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

TRAF3 alterations are frequent in del-3'IGH chronic lymphocytic leukemia patients and define a specific subgroup with adverse clinical features

Interstitial 14q32 deletions involving IGH gene are infrequent events in chronic lymphocytic leukemia (CLL), affecting less than 5% of patients. To date, little is known about their clinical impact and molecular underpinnings, and its mutational landscape is currently unknown. In this work, a total of 871 CLLs were tested for the IGH break-apart probe, and 54 (6.2%) had a 300 kb deletion of 3'IGH (del-3'IGH CLLs), which contributed to a shorter time to first treatment (TFT). The mutational analysis by next-generation sequencing of 317 untreated CLLs (54 del-3'IGH and 263 as the control group) showed high mutational frequencies of NOTCH1 (30%), ATM (20%), genes involved in the RAS signaling pathway (BRAF, KRAS, NRAS, and MAP2K1) (15%), and TRAF3 (13%) within del-3'IGH CLLs. Notably, the incidence of TRAF3 mutations was significantly higher in del-3'IGH CLLs than in the control group (p < .001). Copy number analysis also revealed that TRAF3 loss was highly enriched in CLLs with 14q deletion (p < .001), indicating a complete biallelic inactivation of this gene through deletion and mutation. Interestingly, the presence of mutations in the aforementioned genes negatively refined the prognosis of del-3'IGH CLLs in terms of overall survival (NOTCH1, ATM, and RAS signaling pathway genes) and TFT (TRAF3). Furthermore, TRAF3 biallelic inactivation constituted an independent risk factor for TFT in the entire CLL cohort. Altogether, our work demonstrates the distinct genetic landscape of del-3'IGH CLL with multiple molecular pathways affected, characterized by a TRAF3 biallelic inactivation that contributes to a marked poor outcome in this subgroup of patients.

IGH Translocations in Chinese Patients With Chronic Lymphocytic Leukemia: Clinicopathologic Characteristics and Genetic Profile

Immunoglobulin heavy chain translocations (IGH-t) have occasionally been reported in Chinese patients with chronic lymphocytic leukemia (CLL). The objective of the present study was to identify the clinicopathologic features of patients with IGH-t CLL and compare them with those of patients with non-IGH-t CLL. We performed fluorescence in situ hybridization (FISH) based on a routine CLL prognostic FISH panel using IGH, IGH-BCL2, BCL3, IGH-CMYC, and BCL6 FISH probes. Furthermore, we retrospectively evaluated the clinical features of 138 newly diagnosed CLL patients via chromosome banding analysis (CBA), FISH, and targeted next-generation sequencing. IGH-t was identified in 25 patients (18.1%). Patients with IGH-t CLL had lower flow scores than those with non-IGH-t CLL. The most frequent translocation was t(14;18) (10 patients), followed by t(14;19) (3 patients), and t(2;14)(p13;q32), t(7;14)(q21.2;q12), t(9;14)(p13;q32) (3 patients). The remaining nine patients included three with abnormal karyotypes without translocation involving 14q32, four with a normal karyotype, and two who failed CBA. The most frequently concomitant FISH-detected aberrations were 13q deletion, followed by +12 and TP53 deletion, while one case involved ATM deletion. Complex karyotypes were detected in five patients with IGH-t CLL, in whom all partner genes were non-BCL2. Available mutational information indicated that KMT2D mutation was the most frequent mutation among tested 70 patients, while TP53 mutation was the most frequent mutation in the IGH-t group. Moreover, the IGH-t group had higher FBXW7 (P=0.014) and ATM (P=0.004) mutations than the non-IGH-t group, and this difference was statistically significant. Our study demonstrates that IGH-t is not uncommon among Chinese CLL patients, and that its partner genes are multiple. The gene mutational profile of the IGH-t group was distinct from that of the non-IGH-t group, and the concomitant chromosomal abnormalities within the IGH-t CLL group differed. Thus, identification of IGH-t and its partner genes in CLL patients may help further refine risk stratification and strengthen the accurate management in CLL patients.

Incorporating molecular biomarkers into the continuum of care in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy characterized by marked heterogeneity. Discoveries in disease biology over the past two decades have helped explain clinical variability and heralded the arrival of the targeted therapy era. In this article, we review improvements in risk stratification which have coincided with this progress, including individual biomarkers and their incorporation into prognostic models. Amidst an ever-expanding list of biomarkers, we seek to bring focus to the essential tests to improve patient care and counseling at particular times in the disease course, beginning with prognosis at diagnosis. The majority of patients do not require treatment at the time of diagnosis, making time-to-first-treatment a key initial prognostic concern. Prognostic and predictive biomarkers are then considered at subsequent major junctures, including at the time of treatment initiation, while on therapy, and at the time of relapse on novel agents.

