The management of chronic lymphocytic leukemia at a single centre over a 24-year period: prognostic factors for survival

Prognostic models for newly-diagnosed chronic lymphocytic leukaemia in adults: a systematic review and meta-analysis

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the most common cancer of the lymphatic system in Western countries. Several clinical and biological factors for CLL have been identified. However, it remains unclear which of the available prognostic models combining those factors can be used in clinical practice to predict long-term outcome in people newly-diagnosed with CLL.

OBJECTIVES

To identify, describe and appraise all prognostic models developed to predict overall survival (OS), progression-free survival (PFS) or treatment-free survival (TFS) in newly-diagnosed (previously untreated) adults with CLL, and meta-analyse their predictive performances.

SEARCH METHODS

We searched MEDLINE (from January 1950 to June 2019 via Ovid), Embase (from 1974 to June 2019) and registries of ongoing trials (to 5 March 2020) for development and validation studies of prognostic models for untreated adults with CLL. In addition, we screened the reference lists and citation indices of included studies.

SELECTION CRITERIA

We included all prognostic models developed for CLL which predict OS, PFS, or TFS, provided they combined prognostic factors known before treatment initiation, and any studies that tested the performance of these models in individuals other than the ones included in model development (i.e. 'external model validation studies'). We included studies of adults with confirmed B-cell CLL who had not received treatment prior to the start of the study. We did not restrict the search based on study design.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form to collect information based on the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Independent pairs of review authors screened references, extracted data and assessed risk of bias according to the Prediction model Risk Of Bias ASsessment Tool (PROBAST). For models that were externally validated at least three times, we aimed to perform a quantitative meta-analysis of their predictive performance, notably their calibration (proportion of people predicted to experience the outcome who do so) and discrimination (ability to differentiate between people with and without the event) using a random-effects model. When a model categorised individuals into risk categories, we pooled outcome frequencies per risk group (low, intermediate, high and very high). We did not apply GRADE as guidance is not yet available for reviews of prognostic models.

MAIN RESULTS

From 52 eligible studies, we identified 12 externally validated models: six were developed for OS, one for PFS and five for TFS. In general, reporting of the studies was poor, especially predictive performance measures for calibration and discrimination; but also basic information, such as eligibility criteria and the recruitment period of participants was often missing. We rated almost all studies at high or unclear risk of bias according to PROBAST. Overall, the applicability of the models and their validation studies was low or unclear; the most common reasons were inappropriate handling of missing data and serious reporting deficiencies concerning eligibility criteria, recruitment period, observation time and prediction performance measures. We report the results for three models predicting OS, which had available data from more than three external validation studies: CLL International Prognostic Index (CLL-IPI) This score includes five prognostic factors: age, clinical stage, IgHV mutational status, B2-microglobulin and TP53 status. Calibration: for the low-, intermediate- and high-risk groups, the pooled five-year survival per risk group from validation studies corresponded to the frequencies observed in the model development study. In the very high-risk group, predicted survival from CLL-IPI was lower than observed from external validation studies. Discrimination: the pooled c-statistic of seven external validation studies (3307 participants, 917 events) was 0.72 (95% confidence interval (CI) 0.67 to 0.77). The 95% prediction interval (PI) of this model for the c-statistic, which describes the expected interval for the model's discriminative ability in a new external validation study, ranged from 0.59 to 0.83. Barcelona-Brno score Aimed at simplifying the CLL-IPI, this score includes three prognostic factors: IgHV mutational status, del(17p) and del(11q). Calibration: for the low- and intermediate-risk group, the pooled survival per risk group corresponded to the frequencies observed in the model development study, although the score seems to overestimate survival for the high-risk group. Discrimination: the pooled c-statistic of four external validation studies (1755 participants, 416 events) was 0.64 (95% CI 0.60 to 0.67); 95% PI 0.59 to 0.68. MDACC 2007 index score The authors presented two versions of this model including six prognostic factors to predict OS: age, B2-microglobulin, absolute lymphocyte count, gender, clinical stage and number of nodal groups. Only one validation study was available for the more comprehensive version of the model, a formula with a nomogram, while seven studies (5127 participants, 994 events) validated the simplified version of the model, the index score. Calibration: for the low- and intermediate-risk groups, the pooled survival per risk group corresponded to the frequencies observed in the model development study, although the score seems to overestimate survival for the high-risk group. Discrimination: the pooled c-statistic of the seven external validation studies for the index score was 0.65 (95% CI 0.60 to 0.70); 95% PI 0.51 to 0.77.

