Prognostic importance of cytogenetic abnormalities in patients with chronic lymphocytic leukemia

The molecular map of CLL and Richter's syndrome

Clonal expansion of B-cells, from the early stages of monoclonal B-cell lymphocytosis through to chronic lymphocytic leukemia (CLL), and then in some cases to Richter's syndrome (RS) provides a comprehensive model of cancer evolution, notable for the marked morphological transformation and distinct clinical phenotypes. High-throughput sequencing of large cohorts of patients and single-cell studies have generated a molecular map of CLL and more recently, of RS, yielding fundamental insights into these diseases and of clonal evolution. A selection of CLL driver genes have been functionally interrogated to yield novel insights into the biology of CLL. Such findings have the potential to impact patient care through risk stratification, treatment selection and drug discovery. However, this molecular map remains incomplete, with extant questions concerning the origin of the B-cell clone, the role of the TME, inter- and intra-compartmental heterogeneity and of therapeutic resistance mechanisms. Through the application of multi-modal single-cell technologies across tissues, disease states and clinical contexts, these questions can now be addressed with the answers holding great promise of generating translatable knowledge to improve patient care.

Cytogenetics in Chronic Lymphocytic Leukemia: ERIC Perspectives and Recommendations

Mounting evidence underscores the clinical value of cytogenetic analysis in chronic lymphocytic leukemia (CLL), particularly as it allows the identification of complex karyotype, that has recently emerged as a prognostic and potentially predictive biomarker. That said, explicit recommendations regarding the methodology and clinical interpretation of either chromosome banding analysis (CBA) or chromosome microarray analysis (CMA) are still lacking. We herein present the consensus of the Cytogenetic Steering Scientific Committee of ERIC, the European Research Initiative on CLL, regarding methodological issues as well as clinical interpretation of CBA/CMA and discuss their relevance in CLL. ERIC considers CBA standardized and feasible for CLL on the condition that standards are met, extending from the use of novel mitogens to the accurate interpretation of the findings. On the other hand, CMA, is also standardized, however, robust data on its clinical utility are still scarce. In conclusion, cytogenetic analysis is not yet mature enough to guide treatment choices in CLL. That notwithstanding, ERIC encourages the wide application of CBA, and potentially also CMA, in clinical trials in order to obtain robust evidence regarding the predictive value of specific cytogenetic profiles towards refining risk stratification and improving the management of patients with CLL.

Prognostic and Predictive Implications of Cytogenetics and Genomics

Chronic lymphocytic leukemia (CLL) is characterized by extreme genomic heterogeneity. Numerous recurrent genetic abnormalities are associated with dismal clinical outcome in patients treated with chemo(immuno)therapy, with aberrations of the TP53 gene being the main genomic abnormalities that dictate treatment choice. In the era of novel agents the predictive significance of the genomic aberrations is highly challenged as the results of the clinical trials performed thus far question the previously established unfavorable impact of genomic aberrations, even that of the TP53 gene. The prognostic and predictive value of the most common genomic abnormalities is discussed in the present review.

The importance of complex karyotype in prognostication and treatment of chronic lymphocytic leukemia (CLL): a comprehensive review of the literature

Cytogenetic examination and the detection of chromosomal aberrations in chronic lymphocytic leukemia (CLL) is an integral part of prognostic stratification and treatment decisions. Improvements in cytogenetic methods, notably the introduction of the cell stimulation method, have led to the detection of chromosomal aberrations in 80% of CLL cases. A comprehensive analysis of cytogenetic aberrations recently showed that complex karyotypes (CKs) defined as the detection of either three or more or five or more chromosomal changes in a karyotype have a poor prognostic impact. The current efforts at the international level are focused on the goal of including CK assessment among prognostic markers for CLL patients at diagnosis as well as after treatment. This review of the literature documents the clinical importance of CK findings in CLL and the necessity of including this factor in other poor prognostic indicators.

6q deletion detected by fluorescence in situ hybridization using bacterial artificial chromosome in chronic lymphocytic leukemia

Deletions of the long arm of chromosome 6 are known to occur at relatively low frequency (3-6%) in chronic lymphocytic leukemia (CLL), and they are more frequently observed in 6q21. Few data have been reported regarding other bands on 6q involved by cytogenetic alterations in CLL. The cytogenetic study was performed in nuclei and metaphases obtained after stimulation with a combination of CpG-oligonucleotide DSP30 and interleukin-2. Four bacterial artificial chromosome (BAC) clones mapping regions in bands 6q16, 6q23, 6q25, 6q27 were used as probes for fluorescence in situ hybridization in 107 CLL cases in order to analyze the occurrence and localization of 6q aberrations. We identified 11 cases (10.2%) with 6q deletion of 107 patients studied with CLL. The trends of survival curves and the treatment-free intervals (TFI) of patients with deletion suggest a better outcome than the other cytogenetic risk groups. We observed two subgroups with 6q deletion as the sole anomaly: two cases with 6q16 deletion, and three cases with 6q25.2-27 deletion. There were differences of age, stage, and TFI between both subgroups. By using BAC probes, we observed that 6q deletion has a higher frequency in CLL and is linked with a good prognosis. In addition, it was observed that the deletion in 6q16 appears to be the most frequent and, if present as the only abnormality, it could be associated with a most widespread disease.

What is the best frontline therapy for patients with CLL and 17p deletion?

Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disease with significant variation in disease progression, response to therapy, and survival outcome. Deletions of 17p or mutations of TP53 have been identified as one of the poorest prognostic factors, being predictive of short time for disease progression, lack of response to therapy, short response duration, and short overall survival. The treatment of patients with CLL has improved significantly with the development of chemoimmunotherapy, but this benefit was not pronounced in patients with 17p deletion. We compare various treatment strategies used in these patients, including FCR-like chemoimmunotherapy, alemtuzumab, other antibody combinations, or novel targeted therapies with promising results. Allogeneic stem cell transplantation offers the possibility for long-term disease control in these patients and should be considered early in younger, transplant-eligible patients. The current state of therapy is far from optimal and resources should be applied to studying therapeutic options for patients who have CLL with loss of p53 function.

Chromosomal abnormalities detected by multicolor fluorescence in situ hybridization in fine-needle aspirates from patients with small lymphocytic lymphoma are useful for predicting survival

BACKGROUND

Fine-needle aspiration (FNA) of lymph nodes is commonly used to assess disease progression in patients with small lymphocytic lymphoma (SLL). Although cytologic features are helpful for diagnosing typical SLL and transformed large-cell lymphoma (tLCL), SLL in accelerated phase (SLLacc) is more difficult to diagnose. Additional tests are needed to identify those patients who are transforming to a higher-grade lymphoma. This study evaluated the use of a multicolor fluorescence in situ hybridization (FISH) probe panel specifically designed for chronic lymphocytic leukemia (CLL)/SLL and assessed the association between FISH findings and cytologic diagnosis, proliferation index, and risk of death.

