene rearrangement and an appropriate donor, HSCT was the preferred treatment on CCG 1953 and investigator option on POG 9407 after completion of the second phase of therapy. Fifty-three infants underwent HSCT.
The 5-year EFS rate was 48.8% (95% CI, 33.9% to 63.7%) in patients who received HSCT and 48.7% (95% CI, 33.8% to 63.6%) in patients treated with chemotherapy alone (P = .60). Transplantation outcomes were not affected by the preparatory regimen or donor source.
Our data suggest that routine use of HSCT for infants with MLL-rearranged ALL is not indicated. However, limited by small numbers, this study should not be considered the definitive answer to this question.
Cytogenetic abnormalities in CLL are important prognostic indicators. Historically, only interphase cytogenetics was clinically useful in CLL because traditional mitogens are not effective mitotic stimulants. Recently, CpG-oligodeoxynucleotide (ODN) stimulation has shown effectiveness in CLL. The CLL Research Consortium (CRC) tested the effectiveness and reproducibility of CpG-ODN stimulation to detect chromosomally abnormal clones by five laboratories. More clonal abnormalities were observed after culture of CLL cells with CpG-ODN than with pokeweed mitogen (PWM)+12-O-tetradecanoyl-phorobol-13-acetate (TPA). All clonal abnormalities in PWM+TPA cultures were observed in CpG-ODN cultures, whereas CpG-ODN identified some clones not found by PWM+TPA. CpG-ODN stimulation of one normal control and 12 CLL samples showed that excepting clones of del(13q) in low frequencies and one translocation, results in all five laboratories were consistent, and all abnormalities were concordant with FISH. Thus, abnormal clones in CLL are more readily detected with CpG-ODN stimulation than with traditional B-cell mitogens. After CpG-ODN stimulation, abnormalities were reproducible among cytogenetic laboratories. CpG-ODN did not appear to induce aberrations in cell culture and enhanced detection of abnormalities and complexity in CLL. Since karyotypic complexity is prognostic and is not detectable by standard FISH analyses, stimulation with CpG-ODN is useful to identify this additional prognostic factor in CLL.
Little is known about the potential risk factors for infant leukemia. With its very young age at diagnosis, exposures occurring in the perinatal period are suspected. Parental infertility and infertility treatment have been studied with regard to childhood cancer in general, but rarely in individual cancer subtypes.
A case–control study of infant leukemia was conducted through the Children's Oncology Group, including cases diagnosed from January 1996 to December 2006 and controls selected through random digit dialing and birth certificate tracing. Maternal phone interviews were conducted to obtain information about infertility, infertility treatment and demographic factors. All cases as well as subgroups defined by mixed lineage leukemia (MLL) translocation status and leukemia subtype were examined. Statistical analysis was performed using multivariate logistic regression models.
No significant associations between infertility or its treatment and combined infant leukemia were found. In subgroup analyses, there was a significant increase in the risk of MLL− leukemia for children born to women not trying to conceive compared with those trying for <1 year for all types combined [odds ratio (OR) = 1.62, 95% confidence interval (CI) = 1.01–2.59] and for acute lymphoblastic leukemia (OR = 2.50, 95% CI = 1.36–4.61).
There were no positive associations between parental infertility or infertility treatment and infant leukemia. While this is the largest study to date, both selection and recall bias may have impacted the results. However, for infant leukemia, we can potentially rule out large increases in risk associated with parental infertility or its treatment.
infant leukemia; infertility; childhood cancer; MLL translocations
Burkitt lymphoma (BL), an aggressive B-cell malignancy, is often curable with short intensive treatment regiments. Nearly all BLs contain rearrangements of the MYC/8q24 region; however, recent cytogenetic studies suggest that certain secondary chromosomal aberrations in BL correlate with an adverse prognosis. In this multi-center study, the frequency and impact on clinical outcome of del(13q) and +7 in addition to MYC rearrangements as detected by fluorescence in situ hybridization (FISH) in children and adolescents with intermediate and high-risk BL registered on Children's Cancer Group study CCG-5961 were investigated. Analysis with 13q14.3 and 13q34 loci specific probes demonstrated deletions of 13q in 38/90 (42%) cases. The loss of either 13q14.3 or 13q34 alone occurred in 14% and 8%, respectively, while 20% exhibited loss of both regions. Gain of chromosome 7 was observed in 7/68 (10%) cases and MYC rearrangements were detected in 84/90 (93%). Prognostic analysis controlling for known risk factors demonstrated that patients exhibiting loss of 13q, particularly 13q14.3, had a significant decrease in 5-year overall survival (77% vs. 95%, p=0.012). These observations indicate that del(13q) occurs in childhood BL at frequencies higher than previously detected by classical cytogenetics and underscores the importance of molecular cytogenetics in risk stratification.
Burkitt lymphoma; chromosome 13 deletion; fluorescence in situ hybridization; FISH; survival
Patients with chronic lymphocytic leukemia (CLL) with high-risk genomic features achieve poor outcomes with traditional therapies. A phase I study of a pharmacokinetically derived schedule of flavopiridol suggested promising activity in CLL, irrespective of high-risk features. Given the relevance of these findings to treating genetically high-risk CLL, a prospective confirmatory study was initiated.
Patients and Methods
Patients with relapsed CLL were treated with single-agent flavopiridol, with subsequent addition of dexamethasone to suppress cytokine release syndrome (CRS). High-risk genomic features were prospectively assessed for response to therapy.
Sixty-four patients were enrolled. Median age was 60 years, median number of prior therapies was four, and all patients had received prior purine analog therapy. If patients tolerated treatment during week 1, dose escalation occurred during week 2. Dose escalation did not occur in four patients, as a result of severe tumor lysis syndrome; three of these patients required hemodialysis. Thirty-four patients (53%) achieved response, including 30 partial responses (PRs; 47%), three nodular PRs (5%), and one complete response (1.6%). A majority of high-risk patients responded; 12 (57%) of 21 patients with del(17p13.1) and 14 (50%) of 28 patients with del(11q22.3) responded irrespective of lymph node size. Median progression-free survival among responders was 10 to 12 months across all cytogenetic risk groups. Reducing the number of weekly treatments per cycle from four to three and adding prophylactic dexamethasone, which abrogated interleukin-6 release and CRS (P ≤ .01), resulted in improved tolerability and treatment delivery.
Flavopiridol achieves significant clinical activity in patients with relapsed CLL, including those with high-risk genomic features and bulky lymphadenopathy. Subsequent clinical trials should use the amended treatment schedule developed herein and prophylactic corticosteroids.