Phase III trial of fludarabine plus cyclophosphamide compared with fludarabine for patients with previously untreated chronic lymphocytic leukemia: US Intergroup Trial E2997

PURPOSE

The combination of fludarabine and cyclophosphamide is an effective regimen for patients with chronic lymphocytic leukemia (CLL). However, it may be accompanied by increased toxicity compared with fludarabine alone. E2997 is a phase III randomized Intergroup trial comparing fludarabine and cyclophosphamide (FC arm) versus fludarabine (F arm) alone in patients receiving their first chemotherapy regimen for CLL.

PATIENTS AND METHODS

Symptomatic, previously untreated patients with CLL were randomly assigned to receive either fludarabine 25 mg/m2 intravenously (IV) days 1 through 5 or cyclophosphamide 600 mg/m2 IV day 1 and fludarabine 20 mg/m2 IV days 1 through 5. These cycles were repeated every 28 days for a maximum of six cycles.

RESULTS

A total of 278 patients were randomly assigned in this Intergroup study. Treatment with fludarabine and cyclophosphamide was associated with a significantly higher complete response (CR) rate (23.4% v 4.6%; P < .001) and a higher overall response (OR) rate (74.3% v 59.5%, P = .013) than treatment with fludarabine as a single agent. Progression-free survival (PFS) was also superior in patients treated with fludarabine and cyclophosphamide than those treated with fludarabine (31.6 v 19.2 months, P < .0001). Fludarabine and cyclophosphamide caused additional hematologic toxicity, including more severe thrombocytopenia (P = .046), but it did not increase the number of severe infections (P = .812).

CONCLUSION

Fludarabine and cyclophosphamide produced an increase in OR and CR, and it improved PFS in patients with previously untreated CLL compared with fludarabine alone and was not associated with an increase in infectious toxicity.

Comprehensive assessment of genetic and molecular features predicting outcome in patients with chronic lymphocytic leukemia: results from the US Intergroup Phase III Trial E2997

PURPOSE

Genomic features including unmutated immunoglobulin variable region heavy chain (IgVH) genes, del(11q22.3), del(17p13.1), and p53 mutations have been reported to predict the clinical course and overall survival of patients with chronic lymphocytic leukemia (CLL). In addition, ZAP-70 and Bcl-2 family proteins have been explored as predictors of outcome.

PATIENTS AND METHODS

We prospectively evaluated the prognostic significance of a comprehensive panel of laboratory factors on both response and progression-free survival (PFS) using samples and data from 235 patients enrolled onto a therapeutic trial. Patients received either fludarabine (FL; n = 113) or fludarabine plus cyclophosphamide (FC; n = 122) as part of a US Intergroup randomized trial for previously untreated CLL patients.

RESULTS

Complete response (CR) rates were 24.6% for patients receiving FC and 5.3% for patients receiving FL (P = .00004). PFS was statistically significantly longer in patients receiving FC (median, 33.5 months for patients receiving FC and 19.9 months for patients receiving FL; P < .0001). The occurrence of del(17p13.1) (hazard ratio, 3.428; P = .0002) or del(11q22.3) (hazard ratio, 1.904; P = .006) was associated with reduced PFS. CR and overall response rates were not significantly different based on cytogenetics, IgVH mutational status, CD38 expression, or p53 mutational status. Expression of ZAP-70, Bcl-2, Bax, Mcl-1, XIAP, Caspase-3, and Traf-1 was not associated with either clinical response or PFS.

CONCLUSION

These results support the use of interphase cytogenetic analysis, but not IgVH, CD38 expression, or ZAP-70 status, to predict outcome of FL-based chemotherapy. Patients with high-risk cytogenetic features should be considered for alternative therapies.

Combination chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab shows significant clinical activity with low accompanying toxicity in previously untreated B chronic lymphocytic leukemia

Building on the prior work of use of pentostatin in chronic lymphocytic leukemia (CLL), we initiated a trial of combined pentostatin (2 mg/m2), cyclophosphamide (600 mg/m2), and rituximab (375 mg/m2) for 65 symptomatic, previously untreated patients. Of 64 evaluable patients, 34 (53%) were high Rai risk, 71% were nonmutated for the immunoglobulin heavy-chain variable region gene, 34% were CD38+, and 34% were ZAP-70+. Thirty patients (52%) had one anomaly detected by fluorescence in situ (FISH) hybridization, and 21 (36%) had complex FISH defects. Thirty-eight patients (58%) had grade 3+ hematologic toxicity but minimal transfusion needs and no major infections. Responses occurred in 58 patients (91%), with 26 (41%) complete responses (CRs), 14 (22%) nodular partial responses (nodular PRs), and 18 (28%) partial responses (PRs). Many patients with a CR also lacked evidence of minimal residual disease by 2-color flow cytometry. Examination of prognostic factors demonstrated poor response in the 3 patients with del(17p). In contrast, we found this regimen was equally effective in young versus older (>70 years) patients and in del(11q22.3) versus other favorable prognostic factors. Thus, this novel regimen of pentostatin, cyclophosphamide, and rituximab for previously untreated patients with CLL demonstrated significant clinical activity despite poor risk-based prognoses, achievement of minimal residual disease in some, and modest toxicity.

