Predictive value of serum thymidine kinase level for Ig-V mutational status in B-CLL

Expert consensus on the management of chronic lymphocytic leukaemia in Asia

In recent years, considerable progress has been made in the standard treatment for chronic lymphocytic leukaemia (CLL) due to the availability of new potent drugs. However, the majority of data on CLL were derived from Western populations, with limited studies and guidelines on the management of CLL from an Asian population perspective. This consensus guideline aims to understand treatment challenges and suggest appropriate management approaches for CLL in the Asian population and other countries with a similar socio-economic profile. The following recommendations are based on a consensus by experts and an extensive literature review and contribute towards uniform patient care in Asia.

The Evolving Landscape of Chronic Lymphocytic Leukemia on Diagnosis, Prognosis and Treatment

The knowledge of chronic lymphocytic leukemia (CLL) has progressively deepened during the last forty years. Research activities and clinical studies have been remarkably fruitful in novel findings elucidating multiple aspects of the pathogenesis of the disease, improving CLL diagnosis, prognosis and treatment. Whereas the diagnostic criteria for CLL have not substantially changed over time, prognostication has experienced an expansion with the identification of new biological and genetic biomarkers. Thanks to next-generation sequencing (NGS), an unprecedented number of gene mutations were identified with potential prognostic and predictive value in the 2010s, although significant work on their validation is still required before they can be used in a routine clinical setting. In terms of treatment, there has been an impressive explosion of new approaches based on targeted therapies for CLL patients during the last decade. In this current chemotherapy-free era, BCR and BCL2 inhibitors have changed the management of CLL patients and clearly improved their prognosis and quality of life. In this review, we provide an overview of these novel advances, as well as point out questions that should be further addressed to continue improving the outcomes of patients.

Recent progress of prognostic biomarkers and risk scoring systems in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia with high heterogeneity in the western world. Thus, investigators identified a number of prognostic biomarkers and scoring systems to guide treatment decisions and validated them in the context of immunochemotherapy. A better understanding of prognostic biomarkers, including serum markers, flow cytometry outcomes, IGHV mutation status, microRNAs, chromosome aberrations and gene mutations, have contributed to prognosis in CLL. Del17p/ TP53 mutation, NOTCH1 mutation, CD49d, IGHV mutation status, complex karyotypes and microRNAs were reported to be of predictive values to guide clinical decisions. Based on the biomarkers above, classic prognostic models, such as the Rai and Binet staging systems, MDACC nomogram, GCLLSG model and CLL-IPI, were developed to improve risk stratification and tailor treatment intensity. Considering the presence of novel agents, many investigators validated the conventional prognostic biomarkers in the setting of novel agents and only TP53 mutation status/del 17p and CD49d expression were reported to be of prognostic value. Whether other prognostic indicators and models can be used in the context of novel agents, further studies are required.

Prognostic model for newly diagnosed CLL patients in Binet stage A: results of the multicenter, prospective CLL1 trial of the German CLL study group

The heterogeneity of early stage CLL challenges prognostication, and refinement of prognostic indices for risk-adapted management in this population is essential. The aim of the multicenter, prospective CLL1 trial was to explore a novel prognostic model (CLL1-PM) developed to identify risk groups, separating patients with favorable from others with dismal prognosis. A cohort of 539 clinically, biochemically, and genetically characterized Binet stage A patients were observed until progression, first-line treatment, or death. Multivariate analysis identified six independent factors associated with overall survival (OS) and time-to-first treatment (TTFT): del(17p), unmutated IGHV, del(11q), ß2-microglobulin >3.5 mg/dL, lymphocyte doubling time (LDT) <12 months, and age >60 years. These factors were integrated into the CLL1-PM, which stratified patients into four risk groups. The CLL1-PM was prognostic for OS and TTFT, e.g., the risk of treatment at 5 years was 85.9, 51.8, 27.6, and 11.3% for very low (0-1.5), low (2-4), high (4.5-6.5), and very high-risk (7-14) scores, respectively (P < 0.001). Notably, in addition to factors comprising CLL-IPI, we substantiated del(11q) and LDT as prognostic factors in early CLL. Altogether, our findings would be useful to effectively stratify Binet stage A patients, particularly within the scope of clinical trials evaluating novel agents.

iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL

The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.

State of the art in microRNA as diagnostic and therapeutic biomarkers in chronic lymphocytic leukemia

Early diagnostic is one of the most important steps in cancer therapy which helps to design and choose a better therapeutic approach. The finding of biomarkers in various levels including genomics, transcriptomics, and proteomics levels could provide better treatment for various cancers such as chronic lymphocytic leukemia (CLL). The CLL is the one of main lymphoid malignancies which is specified by aggregation of mature B lymphocytes. Among different biomarkers (e.g., CD38, chromosomes abnormalities, ZAP-70, TP53, and microRNA [miRNA]), miRNAs have appeared as new diagnostic and therapeutic biomarkers in patients with the CLL disease. Multiple lines of evidence indicated that deregulation of miRNAs could be associated with pathological events which are present in the CLL. These molecules have an effect on a variety of targets such as Bcl2, c-fos, c-Myc, TP53, TCL1, and STAT3 which play critical roles in the CLL pathogenesis. It has been shown that expression of miRNAs could lead to the activation of B cells and B cell antigen receptor (BCR). Moreover, exosomes containing miRNAs are one of the other molecules which could contribute to BCR stimulation and progression of CLL cells. Hence, miRNAs and exosomes released from CLL cells could be used as potential diagnostic and therapeutic biomarkers for CLL. This critical review focuses on a very important aspect of CLL based on biomarker discovery covers the pros and cons of using miRNAs as important diagnostics and therapeutics biomarkers for this deadly disease.

