Sheila J.M. O'Connor

Monoclonal B-Cell Lymphocytosis and Chronic Lymphocytic Leukemia

BACKGROUNDnA diagnosis of chronic lymphocytic leukemia (CLL) requires a count of over 5000 circulating CLL-phenotype cells per cubic millimeter. Asymptomatic persons with fewer CLL-phenotype cells have monoclonal B-cell lymphocytosis (MBL). The goal of this study was to investigate the relation between MBL and CLL.nnnMETHODSnWe investigated 1520 subjects who were 62 to 80 years of age with a normal blood count and 2228 subjects with lymphocytosis (>4000 lymphocytes per cubic millimeter) for the presence of MBL, using flow cytometry. Monoclonal B cells were further characterized by means of cytogenetic and molecular analyses. A representative cohort of 185 subjects with CLL-phenotype MBL and lymphocytosis were monitored for a median of 6.7 years (range, 0.2 to 11.8).nnnRESULTSnMonoclonal CLL-phenotype B cells were detected in 5.1% of subjects (78 of 1520) with a normal blood count and 13.9% (309 of 2228) with lymphocytosis. CLL-phenotype MBL had a frequency of 13q14 deletion and trisomy 12 similar to that of CLL and showed a skewed repertoire of the immunoglobulin heavy variable group (IGHV) genes. Among 185 subjects presenting with lymphocytosis, progressive lymphocytosis occurred in 51 (28%), progressive CLL developed in 28 (15%), and chemotherapy was required in 13 (7%). The absolute B-cell count was the only independent prognostic factor associated with progressive lymphocytosis. During follow-up over a median of 6.7 years, 34% of subjects (62 of 185) died, but only 4 of these deaths were due to CLL. Age above 68 years and hemoglobin level below 12.5 g per deciliter were the only independent prognostic factors for death.nnnCONCLUSIONSnThe CLL-phenotype cells found in the general population and in subjects with lymphocytosis have features in common with CLL cells. CLL requiring treatment develops in subjects with CLL-phenotype MBL and with lymphocytosis at the rate of 1.1% per year.

Rearrangement of the BCL6 locus at 3q27 is an independent poor prognostic factor in nodal diffuse large B‐cell lymphoma

Summary. Diffuse large B‐cell lymphomas (DLBCL) are a heterogeneous group of tumours, varying in clinical features, immunophenotype and cytogenetics. The aim of this study was to investigate the prognostic significance of BCL6 gene rearrangement at the 3q27 locus in patients with primary nodal disease, and to examine interrelationships with immunophenotype and International Prognostic Index (IPI). We have developed a fluorescent in situ hybridization (FISH)‐based technique for the retrospective analysis of the effect of BCL6 gene rearrangements on survival, using nuclei extracted from paraffin‐embedded tissue. FISH results were obtained in 111 presentation cases of nodal DLBCL. The IPI was calculated and each case was stained immunocytochemically for BCL6, BCL2 and CD10. 3q27 rearrangements were detected in 25% of cases. BCL2 protein and a germinal centre (GC) phenotype (defined as CD10+, BCL6+) were expressed in 56% and 41% of cases respectively. In multivariate analysis, rearrangement of 3q27 and BCL2 expression and the absence of a GC phenotype were associated with a poor prognosis. These factors can be used in conjunction with the IPI to improve risk stratification in nodal DLBCL.

The detection of t(14;18) in archival lymph nodes: development of a fluorescence in situ hybridization (FISH)-based method and evaluation by comparison with polymerase chain reaction.

Fluorescence in situ hybridization (FISH) has been used to demonstrate the t(14;18) in up to 100% of follicular lymphoma (FL) cases, however, there is little reproducible data using fixed tissue. The aim was therefore to develop a robust FISH method for the demonstration of translocations in archival tissue. The technique was evaluated by comparison with multiplex polymerase chain reaction (PCR), capable of detecting the majority of known breakpoints. Twenty-eight paired frozen and fixed cases of FL and 20 reactive controls were analyzed. The t(14;18) was detected in 23 of 28 cases using PCR on frozen material and 8 of 20 in paraffin. Using FISH, 24 of 26 frozen and 26 of 28 paraffin cases had a demonstrable translocation. All 20 reactive nodes were negative for the t(14;18) by PCR. Using FISH, one of the reactive cases had occasional cells with a translocation FISH pattern, demonstrable in frozen and paraffin samples. This is consistent with the presence of the t(14;18), which is well described in normal individuals. Both PCR and FISH are highly effective for t(14;18) analysis in unfixed tissue. When only paraffin blocks are available, FISH is the method of choice, and a result was achieved in 100% of cases. The method is applicable to the retrospective analysis of a range of translocations.