AUTHORS' CONCLUSIONS

Despite the large number of published studies of prognostic models for OS, PFS or TFS for newly-diagnosed, untreated adults with CLL, only a minority of these (N = 12) have been externally validated for their respective primary outcome. Three models have undergone sufficient external validation to enable meta-analysis of the model's ability to predict survival outcomes. Lack of reporting prevented us from summarising calibration as recommended. Of the three models, the CLL-IPI shows the best discrimination, despite overestimation. However, performance of the models may change for individuals with CLL who receive improved treatment options, as the models included in this review were tested mostly on retrospective cohorts receiving a traditional treatment regimen. In conclusion, this review shows a clear need to improve the conducting and reporting of both prognostic model development and external validation studies. For prognostic models to be used as tools in clinical practice, the development of the models (and their subsequent validation studies) should adapt to include the latest therapy options to accurately predict performance. Adaptations should be timely.

The prognostic value of clinical and laboratory parameters in patients with chronic lymphocytic leukemia

PURPOSE

Chronic lymphocytic leukemia (CLL) is heterogeneous in its clinical course. The aim of the present study was to identify some clinical and laboratory parameters with prognostic value in relation to survival of patients with CLL.

PATIENTS AND METHODS

One hundred thirty one patients with CLL, treated in the Clinic of Hematology, Plovdiv, between 1992 and 2003 were studied. The patients' survival was analyzed by using the Kaplan-Meier method. Log-rank test was used to compare cumulative survival functions between different groups of patients. The parameters studied were: age, sex, Rai clinical stage, ECOG Performance status (PS), FAB morphological type, mediastinal lymphadenopathy, abdominal nodal mass, extranodal localization, absolute lymphocyte count, autoimmune hemolytic anemia, and response to therapy.

RESULTS

The mean survival of patients was 76 months (95% Confidence Interval, 64-87). The following factors were found to carry significant prognostic value in relation to survival: Rai clinical stage, ECOG PS, mediastinal lymphadenopathy, extranodal localization, FAB morphological type and response to initial standard treatment.

CONCLUSION

The prognostic factors identified in the present study can be easily applied in the clinical practice and may be used as a basis for creating mathematical prognostic models.

Infectious complications in chronic lymphocytic leukemia

Infectious complications have been known to be a major cause of morbidity and mortality in Chronic Lymphocytic Leukemia (CLL) patients who are prone to infections because of both the humoral immunodepression inherent to the hematologic disease and to the immunosuppression related to the therapy. The majority of infections in CLL patients treated with alkilating agents is of bacterial origin. The immunodeficiency and natural infectious history of alkylator-resistant, corticosteroid-treated patients appears to have changed with the administration of purine analogs, which has been complicated by very severe and unusual infections and also more viral infections due to sustained reduction of CD4-positive T lymphocytes. The subsequent introduction of monoclonal antibodies in therapies, in particular alemtuzumab, further increased the immunodepression, increasing also infections which appeared more often in patients with recurrent neutropenia due to chemotherapy cycles.Epidemiological data regarding fungal infections in lymphoproliferative disorders are scarce. Italian SEIFEM group in a retrospective multicentre study regarding CLL patients reported an incidence of mycoses 0.5%; however, chronic lymphoproliferative disorders emerged as second haematological underlying disease after acute leukemia in a French study on aspergillosis; in particular CLL with aspergillosis accounted for a third of these chronic lymphoproliferative diseases presenting mould infection.

Assessment of 285 cases of chronic lymphocytic leukemia seen at single large tertiary center in Northern India

Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disorder in the West accounting for about 30% of leukemias, but about 2-4% in India. There is no large series reported from India, and hence we decided to undertake this study. We assessed the clinicohematological profiles and treatment outcomes in 285 patients seen over 11 years at our center (median age 59 years, 209 males). Sixty-three patients (22%) were asymptomatic and diagnosed incidentally. The median total leukocyte count at presentation was 50 × 10(9)/L. Rai stage distribution was: stage 0, 10%; stage I, 16%; stage II, 33%; stage III, 20%; and stage IV, 21%. Fifty percent of patients required treatment at presentation. Ninety-six patients received chlorambucil-based (overall response rate [ORR] 69%, complete remission [CR] 3%) and 27 patients received fludarabine-based (ORR 89%, CR 44%) chemotherapy. With a median follow-up of 2.9 years, the median overall survival (OS) and event-free survival (EFS) were 5.1 and 4.6 years, respectively. Fludarabine was more toxic, as half of the patients developed febrile neutropenia and various infections. The majority of patients presented with advanced stage disease. Fludarabine was less commonly used as first-line therapy. Advanced clinical stage (Rai III and IV) was associated with poor OS (hazard ratio [HR] 2.46, 95% confidence interval [CI] 1.19-5.11, p = 0.001) and EFS.

