Molecular classification improves risk assessment in adult BCR-ABL1-negative B-ALL

Genomic classification has improved risk assignment of pediatric, but not adult B-lineage acute lymphoblastic leukemia (B-ALL). The international UKALLXII/ECOG-ACRIN E2993 (#NCT00002514) trial accrued 1229 adolescent/adult patients with BCR-ABL1- B-ALL (aged 14 to 65 years). Although 93% of patients achieved remission, 41% relapsed at a median of 13 months (range, 28 days to 12 years). Five-year overall survival (OS) was 42% (95% confidence interval, 39, 44). Transcriptome sequencing, gene expression profiling, cytogenetics, and fusion polymerase chain reaction enabled genomic subtyping of 282 patient samples, of which 264 were eligible for trial, accounting for 64.5% of E2993 patients. Among patients with outcome data, 29.5% with favorable outcomes (5-year OS 65% to 80%) were deemed standard risk (DUX4-rearranged [9.2%], ETV6-RUNX1/-like [2.3%], TCF3-PBX1 [6.9%], PAX5 P80R [4.1%], high-hyperdiploid [6.9%]); 50.2% had high-risk genotypes with 5-year OS of 0% to 27% (Ph-like [21.2%], KMT2A-AFF1 [12%], low-hypodiploid/near-haploid [14.3%], BCL2/MYC-rearranged [2.8%]); 20.3% had intermediate-risk genotypes with 5-year OS of 33% to 45% (PAX5alt [12.4%], ZNF384/-like [5.1%], MEF2D-rearranged [2.8%]). IKZF1 alterations occurred in 86% of Ph-like, and TP53 mutations in patients who were low-hypodiploid (54%) and BCL2/MYC-rearranged (33%) but were not independently associated with outcome. Of patients considered high risk based on presenting age and white blood cell count, 40% harbored subtype-defining genetic alterations associated with standard- or intermediate-risk outcomes. We identified distinct immunophenotypic features for DUX4-rearranged, PAX5 P80R, ZNF384-R/-like, and Ph-like genotypes. These data in a large adult B-ALL cohort treated with a non-risk-adapted approach on a single trial show the prognostic importance of genomic analyses, which may translate into future therapeutic benefits.

Cytogenetic prioritization with inclusion of molecular markers predicts outcome in previously untreated patients with chronic lymphocytic leukemia treated with fludarabine or fludarabine plus cyclophosphamide: a long-term follow-up study of the US intergroup phase III trial E2997

Fludarabine (F) and cyclophosphamide (C) remain backbones of up-front chemotherapy regimens for chronic lymphocytic leukemia (CLL). We report long-term follow-up of a randomized F vs. FC trial in untreated CLL (#) . With median follow-up of 88 months, estimated median progression-free survival (PFS) was 19.3 vs. 48.1 months for F (n = 109) and FC (n = 118), respectively (p < 0.0001), and median overall survival (OS) was 88.0 vs. 79.1 months (p = 0.96). In multivariable analyses, variables associated with inferior PFS and OS respectively were age (p = 0.002, p < 0.001), Rai stage (p = 0.006, p = 0.02) and sex (p = 0.03, PFS only). Del(17)(p13.1) predicted shorter PFS and OS (p < 0.0001 for each), as did del(11q)(22.3) (p < 0.0001, p = 0.005, respectively), trisomy 12 with mutated Notch1 (p = 0.003, p = 0.03, respectively) and unmutated IGHV (p = 0.009, p = 0.002, respectively), all relative to patients without these features. These data confirm results from shorter follow-up and further justify targeted therapies for CLL.

Standardization of fluorescence in situ hybridization studies on chronic lymphocytic leukemia (CLL) blood and marrow cells by the CLL Research Consortium

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.