Key Molecular Drivers of Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is an adult neoplastic disease of B cells characterized by variable clinical outcomes. Although some patients have an aggressive form of the disease and often encounter treatment failure and short survival, others have more stable disease with long-term survival and little or no need for theraphy. In the past decade, significant advances have been made in our understanding of the molecular drivers that affect the natural pathology of CLL. The present review describes what is known about these key molecules in the context of their role in tumor pathogenicity, prognosis, and therapy.

Chronic Lymphocytic Leukemia in the Elderly, Which Investigations Are Necessary: A Map for the Practicing Oncologist

BACKGROUND

Chronic lymphocytic leukemia (CLL), the most prevalent leukemia in the Western world, is predominantly a disease of older individuals who also have other comorbidities as well as declining organ and bone marrow reserve. Although chemoimmunotherapy is the frontline therapy for fit CLL patients who can tolerate the therapy, many elderly patients cannot tolerate such intense therapy.

METHODS

The authors first reviewed the most recent findings concerning CLL cytogenetics, molecular biology, and prognostic models. They then surveyed recent and ongoing trials of novel CLL agents and strategies, with a focus on those most relevant to elderly patients.

RESULTS

Novel therapies, revised staging procedures, and careful assessment of individual patients' frailty and functional status will allow clinicians to provide optimal care management for older CLL patients.

CONCLUSION

Therapy for the elderly CLL population must be tailored to each patient's fitness level and comorbid conditions, with special consideration for the potential quality-of-life impacts of various treatment recommendations.

Evaluation of serum markers in the LRF CLL4 trial: β2-microglobulin but not serum free light chains, is an independent marker of overall survival

Chronic lymphocytic leukemia (CLL) is characterized by heterogeneous clinical behavior and there is a need for improved biomarkers. The current study evaluated the prognostic significance of serum free light chains (sFLC, kappa, and lambda) and other serum markers (bar, serum thymidine kinase (sTK), soluble CD23, and LDH) together with established biomarkers in 289 patients enrolled into the LRF CLL4 trial. In a multivariable analysis of serum markers alone, higher big and kappa light chains were statistically significant in predicting disease progression and higher blg, and sTK in predicting mortality. In multivariable analysis for overall survival the following were independently significant: β2M levels, immunoglobulin gene (IGHV) mutational status (>98% homology), age, 17p13 deletions (>10%), and CD38 expression. β2M is the only serum marker that retained clear independent value as a biomarker in the LRF CLL4 trial and remains powerfully prognostic requiring evaluation in any future method of risk stratifying patients.

Unavailability of thymidine kinase does not preclude the use of German comprehensive prognostic index: results of an external validation analysis in early chronic lymphocytic leukemia and comparison with MD Anderson Cancer Center model

A comprehensive prognostic index that includes clinical (i.e., age, sex, ECOG performance status), serum (i.e., ß2-microglobulin, thymidine kinase [TK]), and molecular (i.e., IGVH mutational status, del 17p, del 11q) markers developed by the German CLL Study Group (GCLLSG) was externally validated in a prospective, community-based cohort consisting of 338 patients with early chronic lymphocytic leukemia (CLL) using as endpoint the time to first treatment (TTFT). Because serum TK was not available, a slightly modified version of the model based on seven instead of eight prognostic variables was used. By German index, 62.9% of patients were scored as having low-risk CLL (score 0-2), whereas 37.1% had intermediate-risk CLL (score 3-5). This stratification translated into a significant difference in the TTFT [HR = 4.21; 95% C.I. (2.71-6.53); P < 0.0001]. Also the 2007 MD Anderson Cancer Center (MDACC) score, barely based on traditional clinical parameters, showed comparable reliability [HR = 2.73; 95% C.I. (1.79-4.17); P < 0.0001]. A comparative performance assessment between the two models revealed that prediction of the TTFT was more accurate with German score. The c-statistic of the MDACC model was 0.65 (range, 0.53-0.78) a level below that of the German index [0.71 (range, 0.60-0.82)] and below the accepted 0.7 threshold necessary to have value at the individual patient level. Results of this external comparative validation analysis strongly support the German score as the benchmark for comparison of any novel prognostic scheme aimed at evaluating the TTFT in patients with early CLL even when a modified version which does not include TK is utilized.