Chronic lymphocytic leukemia patients with IGH translocations are characterized by a distinct genetic landscape with prognostic implications

Chromosome 14q32 rearrangements/translocations involving the immunoglobulin heavy chain (IGH) are rarely detected in chronic lymphocytic leukemia (CLL). The prognostic significance of the IGH translocation is controversial and its mutational profile remains unknown. Here, we present for the first time a comprehensive next-generation sequencing (NGS) analysis of 46 CLL patients with IGH rearrangement (IGHR-CLLs) and we demonstrate that IGHR-CLLs have a distinct mutational profile with recurrent mutations in NOTCH1, IGLL5, POT1, BCL2, FBXW7, ZMYM3, MGA, BRAF and HIST1H1E genes. Interestingly, BCL2 and FBXW7 mutations were significantly associated with this subgroup and almost half of BCL2, IGLL5 and HISTH1E mutations reported were previously identified in non-Hodgkin lymphomas. Notably, IGH/BCL2 rearrangements were associated with a lower mutation frequency and carried BCL2 and IGLL5 mutations, while the other IGHR-CLLs had mutations in genes related to poor prognosis (NOTCH1, SF3B1 and TP53) and shorter time to first treatment (TFT). Moreover, IGHR-CLLs patients showed a shorter TFT than CLL patients carrying 13q-, normal fluorescence in situ hybridization (FISH) and +12 CLL, being this prognosis particularly poor when NOTCH1, SF3B1, TP53, BIRC3 and BRAF were also mutated. The presence of these mutations not only was an independent risk factor within IGHR-CLLs, but also refined the prognosis of low-risk cytogenetic patients (13q-/normal FISH). Hence, our study demonstrates that IGHR-CLLs have a distinct mutational profile from the majority of CLLs and highlights the relevance of incorporating NGS and the status of IGH by FISH analysis to refine the risk-stratification CLL model.

IGH translocations in chronic lymphocytic leukemia: Clinicopathologic features and clinical outcomes

The prevalence, clinicopathologic correlates, and outcomes of previously untreated chronic lymphocytic leukemia (CLL) patients with IGH-BCL2 and IGH-BCL3 translocations are not well known. Using the Mayo Clinic CLL database, we identified patients seen between March 1, 2002 and September 30, 2016 who had FISH testing performed within 3 years of CLL diagnosis. The prognostic profile, time to first therapy (TTT), and overall survival (OS) of patients with IGH-BCL2 and IGH-BCL3 translocation were compared to patients without these abnormalities (non-IGH group). Of 1684 patients who met the inclusion criteria, 38 (2.2%) had IGH-BCL2, and 16 (0.9%) had IGH-BCL3 translocation at diagnosis. Patients with IGH-BCL3 translocation were more likely to have high and very-high CLL-International Prognostic Index, compared to patients with IGH-BCL2 translocation and the non-IGH group. The 5-year probability of requiring therapy was significantly higher for IGH-BCL3 compared to IGH-BCL2 and non-IGH groups (84% vs 33% vs 29%, respectively, P < 0.0001). The 5-year OS was significantly shorter for IGH-BCL3 compared to IGH-BCL2 and non-IGH groups (45% vs 89% vs 86%, respectively, P < 0.0001). On multivariable analyses, IGH-BCL3 translocation was associated with a shorter TTT (hazard ratio [HR] = 2.7; P = 0.005) and shorter OS (HR = 5.5; P < 0.0001); IGH-BCL2 translocation did not impact TTT and OS. In conclusion, approximately 3% of all newly diagnosed CLL patients have either an IGH-BCL2 or IGH-BCL3 translocation. Patients with IGH-BCL3 translocations have a distinct prognostic profile and outcome. These results support the inclusion of an IGH probe during the routine evaluation of FISH abnormalities in newly diagnosed CLL.