The incidence and anatomic site specificity of chromosomal translocations in primary extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in North America

Several balanced translocations have been identified in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) but there are few data regarding their frequency in different anatomic sites or the frequency of translocations involving BCL6 or kappa or lambda immunoglobulin light chain genes (IGK or IGL), particularly in patients from geographic regions other than Europe and Japan. One hundred thirty-three paraffin-embedded North American primary MALT lymphoma specimens from diverse anatomic sites were studied by fluorescence in situ hybridization (FISH) using probes for API2-MALT1, IGH-MALT1, IGH-BCL10, IGH-FOXP1, IGH, +/- centromeres 3, 7, 12, and 18, and a subset (n=74) were analyzed using FISH probes for IGK, IGL, and BCL6. Translocations were mutually exclusive and were detected in 26% of cases (17% API2-MALT1, 5% IGH-MALT1, 3% IGH-unknown translocation partner, and 1% IGH-BCL10). Aneuploidy was associated with IGH-MALT1 and IGH-BCL10 but only rarely with API2-MALT1. There was striking site specificity, with API2-MALT1 showing a marked predilection for lung and intestine, and IGH-MALT1 and IGH-BCL10 occurring almost exclusively in lung. Twenty-three percent of translocation-negative primary MALT lymphomas from diverse sites showed complete/partial trisomy 18. No MALT lymphomas with translocations involving IGK, IGL, BCL6, or FOXP1 were identified. This FISH panel detected cytogenetic abnormalities in half of all MALT lymphomas, and translocations arose preferentially in MALT lymphomas of the lung and gastrointestinal tract. Differences in incidence and anatomic site specificity of translocations between North American and non-North American cases may reflect geographic variability of infectious or other etiologic factors.

Karyotype is an independent prognostic factor in adult acute lymphoblastic leukemia (ALL): analysis of cytogenetic data from patients treated on the Medical Research Council (MRC) UKALLXII/Eastern Cooperative Oncology Group (ECOG) 2993 trial

Pretreatment cytogenetics is a known predictor of outcome in hematologic malignancies. However, its usefulness in adult acute lymphoblastic leukemia (ALL) is generally limited to the presence of the Philadelphia (Ph) chromosome because of the low incidence of other recurrent abnormalities. We present centrally reviewed cytogenetic data from 1522 adult patients enrolled on the Medical Research Council (MRC) UKALLXII/Eastern Cooperative Oncology Group (ECOG) 2993 trial. The incidence and clinical associations for more than 20 specific chromosomal abnormalities are presented. Patients with a Ph chromosome, t(4;11)(q21;q23), t(8;14)(q24.1;q32), complex karyotype (5 or more chromosomal abnormalities), or low hypodiploidy/near triploidy (Ho-Tr) all had inferior rates of event-free and overall survival when compared with other patients. In contrast, patients with high hyperdiploidy or a del(9p) had a significantly improved outcome. Multivariate analysis demonstrated that the prognostic relevance of t(8;14), complex karyotype, and Ho-Tr was independent of sex, age, white cell count, and T-cell status among Ph-negative patients. The observation that Ho-Tr and, for the first time, karyotype complexity confer an increased risk of treatment failure demonstrates that cytogenetic subgroups other than the Ph chromosome can and should be used to risk stratify adults with ALL in future trials.

Prospective evaluation of clonal evolution during long-term follow-up of patients with untreated early-stage chronic lymphocytic leukemia

PURPOSE

Retrospective studies suggest cytogenetic abnormalities detected by interphase fluorescent in situ hybridization (FISH) can identify patients with chronic lymphocytic leukemia (CLL) who will experience a more aggressive disease course. Other studies suggest that patients may acquire chromosome abnormalities during the course of their disease. There are minimal prospective data on the clinical utility of the widely used hierarchical FISH prognostic categories in patients with newly diagnosed early-stage CLL or the frequency of clonal evolution as determined by interphase FISH.