Failure of three novel regimens to improve outcome for patients with relapsed or refractory acute myeloid leukaemia: a report from the Eastern Cooperative Oncology Group

The treatment of relapsed acute myeloid leukaemia (AML) remains unsatisfactory. We conducted a phase II randomized trial where patients received intermediate-dose cytarabine for 4 d followed by gemtuzumab ozogamicin on day 5 (Arm A), or combined with liposomal daunorubicin for 3 d (Arm B), or cytarabine given for 5 d combined with cyclophosphamide for 3 d and topotecan by continuous infusion for 5 d (Arm C). Eligible patients had primary refractory AML, a first relapse after a remission of <1 year, or a second or greater relapse. The primary objective of this trial was attainment of a conventional complete remission (CR) or a CR without platelet recovery (CRp) in at least 40% of patients. The CR/CRp rates for the 82 eligible patients were 3/26 (12%) in Arm A, 2/29 (7%) in Arm B, and 1/27 (4%) in Arm C. No patients who had relapsed within 6 months of initial CR or who had suffered multiple relapses responded. More than 95% of patients subsequently died of AML. No unexpected toxicities were encountered. We conclude that none of these three regimens were effective enough in the treatment of high-risk relapsed or refractory AML to warrant further study. This trial was registered at http://www.clinicaltrials.gov as #NCT00005962.

Anthracycline dose intensification in acute myeloid leukemia

BACKGROUND

In young adults with acute myeloid leukemia (AML), intensification of the anthracycline dose during induction therapy has improved the rate of complete remission but not of overall survival. We evaluated the use of cytarabine plus either standard-dose or high-dose daunorubicin as induction therapy, followed by intensive consolidation therapy, in inducing complete remission to improve overall survival.

METHODS

In this phase 3 randomized trial, we assigned 657 patients between the ages of 17 and 60 years who had untreated AML to receive three once-daily doses of daunorubicin at either the standard dose (45 mg per square meter of body-surface area) or a high dose (90 mg per square meter), combined with seven daily doses of cytarabine (100 mg per square meter) by continuous intravenous infusion. Patients who had a complete remission were offered either allogeneic hematopoietic stem-cell transplantation or high-dose cytarabine, with or without a single dose of the monoclonal antibody gemtuzumab ozogamicin, followed by autologous stem-cell transplantation. The primary end point was overall survival.

RESULTS

In the intention-to-treat analysis, high-dose daunorubicin, as compared with a standard dose of the drug, resulted in a higher rate of complete remission (70.6% vs. 57.3%, P<0.001) and improved overall survival (median, 23.7 vs. 15.7 months; P=0.003). The rates of serious adverse events were similar in the two groups. Median follow-up was 25.2 months.

CONCLUSIONS

In young adults with AML, intensifying induction therapy with a high daily dose of daunorubicin improved the rate of complete remission and the duration of overall survival, as compared with the standard dose. (ClinicalTrials.gov number, NCT00049517.)

Fluorescence in situ hybridization to visualize genetic abnormalities in interphase cells of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas

OBJECTIVE

To use fluorescence in situ hybridization (FISH) to visualize genetic abnormalities in interphase cell nuclei (interphase FISH) of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas.

PATIENTS AND METHODS

Between April 4, 2007, and December 4, 2008, interphase FISH was used to study paraffin-embedded preparations of tissue obtained from 18 patients listed in the Mayo Clinic Biospecimen Resource for Pancreas Research with a confirmed diagnosis of acinar cell carcinoma, ductal adenocarcinoma, islet cell carcinoma, or pancreas without evidence of neoplasia. FISH probes were used for chromosome loci of APC (see glossary at end of article for expansion of all gene symbols), BRCA2, CTNNB1, EGFR, ERBB2, CDKN2A, TP53, TYMP, and TYMS. These FISH probes were used with control probes to distinguish among various kinds of chromosome abnormalities of number and structure.

RESULTS

FISH abnormalities were observed in 12 (80%) of 15 patients with pancreatic cancer: 5 of 5 patients with acinar cell carcinoma, 5 of 5 patients with ductal adenocarcinoma, and 2 (40%) of 5 patients with islet cell carcinoma. All 3 specimens of pancreatic tissue without neoplasia had normal FISH results. Gains of CTNNB1 due to trisomy 3 occurred in each tumor with acinar cell carcinoma but in none of the other tumors in this study. FISH abnormalities of all other cancer genes studied were observed in all forms of pancreatic tumors in this investigation.

CONCLUSION

FISH abnormalities of CTNNB1 due to trisomy 3 were observed only in acinar cell carcinoma. FISH abnormalities of genes implicated in familial cancer, tumor progression, and the 5-fluorouracil pathway were common but were not associated with specific types of pancreatic cancer.