Analysis of Common Abnormalities Seen in Chronic Lymphocytic Leukemia Using Fluorescence In Situ Hybridization

Since fluorescence in situ hybridization (FISH) was used to define a prognostic heierarchy for chronic lymphocytic leukemia (CLL) in 2000, the method has been employed widely in cytogenetics laboratories worldwide. This chapter describes techniques and trouble-shooting to maximize the efficiency of microscope slide preparation for FISH analysis in CLL.

t(14;18)(q32;q21) in chronic lymphocytic leukemia patients: Report of two cases and a literature review

The chromosomal abnormality t(14;18)(q32;q21) is most commonly associated with germinal center-derived B-cell lymphomas, particularly follicular lymphoma (FL). Generally, it is considered a hallmark of FL. The t(14;18)(q32;q21) translocation is rare in chronic lymphocytic leukemia (CLL) and its prognostic significance remains unclear. In the present study, two cases of CLL with t(14;18)(q32;q21) were diagnosed using conventional cytogenetic analysis and fluorescence in situ hybridization. Both patients presented with leukemia and the morphological features and immunophenotypes were typical of CLL. Case 2 underwent a further lymph node biopsy, which established a diagnosis of CD5^- CLL/small lymphocyte lymphoma. In addition to t(14;18)(q32;q21), trisomy 12 was identified in the same clone in Case 2. Both cases exhibited immunoglobulin heavy chain variable mutations, and heavy-chain variable region gene (VH) 4-39 and VH3-62 were used in Case 1 and Case 2, respectively. In addition, direct Sanger sequencing of exons 4-9 revealed that Case 2 harbored the tumor protein p53 mutation, c.829T>G. Both cases had indications for therapy. Case 1 responded well to chlorambucil treatment, and was still alive at the last follow-up. Conversely, Case 2 exhibited aggressive disease that appeared refractory to treatment, and eventually succumbed to the disease.

Immunoglobulin gene translocations in chronic lymphocytic leukemia: A report of 35 patients and review of the literature

Chronic lymphocytic leukemia (CLL) represents the most common hematological malignancy in Western countries, with a highly heterogeneous clinical course and prognosis. Translocations involving the immunoglobulin (IG) genes are regularly identified. From 2000 to 2014, we identified an IG gene translocation in 18 of the 396 patients investigated at diagnosis (4.6%) and in 17 of the 275 analyzed during follow-up (6.2%). A total of 4 patients in whom the IG translocation was identified at follow-up did not carry the translocation at diagnosis. The IG heavy locus (IGH) was involved in 27 translocations (77.1%), the IG κ locus (IGK) in 1 (2.9%) and the IG λ locus (IGL) in 7 (20.0%). The chromosome band partners of the IG translocations were 18q21 in 16 cases (45.7%), 11q13 and 19q13 in 4 cases each (11.4% each), 8q24 in 3 cases (8.6%), 7q21 in 2 cases (5.7%), whereas 6 other bands were involved once (2.9% each). At present, 35 partner chromosomal bands have been described, but the partner gene has solely been identified in 10 translocations. CLL associated with IG gene translocations is characterized by atypical cell morphology, including plasmacytoid characteristics, and the propensity of being enriched in prolymphocytes. The IG heavy chain variable region (IGHV) mutational status varies between translocations, those with unmutated IGHV presumably involving cells at an earlier stage of B-cell lineage. All the partner genes thus far identified are involved in the control of cell proliferation and/or apoptosis. The translocated partner gene becomes transcriptionally deregulated as a consequence of its transposition into the IG locus. With the exception of t(14;18)(q32;q21) and its variants, prognosis appears to be poor for the other translocations. Therefore, searching for translocations involving not only IGH, but also IGL and IGK, by banding and molecular cytogenetics is required. Furthermore, it is important to identify the partner gene to ensure the patients receive the optimal treatment.

Chronic Lymphocytic Leukemia with t(14;18)(q32;q21) As a Sole Cytogenetic Abnormality

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. The chromosomal abnormality t(14;18)(q32;q21) is most commonly associated with neoplasms of a follicular center cell origin. However, t(14;18) has also been reported in rare cases of CLL.

OBJECTIVE

We describe the clinicopathologic, immunophenotypic, conventional, and molecular cytogenetic features of two rare cases proven to be CLL morphologically and immunologically in which t(14;18) was found as the sole cytogenetic abnormality.

METHODS

Morphologic, flow cytometric analysis and molecular cytogenetic of peripheral blood and/or bone marrow samples were analyzed.

RESULTS

Cytomorphologically, the cells were small mature lymphocytes without any findings that had characteristics of follicular lymphoma (FL) such as indented or clefted nuclei. Immunologic findings were characteristic of typical CLL without expression of CD10. A cytogenetic study revealed the two cases of CLL carrying t(14;18)(q32;q21).

CONCLUSION

We concluded that CLL with t(14;18) is rare and should be differentiated from FL as the therapy is highly diverse between both diseases. Using immunoglobulin heavy chain gene (IGH) probes are important in the workup of patients with suspected CLL and suggest that the IGH probe should be used routinely in all CLL fluorescence in situ hybridization (FISH) panels.