B-chronic lymphocytic leukemia: practical aspects

B-CLL is the most common adult leukemia in the Western world. It is a neoplasia of mature looking B-monoclonal lymphocytes co-expressing the CD5 antigen (involving the blood, the bone marrow, the lymph nodes and related organs). Much new information about the nature of the neoplastic cells, including chromosomal and molecular changes as well as mechanisms participating in the survival of the leukemic clone have been published recently, in an attempt to elucidate the biology of the disease and identify prognostic subgroups. For the time being, clinical stage based on Rai and Binet staging systems remains the strongest predictor of prognosis and patients' survival, and therefore it affects treatment decisions. In the early stages treatment may be delayed until progression. When treatment is necessary according to well-established criteria, there are nowadays many different options. Chlorambucil has been the standard regimen for many years. During the last decade novel modalities have been tried with the emphasis on fludarabine and 2-chlorodeoxyadenosine and their combinations with other drugs. Such an approach offers greater probability of a durable complete remission but no effect on overall survival has been clearly proven so far. Other modalities, included in the therapeutic armamentarium, are monoclonal antibodies, stem cell transplantation (autologous or allogeneic) and new experimental drugs. Supportive care is an important part of patient management and it involves restoring hypogammaglobulinemia and disease-related anemia by polyvalent immunoglobulin administration and erythropoietin respectively.

Impact of cardiac surgery using cardiopulmonary bypass on course of chronic lymphatic leukemia: a case-control study

BACKGROUND

Chronic lymphatic leukemia (CLL) is a common disease among elderly individuals. The number of older patients undergoing operations with cardiopulmonary bypass (CPB) is increasing. The aim of the present study was to evaluate the impact of cardiac surgery using CPB on the long-term course of CLL.

METHODS

From 1992 to 2000, a total of 28 patients with CLL underwent heart surgery using CPB at our institution (group I). These patients were compared with 25 patients from the CLL register who were retrospectively matched with regard to preoperative administration of chemotherapy, Binet classification, age, and sex (group II). A time-point was selected for each patient in group II so that the variables for the two groups corresponded in relation to the time of operation of the patients in group I. Midterm follow-up data in both groups were analyzed.

RESULTS

There were no differences between groups regarding matched variables. The mean follow-up time was similar in both groups (2.6 +/- 2.2 vs 2.3 +/- 1.3 years, p > 0.5). The 30-day mortality in group I was 14.3%. The mean stay in the intensive care unit was 4.2 +/- 7.5 days; the median number of units of packed red blood cells transfused was three (range 0 to 17). Compared with group II, in group I significantly fewer patients (11 vs 17, p = 0.049) required chemotherapy significantly later (1.98 +/- 2.06 vs 0.84 +/- 1.18 years, p = 0.018). During follow-up, no difference was found between groups regarding severe infections (10 vs 14, p = 0.14). Despite postoperative mortality in group I, the long-term mortality was similar in both groups (p = 0.3).

CONCLUSIONS

Cardiac surgery using CPB did not have a negative impact on the natural course of CLL. Moreover, this procedure seems to be associated with a decrease in the number of postoperative chemotherapy administrations and with an increase of chemotherapy-free survival time. Although CLL may be a risk factor in the early postoperative period, it is not a contraindication for cardiac surgery using CPB.