Development of a comprehensive prognostic index for patients with chronic lymphocytic leukemia

In addition to clinical staging, a number of biomarkers predicting overall survival (OS) have been identified in chronic lymphocytic leukemia (CLL). The multiplicity of markers, limited information on their independent prognostic value, and a lack of understanding of how to interpret discordant markers are major barriers to use in routine clinical practice. We therefore performed an analysis of 23 prognostic markers based on prospectively collected data from 1948 CLL patients participating in phase 3 trials of the German CLL Study Group to develop a comprehensive prognostic index. A multivariable Cox regression model identified 8 independent predictors of OS: sex, age, ECOG status, del(17p), del(11q), IGHV mutation status, serum β2-microglobulin, and serum thymidine kinase. Using a weighted grading system, a prognostic index was derived that separated 4 risk categories with 5-year OS ranging from 18.7% to 95.2% and having a C-statistic of 0.75. The index stratified OS within all analyzed subgroups, including all Rai/Binet stages. The validity of the index was externally confirmed in a series of 676 newly diagnosed CLL patients from Mayo Clinic. Using this multistep process including external validation, we developed a comprehensive prognostic index with high discriminatory power and prognostic significance on the individual patient level. The studies were registered as follows: CLL1 trial (NCT00262782, http://clinicaltrials.gov), CLL4 trial (ISRCTN 75653261, http://www.controlled-trials.com), and CLL8 trial (NCT00281918, http://clinicaltrials.gov).

Five important advances in hematopathology

CONTEXT

Hematopathology is a dynamic field that has always been on the frontier of clinical research within the scope of pathology. Several recent developments in hematopathology will likely affect its practice clinically.

OBJECTIVE

To review 5 important recent advances in hematopathology: (1) detection and prognostic implication of MYC in diffuse large B-cell lymphomas, (2) determining origin and prognosis through immunoglobulin gene usage in mature B-cell neoplasms, (3)detecting minimal residual disease in multiple myeloma, (4) using genome-wide analysis in myelodysplastic syndromes, and (5) employing whole-genome sequencing in acute myeloid leukemias.

DATA SOURCES

Literature review and the authors' experiences in an academic center.

CONCLUSIONS

These advances will bring hematopathology into a new molecular era and help us to better understand the molecular, pathologic mechanisms of lymphomas, leukemias, myelomas, and myelodysplastic syndromes. They will help us to identify diagnostic and prognostic markers and eventually provide new therapeutic targets and treatments for these diseases.

Serum thymidine kinase activity: analytical performance, age-related reference ranges and validation in chronic lymphocytic leukemia

Background

To date no age-related reference ranges are available for serum thymidine kinase (TK1) activity. Being a proliferation marker, it may be used as a prognostic marker in malignant diseases, including chronic lymphocytic leukemia (CLL). Our aim was to establish age-specific reference ranges for TK1 and examine its utility as a screening marker in CLL, a disease of the elderly.

Methods

Serum TK1 activity was measured by a competitive chemiluminescent immunoassay in 369 healthy adults and 115 de novo CLL patients.

Results

We observed a statistically significant decline in TK1 activity from young (18–35 years) to middle-aged (36–60 years) and further on to elderly (60–86 years) healthy individuals. Age-related reference range was: <30 U/L for young, <25 U/L for middle-aged and <19 U/L for elderly. There was no difference in TK1 activity between the studied healthy men and women. In CLL patients, TK1 activity was the highest in the advanced Rai stages. The area under the receiver operating characteristic curve (ROC-AUC) for TK1 was 0.840 (95% CI: 0.787–0.892), for differentiating CLL patients from age and sex matched healthy controls, with a cut-off value of 10.5 U/L (sensitivity: 80.9%, specificity: 73.4%). TK1 was significantly elevated in CD38+/Zap70+ CLL patients, and showed significant correlation with WBC and absolute B-cell count.

Conclusion

In the healthy, serum TK1 activity does not differ in the two sexes but declines significantly with age. As such, use of age-related reference ranges is warranted, especially when evaluating CLL patients who generally belong to the elderly age group.

Thymidine kinase 1 as a diagnostic tumor marker is of moderate value in cancer patients: A meta-analysis

Thymidine kinase 1 (TK1) is an enzyme involved in nucleic acid synthesis and is therefore considered to be an important tumor proliferation marker. The aim of the present study was to determine the diagnostic role of TK1 measurement in cancer. An extensive electronic search was performed in PubMed, EMBASE and the Cochrane Library using the keywords 'thymidine kinase 1' and 'tumor' and synonyms. This study was conducted as part of a project to establish evidence-based guidelines for the diagnosis and treatment of cancer. A total of 453 abstracts were screened, after which the full text of 40 studies were selected for further investigation, including screening of the references cited by studies in the original search. Fifteen studies were enrolled following full-text evaluation. The areas under the receiver operating characteristic curves for the radioenzymatic assay (REA), the chemiluminescence immunoassay (CLIA) and the total were 0.88, 0.75 and 0.8, respectively. These results were all between <0.9 and >0.7, which suggested a moderate diagnostic efficacy. The positive likelihood ratio of the CLIA method was the highest (10.229), which demonstrated that CLIA exhibited a satisfactory specificity in tumor diagnosis. However, TK1 as a single diagnostic tumor marker was not of significant value and the combination of more tumor markers in the diagnosis of tumors may be preferable.

Prognostic markers and their clinical applicability in chronic lymphocytic leukemia: where do we stand?