Population-based characterization of the genetic landscape of chronic lymphocytic leukemia patients referred for cytogenetic testing in British Columbia, Canada: the role of provincial laboratory standardization

Detection of recurrent chromosome abnormalities by fluorescence in situ hybridization (FISH) is an essential component of care in chronic lymphocytic leukemia (CLL) patients. In the province of British Columbia (BC), Canada, population 4.6 million, CLL patients receive uniform evaluation and therapy with FISH testing performed in three jurisdictions. The aims of this study were to (i) validate CLL-FISH testing among the BC cytogenetic laboratories to ensure standardization of results and (ii) characterize population-level CLL-FISH abnormalities by pooling provincial data. From 2004 to 2011, 585 consecutive patients underwent pretreatment CLL-FISH testing at laboratory A (50.1%), laboratory B (32.3%), or laboratory C (17.6%). For validation purposes, 26 CLL-FISH abnormalities were tested by each laboratory's protocol, with 91% result concordance. Discordant results involved percent abnormalities at or near cutoff values; therefore, a 10% universal cutoff was established when pooling results. Applying the universal cutoff to the provincial cohort, CLL-FISH abnormalities were detected in 74.9%: 54.9% 13q-, 18.8% +12, 8.5% 11q-, and 7.7% 17p-. In this large population-based cohort of patients referred for CLL-FISH testing, frequencies of abnormalities detected by FISH analysis were highly consistent with those reported in single-institution and clinical trial populations. Provinces or districts that work together to care for CLL patients can effectively pool data with appropriate laboratory validation to ensure standardization of results.

Chronic lymphocytic leukemia and prolymphocytic leukemia with MYC translocations: a subgroup with an aggressive disease course

Translocations involving MYC are rare in chronic lymphocytic leukemia (CLL), and up to now, their prognostic significance remains unclear. We report the characteristics of 21 patients with CLL and nine patients with prolymphocytic leukemia (PLL), diagnosed in multiple centers (n = 13), which showed an MYC translocation demonstrated by fluorescence in situ hybridization. The prevalence was estimated to be <1%. Advanced age and male predominance were observed. Morphological analysis frequently revealed the presence of prolymphocytes. A typical "CLL-immunophenotype" was found in four of nine cases with PLL. Moreover, CD5 and CD23 were frequently expressed in PLL. The latter findings are atypical for PLL and may suggest transformation or progression of an underlying CLL. MYC translocations were frequently observed with concomitant adverse cytogenetic markers, such as del(11q) (n = 8/30) and/or del(17p)/monosomy 17 (n = 7/30). In addition, the presence of unbalanced translocations (n = 24 in 13/30 cases) and complex karyotype (n = 16/30) were frequent in cases with MYC translocations. Altogether, del(17p)/monosomy 17, del(11q), and/or complex karyotype were observed in 22 of 30 patients. Survival outcome was poor: the median time to treatment was only 5 months, and overall survival (OS) from clinical diagnosis and from genetic detection was 71 and 19 months, respectively. In conclusion, CLL/PLL with MYC translocations is a rare entity, which seems to be associated with adverse prognostic features and unfavorable outcome.

Management of patients with chronic lymphocytic leukemia with a high risk of adverse outcome: the Mayo Clinic approach

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) is usually an incidental diagnosis in patients with early-intermediate stage disease. However, most patients with a diagnosis of CLL will subsequently have significant morbidity and die from their disease and its complications. For these patients, CLL is not the 'good leukemia' with a predictably 'benign' outcome. Indeed, we can now identify a cohort of patients with high-risk CLL at diagnosis who will have rapid disease progression, poor response to treatment, and poor survival based on prognostic methods developed from an improved understanding of the biology of CLL. The concomitant development of improved treatments has led to risk-adjusted management approaches that could improve outcomes. We discuss the clinical and laboratory components of comprehensive risk evaluation of patients with CLL and our approach to the management of patients with a high to very high risk of disease progression and poor outcome. In addition, we review the challenges and prospects for improving prognostic precision and the development of new drugs to improve the treatment of patients with CLL with a high risk of adverse outcome.

Clinicobiologic importance of cytogenetic lesions in chronic lymphocytic leukemia

Molecular cytogenetic lesions play a major role in the pathogenesis of chronic lymphocytic leukemia (CLL) and represent important prognostic markers. Besides FISH, conventional banding analysis using effective mitogens is important for an accurate assessment of the cytogenetic profile of CLL. The most frequent aberrations are represented by 13q-, 11q-, +12, 6q- and 14q32/IGH translocations and 17p-. Chromosome translocations and complex karyotype may occur in up to 30 and 16% of the cases, respectively. The frequency of 17p- and 11q- is higher in patients requiring treatment and in relapsed/refractory patients, reflecting the association of these rearrangements with unfavorable prognosis. Mutations of the TP53 gene may also confer an inferior outcome, as is the case with 14q32 translocations and unbalanced translocations. Evidence was provided that distinct treatment approaches may be effective in specific cytogenetic entities of CLL, making molecular cytogenetic investigations a necessary tool for a modern diagnostic work-up in 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.