PATIENTS AND METHODS

Between 1994 and 2002, we enrolled 159 patients with previously untreated CLL (83% Rai stage 0/I) on a prospective trial evaluating clonal evolution by FISH. Patients provided baseline and follow-up specimens for FISH testing during 2 to 12 years.

RESULTS

Chromosomal abnormalities detected by FISH at study entry predicted overall survival. Eighteen patients experienced clonal evolution during follow-up. The rate of clonal evolution increased with duration of follow-up with only one occurrence in the first 2 years (n = 71; 1.4%) but 17 occurrences (n = 63; 27%) among patients tested after 5+ years. Clonal evolution occurred among 10% of ZAP-70-negative and 42% of ZAP-70-positive patients at 5+ years (P = .008).

CONCLUSION

This clinical trial confirms prospectively that cytogenetic abnormalities detected by FISH can predict overall survival for CLL patients at the time of diagnosis, but also suggests that many patients acquire new abnormalities during the course of their disease. Patients with higher ZAP-70 expression may be more likely to experience such clonal evolution. These findings have important implications for both clinical management and trials of early treatment for patients with high-risk, early-stage CLL.

The clinical spectrum of adult acute myeloid leukaemia associated with core binding factor translocations

To better understand the spectrum of adult acute myeloid leukaemia (AML) associated with core binding factor (CBF) translocations, 370 patients with newly diagnosed CBF-associated AML were analysed. Patients' age ranged from 16-83 years (median 39 years) with a slight male predominance (55%); 53% had inv(16); 47% had t(8;21). Patients with t(8;21) tended to be younger (P = 0.056), have lower peripheral blood white cell counts (P < 0.0001) and were more likely to have additional cytogenetic abnormalities (P < 0.0001). Loss of sex chromosome, del(9q) and complex abnormalities were more common among patients with t(8;21), while +22 and +21 were more common with inv(16). Overall, 87% [95% confidence interval (CI) 83-90%] of patients achieved complete response (CR) with no difference between t(8;21) and inv(16); however, the CR rate was lower in older patients due to increased resistant disease and early deaths. Ten-year overall survival (OS) was 44% (95% CI 39-50%) and, in multivariate analysis, was shorter with increasing age (P < 0.0001), increased peripheral blast percentage (P = 0.0006), in patients with complex cytogenetic abnormalities in addition to the CBF translocation (P = 0.021), and in patients with t(8;21) (P = 0.025). OS was superior in patients who received regimens with high-dose cytarabine, a combination of fludarabine and intermediate-dose cytarabine, or haematopoietic cell transplantation.

Utility of interphase FISH to stratify patients into cytogenetic risk categories at diagnosis of AML in an Eastern Cooperative Oncology Group (ECOG) clinical trial (E1900)

We evaluated the efficacy of FISH to detect chromosome anomalies in the evaluation of young (<60 years) patients with AML. Patients were enrolled in E1900, an ECOG clinical trial for AML. The protocol was designed to collect bone marrow or blood for both cytogenetic and FISH studies at study entry (diagnosis). FISH for each patient was performed and utilized eight probe sets to detect t(8;21), t(9;22), t(11;var), t(15;17), inv(16), +8, -5/5q, and -7/7q. We analyzed 237 specimens with complete cytogenetic and FISH results. Results for each specimen were classified by probe set into one of six categories. The concordance rate between cytogenetic and FISH results ranged from 98 to 100% for all probe sets and kappa analysis for concordance had a p-value of <0.0001. The high level of agreement between cytogenetic and FISH results demonstrate the accuracy of a panel of eight FISH probe sets for the detection of significant abnormalities in AML. Data from this investigation support the use of FISH as an adjunct method to increase the yield of useful cytogenetic results in large cooperative trials and demonstrate the potential of FISH as a follow-up study of minimal residual disease in ECOG trials.

A phase II trial of arsenic trioxide for relapsed and refractory acute lymphoblastic leukemia

We designed a phase II trial of arsenic trioxide (AT) for the treatment of relapsed and refractory acute lymphoblastic leukemia (ALL). The dose administered was 0.25 mg/kg/day intravenously for 5-7 days per week for up to 60 days. Of 11 patients eligible, eight had B-cell and three T-cell ALL and two were Philadelphia chromosome-positive. The median duration of therapy was 21 days (range 7-28). One patient died of an infection. There were no responses. Ten patients have died. The median survival was 3.2 months (range 1.2-4.1). We conclude that AT is not active in the treatment of ALL.

