The complex karyotype landscape in chronic lymphocytic leukemia allows the refinement of the risk of Richter syndrome transformation.

Complex karyotype (CK) at chronic lymphocytic leukemia (CLL) diagnosis is a negative biomarker of adverse outcome. Since the impact of CK and its subtypes, namely type-2 CK (CK with major structural abnormalities) or high-CK (CK with ≥5 chromosome abnormalities), on the risk of developing Richter syndrome (RS) is unknown, we carried out a multicenter real-life retrospective study to test its prognostic impact. Among 540 CLL patients, 107 harbored a CK at CLL diagnosis, 78 were classified as CK2 and 52 as high-CK. Twenty-eight patients developed RS during a median follow-up of 6.7 years. At the time of CLL diagnosis, CK2 and high-CK were more common and predicted the highest risk of RS transformation, together with advanced Binet stage, unmutated (U)-IGHV, 11q-, and TP53 abnormalities. We integrated these variables into a hierarchical model: high-CK and/or CK2 patients showed a 10-year time to RS (TTRS) of 31%; U-IGHV/11q- /TP53 abnormalities/Binet stage B-C patients had a 10-year TTRS of 12%; mutated (M)-IGHV without CK and TP53 disruption a 10-year TTRS of 3% (P<0.0001). We herein demonstrate that CK landscape at CLL diagnosis allows the risk of RS transformation to be refined and we recapitulated clinico-biological variables into a prognostic model.

In chronic lymphocytic leukaemia, SLAMF1 deregulation is associated with genomic complexity and independently predicts a worse outcome.

In a series of 349 patients with chronic lymphocytic leukaemia (CLL), we found lower levels of signalling lymphocytic activation molecule family member 1 (SLAMF1) expression in cases with highly complex karyotypes, as defined by the presence of five or more chromosomal abnormalities (CK5; P < 0·001) and with major chromosomal structural abnormalities (P < 0·001). SLAMF1 downregulation was significantly associated with advanced Binet Stage (P = 0·001), CD38 positivity (P < 0·001), high ß2 -microglobulin levels (P < 0·001), immunoglobulin heavy chain variable region gene (IGHV) unmutated status (P < 0·001), 11q deletion (P < 0·001), tumour protein p53 (TP53) disruption (P = 0·011) and higher risk CLL International Prognostic Index categories (P < 0·001). Multivariate analysis showed that downregulated SLAMF1 levels had independent negative prognostic impact on time-to-first treatment (P < 0·001) and overall survival (P < 0·001).

The combination of complex karyotype subtypes and IGHV mutational status identifies new prognostic and predictive groups in chronic lymphocytic leukaemia.

BACKGROUND: Complex karyotype (CK) is a heterogeneous category with a negative impact in chronic lymphocytic leukaemia (CLL). Our group has recently reported that CK patients with major structural abnormalities (i.e. CK2) are characterised by a worse prognosis, as compared to other lesions within CK(CK1). METHODS: We performed a multicentre retrospective study to test whether the combination of CK subtypes with IGHV status could be a relevant prognostic and predictive tool. RESULTS: Among 522 patients 13% harboured CK2, 41% CK1 and/or U-IGHV (U-CK1) and 46% M-IGHV without any CK subtypes (M-noCK). After a median follow-up of 5.8 years, CK2 patients had the shortest TTFT (5-year TTFT 31%, 39 and 81%, p < 0.0001) and OS (5-year OS 67%, 85 and 93%, p < 0.0001) as compared to U-CK1 or M-noCK cases, regardless of TP53 abnormalities. CK2 patients also had the worst outcome after chemoimmunotherapy. In fact, the median TTNT after FCR or BR was 1.86 and 4.79 years for CK2 and U-CK1, but not reached for M-noCK patients (p < 0.0005). CONCLUSIONS: We herein suggest that the combined assessment of the IGHV mutational status and CK subtypes refines the prognostication of CLL, allowing to identify M-IGHV patients without any CK subtypes who are characterised by an indolent disease and excellent outcome after chemoimmunotherapy.

In chronic lymphocytic leukaemia with complex karyotype, major structural abnormalities identify a subset of patients with inferior outcome and distinct biological characteristics.