CD5-positive chronic B-cell lymphoproliferative disorders: diagnosis and prognosis of a heterogeneous disease entity

BACKGROUND

The pathology and clinical course of patients with CD5+ chronic B-cell lymphoproliferative disorders, excluding those that present with typical chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) or mantle cell lymphoma, (i.e. CD5+B-CLPD) are poorly defined.

METHODS

We studied patients with CD5+B-CLPD to (1) more completely define the clinical features and pathology of CD5+B-CLPD, (2) compare these features to patients presenting with typical CLL, and (3) test the hypothesis that a subset of patients with CD5+B-CLPD could have a unique B-cell malignancy.

RESULTS

We identified 229 patients with CD5+B-CLPD. A definitive pathological diagnosis was made in all 61 (27%) CD5+B-CLPD patients with nonbone marrow (BM) biopsy specimens considered adequate for a comprehensive pathological examination. The most common diagnosis among these 61 patients was CLL (44%) followed by the leukemic phase of marginal zone lymphoma (34%), lymphoplasmacytic lymphoma (11%), diffuse large B cell lymphoma (8%), and high-grade B cell lymphoma not otherwise specified (2%). In contrast, among 168 patients without a non-BM tissue biopsy specimen, a specific diagnosis could be made on review of all available data in only 24 (14%) with 144 (86%) remaining "unclassified."

CONCLUSIONS

In patients with CD5+B-CLPD, a definitive diagnosis can be made on an adequate non-BM tissue biopsy suggesting that this entity does not include a novel disease. We recommend that all patients with CD5+B-CLPD should have a non-BM tissue biopsy to make a definitive diagnosis prior to initiation of treatment.

Treatment of autoimmune cytopenia complicating progressive chronic lymphocytic leukemia/small lymphocytic lymphoma with rituximab, cyclophosphamide, vincristine, and prednisone

Treatment of autoimmune cytopenia complicating progressive chronic lymphocytic leukemia (CLL) is constrained by intolerance of myelosuppression and the risk of exacerbation of autoimmune cytopenia by purine analogs particularly when used as single agents. We report on 20 such patients treated with rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP). Autoimmune cytopenia responded in 19 patients (14 complete remissions (CR), five partial remissions (PR)) with a median time to next treatment (TTT) for autoimmune cytopenia of 21.7 months. Progressive CLL responded in 17 patients (nine CR/complete clinical response, eight PR) with a median TTT of 27.7 months. Five patients have not required any re-treatment at 15-30 months. Grade 3-4 toxicities were infections (n = 3) and drug-induced pneumonitis (n = 1). No patient required blood cell transfusions after cycle 1 of therapy. We conclude that R-CVP is effective and tolerable therapy for autoimmune cytopenia complicating progressive CLL, but the duration of response is suboptimal.

Deciphering leukemic B-cell chronic lymphoproliferative disorders

Diagnosis of leukemic B-cell chronic lymphoproliferative disorders (B-CLPD) is a frequent challenge in hematology. In this multicentric study, we prospectively studied 165 new consecutive leukemic patients with B-CLPD selected on the basis of Royal Marsden Hospital scoring system < or =3. The primary aim of the study was to try to decipher the atypical cases and identify homogenous subgroups. Overall, morphological examination contributed to diagnosis in only 20% cases, all of them CD5 negative. Thirty additional cases were CD5 negative suggestive of leukemic marginal zone lymphoma in most cases. The significantly poorer survival of the 26 cyclin D1 positive cases justifies recommending its systematic determination among atypical B-CLPD. CD20 expression segregated clearly two subgroups among CD5 positive cyclin D1 negative B-CLPD. The 17 patients with the CD20 dim profile represent a homogeneous subgroup very close to typical B-cell chronic lymphocytic leukemia (B-CLL) on morphological, phenotypical and cytogenetical criteria. In contrast, the subgroup of 51 patients with a CD20 bright profile is heterogeneous. Their significantly lower p27 expression level suggest the presence of a proliferative component, underlying a more aggressive disease. Further genomic studies are warranted to establish their precise nature. These cases should not be included in the same therapeutic trials as B-CLL.