The development of marked elevation in white blood cell count does not predict inferior outcome in chronic lymphocytic leukemia

Although elevation of the white blood cell (WBC) count at diagnosis of chronic lymphocytic leukemia (CLL) appears to predict shortened survival, its significance later in the course of the disease remains unclear. We reviewed all cases of CLL seen in our center between 1980 and 1999 to evaluate the frequency and clinical significance of WBC elevation > 100 x 10(9)/L. CLL was confirmed according to standard diagnostic criteria and data was collected from diagnosis, occurrence of WBC > 100 x 10(9)/L, and last follow-up. 235 consecutive patients with CLL were identified; 94 were excluded. 141 included patients had a median age of 61 years and median WBC 19.7 x 10(9)/L at diagnosis. Median follow-up for all patients was 56 months, and median survival was 104 months. 41 patients (29%) had > or = 1 episode of WBC > 100 x 10(9)1/L, occurring at a median of 38 months from diagnosis. Compared to controls matched for modified Rai stage, development of a WBC > 100 x 10(9)/L did not predict inferior survival (median 107 vs. 101 months, p = 0.72). We conclude that the occurrence of a WBC count > 100 x 10(9)/L in patients with CLL does not shorten the survival, and patients require therapy only if other indications for treatment are present.

Does intensive treatment with high dose chlorambucil and prednisone as first line and cladribine as second line influence the survival of the patients with chronic lymphocytic leukemia?

Cladribine (2-CdA) and fludarabine are the new purine analogs introduced in the treatment of chronic lymphocytic leukemia (CLL). Despite the high response rate, their influence on survival is still uncertain. The aim of this study was a retrospective analysis and comparison of the response rate and survival of CLL patients treated with high dose chlorambucil (HDChl) as first and 2-CdA as second line, with an historical group of patients never treated with purine analogs who received standard doses of chlorambucil (SDChl). We analyzed 347 patients with CLL treated between January 1985 and January 2000. Group A (190 patients) received HDChl (12 mg/m(2) ) with prednisone (P) 30 mg/m(2) daily for 7 days monthly as first line and in refractory or early relapsed patients 2-CdA (0.12 mg/kg/day) for 5 days with or without P (30mg/m(2) ) as second line. Group B (157 patients) received continuous SDChl (4-8 mg/m(2) /day) and P as first line and COP or CHOP as second line. The overall response rate (OR) for the first line was 48,4% in group A and 38,9% in group B (p=0.09). 148 patients in group A and 52 in group B received the second line treatment and the second OR was 19.6% and 13.5%, respectively (p=0.4). At the time of analysis, 124 patients died in group A and 139 in group B. Median survival was 65 months and 50 months, respectively. In group A, survival was longer in advanced Rai stage patients (p=0.001) but in early Rai stage was similar for both groups (p=0.4). We suggest that intensive treatment with HDChl as first line and 2-CdA as second line should be applied in more advanced rather than in less advanced stages of CLL until the final results of randomized clinical trials are available.

Allogeneic bone marrow transplantation for low-grade lymphoma and chronic lymphocytic leukemia

Twenty-six patients with low-grade lymphoma (LGL) (n = 18) or chronic lymphocytic leukemia (CLL) (n = 8) received allogeneic BMTs between 1985 and 1998. Median age was 42 years, median interval from diagnosis to transplant 22 months and median number of prior treatments three. Twenty (77%) had stage IV disease; 22 (85%) had never achieved CR. Donor source was HLA matched sibling (n = 19, 73%), matched unrelated (n = 6, 23%) or syngeneic (n = 1). Conditioning therapy included total body irradiation in 23 patients and busulphan in three. Twenty-five received GVHD prophylaxis with cyclosporine A; + methotrexate (n = 19), + methylprednisolone (n = 2) or + T cell depletion of allograft +/- methotrexate (n = 4). Sixteen patients are alive, a median of 2.4 years post BMT. Death occurred due to transplant complications (n = 7) or underlying disease (n = 3). Eighteen (12 LGL, six CLL) of 22 evaluable patients (82%) achieved CR post BMT. Cumulative incidence of refractory/recurrent disease was 18% (95% confidence interval (CI) 7-42%). Overall and event-free survivals were 58% (95% CI 35-75%) and 54% (95% CI 32-72%), respectively. Allogeneic BMT for young patients with advanced LGL or CLL is feasible and can result in long-term disease-free survival.

Cardiac operations in patients with low-grade small lymphocytic malignancies

BACKGROUND

Low-grade small lymphocytic (B cell) malignancies (encompassing chronic lymphocytic leukemia and some types of non-Hodgkin lymphoma) are diseases of the elderly. Open cardiac procedures are known to have increased risk of postoperative infection and other morbidities in these immunodeficient patients. Outcome of open cardiac procedures in these patients was reviewed retrospectively.