METHODS

FNA specimens from 50 patients (32 men and 18 women; mean age, 57 years [range, 36-77 years]) with histologically confirmed CLL and/or SLL were evaluated in this study for chromosomal abnormalities of 11q22 (ATM), 12, 13q14.3, 13q34.3 (LAMP1), and 17p13.1 (p53) by using a multiprobe FISH kit. One of the 50 cases was excluded because of an insufficient number of cells for FISH analysis. The FISH findings were compared with the cytologic diagnoses (26 SLLs, 12 SLLaccs, and 11 tLCLs), Ki-67 immunostaining, and risk of death.

RESULTS

Abnormal signal patterns for 17p13.1 and 13q34.3 were associated with tLCL. Aberrations of 17p13.1 were found to be significantly associated with Ki-67 staining. Of the 49 patients with interpretable FISH results, 22 (45%) had died at the time of the study, with a mean overall survival time of 17 months after FNA. Patients with aberrations of 17p13.1 and 11q22 had 3.7 and 2.7 times the risk of death, respectively, compared with patients with normal patterns.

CONCLUSIONS

FISH can be performed on FNA specimens from patients with a history of SLL/CLL. Chromosomal aberrations of 17p13.1 and 11q22 are associated with an increased risk of death. Knowledge of genetic abnormalities from FNAs may be useful in deciding when and how to treat indolent or progressive SLL.

Novel genomic alterations and clonal evolution in chronic lymphocytic leukemia revealed by representational oligonucleotide microarray analysis (ROMA)

We examined copy number changes in the genomes of B cells from 58 patients with chronic lymphocytic leukemia (CLL) by using representational oligonucleotide microarray analysis (ROMA), a form of comparative genomic hybridization (CGH), at a resolution exceeding previously published studies. We observed at least 1 genomic lesion in each CLL sample and considerable variation in the number of abnormalities from case to case. Virtually all abnormalities previously reported also were observed here, most of which were indeed highly recurrent. We observed the boundaries of known events with greater clarity and identified previously undescribed lesions, some of which were recurrent. We profiled the genomes of CLL cells separated by the surface marker CD38 and found evidence of distinct subclones of CLL within the same patient. We discuss the potential applications of high-resolution CGH analysis in a clinical setting.

6q deletion in Waldenström macroglobulinemia is associated with features of adverse prognosis

Fluorescence in situ hybridisation (FISH) is an effective technique for the cytogenetic analysis of Waldenström macroglobulinemia (WM), but the potential impact of molecular cytogenetics on disease evolution and as a prognostic marker is still unknown. Deletion of the long arm of chromosome 6 (6q-) is the most frequent cytogenetic abnormality in WM. This study analysed the prevalence of this aberration in 102 WM patients, and correlated it with disease characteristics. The incidence of 6q21 deletion was 7% by conventional cytogenetics and 34% when analysed by FISH (54% when cytoplasmic immunoglobulin M-FISH was used). Patients with deletion of 6q displayed features of adverse prognosis, such as higher levels of beta2-microglobulin and monoclonal paraprotein and a greater tendency to display anaemia and hypoalbuminemia. Interestingly, there was a correlation between the presence of 6q deletion and the International Staging System prognostic index (incidence of 6q- among patients stratified in stages 1, 2 and 3 was 24%, 42% and 67% respectively). Those patients diagnosed with smouldering WM who displayed the abnormality showed a trend to an earlier requirement of treatment. Finally, the survival analysis did not show differences between the two groups of patients, probably due to the short follow up of our series.

The clinical significance of large cells in bone marrow in patients with chronic lymphocytic leukemia

BACKGROUND

Patients with chronic lymphocytic leukemia (CLL) that transforms to Richter syndrome (RS) frequently show atypical lymphocytes in bone marrow; however, a diagnosis of RS requires confirmation of the presence of sheets of large cells in bone marrow or lymph nodes.

METHODS

In this study, the authors evaluated the clinical significance of scattered large cells in bone marrow. They assessed the possibility of predicting transformation to RS in bone marrow smears by counting the percentages of prolymphocytes and large cells in 78 patients with CLL and 29 patients with lymph node biopsy-confirmed RS.

RESULTS

The percentage of large cells was found to be correlated with decreasing survival in a continuous fashion (P = 0.006). It is interesting to note that patients who had > 7% large cells in the bone marrow and elevated beta(2)-microglobulin (beta(2)-M) levels (> 5 mg/L) had a survival duration identical to that of patients with RS, and these factors together were a strong predictor of RS (P < 0.001).

CONCLUSIONS

Patients with CLL who had bone marrow that contained > 7% large cells and who had beta(2)-M levels > 5 mg/L had a disease that was similar to RS, and the combination of large cells and beta(2)-M can be used as a surrogate marker for RS.

Chromosome anomalies detected by interphase fluorescence in situ hybridization: correlation with significant biological features of B-cell chronic lymphocytic leukaemia

Fluorescence in situ hybridization (FISH) was used to detect 6q-, 11q-, +12, 13q-, 17p- and translocations involving 14q32 in interphase nuclei from blood and/or bone marrow from 113 patients with B-cell chronic lymphocytic leukaemia (B-CLL). A total of 87 patients (77%) had a FISH anomaly: 13q- x 1 was most frequent (64%) followed by 13q- x 2 (28%), +12 (25%), 11q- (15%), 17p- (8%) and 6q- (0%). FISH results for blood and bone marrow cells in 38 patients were similar. Purified CD5+/CD19+ cells from blood were studied in eight patients and results indicate that in some patients not all B cells have FISH anomalies. We used a defined set of hierarchical FISH risk categories to compare FISH results by stable versus progressive disease, age, sex, Rai stage, CD38+ expression and IgVH mutational status. Significant differences in FISH risk distributions were associated with Rai stage, disease status and CD38+, but not by age, sex or IgVH mutational status. To look for baseline factors associated with high-risk disease, multivariate analysis of age, sex, Rai stage, CD38+ and disease status versus FISH risk category was performed. Importantly, only CD38+ was significantly associated with high-risk FISH categories (+12, 11q- and 17p-) after adjustment for the effects of other variables.

Chronic lymphocytic leukemia with t(14;18) and trisomy 12

The chromosomal abnormality t(14;18) is most commonly associated with neoplasms of follicular center cell origin. However, t(14;18) also has been reported in rare cases of chronic lymphocytic leukemia (CLL). In 2215 cases of CLL studied by conventional cytogenetics in our institution, we identified 2 cases of CLL carrying t(14;18). Both patients were men, aged 52 and 71 years at the time of diagnosis. One patient presented with leukemia and the other primarily with nodal disease. In addition to t(14;18), trisomy 12 (+12) was identified in the same clone in both cases. Atypical morphologic features were identified: case 1 contained more than 15% lymphoid cells with cleaved nuclei, whereas case 2 contained more than 15% plasmacytoid lymphoid cells. The immunophenotype of case 2 was also unusual for CLL, showing weak CD23 expression and FMC7 positivity. We identified 6 other t(14;18)-carrying CLL cases in the literature; 2 had t(14;18) as the sole abnormality and 2 contained +12 as the additional abnormality. To conclude, cases of CLL carrying t(14;18) are exceedingly rare, and +12 appears to be the most common cytogenetic abnormality coexisting with t(14;18) in CLL.