FIP1L1-PDGFRA in eosinophilic disorders: Prevalence in routine clinical practice, long-term experience with imatinib therapy, and a critical review of the literature

We previously studied clinico-pathologic features of 89 consecutive adult patients with moderate-to-severe eosinophilia, and reported a FIP1L1-PDGFRA prevalence of 12%. In that series, all 11 FIP1L1-PDGFRA+ patients receiving imatinib achieved a complete response. We now extend our observations through a study of 741 unselected patients with eosinophilia for FIP1L1-PDGFRA, and present longer term follow up data for the imatinib-treated cohort. We also include data for three previously unreported FIP1L1-PDGFRA+ patients. Among the 741 requests, only 21 (3%) were found to carry the FIP1L1-PDGFRA mutation. While all 14 FIP1L1-PDGFRA+ patients receiving imatinib achieved a complete response, the 4 patients who attempted to discontinue imatinib all relapsed. We also find that it is possible to maintain patients in clinical remission with an empirically derived schedule of low-dose (50-100 mg), intermittent (once daily to once weekly) imatinib. Lastly, we present a comprehensive review of the literature pertaining to FIP1L1-PDGFRA in order to address several key aspects of this mutation from a clinical standpoint.

Loss of TP53 is due to rearrangements involving chromosome region 17p10 approximately p12 in chronic lymphocytic leukemia

Loss of tumor protein 53 (TP53) has been associated with aggressive disease and poor response to therapy in B-cell chronic lymphocytic leukemia (B-CLL). TP53 is located at chromosome band 17p13 and its absence can be detected by fluorescence in situ hybridization (FISH) in the interphase nuclei of 8-10% patients with B-CLL. To study the cytogenetic mechanism for loss of TP53, metaphase and interphase FISH studies were conducted on 16 B-CLL patients to investigate 17p10 to 17p12, a chromosome region known to be rich in low-copy DNA repeats. Loss of TP53 was caused by an isochromosome with breakpoints between 17p10 and 17p11.2 in four patients, an unbalanced translocation involving 17p10 to 17p11.2 in nine patients, and an unbalanced translocation involving 17p11.2 to 17p12 in three patients. These findings indicate that loss of TP53 results from the absence of nearly the entire chromosome 17 p-arm rather than to monosomy 17 or deletions of TP53. Translocations or isochromosome formations at sites of low-copy DNA repeats in 17p10 to 17p12 appear to be the mechanism for the loss of TP53 in B-CLL.

Cytogenetic Heteromorphisms: Survey Results and Reporting Practices of Giemsa-Band Regions That We Have Pondered for Years

Context.—Cytogenetic heteromorphisms (normal variants) pose diagnostic dilemmas. Common Giemsa-band heteromorphisms are not described in the literature, although Giemsa-banding is the method most frequently used in cytogenetic laboratories.

Objective.—To summarize the responses from more than 200 cytogeneticists concerning the definition and reporting of cytogenetic heteromorphisms, to offer these responses as a reference for use in clinical interpretations, and to provide guidance for interpretation of newly defined molecular cytogenetic heteromorphisms.

Design.—The Cytogenetics Resource Committee of the College of American Pathologists and the American College of Medical Genetics administered a proficiency testing survey in 1997 to 226 participant cytogenetic laboratories. Supplemental questions asked whether participants considered particular Giemsa-banded chromosomal features to be heteromorphisms and if these would be described in a cytogenetic clinical report.

Results.—Responses were obtained from 99% of participants; 61% stated they would include selected heteromorphism data in a clinical report. More than 90% considered prominent short arms, large or double satellites, or increased stalk length on acrocentric chromosomes to be heteromorphisms; 24% to 36% stated that they would include these in a clinical report. Heterochromatic regions on chromosomes 1, 9, 16, and Y were considered heteromorphisms by 97% of participants, and 24% indicated they would report these findings. Pericentric inversions of chromosomes 1, 2, 3, 5, 9, 10, 16, and Y were considered heteromorphisms with more than 75% of respondents indicating they would report these findings.

Conclusions.—Responses were not unanimous, but a clear consensus is presented describing which Giemsa-band regions were considered heteromorphisms and which would be reported.

Presence of unfavorable cytogenetic abnormalities is the strongest predictor of poor survival in secondary myelofibrosis

BACKGROUND

Postpolycythemic (PV) and postthrombocythemic (ET) myeloid metaplasia are consensually referred to as secondary myelofibrosis (sMF). Prognostic variables in sMF are not as well defined as they are for de novo myelofibrosis with myeloid metaplasia (MMM), which is also known as agnogenic myeloid metaplasia (AMM). Such information is particularly crucial for management decisions in transplant-eligible patients.