Fluorescence in situ hybridization to visualize genetic abnormalities in interphase cells of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas

OBJECTIVE

To use fluorescence in situ hybridization (FISH) to visualize genetic abnormalities in interphase cell nuclei (interphase FISH) of acinar cell carcinoma, ductal adenocarcinoma, and islet cell carcinoma of the pancreas.

PATIENTS AND METHODS

Between April 4, 2007, and December 4, 2008, interphase FISH was used to study paraffin-embedded preparations of tissue obtained from 18 patients listed in the Mayo Clinic Biospecimen Resource for Pancreas Research with a confirmed diagnosis of acinar cell carcinoma, ductal adenocarcinoma, islet cell carcinoma, or pancreas without evidence of neoplasia. FISH probes were used for chromosome loci of APC (see glossary at end of article for expansion of all gene symbols), BRCA2, CTNNB1, EGFR, ERBB2, CDKN2A, TP53, TYMP, and TYMS. These FISH probes were used with control probes to distinguish among various kinds of chromosome abnormalities of number and structure.

RESULTS

FISH abnormalities were observed in 12 (80%) of 15 patients with pancreatic cancer: 5 of 5 patients with acinar cell carcinoma, 5 of 5 patients with ductal adenocarcinoma, and 2 (40%) of 5 patients with islet cell carcinoma. All 3 specimens of pancreatic tissue without neoplasia had normal FISH results. Gains of CTNNB1 due to trisomy 3 occurred in each tumor with acinar cell carcinoma but in none of the other tumors in this study. FISH abnormalities of all other cancer genes studied were observed in all forms of pancreatic tumors in this investigation.

CONCLUSION

FISH abnormalities of CTNNB1 due to trisomy 3 were observed only in acinar cell carcinoma. FISH abnormalities of genes implicated in familial cancer, tumor progression, and the 5-fluorouracil pathway were common but were not associated with specific types of pancreatic cancer.

Percentage of smudge cells on routine blood smear predicts survival in chronic lymphocytic leukemia

PURPOSE

Smudge cells are ruptured chronic lymphocytic leukemia (CLL) cells appearing on the blood smears of CLL patients. Our recent findings suggest that the number of smudge cells may have important biologic correlations rather than being only an artifact of slide preparation. In this study, we evaluated whether the smudge cell percentage on a blood smear predicted survival of CLL patients.

PATIENTS AND METHODS

We calculated smudge cell percentages (ratio of smudged to intact cells plus smudged lymphocytes) on archived blood smears from a cohort of previously untreated patients with predominantly early-stage CLL enrolled onto a prospective observational study. The relationship between percentage of smudge cells, patient survival, and other prognostic factors was explored.

RESULTS

Between 1994 and 2002, 108 patients were enrolled onto the study and had archived blood smears available for review; 80% of patients had Rai stage 0 or I disease. The median smudge cell percentage was 28% (range, 1% to 75%). The percentage of smudge cells was lower in CD38(+) versus CD38(-) patients (P = .019) and in Zap70-positive versus Zap70-negative patients (P = .028). Smudge cell percentage as a continuous variable was associated with prolonged survival (P = .042). The 10-year survival rate was 50% for patients with 30% or less smudge cells compared with 80% for patients with more than 30% of smudge cells (P = .015). In multivariate analysis, the percentage of smudge cells was an independent predictor of overall survival.

CONCLUSION

Percentage of smudge cells on blood smear is readily available and an independent factor predicting overall survival in CLL.

Myelodysplastic syndromes associated with interstitial deletion of chromosome 5q: clinicopathologic correlations and new insights from the pre-lenalidomide era