CD40L stimulation enhances the ability of conventional metaphase cytogenetics to detect chromosome aberrations in B-cell chronic lymphocytic leukaemia cells

Conventional metaphase cytogenetics underestimates the frequency of specific chromosome aberrations in B-cell chronic lymphocytic leukaemia (B-CLL) as a result of the very low proliferative activity of these cells in vitro. New molecular approaches, such as fluorescence in situ hybridization (FISH) or comparative genomic hybridization (CGH), may circumvent this problem, at least in part, but these techniques are either strongly dependent on the knowledge of candidate regions or detect only unbalanced aberrations. In the present study, we analysed 27 B-CLL peripheral blood samples by metaphase cytogenetics after CD40 ligand (CD40L)-induced cell cycle stimulation. In comparison with the simultaneous use of B-cell mitogens such as 12-O-tetradecanoylphorbol-13-acetate (TPA), lipopolysaccharide (LPS) and pokeweed mitogen (PWM), CD40L stimulation of B-CLL cells induced a threefold increase in metaphases amenable to analysis by conventional cytogenetics. The analysis of these metaphases confirmed all genetic abnormalities detected by FISH. Moreover, CD40L-enhanced cytogenetics revealed complex karyotypic aberrations in 11 out of 27 patients (41%). In one case, a balanced translocation t(11;16)(p15;p13.1), so far unreported in B-CLL, was detected. Taken together, the results of our study show the potential of CD40L-enhanced metaphase cytogenetics to detect more and new chromosome aberrations in B-CLL.

Cytogenetic and FISH studies in myelodysplasia, acute myeloid leukemia, chronic lymphocytic leukemia and lymphoma

Conventional cytogenetic studies are widely used today to diagnose and manage patients with hematological malignancies. The application of fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes helps to further define molecular subclasses and cytogenetic risk categories for patients with these disorders. Moreover, FISH permits analysis of proliferating (metaphase cells) and non-proliferating (interphase nuclei) cells, and is useful in establishing the percentage of neoplastic cells before and after therapy (minimal residual disease). For patients with myelodysplasia or acute myeloid leukemia, these chromosome techniques are important for accurate diagnosis and classification of disease and to help decide treatment and monitor response to therapy. Conventional cytogenetic studies have been problematic in chronic lymphocytic leukemia because the neoplastic cells divide infrequently. However, interphase FISH studies now permit detection of chromosome anomalies with prognostic significance in chronic lymphocytic leukemia. The World Health Organization recognizes that genetic anomalies are one of the most reliable criteria for classification of malignant lymphomas. New methods to extract individual nuclei from paraffin-embedded tissue are now available which permit the use of interphase FISH to detect important chromosome anomalies in lymphoma.

Genetics of chronic lymphocytic leukemia: genomic aberrations and V(H) gene mutation status in pathogenesis and clinical course

The genetic characterization of chronic lymphocytic leukemia (CLL) has made significant progress over the past few years. While conventional cytogenetic analyses only detected chromosome aberrations in 40-50% of cases, new molecular cytogenetic methods, such as fluorescence in situ hybridization (FISH), have greatly enhanced our ability to detect chromosomal abnormalities in CLL. Today, genomic aberrations are detected in over 80% of CLL cases. Genes potentially involved in the pathogenesis were identified with ATM in a subset of cases with 11q deletion and p53 in cases with 17p13 deletion. For the most frequent aberration, the deletion 13q14, candidate genes have been isolated. Genetic subgroups with distinct clinical features have been identified. 11q deletion is associated with marked lymphadenopathy and rapid disease progression. 17p deletion predicts for treatment failure with alkylating agents, as well as fludarabine and short survival times. In multivariate analysis 11q and 17p deletions provided independent prognostic information. Recently, another important issue of genetic risk classification in CLL was identified with the mutation status of the immunoglobulin variable heavy chain genes (V(H)). CLL cases with unmutated V(H) show more rapid disease progression and shorter survival times. Whether CD38 expression can serve as a surrogate marker for V(H) mutation status is currently discussed controversially. V(H) mutation status and genomic abnormalities, such as 17p and 11q deletion, have recently been shown to be related to each other, but were of independent prognostic information in multivariate analysis. Moreover, genomic aberrations and V(H) mutation status appear to give prognostic information irrespective of the clinical stage and may therefore allow a risk assessment for individual patients early in the course of their disease.

Chronic lymphocytic leukemia

This update of early stage B-cell chronic lymphocytic leukemia (B-CLL) embraces current information on the diagnosis, biology, and intervention required to more fully develop algorithms for management of this disease. Emphasis on early stage is based on the rapid advancement in our understanding of the disease parameters and our increasing ability to predict for a given early stage patient whether there is a need for more aggressive management. In Section I, Dr. Terry Hamblin addresses the nature of the disease, accurate diagnostic procedures, evidence for an early "preclinical" phase, the use of newer prognostic features to distinguish who will be likely to progress or not, and whether it is best to watch or treat early stage disease. In Section II, Dr. Neil Kay and colleagues address the biologic aspects of the disease and how they may relate to disease progression. Review of the newer insights into gene expression, recurring genetic defects, role of cytokines/autocrine pathways, and the interaction of the CLL B cell with the microenvironment are emphasized. The relationship of these events to both trigger disease progression and as opportunities for future therapeutic intervention even in early stage disease is also considered. In Section III, Dr. John Byrd and colleagues review the historical and now current approaches to management of the previously untreated progressive B-CLL patient. They discuss what decision tree could be used in the initial decision to treat a given patient. The use of single agents versus newer combination approaches such as chemoimmunotherapy are discussed here. In addition, the place of marrow transplant and some of the newer antibodies available for treatment of B-CLL are considered. Finally, a challenge to utilize our growing knowledge of the biology of B-CLL in the early stage B-CLL is proffered.

Biology of chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (CLL) lies at the cross-roads of hematology, immunology and oncology for at least three major reasons: (a) it is the prototype of human malignancies that primarily involve defects in the induction of apoptosis; (b) CLL patients develop a severe immunodeficiency with progressive hypogammaglobulinemia; and (c) they have a high prevalence of autoimmune phenomena. Recent advances in the biology of the malignant cell in CLL lead to a scenario comprised of two basic elements: first, CLL cells are optimally organized to survive in their niches because their ability to undergo apoptosis is severely hampered; second, they have a microenvironment-dependence that promotes their extended survival, a situation that arises most probably through direct cell-to-cell contacts. In addition, CLL cells themselves are the major accessory cells in CLL, but are inefficient antigen-presenting cells. This latter defect may provide a clue to reinterpret the events of immunodeficiency and autoimmunity.

