Emanuele Cencini

The prognosis of clinical monoclonal B cell lymphocytosis differs from prognosis of Rai 0 chronic lymphocytic leukaemia and is recapitulated by biological risk factors

Monoclonal B‐cell lymphocytosis (MBL) is an asymptomatic monoclonal expansion of <5·0 × 109/l circulating CLL‐phenotype B‐cells. The relationship between MBL and Rai 0 CLL, as well as the impact of biological risk factors on MBL prognosis, are unknown. Out of 460 B‐cell expansions with CLL‐phenotype, 123 clinical MBL (cMBL) were compared to 154 Rai 0 CLL according to clinical and biological profile and outcome. cMBL had better humoral immune capacity and lower infection risk, lower prevalence of del11q22‐q23/del17p13 and TP53 mutations, slower lymphocyte doubling time, and longer treatment‐free survival. Also, cMBL diagnosis was a protective factor for treatment risk. Despite these favourable features, all cMBL were projected to progress, and lymphocytes <1·2 × 109/l and >3·7 × 109/l were the best thresholds predicting the lowest and highest risk of progression to CLL. Although IGHV status, CD38 and CD49d expression, and fluorescence in situ hybridization (FISH) karyotype individually predicted treatment‐free survival, multivariate analysis identified the presence of +12 or del17p13 as the sole independent predictor of treatment requirement in cMBL (Hazard ratio: 5·39, 95% confidence interval 1·98–14·44, P = 0·001). Overall, these data showed that cMBL has a more favourable clinical course than Rai 0 CLL. Given that the biological profile can predict treatment requirement, stratification based on biological prognosticators may be helpful for cMBL management.

Chlorambucil plus rituximab with or without maintenance rituximab as first‐line treatment for elderly chronic lymphocytic leukemia patients

In a phase II trial, we evaluated chlorambucil and rituximab (CLB‐R) as first‐line induction treatment with or without R as maintenance for elderly chronic lymphocytic leukemia (CLL) patients. Treatment consisted of eight 28‐day cycles of CLB (8 mg/m2/day, days 1–7) and R (day 1 of cycle 3, 375 mg/m2; cycles 4–8, 500 mg/m2). Responders were randomized to 12 8‐week doses of R (375 mg/m2) or observation. As per intention‐to‐treat analysis, 82.4% (95% CI, 74.25–90.46%) of 85 patients achieved an overall response (OR), 16.5% a complete response (CR), 2.4% a CR with incomplete bone marrow recovery. The OR was similar across Binet stages (A 86.4%, B 81.6%, and C 78.6%) and age categories (60–64 years, 92.3%; 65–69, 85.2%; 70–74, 75.0%; ≥75, 81.0%). CLB‐R was well tolerated. After a median follow‐up of 34.2 months, the median progression‐free survival (PFS) was 34.7 months (95% CI, 33.1–39.5). TP53 abnormalities, complex karyotype, and low CD20 gene expression predicted lack of response; SF3B1 mutation and BIRC3 disruption low CR rates. IGHV mutations significantly predicted PFS. R maintenance tended towards a better PFS than observation and was safe and most beneficial for patients in partial response and for unmutated IGHV cases. CLB‐R represents a promising option for elderly CLL patients. Am. J. Hematol. 89:480–486, 2014.

Hairy cell leukemias with unmutated IGHV genes define the minor subset refractory to single agent cladribine and with more aggressive behavior

Hairy cell leukemia (HCL) is generally responsive to single-agent cladribine, and only a minority of patients are refractory and with poor prognosis. HCLs generally express mutated (M) and, in a minority, unmutated (UM) IGHV. In a multicenter clinical trial in newly diagnosed HCL, we prospectively investigated clinical and molecular parameters predicting response and event-free survival after single-agent cladribine. Of 58 HCLs, 6 expressed UM-IGHV (UM-HCL) and 52 M-IGHV (M-HCL). Beneficial responses were obtained in 53 of 58 patients (91%), whereas treatment failures were observed in 5 of 58 patients (9%). Failures were associated significantly with UM-IGHV (5 of 5 failures vs 1 of 53 beneficial responses had UM-IGHV, P < .001), leukocytosis (3 of 5 vs 3 of 53, P = .006), and bulky spleen (4 of 5 vs 4 of 53, P < .001). The UM-HCL not benefiting from cladribine characteristically had bulky spleen (4 of 5, 80%), leukocytosis (3 of 5, 60%), and TP53 defects (2 of 5, 40%), and progressed rapidly after first treatment (median event-free survival, 7.5 months). Our data suggest that UM-HCLs identify the minor subgroup failing cladribine treatment and with more aggressive disease. High incidence of TP53 dysfunction indicates a potential mechanism of resistance to cladribine in the UM-HCL group. Overall, our data provide new molecular elements relevant for treatment concerns in HCL.