The effect of salvage autologous stem-cell transplantation on overall survival in patients with relapsed multiple myeloma (final results from BSBMT/UKMF Myeloma X Relapse [Intensive]): a randomised, open-label, phase 3 trial

BACKGROUNDnThe Myeloma X trial previously reported improved durability of response (time to disease progression) in patients with relapsed multiple myeloma with salvage autologous stem-cell transplantation (ASCT) compared with oral cyclophosphamide in patients with multiple myeloma relapsing after a first ASCT. We report the final overall survival results of the trial.nnnMETHODSnBSBMT/UKMF Myeloma X was a multicentre, randomised, open-label, phase 3 trial done at 51 centres in the UK. Eligible patients with multiple myeloma relapsing after a previous ASCT were re-induced with intravenous bortezomib (1·3 mg/m(2) on days 1, 4, 8, 11), intravenous doxorubicin (9 mg/m(2) per day on days 1-4), and oral dexamethasone (40 mg/day on days 1-4, 8-11, and 15-18 during cycle 1 and days 1-4 during cycles 2-4), with supportive care as per local institutional protocols before randomisation in a 1:1 ratio to either high-dose melphalan (200 mg/m(2)) and salvage ASCT or weekly oral cyclophosphamide (400 mg/m(2) per week for 12 weeks). Randomisation was by permuted blocks stratified by length of first remission and response to re-induction treatment. The primary endpoint was time to disease progression; the study was also powered to detect a difference in the secondary endpoint, overall survival. Further secondary endpoints were the proportion of patients achieving an objective response, progression-free survival, overall survival, toxic effects and safety, pain, and quality of life. Prespecified exploratory endpoints included time to second objective disease progression (PFS2). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and the European Clinical Trials Database, number 2006-005890-24, and is now in long-term follow-up.nnnFINDINGSnBetween April 16, 2008, and Nov 19, 2012, 297 patients were registered into the study and 174 were randomly assigned to receive either high-dose melphalan and salvage ASCT (n=89) or oral weekly cyclophosphamide (n=85). 173 (58%) of 297 patients relapsed after more than 24 months from first ASCT. 75 (43%) of 174 randomised patients had died at follow-up: salvage ASCT (n=31 [35%]) versus oral weekly cyclophosphamide (n=44 [52%]). Updated time to disease progression shows continued advantage in the salvage ASCT group compared with the weekly cyclophosphamide group (19 months [95% CI 16-26] vs 11 months [9-12]; hazard ratio [HR] 0·45 [95% CI 0·31-0·64] log-rank p<0·0001). Median overall survival was superior in the salvage ASCT group compared with weekly cyclophosphamide group (67 months [95% CI 55-not estimable] vs 52 months [42-60]; log-rank p=0·022; HR 0·56 [0·35-0·90], p=0·0169). Time to second objective disease progression was superior in the salvage ASCT group compared with the weekly cyclophosphamide group (67 months [52-not estimable] vs 35 months [31-43]; HR 0·37 [0·24-0·57], log-rank p<0·0001). During extended follow-up, no further treatment-related or treatment-unrelated adverse events were reported. 15 second primary malignancies were reported in 12 patients (salvage ASCT [n=7] vs oral weekly cyclophosphamide [n=5]). The cumulative incidence of second primary malignancies at 60 months after trial entry was 5·2% (2·1-8·2).nnnINTERPRETATIONnSalvage ASCT increases overall survival during consolidation of re-induction treatment in patients with multiple myeloma at first relapse after a first ASCT. The delay of salvage ASCT to third-line treatment or later might not confer the same degree of advantage as seen with salvage ASCT at first relapse.nnnFUNDINGnCancer Research UK, Janssen-Cilag, and Chugai Pharma UK.

The rapid diagnosis of acute promyelocytic leukaemia using PML (5E10) monoclonal antibody

Acute promyelocytic leukaemia (APL) is characterized cytogenetically by t(15;17)(q22;q21) which results in the production of a PML/RARα fusion protein. Detection of the translocation or the fusion gene product is required for objective diagnosis of APL. This can be accomplished by conventional cytogenetic methods, fluorescence in situ hybridization or RT‐PCR. Such techniques are time consuming and not universally available. The intracellular distribution of the PML protein in promyelocytes is characteristically altered in APL and this can be detected by immunocytochemistry. We have assessed two immunocytochemical methods, immunofluorescence and alkaline phosphatase–anti‐alkaline phosphatase staining (APAAP), with regard to sensitivity, specificity and rapidity of diagnosis. 85 patients with AML including 15 cases of APL were studied. Immunofluorescence PML detection was concordant with RT‐PCR for t(15;17) in 14/15 (93.3%) cases with no false positives. The negative APL case in our series was a patient with a 5′ PML breakpoint who did not express the reciprocal t(17;15) fusion product. APAAP was concordant in only 6/13 (46%) APL cases with one false positive. In conclusion, immunofluorescent localization of PML using 5E10 monoclonal antibody is a rapid, sensitive and specific diagnostic tool for APL.