Genetic features of B-cell chronic lymphocytic leukemia

The genetic features of B-cell chronic lymphocytic leukemia (CLL) are currently being reassessed by molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH). Conventional cytogenetic studies by chromosome banding are difficult in CLL mainly because of the low in vitro mitotic activity of the tumor cells, which leads to poor quantity and quality of metaphase spreads. Molecular genetic analyses are limited because candidate genes are known for only a few chromosomal aberrations that are observed in CLL. FISH was found to be a powerful tool for the genetic analysis of CLL as it overcomes both the low mitotic activity of the CLL cells and the lack of suitable candidate genes for analysis. Using FISH, the detection of chromosomal aberrations can be performed at the single cell level in both dividing and non-dividing cells, thus circumventing the need of metaphase preparations from tumor cells. Probes for the detection of trisomies, deletions and translocation breakpoints can be applied to the regions of interest with the growing number of clones available from genome-wide libraries. Using the interphase cytogenetic FISH approach with a disease specific set of probes, chromosome aberrations can be found in more than 80% of CLL cases. The most frequently observed abnormalities are losses of chromosomal material, with deletions in band 13q14 being the most common, followed by deletions in 11q22-q23, deletions in 17p13 and deletions in 6q21. The most common gains of chromosomal material are trisomies 12q, 8q and 3q. Translocation breakpoints, in particular involving the immunoglobulin heavy chain locus at 14q32, which are frequently observed in other types of non-Hodgkin's lymphoma, are rare events in CLL. Genes affected by common chromosome aberrations in CLL appear to be p53 in cases with 17p deletion and ataxia telangiectasia mutated (ATM), which is mutated in a subset of cases with 11q22-q23 aberrations. However, for the other frequently affected genomic regions, the search for candidate genes is ongoing. In parallel, the accurate evaluation of the incidence of chromosome aberrations in CLL by FISH allows the correlation of genetic abnormalities with clinical disease manifestations and outcome. In particular, 17p abnormalities and deletions in 11q22-q23 have already been shown to be among the most important independent prognostic factors identifying subgroups of patients with rapid disease progression and short survival. In addition, deletion 17p has been associated with resistance to treatment with purine analogs. Therefore, genetic abnormalities may allow a risk assessment for individual patients at the time of diagnosis, thus giving the opportunity for a risk-adapted management.

B-cell chronic lymphocytic leukemia: a bird of a different feather

PURPOSE

To review the recent major advances in the molecular and cell biology of B-cell chronic lymphocytic leukemia (B-CLL).

METHODS

We analyzed the nature of malignant B-CLL B cells and their interactions with the microenvironment.

RESULTS

B-CLL is a malignancy of a mantle zone-based subpopulation of anergic, self-reactive, activated CD5+ B cells devoted to the production of polyreactive natural autoantibodies. It is the quintessential example of a human malignancy that primarily involves defects in the induction of programmed cell death. An abnormal karyotype is observed in about 50% of patients with B-CLL. Patients with 13q14 abnormalities show heavy somatic mutation and have a benign disease. Trisomy 12 is associated with unmutated VH genes, atypical cellular morphology, and progressive disease. Extended cell survival is further shielded by a kinetic refractoriness likely promoted by abnormalities of the B-cell antigen receptor complex and favored by some cytokines that highlight a reciprocal dialog between malignant B and T cells. Because the tumor cells act as the major accessory cells, the accumulating malignant B-cell population per se is a hurdle to the production of normal antibodies and leads to a progressive and severe hypogammaglobulinemia. Conceivably, in the presence of certain immunoglobulin genes and when the T-cell control becomes deficient, activated malignant B cells may become able to present self-antigens and drive residual normal B cells to produce polyclonal autoantibodies restricted to self-antigens expressed only by blood cells and cause autoimmune cytopenias.

CONCLUSION

The distinctiveness of B-CLL B cells explains why B-CLL is different from other B-cell tumors and accounts for the development of immune deficiency and autoimmunity.

Chronic lymphocytic leukaemia: the nature of the leukaemic cell

Far from being the boring, inactive, inert lymphocyte that haematologists of old perceived it to be, the chronic lymphocytic leukaemia (CLL) cell has set us many complex problems. The cell is apparently stuck in G0 in cell cycle, yet expresses many activation markers. The cells apparently manufacture many cytokines and respond in vitro to even more, yet cells entering even G1 are few. The cell surface marker profile is unique. There is apparently no normal equivalent of the CLL cell. In part, this may be because the cell is malignant; malignant cells often express aberrant markers. Consistent chromosomal abnormalities are emerging but we have no idea how these abnormalities translate into molecular mistakes that dictate the peculiar nature of the cell. CLL cells carry a characteristics set of adhesion molecules, but we cannot read their homing and recycling instructions. The outstanding irregularities of the CLL cell are its CD5 positivity and its sparse surface immunoglobulin. This ought to translate as an anergic B1 cell, perhaps programmed for autoimmunity. If the tumour cell were responsible for the patient's production of immunoglobulin or secretion of autoantibodies, then a pattern might have emerged. Alas, these are the product of the normal B cells. How the CLL cell induces these complications is unknown. Thus, despite the information contained in this review, the CLL cell remains a puzzle.

Genetic abnormalities in chronic lymphocytic leukemia and their clinical and prognostic implications

Clonal chromosome abnormalities can be detected in approximately 50% of patients with chronic lymphocytic leukemia (CLL). The most common changes are trisomy 12, followed by structural abnormalities of 13q, 11q, 6q, and 14q. By fluorescence in situ hybridization (FISH), these aberrations can be demonstrated even in cases with insufficient mitotic yield or a normal karyotype. The biologic consequences of trisomy 12 are unknown, but a gene dosage effect is suspected and studies on partial trisomy 12 indicate that the region 12q13 to 12q22 might be of particular pathogenetic importance. Trisomy 12 is strongly associated with atypical lymphocyte morphology and seems to be a secondary event in leukemogenesis, as shown by combined immunophenotyping and interphase FISH. Structural abnormalities of 13q frequently involve hetero- and homozygous deletions of a region in 13q14, distal to the retinoblastoma gene, which may be the site of a tumor suppressor gene. In contrast to a normal karyotype or structural changes of 13q, complex karyotypic abnormalities, high percentage of abnormal metaphases, trisomy 12 and structural changes involving the P53 tumor suppressor gene on 17p13 are adverse prognostic indicators. Cytogenetic and molecular findings provide important diagnostic, clinical, and prognostic information which can contribute to treatment decisions and follow-up of CLL patients.