Chronic lymphocytic leukemia (CLL) is a clinically and biologically heterogeneous disease where the majority of patients have an indolent disease course, while others may experience a far more aggressive disease, treatment failure and poor overall survival. During the last two decades, there has been an intense search to find novel biomarkers that can predict prognosis as well as guide treatment decisions. Two of the most reliable molecular prognostic markers, both of which are offered in routine diagnostics, are the immunoglobulin heavy chain variable (IGHV) gene mutational status and fluorescence in situ hybridization (FISH) detection of prognostically relevant genomic aberrations (e.g. 11q-, 13q-, +12 and 17p-). In addition to these markers, a myriad of additional biomarkers have been postulated as potential prognosticators in CLL, on the protein (e.g. CD38, ZAP70, TCL1), the RNA (e.g. LPL, CLLU1, micro-RNAs) and the genomic (e.g. TP53, NOTCH1, SF3B1 and BIRC3 mutations) level. Efforts are now being made to test these novel markers in larger patient cohorts as well as in prospective trials, with the ultimate goal to combine the "best" markers in a "CLL prognostic index" applicable for the individual patient. Although it is clear that these studies have significantly improved our knowledge regarding both prognostication and the biology of the disease, there is still an immediate need for recognizing biomarkers that can predict therapy response, and efforts should now focus on addressing this pertinent issue. In the present article, we review the extensive literature in the field of prognostic markers in CLL, focus on the most clinically relevant markers and discuss future directions regarding biomarkers in CLL.

Predicting survival in chronic lymphocytic leukemia

There is increasing interest in the use of prognostic markers that may predict survival and guide management in patients diagnosed with the early stages of chronic lymphocytic leukemia (CLL). Currently, the most important traditional prognostic factors include clinical staging, lymphocyte doubling time and β2-microglobulin/thymidine kinase; and the most important novel markers include karyotypic aberrations (typically assessed by FISH probes or CpG oligonucleotide karyotyping) and IgVH mutation status. Although each of these factors have individually shown significant correlations with survival, there is increasing appreciation that the most complete information may be obtained by using a combination of several factors in prognostic normograms or models. In this article, we review the current state-of-the-art with regards to CLL prognostic factors and discuss how they can be applied in the clinic.

Changes in serum thymidine kinase 1 levels during chemotherapy correlate with objective response in patients with advanced gastric cancer

Serum thymidine kinase 1 (STK1) is a reliable proliferation marker in most solid tumors, including gastric cancer. The aim of this study was to evaluate whether STK1 levels are related to the tumor response to chemotherapy and survival in advanced gastric cancer. The results showed that the average STK1 level in patients with gastric cancer (5.57±3.07 pM) was significantly higher than that in the healthy controls (1.12±0.57) (P<0.001). Among the 84 patients, the average STK1 level (6.02±3.12) in the 56 patients who did not undergo surgery was higher than the level (4.68±2.78) in the 28 patients who received surgery (P=0.049). The STK1 value correlated with clinical stage, ECOG PS and serum CEA levels (P<0.001, P=0.001 and P=0.004, respectively), but not with age and gender. The average STK1 levels after 1,2 and 4 cycles of chemotherapy did not significantly decrease in the total patients, when compared to the levels prior to chemotherapy. Yet, after 2 cycles of chemotherapy, the average level of STK1 was significantly decreased in patients who achieved an objective response (OR) (CR, PR or no recurrence). Particularly after 1 cycle of chemotherapy, the average level of STK1 in patients who achieved OR started to decline, while in most of the patients with disease progression or recurrence, the STK1 level started to increase. In patients receiving palliative chemotherapy or receiving adjuvant chemotherapy, a significant difference in the median PFS (median PFS, not defined vs. 4 months, P<0.001) or RFS (median RFS, not defined vs. 5 months, P<0.001) was noted between patients with decreased STK1 levels and patients with increased STK1 levels during the first 2 months of chemotherapy. The log-rank test showed that patients with decreased STK1 levels had a trend of a longer OS in the palliative chemotherapy group. Our results suggest that serum TK1 levels correlate with clinical stage, ECOG PS and serum CEA levels in patients with gastric cancer, and changes in STK1 levels during the first 2 months of chemotherapy may be more important for evaluating chemotherapy response, predicting PFS and RFS than baseline values of STK1 in patients with advanced gastric cancer.

Prognostic factors in chronic lymphocytic leukemia-what do we need to know?

Of all leukemias, chronic lymphocytic leukemia (CLL) shows the highest variability in its clinical presentation and course. CLL can present as an aggressive and life threatening leukemia or as an indolent form that will not require treatment over decades. The currently available clinical staging systems for CLL are simple and inexpensive but lack accuracy to predict disease progression and survival on an individual basis. The increased understanding of the key events of molecular pathogenesis has provided a plethora of novel molecular and biological factors that correlate with the outcome of CLL. This Review provides a concise discussion of the most important discoveries and gives guidance on how to implement novel prognostic tools in the clinical management of CLL by applying the criteria of evidence, relevance, and simplicity to the selection of prognostic markers.