PATIENTS

Thirteen patients (aged 58-82 years, 11 men, 2 women) with these lymphocytopathologic diseases (8 with chronic lymphocytic leukemia and 5 with non-Hodgkin lymphoma) underwent cardiac operations between January 1977 and June 1998. Mean age was 72 +/- 2.1 years. Isolated coronary artery bypass grafting was performed in 11 and combined procedures and double valve replacement were performed in 1 each. Preoperatively, 9 patients were in a low-risk clinical stage. Mean preoperative duration of lymphocytopathologic disease was 6.1 +/- 1.6 years. Mean preoperative New York Heart Association functional class was 2.8.

RESULTS

There was no operative death. Average stay in the intensive care unit was 41.4 +/- 8.6 hours. Postoperative leg and superficial sternal wound infections were encountered in 3 patients. Average postoperative hospital stay was 10.0 +/- 1.7 days. During the follow-up up to 72 months, 1 patient underwent a second cardiac operation. There was 1 late death 4 years later. Coronary stenting was done in 1 patient and a cardioverter-defibrillator was implanted in another patient for recurrent angina. Three patients underwent chemotherapy. Cardiac and lymphocytopathologic status remained stable in others.

CONCLUSIONS

Acceptable outcome may be anticipated after cardiac operations in patients with low-grade chronic lymphocytic leukemia and non-Hodgkin lymphoma in early stages. However, the possibility of infection and progression of cardiac and lymphocytopathologic status in these patients should call for caution.

Immunocytoma: a retrospective analysis from St Bartholomew's Hospital-1972 to 1996

PURPOSE

To analyze the presentation features and outcome for patients with immunocytoma (IMC) managed at St Bartholomew's Hospital (SBH), London, United Kingdom, between 1972 and 1996. Outcome was compared with that of patients with small lymphocytic lymphoma (SLL)/B-cell chronic lymphocytic leukemia (B-CLL) treated at SBH during the same period.

PATIENTS AND METHODS

One hundred twenty-six patients with newly diagnosed IMC were identified. Patients were subclassified (using the Kiel classification) as having lymphoplasmacytoid (n =92), lymphoplasmacytic (n = 24), polymorphous (n = 9), or undetermined (n = 1) IMC. Six patients (5%) had stage I to IIE disease; the rest had advanced disease. Treatment was given according to disease stage. Seven patients were managed expectantly.

RESULTS

Eighty-two (69%) of 119 patients responded to treatment, but complete remission was seen in only 15 (13%) of 119. Treatment failed in 29 (24%) of 119 patients. There were three treatment-related deaths; five patients were not assessable for response. When survival of patients with IMC was compared with that of patients with B-CLL/SLL, a significant difference was found (P <. 01); this difference was maintained when only patients in whom the diagnosis was based on lymph node biopsy were considered (P =.01). A comparison of the three IMC subgroups showed that there was a trend (P =.06) toward a difference between B-CLL/SLL and the lymphoplasmacytoid subtype.

CONCLUSION

Patients diagnosed with IMC are generally older and present with advanced disease. Conventional therapies usually result in incomplete responses of short duration. Overall, these results support the proposed World Health Organization reclassification of IMC to include lymphoplasmacytoid lymphoma (Kiel classification) as a variant of B-CLL/SLL.

Mantle cell lymphoma: natural history defined in a serially biopsied population over a 20-year period

BACKGROUND

The histological, immunological and molecular characteristics of mantle cell lymphoma have only recently been delineated. Amongst these characteristics possible factors of prognostic significance include histological growth pattern and blastoid change.

PATIENTS AND METHODS

66 previously untreated cases of mantle cell lymphoma were identified in a retrospective analysis. In 50 cases serial biopsies had been taken during the disease and in 20 cases autopsies had been performed. Besides established factors of prognostic significance, histological growth pattern and blastoid change were examined.

RESULTS

32 patients achieved an initial complete remission or good partial remission with most cases relapsing or progressing within 2 years. The median survival was 36 months. Factors predicting a poor outcome were high presenting stage, age > 70, low sodium, low albumin and splenomegaly. Blastoid transformation was also a poor prognostic feature, occurring in 32% of cases during life and in 70% of autopsies. Histological growth pattern had no influence on outcome.

CONCLUSION

This study emphasises the difficulties in treating mantle cell lymphoma and the high frequency and prognostic importance of histological transformation.