Genes and chromosomes in chronic B-cell leukemia

Cytogenetic analysis of patients with chronic B-cell leukemia (B-CLL) indicates that 50% have chromosome abnormalities, while fluorescence in situ hybridization (FISH) and molecular techniques reveal an even higher incidence. Trisomy 12 and deletions or translocation of chromosome 13q14 are the most common abnormalities, but in neither case has the gene or genes involved in the abnormalities been identified. Combined FISH and immunophenotyping studies suggest that both abnormalities are secondary events in B-CLL. Other recurring chromosome abnormalities include 6q-, 11q- and 12p-, but the genes involved in these abnormalities have not been identified. Involvement of the BCL1, BCL2, and BCL3 genes has been reported, but the numbers are low and the cases tend to be atypical. Trisomy 12 in association with complex karyotypic abnormalities is associated with a poor prognosis, and FISH studies show a strong correlation between trisomy 12, atypical morphology, and advanced disease. Ten to 15% of patients have mutations of p53 which is associated with advanced disease, resistance to treatment, and poor survival.

The pathology of the chronic lymphoid leukaemias

The chronic lymphoid leukaemias, though they all possess relatively mature lymphoid phenotypes, are a diverse group of diseases at the clinical, morphological, immunophenotypical, and biological levels. Generally accepted entities within this category include B-cell chronic lymphocytic leukaemia of classical and mixed-cell types, B-cell and T-cell prolymphocytic leukaemia, hairy-cell leukaemia and hairy-cell variant, splenic lymphoma with circulating villous lymphocytes, large granular lymphocytic leukaemia, adult T-cell leukaemia/lymphoma syndrome, and leukaemic phases of malignant lymphomas of both B-cell and T-cell types. Recent advances have helped to differentiate these diseases, allowing the development of more specific therapy and more accurate prognostication. In this article, we review the pathological aspects of these diseases.

Clinical, biological, and immunophenotypical characteristics of B-cell chronic lymphocytic leukemia with trisomy 12 by fluorescence in situ hybridization

The clinical, biological, and immunophenotypical characteristics of B-cell chronic lymphocytic leukemia (B-CLL) patients with trisomy 12 detected by fluorescence in situ hybridization (FISH) using a chromosome 12 alpha-centromeric probe (D12Z3) were analyzed in the present study. From a total of 104 consecutive B-CLL patients, 21 (20%) displayed trisomy 12, the percentage of trisomic cells ranging from 13% to 76%. From the clinico-biological point of view, patients with trisomy 12 were associated with atypical CLL morphology (43% vs 10%, P = 0.04) and BM diffuse pattern (75% vs. 25%, P = 0.02) together with increased WBC counts (141 +/- 220 vs. 58 +/- 67 x 10(9)/L, P = 0.04). In contrast, no association was detected between the presence of trisomy 12 and other disease characteristics such as age, sex, clinical stage, hepatomegaly, lymphadenopathies, haemoglobin levels and platelet counts, and the cell cycle distribution of PB leukocytes in both groups of patients. Trisomy 12 patients had a significantly higher expression of the FMC7 antigen both in percentage (34 +/- 34% vs. 13 +/- 20%, P = 0.02) and absolute numbers (29 +/- 62 vs. 7 +/- 17 x 10(9)/L, P = 0.007). No major differences were found regarding the expression of mouse rosettes, CD19+, and CD19+/CD5+ lymphocytes. Upon analyzing the correlations between the disease characteristics of trisomy 12 cases, significant associations were found between the percentage of trisomic cells and both the WBC count (r = 0.52, P = 0.02) and the PB lymphocyte count (r = 0.60, P = 0.007).(ABSTRACT TRUNCATED AT 250 WORDS)

A scoring system for the classification of CD5-B CLL versus CD5+ B CLL and B PLL

B CLL is a monoclonal proliferation of lymphocytes which express the CD5 antigen (CD5+ CLL). Rare exceptions (less than 10%) are CD5-, as are the majority of B PLL. We have studied the clinical, cytological and immunophenotypic characteristics of a series of 12 CD5-CLL and have established a score which allows the distinction between CD5+ CLL, CD5- CLL and PLL. Among the CD5- CLL, there were significantly more cases with advanced stage (Rai and Binet) and splenomegaly. The cytological study found more mixed CLL according to FAB classification (more prolymphocytes). There were significantly more CD23-, FMC7+, SIg strong positive cases. A score from 0 to 6 was established based on clinical, cytological and immunophenotypic criteria. Typical CD5+ CLL was scored 0, score 6 corresponded to typical PLL. There were significantly more higher scores amongst CD5- CLL. It therefore appears that CD5- CLLs share certain features with B PLL. The use of this scoring system will allow determination of prognosis within these different categories, thus identifying groups which require specific therapy.

Chronic lymphoid leukemias: recent advances in biology and therapy

There exists a wide variety of lymphoid leukemias derived from B and T lymphocytes. These diseases have distinct immunologic and biologic features as well as varied responses to therapeutics. The most common lymphoid leukemia is chronic lymphocytic leukemia (CLL) which is a clonal proliferation of a subset of B cells expressing the CD5 antigen. Prolymphocytic leukemia is usually derived from B cells and shares some features with CLL but is clearly a distinct entity. Hairy-cell leukemia is a B cell malignancy that is uniquely responsive to a variety of biologic and chemotherapeutic agents. Waldenström's macroglobulinemia is a B cell malignancy that secretes immunoglobulin M (IgM) and may present with the hyperviscosity syndrome. Other B cell malignancies that less commonly present as leukemias include non-Hodgkin's lymphomas such as follicular lymphoma or mantle zone lymphoma. Multiple myeloma may rarely present or evolve into a plasma cell leukemia, typically in far advanced disease. T cell malignancies that may present as chronic lymphoid leukemias, and in the past have often been referred to as T cell chronic lymphocytic leukemia, are large granular lymphocytic leukemia, adult T cell leukemia/lymphoma, Sézary cell leukemia and rare cases of non-Hodgkin's lymphoma that are T cell derived and may present or evolve into a leukemic phase. There is also a rare T cell counterpart of prolymphocytic leukemia. Distinguishing these diseases is critical for optimal care of these patients.

Trisomy 12 in chronic lymphocytic leukemia. An interphase cytogenetic study by fluorescence in situ hybridization

B-cell chronic lymphocytic leukemia (CLL) is a rare disorder in the Chinese population. We evaluated the use of fluorescence in situ hybridization (FISH) with a chromosome 12-specific probe in the detection of trisomy 12 in interphase cell of 19 Chinese CLL patients. FISH successfully detected trisomy 12 in two cases, one of which had normal conventional cytogenetic findings, giving an incidence of 10%. The low incidence of trisomy 12 in our CLL patients may also reflect a biologic difference of this rare disorder in our population, compared to that of the West.