High serum thymidine kinase 1 level predicts poorer survival in patients with chronic lymphocytic leukemia

Serum thymidine kinase 1 (TK1) levels have been reported to have prognostic significance in patients with chronic lymphocytic leukemia (CLL). Until recently, serum TK1 levels were assessed using inconvenient radioenzyme assays. In this study, we used a novel chemiluminescence assay to assess serum TK1 levels in patients with CLL at the time of first examination. We show that high serum TK1 levels predict poorer overall survival and correlate with unmutated immunoglobulin variable region genes, CD38 and ZAP-70 expression, and subsequent risk of developing large B-cell lymphoma (Richter syndrome). Similar findings were observed in a subset of patients treated with current fludarabine-based chemotherapy regimens. We suggest that serum TK1 levels analyzed using this convenient chemiluminescence assay may be useful in the risk assessment of patients with CLL.

Serum thymidine kinase 1 concentration in Chinese patients with chronic lymphocytic leukemia and its correlation with other prognostic factors

Chronic lymphocytic leukemia (CLL) shows a remarkable heterogeneity, with some patients having an almost normal lifespan, others surviving only several months after diagnosis despite intensive therapy. The aim of this study was to investigate the serum thymidine kinase 1 (TK1) concentration in Chinese patients with CLL and its correlation with well-established other prognostic factors. Enhanced chemiluminescent dot blot assay was performed to measure serum TK1 concentration in 80 CLL patients. The concentration of TK1 was significantly increased in patients with Binet C (P = 0.002), higher levels of serum lactate dehydrogenase (LDH) (P = 0.012) and beta2-microglobulin (beta2-MG) (P = 0.025), unmutated IGHV status (P < 0.001), or higher expression levels of ZAP-70 (P = 0.014) and CD38 (P = 0.018) groups compared to the patients with Binet A, lower levels of serum LDH and beta2-MG, mutated IGHV status, or lower expression levels of ZAP-70 and CD38 groups, respectively. Strong correlation of TK1 level with IGHV mutations (r = 0.412, P < 0.001) or ZAP-70 (r = 0.263, P = 0.024) was observed. According to receiver operating characteristic curve analysis for serum TK1 concentration and IGHV mutational status, area under the curve was 0.757 (P = 0.001) and the optimal cut-off value of serum TK1 concentration level was 1.75 pM, with a 87.8% specificity, a 63.6% sensitivity. It was showed that serum TK1 concentration could be a predictive marker of IGHV mutational status, and might be applied for the assessment of prognosis in patients with CLL.

CD38 as a prognostic factor in Chinese patients with chronic lymphocytic leukaemia

B-cell chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia in the Western countries, however, infrequent in the Eastern. It shows a remarkable heterogeneity, with some patients having an almost normal lifespan, others surviving only several years after diagnosis despite intensive therapy. To explore the prognostic significance of CD38 expression in Chinese patients with CLL, multi-parameter flow cytometry was used to detect the expression of CD38 on CD5(+)CD19(+) cells of 147 patients. CD38 expression and its association with some other prognostic factors such as Binet stage, lymphocyte count in peripheral blood, serum lactate dehydrogenase (LDH), beta2-microglobulin (beta2-MG), ZAP-70 expression and cytogenetic abnormalities were analyzed. The Kaplan-Meier method was used to construct survival curves, and results were compared using the log-rank test. Univariate and multivariate Cox regression analyses were used to assess associations between survival time and potential risk factors. Out of the 147 CLL patients, positive expression of CD38 was found in 45 (30.6%) cases. CD38-positivity identified a subgroup of CLL patients with aggressive disease of Binet stage at the time of the test (P=0.036). Furthermore, the presence of higher serum LDH and beta2-MG levels at diagnosis was strongly correlated with CD38-positive (P=0.016 and 0.025, respectively). Prognostically unfavorable cytogenetic abnormalities, including 17p13 and 11q22 deletions, were significantly more frequent in CD38-positive patients than in CD38-negative ones (P=0.047 and 0.001, respectively). There was no significant difference between CD38-positive and CD38-negative groups in molecular cytogenetic aberrations of del(6q23), del(13q14), 14q32 translocation, or trisomy 12. In addition, in CD38-positive patients, the percentage of leukemic cells expressing ZAP-70 protein was not significantly higher than in CD38-negative ones (P=0.120). CD38 expression was associated with poor outcome. Patients with positive expression of CD38 had significantly shorter overall survival (mean, 81 months) than patients without CD38 expression (mean, 179 months) (P=0.015). Univariate analysis showed that serum levels of LDH and beta2-MG, del(17p13) and CD38 expression were the significant factors in determining overall survival (OS). Del(17p13) and CD38 expression were the variables strongly associated with OS by multivariate Cox regression analysis. It was showed that the patients with high level of CD38 expression had poorer outcome; CD38 was a good predictor of OS in Chinese patients with CLL.

Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on Chronic Lymphocytic Leukemia updating the National Cancer Institute-Working Group 1996 guidelines

Standardized criteria for diagnosis and response assessment are needed to interpret and compare clinical trials and for approval of new therapeutic agents by regulatory agencies. Therefore, a National Cancer Institute-sponsored Working Group (NCI-WG) on chronic lymphocytic leukemia (CLL) published guidelines for the design and conduct of clinical trials for patients with CLL in 1988, which were updated in 1996. During the past decade, considerable progress has been achieved in defining new prognostic markers, diagnostic parameters, and treatment options. This prompted the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) to provide updated recommendations for the management of CLL in clinical trials and general practice.

Prognostic markers in chronic lymphocytic leukaemia

Rai and Binet staging of chronic lymphocytic leukaemia (CLL) is being superseded by new prognostic markers. The mutational status of the immunoglobulin variable region heavy-chain genes segregates the disease into more benign and more malignant versions, and has been confirmed as an important prognostic marker in prospective clinical trials. A search for surrogate markers for this difficult-to-perform assay has led to flow cytometric assays for CD38 and ZAP-70 expression, although in both cases there are problems with standardization and interpretation of the assays. A separate pathway of research has revealed two chromosomal aberrations--deletions of 11q and 17p--as important prognostic markers. Fluorescent in-situ hybridization has made their detection readily available. These five markers are in different stages of evaluation, but some of them are ready to be used for risk-adapted therapy in clinical trials. Other assays are in earlier stages of assessment.

Pathology of chronic lymphocytic leukemia: an update

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is a clonal lymphoproliferative disorder characterized by proliferation of morphologically and immunophenotypically mature lymphocytes. CLL/SLL may proceed through different phases: an early phase in which tumor cells are predominantly small in size, with a low proliferation rate and prolonged cell survival, and a transformation phase with the frequent occurrence of extramedullary proliferation and an increase in large, immature cells. Although some patients with CLL have an indolent disease course and die after many years of unrelated causes, others have very rapidly disease progression and die of the disease within a few years of the diagnosis. In the past few years, considerable progress has been made in our ability to diagnose and classify CLL accurately. Through cytogenetics and molecular biology, it has been shown that CLL and variants are associated with a unique genotypic profile and that these genetic lesions often have a direct bearing on the pathogenesis and prognosis of the disease. Similarly, the development of antibodies to new biologic markers has allowed the identification of a unique immunophenotypic profile for CLL and variants. Moreover, accumulating evidence suggests that CLL cells respond to selected microenvironmental signals and that this confers a growth advantage and an extended survival to CLL cells. In this article, we will review the progress in the pathobiology of CLL and give an update on prognostic markers and tools in current pathology practice for risk stratification of CLL.

Igbeta(CD79b) mRNA expression in chronic lymphocytic leukaemia cells correlates with immunoglobulin heavy chain gene mutational status but does not serve as an independent predictor of clinical severity

The etiology of chronic lymphocytic leukemia (CLL) is poorly understood and its course is highly variable. Somatic hypermutation (SHM) of the immunoglobulin heavy chain (IgV(H)) gene and ZAP70 protein expression have been reported as prognostic indicators. However, these assays are not widely available and their concordance is imperfect. Thus a need exists to identify additional molecular determinants of CLL. The Igbeta (CD79b) subunit of the B cell antigen receptor is essential for B lymphocyte function. Defects in Igbeta expression are implicated in CLL pathogenesis. We have analyzed Igbeta mRNA expression in CLL cells in 40 consecutive patient samples. About 75% of the samples showed the expected decrease of Igbeta surface staining. Igbeta mRNA levels covered a wider range, did not correlate with Igbeta surface staining, but clearly distinguished the normal and CLL lymphocyte populations. Remarkably, Igbeta mRNA levels correlated strongly with SHM; Igbeta mRNA levels in CLL cells were significantly higher in patients with an unmutated IgV(H) gene when compared with those in whom IgV(H) was hypermutated (P = 0.008). In contrast, no correlation was observed between Igbeta mRNA levels and ZAP70 expression. Multiple parameters abstracted from chart reviews were used to estimate severity of CLL in each case. While severity correlated strongly with ZAP70 staining, and to a lesser extent with SHM status, there was no correlation with Igbeta mRNA levels. These data establish a strong linkage between Igbeta mRNA expression and SHM in CLL and highlight the complex relationships between biochemical parameters and clinical status in this disease.

Comparison of a quantitative PCR method with FISH for the assessment of the four aneuploidies commonly evaluated in CLL patients

Four chromosomal defects associated with outcome are commonly evaluated by fluorescent in situ hybridization (FISH) in chronic lymphocytic leukemia (CLL), namely deletions of the 13q13-q14, 11q22 and 17p13 regions and trisomy 12. In this study, we compared a quantitative PCR method--quantitative multiplex PCR of short fluorescent fragment (QMPSF)--with FISH for the detection of these acquired aneuploidies in a series of 110 patients with Binet stage A CLL. Genes located in the deleted or gained regions were selected as target genes and amplified using a method based on the simultaneous amplification of short fluorescent genomic fragments under quantitative conditions. A chromosomal imbalance involving one or several of the four loci was detected by either method in 72 patients (65%). A chromosome 13 deletion was present in 61 patients (54%), a 11q22 deletion in nine (8%), a trisomy 12 in nine and a 17p deletion in one. FISH and QMPSF results were identical for 103 out of 110 patients and discrepancies could be explained in most cases. This study demonstrates that a quantitative multiplex PCR represents a cost-effective method that could replace FISH in CLL patients. However, although QMPSF is perfectly adapted to the detection of primary defects, care should be taken when searching for clonal evolutions present in a small proportion of tumor cells.