METHODS

Diagnoses of PV and ET required fulfillment of the World Health Organization criteria for the diagnosis of MMM as well as an antecedent history of either polycythemia vera or essential thrombocythemia that was supported by bone marrow examination. Cytogenetic findings were classified as being either favorable (normal or isolated 13q- or 20q- clones) or unfavorable (presence of abnormalities other than 13q- and 20q-).

RESULTS

The study population was comprised of 66 young patients (age <60 yrs) with sMF, including 37 patients with PV and 29 patients with ET. Multivariate analysis of parameters other than cytogenetics identified older age (P = .02), anemia (hemoglobin level <10 g/dL [P = .007]), and PV (P = .009) to be independent risk factors for shortened survival. However, when such analysis was restricted to patients in whom cytogenetic studies were performed (n = 31 patients), the presence of unfavorable cytogenetic abnormalities (i.e., clones other than 20q- and 13q-) became the only adverse prognostic factor for survival (P = .001). A similar analysis in a temporal cohort of 50 age-matched patients with AMM also identified unfavorable cytogenetics as an independent predictor of poor survival, along with thrombocytopenia and anemia.

CONCLUSIONS

The results of the current study suggest that cytogenetic findings might supersede AMM-derived prognostic scoring systems for predicting survival in patients with sMF.

Metaphase cells with normal G-bands have cryptic interstitial deletions in 13q14 detectable by fluorescence in situ hybridization in B-cell chronic lymphocytic leukemia

Interphase fluorescence in situ hybridization (FISH) studies with D13S319 show that deletions of 13q14 are common in B-cell chronic lymphocytic leukemia (B-CLL). In contrast, conventional cytogenetic studies in B-CLL seldom reveal abnormalities of chromosome 13. We hypothesized that chromosome 13 anomalies might not be detected because they are caused by cryptic deletions rather than by the absence of dividing B-CLL cells. To investigate this possibility, we used FISH with D13S319 to study metaphases from 12 patients known to have 13q- by interphase FISH. These same patients had normal chromosomes by conventional cytogenetic studies. As a result of this study, we report evidence that B-CLL metaphases with 13q- are not detected because these deletions are often cryptic and not visible by standard G-banding.

Respective clustering of unfavorable and favorable cytogenetic clones in myelofibrosis with myeloid metaplasia with homozygosity for JAK2(V617F) and response to erythropoietin therapy

BACKGROUND

Patients who have myelofibrosis with myeloid metaplasia (MMM) display recurrent, albeit nonspecific cytogenetic abnormalities that are diverse prognostically. For the current study, the authors explored the relation between specific cytogenetic clones and JAK2(V617F) mutational status in patients with MMM and the effects on treatment response to erythropoietin (Epo).

METHODS

Concomitantly collected blood granulocytes and bone marrow were processed for JAK2(V617F) mutation analysis and cytogenetic studies, respectively. Genomic DNA was amplified by polymerase chain reaction, and fluorescent dye chemistry sequencing was performed by using the same primers that were used for amplification.

RESULTS

Among 105 study patients, cytogenetic abnormalities were detected in 47 patients (45%), and the JAK2(V617F) mutation was detected in 52 patients (50%). Comparison of mutational frequencies between favorable (normal, sole 13q-, or 20q- clones; n = 70 patients) and unfavorable (all other abnormalities; n = 35 patients) cytogenetic categories revealed a significantly different incidence of homozygous JAK2(V617F) between them (9% vs. 23%, respectively; P = .04). Furthermore, the mutant allele coexisted with several recurrent cytogenetic lesions. Among 25 patients who received Epo either alone (n = 17 patients) or in combination with hydroxyurea (n = 8 patients), 4 patients (16%) achieved a response, and none of them were homozygous for JAK2(V617F). Conversely, a response was more likely (P = .0001) in the presence of favorable cytogenetic abnormalities (i.e., 3 of 4 responders carried sole 13q- or 20q- clones).

CONCLUSIONS

Unfavorable and favorable cytogenetic clones in MMM clustered with homozygosity for JAK2(V617F) and treatment response to Epo-based therapy, respectively.

Preclinical validation of fluorescence in situ hybridization assays for clinical practice

PURPOSE

Validation of fluorescence in situ hybridization assays is required before using them in clinical practice. Yet, there are few published examples that describe the validation process, leading to inconsistent and sometimes inadequate validation practices. The purpose of this article is to describe a broadly applicable preclinical validation process.