To better estimate prognosis for patients with myelodysplastic syndromes (MDS) associated with clonal interstitial deletions of the long arm of chromosome 5 (del(5q)), we reviewed the medical records of 130 adults with del(5q) MDS seen at our institution over a 15-year period. Overall median survival of this cohort was 9.5 months, shorter than reported in earlier series. The least favorable outcomes are associated with complex cytogenetics, lack of any normal metaphases, normocytic rather than macrocytic erythrocyte indices, and low baseline lymphocyte counts. Lymphopenia but not neutropenia at the time of diagnosis appears to be a new adverse prognostic indicator. Cytogenetic breakpoints defined by G-banded karyotyping correlate poorly with particular disease features. Surprisingly, survival of patients with treatment-related MDS was equivalent to that of de novo MDS with del(5q) in this series. Morphologic features associated with del(5q) are diverse. Most patients with del(5q) MDS do not meet criteria for WHO-defined 5q-syndrome, and the presence of del(5q) does not appear to modify the clinical phenotype otherwise risk-stratified by the International Prognostic Scoring System (IPSS). Additional important prognostic factors not taken into account by the IPSS include the baseline erythrocyte indices, lymphocyte count, and clonal burden.

Primary myelofibrosis is the most frequent myeloproliferative neoplasm associated with del(5q): clinicopathologic comparison of del(5q)-positive and -negative cases

Among 23 cases of myeloproliferative neoplasms (MPNs) with an associated del(5q) seen at our institution, 14 (61%) fulfilled diagnostic criteria for primary myelofibrosis (PMF). Other diagnoses included polycythemia vera (PV; n=2), essential thrombocythemia (ET; n=1), post-ET myelofibrosis (n=1), systemic mastocytosis (SM; n=1), and MPN, unclassifiable (n=4). Compared to their del(5q)-negative counterparts, del(5q)-positive PMF cases were significantly more anemic (p<0.001) and thrombocytopenic (p<0.001). However, survival and leukemic transformation rates appear to be similar between the two groups. del(5q)-positive PMF was histologically characterized by a mixture of both small and monolobated megakaryocytes as well as large and bizarre megakaryocytes. When used, lenalidomide therapy induced hematological and cytogenetic remissions in del(5q)-positive PMF. The current study identifies PMF as another del(5q)-associated myeloid malignancy with characteristic megakaryocyte morphology.

CD49d expression is an independent predictor of overall survival in patients with chronic lymphocytic leukaemia: a prognostic parameter with therapeutic potential

In vitro studies have demonstrated that surface expression of CD49d on chronic lymphocytic leukaemia (CLL) B cells facilitates leukaemic cell-stromal interactions by binding to fibronectin. This interaction reduces both spontaneous and drug-induced apoptosis. The present study measured CD49d expression by flow cytometry in a cohort of untreated CLL patients previously accrued to a prospective observational study and evaluated the relationship with overall survival (OS). Among the 158 CLL patients tested, the percentage of leukaemic B cells expressing CD49d ranged from 0 to 100%. When all risk factors were treated as continuous variables, CD49d expression showed moderate correlation with expression of ZAP-70 (r = 0.54; P < 0.0001) and CD38 (r = 0.58; P < 0.0001) but not %IGHV mutation. As a continuous variable, CD49d expression strongly correlated with OS (P < 0.0001). Recursive partitioning analysis suggested the 45% threshold of CD49d expression best predicted OS. Multivariate analysis, controlling for disease stage, ZAP-70, IGHV status and fluorescent in situ hybridization defects identified CD49d as an independent predictor of OS and was a better predictor of clinical outcome than ZAP-70, IGHV, or cytogenetics. This observational cohort study suggests that CLL B-cell expression of CD49d is an easily measurable and independent predictor of OS and CD49d expression in CLL. Importantly, anti-CD49d antibodies are already approved for treatment of other human diseases. Clinical testing of anti-CD49d therapy in CLL appears warranted.

Dysregulated angiogenesis in B-chronic lymphocytic leukemia: morphologic, immunohistochemical, and flow cytometric evidence

BACKGROUND

The extent of enhanced bone marrow angiogenesis in chronic lymphocytic leukemia (CLL) and relationship to proangiogenic factors and prognostic indicators is largely unexplored.

METHODS

To further investigate the role of angiogenesis in CLL by evaluating the topography and extent of angiogenesis in a group of CLL bone marrow biopsies, to study the expression of pro and antiangiogenic vascular factors in CLL cells to more precisely document the cell types producing these factors, and to evaluate the role, if any, of localized hypoxia in upregulation of angiogenesis in CLL We used immunohistochemistry (IHC) (n = 21 pts) with antibodies to CD3 and CD20, proangiogenic (VEGF, HIF-1a) and antiangiogenic (TSP-1) factors, and VEGF receptors -1 and -2 to examine pattern/extent of CLL marrow involvement, microvessel density (MVD), and angiogenic characteristics; flow cytometry (FC) was performed on 21 additional cases for VEGF and TSP-1.