Survival response to B-cell receptor ligation is restricted to progressive chronic lymphocytic leukemia cells irrespective of Zap70 expression

Despite very similar gene expression profiles, the clinical course of B-cell chronic lymphocytic leukemia (B-CLL) is heterogeneous. Immunoglobulin VH (IgVH) mutational status and expression of B-cell receptor (BCR) signaling mediators have been associated with disease progression. However, the consequences of BCR engagement on cell survival and evolution of the disease remain unclear. We show here that B-CLL cell survival is dependent on the threshold of BCR stimulation induced by immobilized antibody, in contrast to soluble anti-mu F(ab)'2 antibody, which leads to apoptosis. Measurement of metabolic activity and apoptotic response discriminated two subgroups. "Nonresponders" showed low metabolic activity and unmodified apoptotic response upon BCR stimulation. In contrast, "responders" exhibited increased metabolic activity and inhibition of spontaneous apoptosis. This survival advantage was associated to a BCR-dependent activation profile leading to induction of cyclin D2/cyclin-dependent kinase 4 (cdk4) expression and G1 cell cycle progression. The ability to respond to BCR ligation correlated with an unfavorable clinical course and allowed to define an additional group of patients among IgVH-mutated cases exhibiting a risk of progression. Remarkably, we show that Zap70 expression was neither mandatory nor sufficient to generate downstream survival signals and cyclin D2/cdk4 up-regulation. In conclusion, BCR engagement has a significant effect on B-CLL cell survival, activation, and G1 progression. Furthermore, our results provide new insights in the physiopathology of progressive IgVH-mutated cases.

Serum TK levels in CLL identify Binet stage A patients within biologically defined prognostic subgroups most likely to undergo disease progression

OBJECTIVE

Serum thymidine kinase (TK) levels have been shown to be correlated with survival in many malignancies, including chronic lymphocytic leukaemia (CLL). This study was designed to investigate associations between TK levels and other prognostic markers, in newly and previously diagnosed Binet stage A patients. Furthermore, the use of serum TK measurement to identify subcategories of disease within those defined by IgV(H) mutational status, gene usage and chromosomal aberrations was investigated.

METHODS

Ninety-one CLL patients were enrolled. Serum TK levels were measured using a radioenzyme assay. IgV(H) mutational status and V(H) gene usage were determined using BIOMED-2 primers and protocol. Recurring chromosomal abnormalities were detected by interphase fluorescent in situ hybridisation (FISH). Flow cytometry and reverse transcriptase polymerase chain reaction (RT-PCR) determined CD38 and Zap-70 expression, respectively.

RESULTS

Significantly higher serum TK levels were found in IgV(H) unmutated, compared with IgV(H) mutated, patients (P < 0.001). Elevated TK levels were also found in patients with CD38 and Zap-70 positivity (P = 0.004, P < 0.001, respectively), short lymphocyte doubling time (LDT) (P = 0.044) and poor or intermediate prognosis chromosomal aberrations (P < 0.001).

CONCLUSION

A TK level of >8.5 U/L best identified patients with progressive disease. Elevated TK levels could identify patients categorised, at diagnosis, into good prognosis subgroups by the various biological markers (mutated IgV(H), good prognosis chromosomal aberrations, Zap-70(-) and CD38(-)) who subsequently showed disease progression. Additionally, patients with V(H)3-21 gene usage showed high TK levels, irrespective of mutational status, and serum TK measurement retained predictive power as disease progressed in all subcategories studied.

A gender-based score system predicts the clinical outcome of patients with early B-cell chronic lymphocytic leukemia

To facilitate the development of a prognostic model for early B-cell chronic lymphocytic leukemia (CLL), the Gruppo Italiano Malattie EMatologiche Maligne dell'Adulto (GIMEMA) proposes its multi-institutional effort as a working model. In total, 1138 newly diagnosed Binet stage A patients managed over the last 10 years outside the setting of clinical trials according to a "wait and see" policy form the basis of the present study aimed at investigating prognostic variables affecting disease progression, a surrogate endpoint for overall survival. A 3-stage risk system, simply obtained by summing the variables that proved significant in the multivariate analysis (i.e. short lymphocyte doubling time, advanced Rai substage, high peripheral blood lymphocytosis), is proposed. Clear-cut differences in the 10 year progression-free survival (PFS) were observed among patients scoring 0 (low risk), 1 (intermediate risk), 2-3 (high risk): 67.8, 41.0 and 24.8%, respectively (P<0.0001). The results of the Medical Research Council (MRC) suggesting a better clinical outcome for females prompted us to verify such a gender-related difference within our prognostic categories. Because changes in PFS only reflected gender for patients scoring 0 (P=0.04), the following prognostic subgroups are proposed: (1) females scoring 0; (2) males scoring 0; (3) patients scoring 1-3 whatever gender (10 year PFS: 76.2, 61.4 and 37.8%; P<0.00001). Our long-term database provides an adequate patient sample to generate a generalized risk stratification model based on clinical data. The indolent clinical outcome of women with early CLL is also supported by the higher frequency of the immunoglobulin heavy-chain variable (IgVH) mutational status and lower proportion of 17p and 11q deletions found in such a patient subset in the MRC CLL4 trial.