13q14 Deletion size and number of deleted cells both influence prognosis in chronic lymphocytic leukemia

Deletion at 13q14 is detected by fluorescence in situ hybridization (FISH) in about 50% of chronic lymphocytic leukemia (CLL). Although CLL with 13q deletion as the sole cytogenetic abnormality (del13q‐only) usually have good prognosis, more aggressive clinical courses are documented for del13q‐only CLL carrying higher percentages of 13q deleted nuclei. Moreover, deletion at 13q of different sizes have been described, whose prognostic significance is still unknown. In a multi‐institutional cohort of 342 del13q‐only cases and in a consecutive unselected cohort of 265 CLL, we investigated the prognostic significance of 13q deletion, using the 13q FISH probes locus‐specific identifier (LSI)‐D13S319 and LSI‐RB1 that detect the DLEU2/MIR15A/MIR16‐1 and RB1 loci, respectively. Results indicated that both percentage of deleted nuclei and presence of larger deletions involving the RB1 locus cooperated to refine the prognosis of del13q‐only cases. In particular, CLL carrying <70% of 13q deleted nuclei with deletions not comprising the RB1 locus were characterized by particularly long time‐to‐treatment. Conversely, CLL with 13q deletion in <70% of nuclei but involving the RB1 locus, or CLL carrying 13q deletion in ≥70% of nuclei, with or without RB1 deletions, collectively experienced shorter time‐to‐treatment. A revised flowchart for the prognostic FISH assessment of del13q‐only CLL, implying the usage of both 13q probes, is proposed.

Genome-wide DNA profiling better defines the prognosis of chronic lymphocytic leukaemia.

The integration of molecular and clinical information to tailor treatments remains an important research challenge in chronic lymphocytic leukaemia (CLL). This study aimed to identify genomic lesions associated with a poor outcome and a higher risk of histological transformation. A mono‐institutional cohort of 147 cases was used as the test series, and a multi‐institutional cohort of 176 cases as a validation series. Genomic profiles were obtained using Affymetrix SNP 6.0. The impact of the recurrent minimal common regions (MCRs) on overall survival was evaluated by univariate analysis followed by multiple‐test correction. The independent prognostic significance was assessed by multivariate analysis. Eight MCRs showed a prognostic impact: gains at 2p25.3‐p22.3 (MYCN), 2p22.3, 2p16.2‐p14 (REL), 8q23.3‐q24.3 (MYC), losses at 8p23.1‐p21.2, 8p21.2, and of the TP53 locus. Gains at 2p and 8q and TP53 inactivation maintained prognostic significance in multivariate analysis and a hierarchical model confirmed their relevance. Gains at 2p also determined a higher risk of Richter syndrome transformation. The prediction of outcome for CLL patients might be improved by evaluating the presence of gains at 2p and 8q as novel genomic regions besides those included in the ‘standard’ fluorescence in situ hybridization panel.

Impaired expression of p66Shc, a novel regulator of B-cell survival, in chronic lymphocytic leukemia

Intrinsic apoptosis defects underlie to a large extent the extended survival of malignant B cells in chronic lymphocytic leukemia (CLL). Here, we show that the Shc family adapter p66Shc uncouples the B-cell receptor (BCR) from the Erk- and Akt-dependent survival pathways, thereby enhancing B-cell apoptosis. p66Shc expression was found to be profoundly impaired in CLL B cells compared with normal peripheral B cells. Moreover, significant differences in p66Shc expression were observed in patients with favorable or unfavorable prognosis, based on the mutational status of IGHV genes, with the lowest expression in the unfavorable prognosis group. Analysis of the expression of genes implicated in apoptosis defects of CLL showed an alteration in the balance of proapoptotic and antiapoptotic members of the Bcl-2 family in patients with CLL. Reconstitution experiments in CLL B cells, together with data obtained on B cells from p66Shc(-/-) mice, showed that p66Shc expression correlates with a bias in the Bcl-2 family toward proapoptotic members. The data identify p66Shc as a novel regulator of B-cell apoptosis which attenuates BCR-dependent survival signals and modulates Bcl-2 family expression. They moreover provide evidence that the p66Shc expression defect in CLL B cells may be causal to the imbalance toward the antiapoptotic Bcl-2 family members in these cells.