METHODS

Validation is performed using four consecutive experiments. The Familiarization experiment tests probe performance on metaphase cells to measure analytic sensitivity and specificity for normal blood specimens. The Pilot Study tests a variety of normal and abnormal specimens, using the intended tissue type, to set a preliminary normal cutoff and establish the analytic sensitivity. The Clinical Evaluation experiment tests these parameters in a series of normal and abnormal specimens to simulate clinical practice, establish the normal cutoff and abnormal reference ranges, and finalize the standard operating procedure. The Precision experiment measures the reproducibility of the new assay over 10 consecutive working days. To illustrate documentation and analysis of data with this process, the results for a new assay to detect fusion of IGH and BCL3 associated with t(14;19)(q32;q13.3) in lymphoproliferative disorders are provided in this report.

RESULTS

These four experiments determine the analytic sensitivity and specificity, normal values, precision, and reportable reference ranges for validation of the new test.

CONCLUSION

This report describes a method for preclinical validation of fluorescence in situ hybridization studies of metaphase cells and interphase nuclei using commercial or home brew probes.

HER-2 Fluorescence In Situ Hybridization: Results From the Survey Program of the College of American Pathologists

Context.—Fluorescence in situ hybridization (FISH) is a common method used to determine HER-2 status in breast cancer. Limited information is available concerning reproducibility of FISH in determining HER-2 gene amplification.

Objective.—To present proficiency testing results of FISH for HER-2 conducted by the Cytogenetics Resource Committee of the College of American Pathologists/American College of Medical Genetics.

Design.—During the past 5 years, unstained sections from 9 invasive breast carcinomas were used for HER-2 FISH proficiency testing, allowing for comparison of FISH results among a large number of laboratories. Additional data were collected using an educational (ungraded) challenge and supplemental questions in the surveys.

Results.—The number of laboratories participating in HER-2 FISH proficiency testing has increased steadily during the past 5 years (from 35 in 2000 to 139 in 2004). Reproducibility of test results among laboratories was excellent for breast tumors with low copy number (no HER-2 amplification) and for breast tumors with high copy number (HER-2 amplification). However, there was considerable variation in interpretation of results for a tumor with low-level HER-2 amplification that was tested on 2 separate occasions. Responses to supplemental questions indicated that there was a need for consensus on the use of a separate equivocal/borderline interpretative category and the need for standardization of cutoff values used to define interpretative categories.

Conclusions.—The College of American Pathologists proficiency survey programs provide useful information concerning the reproducibility of clinical testing for HER-2 by FISH and reflect clinical interpretation of HER-2 FISH analyses from laboratories across the country.

Prognostic diversity among cytogenetic abnormalities in myelofibrosis with myeloid metaplasia

BACKGROUND

Approximately 30-50% of patients with myelofibrosis with myeloid metaplasia (MMM) demonstrate detectable cytogenetic abnormalities, the prognostic value of which has not been completely defined by previous retrospective studies. The current prospective study addresses this issue in the context of currently accepted independent prognostic variables.

METHODS

The current study is a single institution study in which patients with MMM were accrued between January 2000 and August 2001 and followed in a prospective fashion. All study patients underwent bone marrow examination with cytogenetic studies as well as comprehensive clinical and laboratory evaluation at the time of karyotype analysis.

RESULTS

Among the study cohort of 81 patients (with a median age of 61 years; 54 males), the cytogenetic findings were normal in 44 patients (54%; Group 1). The remaining 37 patients (46%) demonstrated either interstitial deletions involving the long arm of chromosome 13 or 20 (9 patients; Group 2) or other abnormalities (28 patients; Group 3). All study patients were followed prospectively for a minimum of 40 months (range, 40-55 months). Survival from the time of karyotypic analysis was found to be similar between Groups 1 and 2 but was significantly worse in Group 3. Furthermore, none of the patients in Group 2 experienced leukemic transformation, whereas five patients each from the other two groups did. Multivariate analysis identified an unfavorable cytogenetic profile (Group 3), > or = 1% circulating blasts, a hemoglobin level of <10 g/dL, and constitutional symptoms as adverse prognostic features for overall survival.

CONCLUSIONS

Specific cytogenetic lesions in patients with MMM might carry an independent prognostic effect for both survival and the risk of leukemic transformation. Such information should assist in decision making when considering aggressive treatment approaches.