Complex karyotype (CK) is a negative prognostic factor in chronic lymphocytic leukaemia (CLL). However, CK is a heterogeneous cytogenetic category. Unbalanced rearrangements were present in 73·3% of 90 CLL patients with CK (i.e. ≥3 chromosome aberrations in the same clone), and were associated with a shorter overall survival (P = 0·025) and a shorter time to first treatment (P = 0·043) by multivariate analysis. Patients with unbalanced rearrangements presented a distinct mRNA expression profile. In conclusion, CLL patients with unbalanced rearrangements might represent a subset of very high-risk CLL patients with distinct clinical and biological characteristics.

An extensive molecular cytogenetic characterization in high-risk chronic lymphocytic leukemia identifies karyotype aberrations and TP53 disruption as predictors of outcome and chemorefractoriness.

We investigated whether karyotype analysis and mutational screening by next generation sequencing could predict outcome in 101 newly diagnosed chronic lymphocytic leukemia patients with high-risk features, as defined by the presence of unmutated IGHV gene and/or 11q22/17p13 deletion by FISH and/or TP53 mutations. Cytogenetic analysis showed favorable findings (normal karyotype and isolated 13q14 deletion) in 30 patients, unfavorable (complex karyotype and/or 17p13/11q22 deletion) in 34 cases and intermediate (all other abnormalities) in 36 cases. A complex karyotype was present in 21 patients. Mutations were detected in 56 cases and were associated with unmutated IGHV status (p = 0.040) and complex karyotype (p = 0.047). TP53 disruption (i.e. TP53 mutations and/or 17p13 deletion by FISH) correlated with the presence of ≥ 2 mutations (p = 0.001) and a complex karyotype (p = 0.012). By multivariate analysis, an advanced Binet stage (p < 0.001) and an unfavorable karyotype (p = 0.001) predicted a shorter time to first treatment. TP53 disruption (p = 0.019) and the unfavorable karyotype (p = 0.028) predicted a worse overall survival. A shorter time to chemorefractoriness was associated with TP53 disruption (p = 0.001) and unfavorable karyotype (p = 0.025). Patients with both unfavorable karyotype and TP53 disruption presented a dismal outcome (median overall survival and time to chemorefractoriness of 28.7 and 15.0 months, respectively). In conclusion, karyotype analysis refines risk stratification in high-risk CLL patients and could identify a subset of patients with highly unfavorable outcome requiring alternative treatments.

Extensive next-generation sequencing analysis in chronic lymphocytic leukemia at diagnosis: clinical and biological correlations.

BACKGROUND: In chronic lymphocytic leukemia (CLL), next-generation sequencing (NGS) analysis represents a sensitive, reproducible, and resource-efficient technique for routine screening of gene mutations. METHODS: We performed an extensive biologic characterization of newly diagnosed CLL, including NGS analysis of 20 genes frequently mutated in CLL and karyotype analysis to assess whether NGS and karyotype results could be of clinical relevance in the refinement of prognosis and assessment of risk of progression. The genomic DNA from peripheral blood samples of 200 consecutive CLL patients was analyzed using Ion Torrent Personal Genome Machine, a NGS platform that uses semiconductor sequencing technology. Karyotype analysis was performed using efficient mitogens. RESULTS: Mutations were detected in 42.0 % of cases with 42.8 % of mutated patients presenting 2 or more mutations. The presence of mutations by NGS was associated with unmutated IGHV gene (p = 0.009), CD38 positivity (p = 0.010), risk stratification by fluorescence in situ hybridization (FISH) (p < 0.001), and the complex karyotype (p = 0.003). A high risk as assessed by FISH analysis was associated with mutations affecting TP53 (p = 0.012), BIRC3 (p = 0.003), and FBXW7 (p = 0.003) while the complex karyotype was significantly associated with TP53, ATM, and MYD88 mutations (p = 0.003, 0.018, and 0.001, respectively). By multivariate analysis, the multi-hit profile (≥2 mutations by NGS) was independently associated with a shorter time to first treatment (p = 0.004) along with TP53 disruption (p = 0.040), IGHV unmutated status (p < 0.001), and advanced stage (p < 0.001). Advanced stage (p = 0.010), TP53 disruption (p < 0.001), IGHV unmutated status (p = 0.020), and the complex karyotype (p = 0.007) were independently associated with a shorter overall survival. CONCLUSIONS: At diagnosis, an extensive biologic characterization including NGS and karyotype analyses using novel mitogens may offer new perspectives for a better refinement of risk stratification that could be of help in the clinical management of CLL patients.