Biology of the neoplastic lymphocyte in B-CLL

Immunological markers have identified the proliferating lymphocyte in CLL as a mature B lymphocyte which, unlike lymphocytes in other B cell malignancies, expresses low amounts of surface membrane immunoglobulin (smIg), forms rosettes with mouse erythrocytes and expresses the CD5 marker. It has been postulated that Ly1 B cells (the murine counterpart of human CD5+B cells) constitute a separate B cell lineage. Whether the CD5 marker defines a discrete lineage or is a maturation marker is one of the main issues that might be solved in the near future. Another recent advance has been the discovery that the B lymphocyte in CLL is in an activated state and can be induced to differentiate. Using B cell mitogens and somatic hybridization, it has been demonstrated that the B-CLL lymphocyte is frequently involved in the production of natural autoantibodies and expresses a restricted set of genes. These results may provide a basis for passive immunotherapy using anti-idiotypic antibodies. Hypogammaglobulinaemia is a distinct feature of B-CLL, observed in 60% of patients. It may result from impaired function of residual normal B cells. This could occur as a consequence of progressive dilution of normal non-clonal B cells, or because normal B cells are downregulated by an unknown mechanism. This decrease in or inhibition of normal CD5-B cells could also explain the classical inability of patients with B-CLL to respond to new antigenic challenges, since Ly1 B cells have been claimed to be unable to respond to exogenous antigens. Although regulatory abnormalities in T cells may play a role in the induction of hypogammaglobulinaemia, data concerning helper, suppressive, NK and ADCC cells are contradictory and fail to establish firmly the contribution of these cells in the development of hypogammaglobulinaemia. Associated autoimmune phenomena are a prominent complication in CLL. They are related to the presence of autoantibodies directed mainly against blood components, which in most cases are not the product of the malignant clone. The relationship between autoimmune phenomena and hypogammaglobulinaemia is not definitively substantiated. That hypogammaglobulinaemia may determine the loss of some anti-idiotypic antibodies designed to antagonize autoimmune clones is an attractive hypothesis, which needs to be substantiated. Several recurrent chromosomal abnormalities, such as trisomy 12, structural aberrations of the 13q14 and 14q32 bands, are frequently observed in B-CLL. Less frequently, alterations of chromosomes 11, 6, 18, 3, 17, 7 and 8 have been reported.(ABSTRACT TRUNCATED AT 400 WORDS)

Cytogenetics in CLL and related disorders

Chromosome analysis of more than 1200 patients with chronic lymphocytic leukaemia reported to the International Working Party on Chromosomes in CLL and in the literature is analysed. Clonal chromosomal abnormalities are found in about half of the patients, and one third of those with clonal aberrations have trisomy 12, with or without additional changes. The most common structural abnormalities involve the long arm of chromosome 13, usually as deletions involving 13q14, the site of the retinoblastoma gene. Other recurrent abnormalities are deletions of the long arms of chromosome 11 and 6. 14q+ markers are frequent in patients at advanced stage, but are almost always within complex abnormalities. The number of clonal abnormalities in the CLL cells has a strong prognostic impact. Trisomy 12 as a single abnormality is an adverse prognostic sign, whereas patients with 13q abnormalities generally do comparatively well. Lymphoid leukaemia with monoclonal immunoglobulin secretion frequently involves clonal chromosomal abnormalities, and the type of change is similar to that seen in true CLL. In B cell prolymphocytic leukaemia, t(11;14) is a common finding, together with trisomy 12. T cell prolymphocytic leukaemia is characterized by an inversion of the long arm of chromosome 14, with breaks at q11 and q32, and trisomy of 8q, whereas large granular lymphocytic leukaemia has shown no consistent abnormality. Hairy cell leukaemia seems to involve a specific set of non-random chromosome abnormalities, such as inv(5)9.

Chronic lymphocytic leukaemia: prognostic factors and natural history

In the past 20 years, important progress has been made in the understanding of the natural history and prognosis of chronic lymphocytic leukaemia (CLL). Based on the notion that the clinical manifestations of CLL are due primarily to the progressive accumulation of lymphocytes over time, several prognostic factors have been identified. The prognostic value of parameters reflecting tumour burden (i.e. lymphadenopathy, splenomegaly, anaemia and/or thrombocytopenia due to bone marrow failure), first identified empirically, has been confirmed in multivariate analyses of large series of patients. Furthermore, clinical staging systems that group the most relevant of these factors have also been developed. Patients in early stage (Binet A; Rai 0) have a long survival which, in some cases, may match that of the general population. In contrast, patients with advanced stage (Binet C; Rai III or IV) have a median survival < 2 years. The major limitation of staging systems is that they do not give information about the likelihood of progression for patients in early stage. Nevertheless, haemoglobin level, blood lymphocyte count, lymphocyte doubling time and bone marrow infiltration pattern are useful to identify subsets of patients in early stage with different progression and survival rates, with the 'smouldering' form of the disease being identified fairly accurately. With all these advances, therapy in CLL can now be indicated on a more rational basis. However, further biological insight is needed to elucidate the mechanism accounting for the different forms of the disease.

Japanese B cell chronic lymphocytic leukaemia: a cytogenetic and molecular biological study

Clinical, cytogenetic, and molecular genetic studies were performed to clarify the pathophysiology of Japanese B cell chronic lymphocytic leukaemia (B-CLL), since the incidence of B-CLL in Japan is significantly lower than in western countries. The clinical and laboratory features of 55 Japanese patients with B-CLL in this study did not differ from those of Americans or Europeans with B-CLL. In the chromosome analyses, suitable metaphases with good band quality were obtained from 48 patients (87.2%), of whom 22 patients (45.8%) showed clonal chromosome aberrations and 14 (29.2%) had non-clonal aberrations. Trisomy 12 and abnormalities of 14q and 13q were found in four (18.2%), two (9.1%) and six patients (27.2%), respectively. There were no particular chromosome abnormalities or specific breakpoints in Japanese B-CLL. However, complex karyotype was found in higher incidence than in western countries. In the Southern blot analyses, rearranged band patterns were observed in the major breakpoint region (mbr) of the bcl-2 gene in one case, in the 5'-breakpoint region (5'-bcl-2) in two, and bcl-3 in one. Of the two patients with 5'-bcl-2 rearrangements, one had a normal karyotype and the other had t(2;18)(p12;q21). The incidence of rearrangements of the bcl-1, bcl-2 and bcl-3 genes in Japanese B-CLL was similar to that in western countries. These findings suggest that the biological characteristics of B-CLL in Japan are almost the same as those in western countries, although the incidence of B-CLL in Japan is quite different; this may be related to racial differences, which seem to be an important factor in the development of B-CLL.