A variant of the LRP4 gene affects the risk of chronic lymphocytic leukaemia transformation to Richter syndrome

Richter syndrome (RS) represents the transformation of chronic lymphocytic leukaemia (CLL) to aggressive lymphoma. Risk factors of CLL transformation to RS are only partly known. We explored the role of the host genetic background as a risk factor for RS occurrence. Forty‐five single nucleotide polimorphisms (SNPs) known to be relevant for CLL prognosis were genotyped in a consecutive cohort of 331 CLL, of which 21 had transformed to RS. After correcting for multiple testing and adjusting for previously reported RS risk factors, the LRP4 rs2306029 TT variant genotype was the sole SNP independently associated with a higher risk of RS transformation (Hazard Ratio: 4·17; P = 0·001; q = 0·047). The enrichment of LRP4 TT genotype in RS was confirmed in an independent series (n = 44) used for validation purposes. The LRP4 protein was expressed in CLL (n = 66). Bioinformatic analysis scored LRP4 rs2306029 as a variant with possible deleterious and damaging variant of LRP4. LRP4 genotyping may help the recognition of patients with increased risk of RS at the time of CLL diagnosis.

Efficacy and safety of rituximab plus low-dose oral fludarabine and cyclophosphamide as first-line treatment of elderly patients with indolent non-Hodgkin lymphomas

Abstract Indolent non-Hodgkin lymphomas (iNHLs) are B-cell neoplasms for which no consensus is available about optimal first-line therapy. Chemoimmunotherapy with fludarabine, cyclophospamide and rituximab is very effective, but may give severe hematological and non-hematological toxicity at standard doses, especially in elderly patients. In this phase II study, 25 untreated elderly patients with iNHL received rituximab (375 mg/m2) plus low-dose oral fludarabine (25 mg/m2 for 4 consecutive days) and cyclophosphamide (150 mg/m2 for 4 consecutive days) for four monthly cycles. Twenty-three patients were responsive (92%) and 12 patients achieved a complete remission (48%). Twenty-one patients (84%) were alive, median follow-up was 30 months and median event-free survival (EFS) was not reached. Patients who we previously treated with chemotherapy alone had a shorter EFS (median 20 months). Compliance was good, with mild toxicity. This regimen is effective for elderly patients with iNHL. The addition of rituximab results in long EFS without affecting toxicity.

Rituximab plus liposomal pegylated doxorubicin in the treatment of primary cutaneous B‐cell lymphomas

In primary cutaneous B‐cell lymphomas (PCBCL), radiotherapy – or surgery in a minority of cases – is the first‐line treatment in follicle center lymphoma (PCFCL) and marginal zone B‐cell lymphoma (PCMZL). Conversely, patients with multifocal skin involvement or relapsed/refractory disease deserve a systemic chemotherapy. In diffuse large B‐cell lymphoma, leg type (PCLBCL‐LT), due its poorer outcome, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)‐like regimens are the most commonly used frontline, although hard to propose in elderly patients. In this regard, the association of rituximab (R) and pegylated liposomal doxorubicin (PLD) can be considered a promising, alternative approach.

Alternative methods of cladribine administration.

Nucleoside derivative cladribine treatment in hairy cell leukemia (HCL) is a rare example of treatment success in cancer. In fact, HCL is generally responsive to single-agent cladribine and only a minority of patients are refractory. Cladribine was originally administered intravenously as a continuous infusion at a dose of 0.1 mg/kg/day for 7 consecutive days. Subsequently cladribine has been administered intravenously, as a 2 h infusion for 5 consecutive days or weekly for 7 weeks, or subcutaneously. These regimens are all very effective but often show relevant toxicity. The subcutaneous route is easier to administer and may increase compliance of the patient. We have had the opportunity to investigate the efficacy and toxicity of subcutaneous cladribine given at the dose of 0.1 mg/kg/day for 5 or 7 days as a single course in newly diagnosed HCL requiring treatment, in an ongoing Italian multicenter clinical trial. Overall responses have been no different in the two arms, while a much lower infection rate was observed when cladribine was given at the lowest dose. Subcutaneous administration may be deemed a very convenient route since it does not require hospitalization. A reduced dosage of cladribine may also be advantageous since it may be associated with reduced toxicity and may set the dose needed for combinations with antibody treatments.