Complex chromosomal rearrangements leading to MECOM overexpression are recurrent in myeloid malignancies with various 3q abnormalities.

Chromosomal rearrangements involving 3q26 are recurrent findings in myeloid malignancies leading to MECOM overexpression, which has been associated with a very poor prognosis. Other 3q abnormalities have been reported and cryptic MECOM rearrangements have been identified in some cases. By fluorescence in situ hybridization (FISH) analysis, we investigated 97 acute myeloid leukemia/myelodysplastic syndrome patients with various 3q abnormalities to determine the role and the frequency of the involvement of MECOM. We identified MECOM rearrangements in 51 patients, most of them showed 3q26 involvement by chromosome banding analysis (CBA): inv(3)/t(3;3) (n = 26) and other balanced 3q26 translocations (t(3q26)) (n = 15); the remaining cases (n = 10) showed various 3q abnormalities: five with balanced translocations involving 3q21 or 3q25; two with homogenously staining region (hsr) on 3q; and three with other various 3q abnormalities. Complex rearrangements with multiple breakpoints on 3q, masking 3q26 involvement, were identified in cases with 3q21/3q25 translocations. Furthermore, multiple breaks were observed in two cases with t(3q26), suggesting that complex rearrangement may also occur in apparently simple t(3q26). Intrachromosomal gene amplification was another mechanism leading to MECOM overexpression in two cases with hsr on 3q. In the last three cases, FISH analysis revealed 3q26 involvement that was missed by CBA because of metaphases' suboptimal quality. All cases with MECOM rearrangements showed overexpression by real-time quantitative PCR. Finally, MECOM rearrangements can occur in patients with 3q abnormalities even in the absence of specific 3q26 involvement, underlining that their frequency is underestimated. As MECOM rearrangement has been associated with very poor prognosis, its screening should be performed in patients with any 3q abnormalities.

Expression of the immunoglobulin superfamily cell membrane adhesion molecule Cd146 in acute leukemia.

BACKGROUND: The expression of the immunoglobulin superfamily cell membrane adhesion molecule CD146 has been reported on several normal and pathological cell types in human. The aim of this study was to investigate CD146 expression in acute leukemia using a multiparametric cytofluorimetric approach. METHODS: Cytofluorimetric and cytogenetic studies were performed on peripheral blood and bone marrow samples from 162 patients with acute myeloid leukemia (AML, n = 121) and acute lymphoblastic leukemia (ALL, n = 41). ALL patients were subdivided in B-ALL (n = 38) and T-ALL (n = 3). Adult (n = 18) and pediatric (n = 20) B-ALL were considered as a whole group. RESULTS: Four out of 121 (3.3%) AML cases, 14/38 (36.8%) B-ALL, and 2/3 (66.6%) T-ALL expressed CD146 on 12-98% of blasts (p < 0.001). CD146 expression was not observed in 10 healthy controls. Among B-ALL CD146-positive cases, 78.6% were associated with a "common"/BII-ALL and 21.4% with a pre-B/BIII-ALL immunophenotype while pro-B/BI-ALL and mature-B/BIV-ALL cases were CD146-negative. Statistical analysis showed CD146 expression strongly associated with Ph+ positivity in B-ALL with the highest percentage of CD146-positive blasts in all Ph-positive B-ALL cases (84 ± 22% Ph-positive B-ALL SD vs. 40 ± 24% SD in Ph-negative B-ALL; p < 0,001). CONCLUSION: In our series, CD146 was expressed in all cases of Ph-positive B-ALL and in the vast majority of T-ALL, whereas it was rarely expressed by AML blasts. We suggest that CD146 may be considered as an additional marker for acute lymphoblastic leukemia diagnosis and monitoring of minimal residual disease in those cases which are CD146-positive at diagnosis. © 2015 International Clinical Cytometry Society.