Biologic and clinical significance of cytogenetic and molecular cytogenetic abnormalities in benign and malignant cartilaginous lesions

Cartilaginous neoplasms are often histologically and therapeutically challenging. Predicting biologic behavior can be difficult. In this study, 120 nonneoplastic, benign, and malignant cartilaginous lesions from 103 patients were cytogenetically analyzed in a 6-year period after short-term culture. For selected cases, fluorescent in situ hybridization (FISH) techniques using chromosome-specific probes were performed on metaphase/interphase preparations and on paraffin-embedded tissue sections. Clonal abnormalities of chromosomes 2, 3, 5, 7, 8, and 12 were most frequently observed. Involvement of chromosomes 5, 8, and 12 may be etiologically significant because of the gene localizations for the human cartilage link protein, Langer-Giedion syndrome (a rare syndrome characterized by multiple exostoses), and type II collagen (a major component of normal cartilage) respectively, to these three chromosomes. That chromosome 7 abnormalities were observed only in malignant tumors is of diagnostic value. The identity of three marker chromosomes and the significance of trisomy 7 (a finding of controversial meaning), were determined with FISH. That the presence of chromosome aberrations and increasing histologic grade strongly correlated (p = 0.001) is of prognostic importance. Moreover, complex aberrations were observed nearly exclusively in high-grade tumors (p = 0.001). The data show that nonrandom chromosome loci are aberrantly affected in cartilaginous lesions and that these abnormalities may be of significant histopathogenetic consequence. In addition, these chromosome abnormalities appear to be diagnostically and prognostically valuable in classifying and grading chondromatous neoplasms.

Confirmation of Rb gene defects in B-CLL clones and evidence for variable predominance of the Rb defective cells within the CLL clone

In 70 B-CLL patients, deletion or translocation, at or near the retinoblastoma (Rb) site, was detected in 20 by cytogenetic analysis. Purified B cell clones from 13 of these B-CLL patients were isolated and studied for Rb gene status, Rb mRNA and the Rb protein product. Southern blot analysis of the Rb site detected internal deletions (N = 1) or a single allele loss (N = 2) in five patients. Northern blots detected reduced Rb mRNA in four patients. Immunoblot of whole cell lysate revealed reduced levels of unphosphorylated Rb protein in six CLL patients. No CLL B cell clone contained phosphorylated Rb species. These molecular studies have confirmed the cytogenetic alteration of 13q12-14 sites in B-CLL cells. In addition, cytogenetic and molecular biologic analysis suggest heterogeneity in the B cell clone for Rb gene abnormality. B-CLL patients with abnormalities in both cytogenetic and Rb DNA/RNA analysis will have a dominance of B cells with an Rb abnormality (N = 5). In patients whose Rb defective CLL cells constitute only a minor subpopulation of the total B cell clone, only cytogenetic defects would likely be detected (N = 7).

Cyclin D and oncogenesis

The D-type cyclins are among the candidate 'G1 cyclins' in higher eukaryotes that may regulate G1-S-phase progression. The human cyclin D1 gene, also known as PRAD1 (and previously as D11S287), is a putative proto-oncogene strongly implicated in several types of human tumors, including parathyroid adenomas, B-cell neoplasms (as the 'BCL-1 oncogene'), and breast and squamous cell cancers. The mechanism by which deregulated production of cyclin D1/PRAD1, and perhaps other D-type cyclins, contributes to tumor development is only beginning to be deciphered.

Multiple myeloma and chronic lymphocytic leukemia: parallels and contrasts

Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) are closely related B-cell cancers. Parallel and divergent features of these diseases are reviewed. In MM, expression of multiple hemopoietic lineage-associated antigens on the malignant cells and the substantial likelihood of progression to acute myelogenous leukemia suggest transformation of a pluripotent stem cell. In CLL, transformation more likely involves a committed B-cell progenitor. Another difference is that clonal evolution with associated cytogenetic progression is common in MM but not CLL. Other data, including studies of proto-oncogenes and tumor suppressor genes, suggest that MM results both from increased proliferation and accumulation of tumor cells, whereas tumor cell accumulation is the predominant feature of CLL. These differences may be reflected in the seemingly greater role of cytokine abnormalities in MM progression. For example, osteoclast-activating properties of some cytokines account for bone involvement in MM but not in CLL. MM and CLL share common features such as stage-dependent anemia and immune deficiency. Both diseases respond to alkylating agents but vary markedly in their sensitivity to fludarabine (CLL greater than MM) and glucocorticoids (MM greater than CLL). Differences between these diseases in progression-free interval and survival may reflect different definitions of premalignant and malignant phases rather than biologic differences. Detailed comparisons between MM and CLL may provide additional insights into these and related B-cell cancers.

Chronic leukaemias

In recent years many subtypes of CLL and some CML variants have been recognized throughout the world by means of careful clinical, epidemiological, immunological, molecular biological and viral studies. Most striking has been the establishment of a close association between certain immunophenotypical subtypes of CLL and infection with HTLV-I and possibly HTLV-II. CLL has consistently been shown to have a strong genetic component and a low incidence among Asians, but a growing body of evidence also links this major leukaemia type with environmental factors including solvents, unidentified farming and other occupational exposures. In contrast, CML is characterized by few genetic associations, relatively homogenous world-wide distribution, greater frequency in Blacks than in Whites, little evidence of viral aetiology, and evidence that exposures to ionizing radiation, benzene and possibly other chemical agents are important aetiological factors. Most studies suggest that acquired rather than genetic factors are of greater importance in the aetiology of CML, but this conclusion is somewhat difficult to reconcile with the relatively small variation in incidence rates internationally. Common to both disorders in most populations are an increasing incidence with age, male predominance, and stability of incidence, survival and mortality over the years, exclusive of improved survival of CML following allogeneic bone marrow transplantation.

Morphologic characteristics of acute lymphoblastic leukemia (ALL) with abnormalities of chromosome 8, band q24

The CALGB prospectively studied 140 adult acute lymphoblastic leukemia (ALL) patients for cytogenetic abnormalities. Seven (5%) patients with adequate cytogenetic preparations had t(8;14)(q24;q32) or t(8;22)(q24;q11). Patients were compared with non-8q24 patients for clinical and laboratory characteristics, response to therapy, and survival. The median age of patients with translocations involving 8q24 (71% males) was 40 years. Forty-three percent had lymphadenopathy, 29% splenomegaly, and 29% hepatomegaly. None exhibited central nervous system (CNS), skin, or gum involvement. These features did not differ significantly from non-8q24 ALLs. Patients with 8q24 translocations had higher hemoglobins (11.5 vs. 9.8 g/dl; P = 0.04) and lower percentage of blasts in the peripheral blood (8.5% vs. 69%; P = 0.007). Although all seven were finally categorized as ALL-L3, a marked variation in the proportion of typical L3 blasts was observed that initially resulted in the diagnoses of ALL-L2 in three cases and prolymphocytic leukemia in one. In five of five patients, the blasts typed as B cells (SIg+ and CD19+). Complete remission rates for patients with 8q24 translocations were 43%, whereas they were 68% for non-8q24 ALLS (P = 0.22). Furthermore, patients with 8q24 abnormalities exhibited significantly shorter survival (4.8 vs. 18.4 mo; P less than 0.001). We conclude that ALL with translocations of 8q24 in adults shows a mature B-cell immunophenotype (SIg+), poor prognosis and morphology ranging from classical ALL-L3 to ALL with a subpopulation of L3 cells. Thus, the diagnosis of ALL-L3 should be made when blastic cells possess a mature B-cell immunophenotype (SIg+) and an 8q24 translocation, even though the number of L3 cells is low.