Early treatment of high-risk chronic lymphocytic leukemia with alemtuzumab and rituximab

BACKGROUND

Patients with chronic lymphocytic leukemia (CLL) usually are treated only for progressive disease. However, the discovery of biologic predictors of a high risk of disease progression, together with the development of newer, more targeted therapies, could change this paradigm. In this phase 2 study, the authors tested the safety and efficacy of early treatment for patients with high-risk CLL using alemtuzumab and rituximab.

METHODS

Patients were eligible for treatment if they were 1) previously untreated, 2) had no National Cancer Institute-Working Group 1996 criteria for treatment, and 3) had at least 1 marker of high-risk disease 17p13-, 11q22-, or a combination of unmutated IgVH and CD38+/ZAP70+). Treatment consisted of subcutaneous alemtuzumab (initial dose escalation followed by 30 mg on Monday, Wednesday, and Friday for 4 weeks) and intravenous rituximab (375 mg/m(2) per week x4 doses). All patients received Pneumocystis pneumonia and herpes virus prophylaxis and were monitored for cytomegalovirus reactivation.

RESULTS

Twenty-seven of 30 patients (90%) responded to therapy with 11 (37%) complete responses (CRs). Five patients (17%) patients who had a CR had no detectable minimal residual disease. The median response duration was 14.4 months, and only 9 patients required retreatment for progressive disease at the time of the current report (median follow-up, 17.6 months). Study patients had a significantly longer time from diagnosis to first treatment for CLL according to conventional indications than a comparison cohort with similar biologic risk profiles.

CONCLUSIONS

The therapy regimen used was safe and effective for early treatment of patients with high-risk CLL. Further studies will be required to determine whether this early treatment strategy decreases morbidity and mortality for high-risk CLL.

Validation of a targeted DNA microarray for the clinical evaluation of recurrent abnormalities in chronic lymphocytic leukemia

Recurrent genomic alterations, mainly losses and gains of specific chromosomes and/or regions, in chronic lymphocytic leukemia (CLL) are recognized as important independent predictors of prognosis and disease progression. The current standard clinical practice for identifying these alterations is chromosome analysis and in situ hybridization with probes targeting 4-5 chromosome regions. We sought to apply array comparative genomic hybridization (array-CGH) technology for the simultaneous detection of genomic imbalances of all loci implicated in CLL. DNA from enriched B-cells from CLL patients were analyzed by array-CGH on a customized CLL BAC array. Copy number changes were detected in 87% of samples with a sensitivity of 100% in samples with clonal abnormalities present in at least 23% of the cells. Furthermore, in nine cases genomic alterations were observed that were undetectable by standard cytogenetic and/or FISH analyses. One of these patients had a 13q14 deletion that was missed by the clinical CLL FISH panel probe set. Our results suggest that a subset of potentially significant genomic alterations in CLL is being missed by the current available techniques. Furthermore, this pilot study clearly shows the robustness, high sensitivity, and high specificity for the targeted CLL microarray analysis as well as the potential for use in routine screening in CLL.

MYC translocation in chronic lymphocytic leukaemia is associated with increased prolymphocytes and a poor prognosis

Chromosomal translocations that involve MYC, characteristic of Burkitt lymphoma, are rare in chronic lymphocytic leukaemia (CLL). We report the clinical, morphological, immunophenotypic, cytogenetic and molecular genetic features of eight CLL cases with MYC rearrangement. The patients, five men and three women (median age, 71 years) had bone marrow involvement and an absolute peripheral blood lymphocytosis; five had lymphadenopathy; seven had splenomegaly. Prolymphocytes were increased (>/=10%) in all cases. Six cases were classified as CLL with increased prolymphocytes (CLL/PL; prolymphocytes 10-55%), and two were classified as CLL in prolymphocytic transformation (CLL/PT; prolymphocytes >55%). All cases co-expressed CD5, CD19, and CD23; five of eight expressed ZAP-70. Of seven cases tested, four had mutated and three had unmutated IGHV genes. Conventional cytogenetic studies demonstrated t(8;14)(q24.1;q32) in five cases, t(8;22)(q24.1;q11) in two cases, and t(2;8)(p12;q24.1) in one case. Seven cases contained additional chromosomal abnormalities. All patients received combination chemotherapy. Two developed Epstein-Barr virus (EBV)-associated diffuse large B-cell lymphomas (DLBCL) that were clonally unrelated to the CLL. At follow-up, two patients are alive, four died of underlying disease, one died of EBV-associated DLBCL, and one died of an unrelated cancer. In summary, MYC rearrangement, which occurs rarely in CLL patients, is associated with increased prolymphocytes, complex cytogenetic abnormalities, and a poor prognosis.