RESULTS

CLL patients had higher MVD (23.8 vs 14.6, p~0.0002) compared to controls (n = 10). MVD was highest at the periphery of focal infiltrates, was not enhanced in proliferation centers, and was increased irrespective of the presence or absence of cytogenetic/immunophenotypic markers of aggressivity. By IHC, CLL cells were VEGF(+), HIF-1a (+), TSP-1(-), VEGFR-1(+), and VEGFR-2(+). By FC, CLL cells were 1.4-2.0-fold brighter for VEGF than T cells and were TSP-1(-).

CONCLUSION

CLL demonstrates enhanced angiogenesis, with increased MVD, upregulated VEGF and downregulated TSP-1. Upregulation of HIF-1a in all CLL cases suggests localized tissue hypoxia as an important stimulant of microvessel proliferation. The presence of VEGF receptors on CLL cells implies an autocrine effect for VEGF. Differences in MVD did not correlate with traditional genetic/immunophenotypic markers of aggressiveness.

Immunoglobulin diversity gene usage predicts unfavorable outcome in a subset of chronic lymphocytic leukemia patients

Survival of patients with B cell chronic lymphocytic leukemia (B-CLL) can be predicted by analysis of mutations in the immunoglobulin heavy chain variable gene (IGHV). Patients without mutations (unmutated [UM]) are at greater risk for disease progression and death than patients with mutations (M). Despite this broad prognostic difference, there remains wide intragroup variation in the clinical outcome of UM patients, especially those with low/intermediate Rai risk disease. We evaluated UM B-CLL patients with low/intermediate Rai risk to determine the relationship between IGHV, IGH diversity (IGHD), and IGH joining (IGHJ) gene usage and time to treatment (TTT). Irrespective of IGHV usage, UM patients whose B-CLL cells expressed the IGHD3-3 gene had a significantly shorter TTT than other UM B-CLL patients, and specifically, use of the IGHD3-3 gene in reading frame 2 (RF2) predicted shorter TTT. As expected, Rai risk was the best single prognostic factor for TTT; however, IGHD usage was also a significant variable for TTT. Therefore, both IGHD gene and IGHD RF usage have prognostic relevance in UM B-CLL patients with low/intermediate Rai risk disease. In addition, these data support the concept that antigen-driven selection of specific Ig receptors plays a role in the clinical course of B-CLL.

Chromosome 5q deletion: Specific diagnoses and cytogenetic details among 358 consecutive cases from a single institution

The purpose of this study was to define the spectrum of hematologic neoplasms and chromosomal breakpoints associated with del(5q); separate analyses were performed to account for prior cytotoxic treatment. A total of 358 consecutive del(5q) cases were identified; specific diagnoses included myelodysplastic syndrome (MDS; 53%), acute myeloid leukemia (AML; 22%), plasma cell proliferative disorder (PCPD; 9%), myeloproliferative disorder (MPD; 7%), acute lymphoblastic leukemia (ALL; 2%), PCPD with MDS (2%), MDS/MPD (2%), and malignant lymphoma (ML; 2%). The corresponding figures in the absence/presence of prior cytotoxic treatment (n=250/108) were 61%/34% for MDS, 24%/19% for AML, 4%/20% for PCPD, 6%/8% for MPD, 1%/4% for ALL, and 2%/4% for ML. del(5q) occurred as the sole cytogenetic abnormality in 88 cases (25%) including 76 without prior cytotoxic therapy. Among the latter, 82% had MDS, 8% AML, 5% MPD, 4% PCPD, and 1% ML. Chromosome 5 breakpoints included q13q33 in 49% of the cases, q15q33 in 22%, q22q33 in 8%, and q13 in 3% and their distribution was not affected by specific diagnosis or treatment history. del(5q)-associated lymphoid disorders featured a higher prevalence of previous cytotoxic therapy and smaller number del(5q)-positive metaphases, when compared to their counterparts with myeloid neoplasms. We conclude that del(5q), although most prevalent in MDS, is seen across the spectrum of myeloid disorders including MPD and its occurrence in lymphoid disorders might signify, for the most part, an occult myeloid clone.