Frequent clonal abnormalities of chromosome band 13q14 in B-cell chronic lymphocytic leukemia: multiple clones, subclones, and nonclonal alterations in 82 midwestern patients

We performed cytogenetic analyses of peripheral blood lymphocytes from 82 Midwestern B-cell chronic lymphocytic leukemia (B-CLL) patients. The cells were cultured with mitogens for 3-4 days. At least 15 metaphase cells were analyzed in 79 (96%) cases. Fifty (63%) of the 79 patients had clonal chromosomal alterations. Structural modifications of the long arm of chromosome 13 at or near band 13q14 were the most frequent abnormalities, identified in 23 (46%) of the patients with clonal abnormalities. In several patients, the abnormality involving band 13q14 was the sole chromosomal alteration. There was a high incidence of complex karyotypes. Nine patients had multiple subclones that appeared to result from clonal evolution; seven patients had cytogenetically unrelated clones; three patients had both subclones and cytogenetically unrelated clones. Nonclonal abnormalities were also prominent. Our study confirms the high incidence of clonal abnormalities involving chromosome arm 13q and documents the clustering of abnormalities at band 13q14 in B-CLL. The evidence for clonal evolution and the presence of multiple unrelated clones in these patients suggest that B-CLL may not be a karyotypically stable disease.

Non-radioactive in situ hybridization for the detection and monitoring of trisomy 12 in B-cell chronic lymphocytic leukaemia

Non-radioactive in situ hybridization (NISH) with a chromosome 12-specific alpha satellite probe was performed on 20 patients with chronic lymphocytic leukaemia (CLL) with normal karyotype (15 cases) or with inadequate mitotic yield (5 cases) from mitogen-stimulated cultures. All patients had over 70% lymphocytes coexpressing the CD5/CD23 antigens. While less than 1% interphase nuclei showed three fluorescent spots in 16/20 patients, evidence of trisomy 12 in 15-25% interphase cells was detected in four patients. According to the FAB classification the diagnosis in these patients was typical B-CLL, stage III (Rai's staging system) in one case, CLL/PLL, stage II and III in two cases, PLL, stage III in one case. In order to confirm these results, NISH was repeated after 1 month in one patient and after 2 years in three patients. All patients had been treated with chemotherapy in the period between the two NISH experiments. In all cases a 1.8-3-fold increase of percentage of trisomic interphase cells was detected. These findings suggest that in B-CLL clones with trisomy 12 may have proliferative advantage over clonal B-lymphocyte without +12 and, possibly, that they may be more resistant to chemotherapy. We conclude that NISH is a sensitive technique allowing for the detection and monitoring of trisomy 12 in a fraction of B-CLL patients with normal karyotype or with no analysable mitoses despite employment of polyclonal B-cell mitogens.

Prognostic value of cytogenetic analysis in human cerebral astrocytomas

Cytogenetic analysis has become an important part of the diagnostic evaluation of most hematological neoplasms. However, there is limited information on the value of cytogenetic analysis in most solid tumors, including cerebral astrocytomas. This report summarizes a prospective cytogenetic study of 99 human cerebral astrocytomas, 16 mixed oligoastrocytomas, and 2 gliosarcomas. The cytogenetic procedure involved in situ culture and robotic harvesting techniques. Correlative clinical and survival data were available on all patients. We successfully cultured and obtained suitable metaphases in 107 of the 117 tumors. One or more chromosomally abnormal clones were observed in 72 tumors, and nonclonal or normal karyotypes were observed in 35 tumors. In a multivariate analysis, survival time was significantly better in patients whose tumors had normal or nonclonal karyotypes on cytogenetic analyses than in those whose tumors had clonal abnormalities (p = 0.0071). Our study demonstrates that cytogenetic analysis provides independent prognostic information in patients with cerebral astrocytomas.

A clinical update on chronic lymphocytic leukemia. I. Diagnosis and prognosis

B-cell chronic lymphocytic leukemia (B-CLL) is a relatively indolent hematologic malignant disease that, despite a good response to nonaggressive orally administered chemotherapy, currently remains incurable. The overall median duration of survival is more than 5 years, and the presence of anemia or thrombocytopenia adversely affects prognosis. B-CLL is readily diagnosed because of the characteristic and specific phenotypic expressions of the neoplastic cells. Clinical staging continues to be the best prognostic indicator in B-CLL. In addition, cytogenetic status, pattern of leukemic infiltration in the bone marrow, and lymphocyte doubling time are now considered to have additional prognostic value. In this article, the diagnostic evaluation of lymphocytosis is discussed, and an updated analysis on the prognostic determinants of B-CLL is provided. The second part of this clinical update, which reviews current chemotherapeutic modalities, will be published in the subsequent issue of this journal.

Chronic lymphocytic leukaemia: prognostic value of lymphocyte morphological subtypes. A multivariate survival analysis in 146 patients

Among other patient and disease characteristics, different morphological lymphocyte subtypes were analysed in 146 patients with chronic lymphocytic leukaemia (CLL) to establish their clinical significance and prognostic value. The univariate analysis selected, among other well-known variables, the following lymphocyte subtypes as significant in prognosis: prolymphocytes, granulated lymphocytes, cleaved lymphocytes and small-size lymphocytes. The presence of prolymphocytes and cleaved lymphocytes was correlated with a poor prognosis, whereas granular lymphocytes and small-size lymphocytes were related to a good prognosis. A multivariate regression analysis showed that, besides clinical stages, haemoglobin level, WBC count, age, percentage of bone marrow erythroid cells, and sex, only prolymphocytes had independent prognostic significance. Prolymphocyte percentage correlated positively with characteristics expressing tumour mass such as WBC count, blood absolute lymphocyte count, serum lactate dehydrogenase level, number of enlarged lymph nodes, splenomegaly, and a high number of lymphocytes in bone marrow aspirate. Finally, a prolymphocyte threshold of 5 x 10(9)/l was found to be useful not only to separate two different groups of patients in the whole series but also in Rai's stages II and III + IV, and in Binet's stages A and C.