CLL biology and prognosis

Chronic lymphocytic leukemia (CLL) follows an extremely variable course with survival ranging from months to decades. Recently, there has been major progress in the identification of molecular and cellular markers that may predict the tendency for disease progression in CLL patients. In particular, the mutational profile of Ig genes and some cytogenetic abnormalities have been found to be important predictors of prognosis in CLL. However, this progress has raised new questions about the biology and prognosis of the disease, some of which are addressed here. Such questions include: 1) What is the role of the B-cell receptor (BCR) in CLL pathogenesis? 2) Is CLL one disease? 3) Is CLL an accumulative disease? 4) What is the normal counterpart of the CLL B lymphocyte? 5) Have the Rai and Binet staging systems become obsolete? 6) Which is the best surrogate for Ig mutational profiles?

Perspectives in chronic lymphocytic leukemia biology and management

Considerable progress has been achieved in the comprehension of the pathogenesis, prognosis, assessment, and treatment of chronic lymphocytic leukemia. However, this progress also has introduced new enigmas in the fields of biology, prognosis, and treatment. This article discusses some unanswered questions in these different topics.

Prognostic impact of p27KIP1 expression in cyclin D1 positive lymphoproliferative disorders

Nodal mantle cell lymphoma (MCL) is a well-defined entity, but non-nodal leukemic cyclin D1 positive lymphoproliferative disorders have been reported and their relationship with MCL remains controversial and their prognosis heterogeneous. We prospectively studied the expression of cyclin D1 in CD5 positive leukemic B lymphoproliferative disorders at diagnosis and identified 65 cases overexpressing cyclin D1. We did not distinguish any clinical or biological criteria allowing one to identify a non-MCL group. Multivariate analysis identified age, anemia and p27kip1 expression as independent prognostic factors of survival. By univariate analysis, p27kip1 high expression proved to be the strongest predictor of prolonged survival. The median survival of p27 low expressors was 30 months, while it was not reached for p27 high expressors. A high level of p27 expression was often found associated with the absence of nodal involvement and the presence of somatic mutations, but neither of them was restricted to the p27 high expression group. In conclusion, we hypothesize that MCL and these cyclin D1 positive leukemic lymphoproliferative disorders represent a continuous spectrum of diseases. Determination of p27 expression level appears as a routine applicable test allowing identification of a subset of patients who could be considered for different therapeutic approaches.

Binet's staging system and VH genes are independent but complementary prognostic indicators in chronic lymphocytic leukemia

PURPOSE

Rai's and Binet's staging systems have contributed significantly to the identification of major prognostic groups in chronic lymphocytic leukemia (CLL), though they fail to accurately predict disease progression at the individual level. Biologic factors, such as the mutational status of the immunoglobulin heavy-chain variable genes (VH, cytogenetics, CD38 expression, and some serum markers, have recently improved prognostic assessment in CLL. In this study, we analyzed the prognostic value of VH mutational status within the different stages of Binet's classification in 145 patients.

PATIENTS AND METHODS

Our series consisted of 83 VH mutated (MT) and 62 VH unmutated (UM) patients. MT cases predominated within Binet's stage A (70%), whereas UM cases predominated among stages B and C (62%).

RESULTS

Median overall survival (OS) was 84 months for UM patients and was not achieved for the MT group (70% 12-year survival, P <.0001). Concerning Binet's stage A, both median OS and progression-free survival were significantly shorter for UM patients when compared with those of MT patients (97 months v not achieved, P =.0017; and 42 v 156 months, P <.0001), which compared favorably with the classical A' and A" substaging. The VH mutational profile could also segregate stage B and C patients into two groups with different survival patterns (median OS, 78 v 120 months for UM and MT patients, respectively; P =.002).

CONCLUSION

The significant survival differences observed between the VH mutational groups, among stage A and stage B and C patients, indicate that Binet's classification and VH genes are independent prognostic variables and are most likely complementary.

Prognosis at diagnosis: integrating molecular biologic insights into clinical practice for patients with CLL

Heterogeneity in the clinical behavior of patients with chronic lymphocytic leukemia (CLL) makes it difficult for physicians to accurately identify which patients may benefit from an early or more aggressive treatment strategy and to provide patients with relevant prognostic information. Given the potential efficacy of newer therapies and the desire to treat patients at "optimum" times, it is more important than ever to develop sensitive stratification parameters to identify patients with poor prognosis. The evolution of risk stratification models has advanced from clinical staging and use of basic laboratory parameters to include relevant biologic and genetic features. This article will review the dramatic progress in prognostication for CLL and will propose statistical modeling techniques to evaluate the utility of these new measures in predictive models to help determine the optimal combination of markers to improve prognostication for individual patients. This discussion will also elaborate which markers and tools should be used in current clinical practice and evaluated in ongoing clinical trials.