Adult B-Cell Lymphomas With Burkitt-Like Morphology Are Phenotypically and Genotypically Heterogeneous With Aggressive Clinical Behavior

Adult, de novo B-cell lymphomas meeting the WHO morphologic criteria for atypical Burkitt/Burkitt-like lymphoma cause diagnostic difficulty for pathologists because the genetic and clinical characteristics of this group of lymphomas have not been clearly defined. Thirty-one such lymphomas, designated as Burkitt-like lymphomas (BLL), were selected based on morphologic features and evaluated for immunophenotype, MYC and BCL2 status, and clinical features. Nine childhood Burkitt lymphomas (BL) and 87 adult, de novo diffuse large B-cell lymphomas (DLBL) were similarly evaluated for comparison. The BL group demonstrated uniform characteristics: all had Burkitt lymphoma morphology, an identical immunophenotype (positive for CD20, CD10, bcl-6, CD43, and p53; negative for CD138, CD23, bcl-2), high MIB-1 positivity, IGH/MYC translocation, no IGH/BCL2 translocation, and all patients were alive at the last follow-up. The BLL and DLBL groups were heterogeneous. Burkitt-like morphology alone correlated with decreased survival. IGH/MYC or IGL/MYC fusion was identified in 11 of 27 (41%) BLL and 4 of 76 (5%) DLBL and was associated with decreased survival in both groups. MIB-1 positivity did not correlate with morphology, MYC abnormalities, or survival. We propose that adult B-cell lymphomas with BLL morphology are a phenotypically and genetically heterogeneous group of aggressive lymphomas, biologically distinct from childhood BL. Until biologically accurate subgroups within this morphologically defined group are identified, it is appears that both recognition of BLL morphology and direct evaluation for the presence of MYC fusion to immunoglobulin genes are important for identification of adult patients with poorer prognosis than those with DLBL.

Relationship of patient survival and chromosome anomalies detected in metaphase and/or interphase cells at diagnosis of myeloma

The clinical efficacy of evaluating genetic anomalies in metaphase cells versus interphase nuclei for multiple myeloma (MM) is poorly understood. Therefore, survival for 154 patients with newly diagnosed untreated MM was compared with results from analysis of metaphase and interphase cells. Metaphases were studied by conventional cytogenetics and fluorescent-labeled DNA probes (fluorescence in situ hybridization [FISH]), whereas inter-phase nuclei were evaluated only by FISH. All FISH studies were done using DNA probes to detect t(4;14)(p16;q32), t(11;14)(q13;q32), t(14;16)(q32;q23), del(17) (p13.1), and chromosome 13 anomalies. Metaphases were abnormal by cytogenetics and/or metaphase FISH in 61 (40%) patients. Abnormal interphase nuclei were observed in 133 (86%) patients, including each patient with abnormal metaphases. FISH was a necessary adjunct to cytogenetics to detect t(4;14) and t(14;16) in metaphase cells. Patient survival was especially poor for patients with greater than 50% abnormal interphase nuclei, although this result was more likely due to level of plasma cells than specific chromosome anomalies. For metaphase data, patients with t(4;14), t(14;16), del(17) (p13.1), and/or chromosome 13 anomalies (primarily monosomy 13) had poor survival. A different outcome was observed for interphase data as patients with t(4;14) or t(14;16) had poor survival, whereas patients with chromosome 13 anomalies had intermediate survival: interphase FISH did not substitute for metaphase analysis.

Interphase fluorescence in situ hybridization with an IGH probe is important in the evaluation of patients with a clinical diagnosis of chronic lymphocytic leukaemia

Translocations involving IGH are common in some lymphoid malignancies but are believed to be rare in chronic lymphocytic leukaemia (CLL). To study the clinical utility of fluorescence in situ hybridization (FISH) for IGH translocations, we reviewed 1032 patients with a presumptive diagnosis of CLL. Seventy-six (7%) patients had IGH translocations. Pathology and clinical data were available for the 24 patients evaluated at the Mayo Clinic. Ten (42%) patients had IGH/cyclin D1 fusion and were diagnosed with mantle cell lymphoma (MCL). The immunophenotype was typical of MCL in three of these patients and atypical for MCL in seven patients. One patient had biclonal disease with typical MCL and CLL with IGH/BCL-2. Eleven (46%) patients had IGH/BCL-2 fusion including the patient with biclonal disease. Two of these patients had leukaemic phase follicular lymphoma and nine patients had CLL. The median progression-free survival of patients with CLL and IGH/BCL-2 translocation was 20.6 months. The two patients with IGH/BCL-3 fusion (one of these also had IGH/BCL-11a) had rapid disease progression. The IGH partner gene was not identified in two patients. We conclude that use of an IGH probe in FISH analysis of monoclonal B-cell lymphocytosis improves diagnostic precision and could have prognostic value in patients with CLL.