Phase 2 study of lenalidomide in transfusion-dependent, low-risk, and intermediate-1 risk myelodysplastic syndromes with karyotypes other than deletion 5q

Lenalidomide is approved for red blood cell (RBC) transfusion-dependent anemia due to low or intermediate-1 (int-1) risk myelodysplastic syndromes (MDSs) associated with a chromosome 5q deletion with or without additional cytogenetic abnormalities. We report results of a multicenter, phase 2 trial evaluating lenalidomide therapy for transfusion-dependent patients with low- or int-1-risk MDS without deletion 5q. Eligible patients had 50,000/mm(3) or more platelets and required 2 U or more RBCs within the previous 8 weeks; 214 patients received 10 mg oral lenalidomide daily or 10 mg on days 1 to 21 of a 28-day cycle. The most common grade 3/4 adverse events were neutropenia (30%) and thrombocytopenia (25%). Using an intention-to-treat analysis, 56 (26%) patients achieved transfusion independence (TI) after a median of 4.8 weeks of treatment with a median duration of TI of 41.0 weeks. In patients who achieved TI, the median rise in hemoglobin was 32 g/L (3.2 g/dL; range, 10-98 g/L [1.0-9.8 g/dL]) from baseline. A 50% or greater reduction in transfusion requirement occurred in 37 additional patients, yielding a 43% overall rate of hematologic improvement (TI response + ||>or= 50% reduction in transfusion requirement). Lenalidomide has clinically meaningful activity in transfusion-dependent patients with low- or int-1-risk MDS who lack the deletion 5q karyotypic abnormality.

Efficacy of conventional cytogenetics and FISH for EGR1 to detect deletion 5q in hematological disorders and to assess response to treatment with Lenalidomide

In clinical practice, whether FISH for EGR1 in interphase nuclei has similar efficacy to detect deletion 5q anomalies as conventional cytogenetic studies is unknown. We compared conventional cytogenetics and FISH for 145 patients with deletion 5q and detected this anomaly by both methods in 144. Nine patients with myelodysplasia were studied before and after treatment with Lenalidomide and results were concordant for 28 of 29 specimens. FISH did not detect anomalies other than deletion 5q in 31 patients. This study suggests FISH is useful to detect deletion 5q, but is not a substitute for conventional cytogenetics.

Chronic lymphocytic leukemia FISH panel: impact on diagnosis

Interphase fluorescence in situ hybridization (FISH) is an alternative to conventional chromosome analysis of chronic lymphocytic leukemia (CLL) cells. We analyzed 172 samples from 136 possible CLL cases using a FISH panel. Reflex testing with probes to CCND1, BCL2, BCL3, BCL11A, c-MYC, MALT1, and a break-apart immunoglobulin heavy chain (IGH) probe was done if more than 2 signals for 14q32 occurred. For 111 cases, there were sufficient data for analysis. Of 111 cases, 81 (72.9%) had 1 or more genetic abnormalities. The most frequent abnormality was 13q-, followed by trisomy 12, 11q-, and 17p-. In 13 cases, there were IGH abnormalities. Two cases with CCND1/IGH fusion were reclassified as mantle cell lymphoma. Four CLL cases had IGH fusion with BCL2, BCL3 (2 cases), and BCL11A; no fusion partner was detected in 7 cases. Morphologic features were atypical for CLL in 2 cases with IGH fusion (BCL11A and BCL3). The FISH CLL panel is useful to identify prognostic aberrations and to clarify diagnosis in cases with unusual morphologic features.

Expression of TCL-1 as a potential prognostic factor for treatment outcome in B-cell chronic lymphocytic leukemia

TCL-1 expression is variable in CLL, and no study has examined its association with treatment response. We measured TCL-1 protein in CLL cells from 51 patients who then received pentostatin, cyclophosphamide, and rituximab. TCL-1 expression did not correlate with any pre-treatment characteristics. Lower TCL-1 levels were associated with higher probability of attaining flow cytometry-negative status post-treatment (52% versus 17%, p=0.046). Trends toward improved complete remission rate (49% versus 19%, p=0.064) and progression-free survival (medians: 33 versus 20 months, p=0.199) were noted with lower TCL-1 expression. These data suggest TCL-1 expression may help predict treatment outcome in CLL patients following chemoimmunotherapy, and examination in larger studies is warranted.