The prognostic significance of cytopenia in chronic lymphocytic leukaemia/small lymphocytic lymphoma

The development of cytopenia in chronic lymphocytic leukaemia (CLL) patients can predict poor prognosis. All CLL patients seen in the Division of Hematology at Mayo Clinic Rochester from 1 January 1995 to 31 December 2004 (n = 1750) were evaluated for cytopenia, aetiology of cytopenia and clinical outcome. Cytopenia occurred in 423 (24.2%) patients and was attributable to CLL in 303 (17.3%) cases, with 228 (75%) of these having bone marrow (BM) failure and 75 (25%) having autoimmune disease (AID). Survival from onset of cytopenia was significantly better for patients with AID (median 9.1 years) compared to patients with BM failure (median 4.4 years, P < 0.001). Patients with AID diagnosed within 1 year of the diagnosis of CLL (n = 35) had similar survival from diagnosis compared to patients without CLL-related cytopenia (median 9.3 vs. 9.7 years, P = 0.881). Although cytopenia caused by BM failure predicted a poorer prognosis in CLL, cytopenia caused by AID was not an adverse prognostic factor. These findings suggest that patients with cytopenia due to AID cannot be meaningfully classified by the current clinical staging systems. Revisions of the National Cancer Institute Working Group 96 criteria should consider the aetiology of cytopenia in staging CLL patients.

A multicenter retrospective clinical study of CD5/CD10-negative chronic B cell leukemias

CD5-negative chronic B cell lymphoproliferative disorders in leukemic phase (B-CLPD) are heterogeneous and relatively uncommon pathologies that often lack a histopathological definition because of the absence of accessible pathological tissue. We describe the clinical features and evolution-related variables of 156 patients with CD5/CD10-negative B-CLPD (median age 66 years, range 25-86). The median follow-up was 51 months (range 6-216), and overall 3- and 5-year survival was respectively 87 and 76%; 50 patients needed therapy at diagnosis, 56 during follow-up, and 50 remained untreated until the last control. A combined clinical, histological, cytomorphological, immunophenotypical, and cytogenetic diagnostic approach allowed the complete classification of only a minority of patients as being affected by splenic marginal zone or lymphoplasmacytic lymphoma; the majority of cases remained unclassifiable. Multivariate analysis showed that the clinicohematological variables adversely related to overall survival were serum LDH levels and age, whereas high serum LDH levels, hemoglobin levels of <11 g/dl, and splenomegaly related to treatment-free time (in "wait and see" cases); only splenomegaly related to time to progression (in treated patients). In conclusion, our retrospective study describes the clinical features and variables related to evolution in a large group of patients with CD5/CD10-negative chronic B-cell lymphoid leukemias and underlines the fact that a probable lymphoplasmacytic or marginal zone normal cell origin can be supposed in such leukemic forms, but never surely demonstrated.

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.

Chronic lymphocytic leukemia: biology and current treatment

There has been considerable recent progress in understanding of the biology of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). These accomplishments have been accompanied by progressive improvement in the management of CLL and its complications. This review summarizes these changes and provides guidelines for a comprehensive approach to patient care.

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.

Telomeric IGH losses detectable by fluorescence in situ hybridization in chronic lymphocytic leukemia reflect somatic VH recombination events

Routine interphase fluorescence in situ hybridization (FISH) analysis of chronic lymphocytic leukemia (CLL) with LSI IGH/CCND1 assay, applied to differentiate CLL from leukemic mantle cell lymphoma, identified a subset of cases (42/174) with translocation-like IGH signal pattern. To unravel the underlying 14q32/IGH aberrations, 14 of these cases were subjected to cytogenetic, detailed FISH, and V(H) mutation analyses. FISH identified cryptic losses of various portions of the IGHV region in all 14 cases. Fine mapping of these V(H) deletions revealed a strict correlation between their distal border and localization of the used VH gene, suggesting that they are not oncogenic but reflect physiological events accompanying somatic V-D-J assembly. This hypothesis was further supported by FISH analysis of 20 CLL and hairy cell leukemia cases with the known V(H) usage showing a constant loss of sequences proximal to the used gene, identification of V(H) deletions in normal B cells, and their exclusive demonstration in B cell malignancies, but not of T cell and myeloid linage. Given that these cryptic physiological VH losses in B cells may seriously complicate analysis of B cell leukemia/lymphoma and lead to false conclusions, FISH users should take them into consideration when interpreting IGH aberrations in these malignancies.

Comprehensive Management of the CLL Patient: A Holistic Approach

The current management of B-chronic lymphocytic leukemia (CLL) is no longer straightforward for the practicing hematologist. Rapid advances in diagnostic precision, methods of predicting prognosis, understanding of natural history of CLL, recognition of clinical complications, clarification of the quality of life (QOL) issues facing the CLL patient, and the exciting array of novel treatment approaches have made the care of the CLL patient more demanding. This review is focused on summarizing these advances in order to provide a framework for integrating this knowledge into routine hematologic practice.