Der(6)t(1;6)(q21-23;p21.3): a specific cytogenetic abnormality in myelofibrosis with myeloid metaplasia

Chromosome anomalies are detected in approximately half of patients with myelofibrosis with myeloid metaplasia (MMM) although none of the most prevalent lesions are specific to the disease. In a prospective cytogenetic study of 81 patients with MMM, we encountered three with an unbalanced translocation between chromosomes 1 and 6 with specific breakpoints; der(6)t(1;6)(q21-23;p21.3). A subsequent Mayo Clinic cytogenetic database search identified 12 patients with this chromosome anomaly among 17 791 consecutive patients. A similar database search from Royal Hallamshire Hospital in Sheffield, UK revealed two additional patients among 8000 cases. The clinical phenotype and survival for each of these 14 patients was typical of MMM. These findings suggested that der(6)t(1;6)(q21-23;p21.3) is a highly specific cytogenetic anomaly that may harbour gene(s) specifically associated with MMM. In a preliminary fluorescence in situ hybridization study, the breakpoints on chromosome 6 in two additional cases were found to be telomeric to the gene for 51 kDa FK506-binding protein (FKBP51).

Hematologic disorders in 13 patients with acquired trisomy 21 and 13 individuals with Down syndrome

To study the role of trisomy 21 in hematologic malignancies, we investigated the hematologic disorders of 13 patients with acquired trisomy 21 and 13 individuals with Down syndrome (DS). The most common hematologic malignancy among the patients with acquired trisomy 21 involved both granulocytic and monocytic lineages. By comparison, the hematologic disorders among the DS patients were predominantly acute lymphocytic leukemia and acute megakaryocytic leukemia. Although our sample was small, our results suggest that most patients with acquired trisomy 21 have different hematologic disorders than individuals with DS. Perhaps the role of trisomy 21 in the development of hematologic malignancy is different in constitutional trisomy 21 than it is in acquired trisomy 21.

Intensified induction chemotherapy in adult acute myeloid leukemia followed by high-dose chemotherapy and autologous peripheral blood stem cell transplantation: an Eastern Cooperative Oncology Group trial (E4995)

The feasibility of intensified therapy in adults < 61-years-old with de novo acute myeloid leukemia (AML) was evaluated by adding high-dose cytarabine (HDAC) to conventional induction therapy and in post-remission therapy prior to peripheral blood stem cell transplantation (PBSCT). Patients were treated with conventional induction therapy (daunorubicin days 1-3 and cytarabine days 1-7), followed by HDAC (2 gm/M2) every 12 h ( x 6) on days 8-10. Patients in complete remission (CR) with HLA-matched siblings were assigned to allogeneic PBSCT; the others received two courses of HDAC (3 gm/M2 every 12 h on days 1, 3, and 5) given 1 month apart. Peripheral blood stem cells were then harvested and infused after high-dose chemotherapy. Of 62 eligible, evaluable patients, 47 (76%) achieved CR. The mortality rate was 10% (6 patients); no deaths occurred during the two post-remission courses of HDAC. Fifteen patients were assigned to allogeneic PBSCT and 32 to autologous PBSCT. All surviving patients have been followed for more than 4 years. Including all patients scheduled to receive autoPBSCT in an intent-to-treat analysis, after a median 5-year follow-up the current, non-actuarial, four-year event-free and overall survival was 47% and 47%, respectively. Intensified induction therapy was associated with more toxicity than conventional induction therapy, and the CR rate did not improve. Nevertheless, intensive post-remission therapy was well tolerated, no treatment-related mortality occurred with autologous PBSCT, and disease-free survival and overall survival were lengthy.

The JAK2 V617F activating tyrosine kinase mutation is an infrequent event in both "atypical" myeloproliferative disorders and myelodysplastic syndromes

A somatic mutation in the JH2 autoinhibitory domain of the Janus kinase 2 (JAK2) tyrosine kinase was recently described in polycythemia vera, essential thrombocythemia, and myelofibrosis with myeloid metaplasia. The prevalence of this mutation in either "atypical" myeloproliferative disorders (MPDs) or the myelodysplastic syndromes (MDSs) is unknown. Bone marrow-derived genomic DNA from 245 patients--119 with chronic myelomonocytic leukemia (CMML), 101 with MDS, 11 with hypereosinophilic syndrome (HES), 8 with systemic mastocytosis (SM), and 6 with chronic neutrophilic leukemia (CNL)--was screened for the JAK2 V617F mutation. A mutant allele was detected in 11 patients: 3 with CMML (3%), 5 with MDS (5%), 2 with SM, and 1 with CNL. Interestingly, one of the patients with SM and the patient with CNL with JAK2 V617F had a history of lymphoma, and this patient with SM also had associated myelofibrosis and CMML. The current observation strengthens the specific association between JAK2 V617F and classic MPD, but also suggests an infrequent occurrence in other myeloid disorders.