Guidance for fluorescence in situ hybridization testing in hematologic disorders

Fluorescence in situ hybridization (FISH) provides an important adjunct to conventional cytogenetics and molecular studies in the evaluation of chromosome abnormalities associated with hematologic malignancies. FISH employs DNA probes and methods that are generally not Food and Drug Administration-approved, and therefore, their use as analyte-specific reagents involves unique pre- and postanalytical requirements. We provide an overview of the technical parameters influencing a reliable FISH result and encourage laboratories to adopt specific procedures and policies in implementing metaphase and interphase FISH testing. A rigorous technologist training program relative to specific types of probes is detailed, as well as guidance for consistent interpretation of findings, including typical and atypical abnormal results. Details are provided on commonly used dual-fusion, extra signal, and break-apart probes, correct FISH nomenclature in the reporting of results, and the use of FISH in relation to other laboratory testing in the ongoing monitoring of disease. This article provides laboratory directors detailed guidance to be used in conjunction with existing regulations to successfully implement a FISH testing program or to assess current practices, allowing for optimal clinical testing for patient care.

Impact of cytogenetics on outcome of matched unrelated donor hematopoietic stem cell transplantation for acute myeloid leukemia in first or second complete remission

We compared the treatment-related mortality, relapse rate, disease-free survival (DFS), and overall survival (OS) by cytogenetic risk group of 261 patients with acute myeloid leukemia in first complete remission (CR1) and 299 patients in CR2 in undergoing matched unrelated donor hematopoietic stem cell transplantation (HSCT). For patients in first CR, the DFS and OS at 5 years were similar for the favorable, intermediate, and unfavorable risk groups at 29% (95% confidence interval [CI], 8%-56%) and 30% (22%-38%); 27% (19%-39%) and 29% (8%-56%); and 30% (95% CI, 22%-38%) and 30% (95% CI, 20%-41%), respectively. For patients in second CR, the DFS and OS at 5 years were 42% (95% CI, 33%-52%) and 35% (95% CI, 28%-43%); 38% (95% CI, 23%-54%) and 45% (95% CI, 35%-55%); and 37% (95% CI, 30%-45%) and 36% (95% CI, 21%-53%), respectively. Cytogenetics had little influence on the overall outcome for patients in first CR. In second CR, outcome was modestly, but not significantly, better for patients with favorable cytogenetics. The graft-versus-leukemia effect appeared effective, even in patients with unfavorable cytogenetics. However, treatment-related mortality was high. Matched unrelated donor HSCT should be considered for all patients with unfavorable cytogenetics who lack a suitable HLA-matched sibling donor.

Frequency, hematopathology, and detection of a new isodicentric variant of deletion 20q

The ider(20)(p11.21)del(20)(q11q13) anomaly was recognized only recently. Thus, its frequency and clinical significance has not been extensively studied. Due to small size and ambiguous G-band pattern, ider(20q) is usually missed in cytogenetic studies. Furthermore, the commercial FISH probe D20S108 does not distinguish among del(20q), ider(20q), and monosomy 20. Thus, we determined the frequency and hematopathology of patients with ider(20q), and the best cytogenetic methods to detect chromosome 20 anomalies. To do this, we performed FISH on interphase and metaphase cells for 12 patients with -20,+mar and 12 patients with only del(20q) in their karyotype. The marker chromosome in patients with -20,+mar proved to be ider(20q). FISH with D20S108 and 20qter distinguished ider(20q) from del(20q) and monosomy 20. Review of blood and bone marrow slides for nine patients with ider(20q) showed that one had acute myeloid leukemia and eight had myelodysplastic syndromes. Patients with ider(20q) had a more consistent presentation of multilineage dysplasia with additional involvement of the granulocytic series than patients with del(20q). This study shows ider(20q) is common in clinical practice--1/10th the incidence of del(20q)--and is strongly associated with myelodysplasia and acute myeloid leukemia.

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.