Comprehensive management of the CLL patient: a holistic approach

The current management of B-chronic lymphocytic leukemia (CLL) is no longer straightforward for the practicing hematologist. Rapid advances in diagnostic precision, methods of predicting prognosis, understanding of natural history of CLL, recognition of clinical complications, clarification of the quality of life (QOL) issues facing the CLL patient, and the exciting array of novel treatment approaches have made the care of the CLL patient more demanding. This review is focused on summarizing these advances in order to provide a framework for integrating this knowledge into routine hematologic practice.

Update on risk-stratified management for chronic lymphocytic leukemia

Major recent advances in understanding the biology of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) have improved clinical evaluation and influenced treatment decisions. CLL can be diagnosed early and accurately, and biological measurements can be used to predict a prognosis at diagnosis. Individual patient care can be risk stratified to optimize benefit and minimize complications of therapy. Purine analogs and monoclonal antibodies have markedly improved the efficacy of initial therapy but are not curative. The treatment of relapsed and refractory CLL is less successful. However, recent developments suggest that allogeneic stem cell transplant could have a larger role in a selected group of these patients. Potential new treatment modalities include targeted molecules that interrupt key components of CLL cell survival pathways, and active and passive immunotherapy. The management of CLL is in a dynamic phase of rapid evolution. Risk stratification using biological prognostic markers can improve current patient care and direct future clinical research.

The t(14;19)(q32;q13)-positive small B-cell leukaemia: a clinicopathologic and cytogenetic study of seven cases

The t(14;19)(q32;q13), involving the BCL3 locus at chromosome 19q13 and the immunoglobulin heavy chain gene at 14q32, is a rare recurrent cytogenetic abnormality identified in B-cell neoplasms, most of which have been classified as chronic lymphocytic leukaemia (CLL) in the literature. We describe the clinicopathological, immunophenotypic and cytogenetic findings in seven patients with B-cell neoplasms associated with t(14;19)(q32;q13). There were five men and two women, with a median age of 48 years (range 33-68). All had absolute lymphocytosis, six had lymphadenopathy, and one had splenomegaly. Lymphocytes in blood and bone marrow aspirate smears were predominantly small and cytologically atypical. Flow cytometric immunophenotyping showed an atypical immunophenotype with low CLL scores. The growth pattern in bone marrow biopsy specimens was interstitial to diffuse; immunohistochemical stains were positive for bcl3 and negative for cyclin D1. Lymph node biopsy specimens of two patients revealed total architectural effacement by neoplasm with proliferation centres. In addition to t(14;19), cytogenetic studies demonstrated trisomy 12 in five patients. These results suggest that B-cell neoplasms with the t(14;19)(q32;q13) present frequently as leukaemia composed of small B-lymphocytes and share many features with CLL. However, these neoplasms also differ from CLL cytologically and in their immunophenotype.

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.

Chronic lymphocytic leukaemia profiled for prognosis using a fluorescence in situ hybridisation panel

A panel of fluorescence in situ hybridisation (FISH) probes was used on 894 cases to target chromosome 11q, 13q, 17p deletions (del), trisomy 12 (+12) in all and 6q deletion in 59. Chronic lymphocytic leukaemia (CLL) immunophenotype (CD5 and CD19 with CD23) was found in 509 cases (average age 67.7 years, 319 males and 190 females). Among the 509 CLL cases 349 (68.6%) had FISH (4-probe panel) abnormalities: 160 del 13q [45.8% (122-del 13q, 18-biallelic del 13q, 20-monoallelic/biallelic del 13q)], 71 tri 12 (20.3%), 17 del ATM (5%), 12 del p53 (3.4%) and 89 > or = 2 FISH abnormalities (25.5%). Of 151/509 cases karyotyped, 108 were normal and 43 (43/151 = 28.5%) abnormal. Del 6q was found in 1/59 (1.6%) FISH cases and in 6/151 (4%) karyotypes. In 14 CD23 negative cases IGH/BCL1 FISH detected t(11;14) and was confirmed to be mantle cell lymphoma. Multiple probes/panels that included IGH probe were ordered for 57 CLL cases, 11 had an IGH rearrangement with an unidentified partner. This study favours the inclusion of del 6q and IGH probes in the CLL panel. The FISH panel could also serve to monitor 13q deletion for secondary changes with adverse prognosis. Understanding prognosis in specific types of 13q deletion would enhance outcome prediction.