Total body computed tomography scan in the initial work-up of Binet stage A chronic lymphocytic leukemia patients: Results of the prospective, multicenter O-CLL1-GISL study

Monoclonal B-cell Lymphocytosis - a review of diagnostic criteria, biology, natural history, and clinical management

Since first described almost two decades ago, there has been significant evolution in our definition and understanding of the biology and implications of monoclonal B-cell lymphocytosis (MBL). This review provides an overview of the definition, classification, biology, and natural history of MBL, mainly focused on the dominant CLL-like phenotype form of MBL. The increasingly recognized implications of MBL with respect to immune dysfunction are discussed, particularly in view of the COVID-19 pandemic, along with management recommendations for MBL in the clinic.

Lymphocyte Doubling Time As A Key Prognostic Factor To Predict Time To First Treatment In Early-Stage Chronic Lymphocytic Leukemia

The prognostic role of lymphocyte doubling time (LDT) in chronic lymphocytic leukemia (CLL) was recognized more than three decades ago when the neoplastic clone’s biology was almost unknown. LDT was defined as the time needed for the peripheral blood lymphocyte count to double the of the initial observed value. Herein, the LDT prognostic value for time to first treatment (TTFT) was explored in our prospective O-CLL cohort and validated in in two additional CLL cohorts. Specifically, newly diagnosed Binet stage A CLL patients from 40 Italian Institutions, representative of the whole country, were prospectively enrolled into the O-CLL1-GISL protocol (clinicaltrial.gov identifier: NCT00917540). Two independent cohorts of newly diagnosed CLL patients recruited respectively at the Division of Hematology in Novara, Italy, and at the Hospital Clinic in Barcelona, Spain, were utilized as validation cohorts. In the training cohort, TTFT of patients with LDT >12 months was significantly longer related to those with a shorter LDT. At Cox multivariate regression model, LDT ≤ 12 months maintained a significant independent relationship with shorter TTFT along with IGHV unmutated (IGHVunmut) status, 11q and 17p deletions, elevated β2M, Rai stage I-II, and NOTCH1 mutations. Based on these statistics, two regression models were constructed including the same prognostic factors with or without the LDT. The model with the LTD provided a significantly better data fitting (χ² = 8.25, P=0.0041). The risk prediction developed including LDT had better prognostic accuracy than those without LDT. Moreover, the Harrell’C index for the scores including LDT were higher than those without LDT, although the accepted 0.70 threshold exceeded in both cases. These findings were also confirmed when the same analysis was carried out according to TTFT’s explained variation. When data were further analyzed based on the combination between LDT and IGHV mutational status in the training and validation cohorts, IGHVunmut and LDT>12months group showed a predominant prognostic role over IGHVmut LTD ≤ 12 months (P=0.006) in the O-CLL validation cohort. However, this predominance was of borden-line significance (P=0.06) in the Barcelona group, while the significant prognostic impact was definitely lost in the Novara group. Overall, in this study, we demonstrated that LDT could be re-utilized together with the more sophisticated prognostic factors to manage the follow-up plans for Binet stage A CLL patients.

Practical approach to management of chronic lymphocytic leukemia

Revolutionary progress has recently changed the landscape of chronic lymphocytic leukemia (CLL). Powerful prognostic factors, especially p53 mutation and/or deletion and IGHV mutation status, have refined individual patient prognosis. Purine analogs and monoclonal antibodies paved the way from palliative treatment to chemoimmunotherapy capable of eradication of minimal residual disease and prolongation of survival. Obinutuzumab (GA-101) and ofatumumab have been recently approved for the treatment of comorbid patients. Bendamustine is available for first-line treatment of patients ineligible for fludarabine, cyclophosphamide, and rituximab (FCR). High-dose glucocorticoids combined with rituximab represent a promising option for refractory CLL; ofatumumab is approved for fludarabine- and alemtuzumab-refractory patients. Allogeneic stem cell transplantation is the only curative option but is feasible in a highly selected group of patients only. The novel small molecule inhibitors ibrutinib and idelalisib have been recently approved for relapsed/refractory CLL. This review provides practical advice for diagnosis, prognostication and treatment of CLL.

Monoclonal B-cell lymphocytosis and early-stage chronic lymphocytic leukemia: diagnosis, natural history, and risk stratification

Monoclonal B lymphocytosis (MBL) is defined as the presence of a clonal B-cell population in the peripheral blood with fewer than 5 × 10(9)/L B-cells and no other signs of a lymphoproliferative disorder. The majority of cases of MBL have the immunophenotype of chronic lymphocytic leukemia (CLL). MBL can be categorized as either low count or high count based on whether the B-cell count is above or below 0.5 × 10(9)/L. Low-count MBL can be detected in ∼5% of adults over the age of 40 years when assessed using standard-sensitivity flow cytometry assays. A number of biological and genetic characteristics distinguish low-count from high-count MBL. Whereas low-count MBL rarely progresses to CLL, high-count MBL progresses to CLL requiring therapy at a rate of 1% to 2% per year. High-count MBL is distinguished from Rai 0 CLL based on whether the B-cell count is above or below 5 × 10(9)/L. Although individuals with both high-count MBL and CLL Rai stage 0 are at increased risk of infections and second cancers, the risk of progression requiring treatment and the potential to shorten life expectancy are greater for CLL. This review highlights challenging questions regarding the classification, risk stratification, management, and supportive care of patients with MBL and CLL.

Surrogate molecular markers for IGHV mutational status in chronic lymphocytic leukemia for predicting time to first treatment

ZAP-70 is a marker of clinical outcome in chronic lymphocytic leukemia (CLL), however its assessment suffers from a lack of standardization consensus. To identify novel markers able to surrogate IGHV mutational status, CD19(+)CD5(+)-B-lymphocytes from 216 patients enrolled in a prospective study (ClinicalTrial.gov Identifier:NCT00917540), underwent gene expression profiling. Samples were split into CLL-Training (n=102) and CLL-Validation (n=114) sets, and an independent supervised analysis for IGHV mutational status was performed considering all genes with gene expression equal or above that of ZAP-70. Thirty-one genes (23 up- and 8 down-regulated) and 23 genes (18 up- and 5 down-regulated) satisfied these criteria in the CLL-Training and CLL-Validation sets, respectively, and 20 common genes (15 up and 5 down) were found to be differentially regulated in both sets. Two (SNORA70F, NRIP1) of the down-regulated and 6 (SEPT10, ZNF667, TGFBR3, MBOAT1, LPL, CRY1) of the up-regulated genes were significantly associated with a reduced risk of disease progression in both sets. Forcing the afore-mentioned genes in a Cox multivariate model together with IGHV mutational status, only CRY1 (HR=2.3, 95% CI: 1.1-4.9, P=.027) and MBOAT1 (HR=2.1, 95% CI: 1.1-3.7, P=.018) retained their independent prognostic impact, supporting the hypothesis that these genes may potentially act as surrogates for predicting IGHV mutational status.

Prospective validation of predictive value of abdominal computed tomography scan on time to first treatment in Rai 0 chronic lymphocytic leukemia patients: results of the multicenter O-CLL1-GISL study

OBJECTIVE

We performed an external and multicentric validation of the predictive value of abdominal computed tomography (aCT) on time to first treatment (TTFT) in early stage chronic lymphocytic leukemia (CLL) patients.

METHODS

aCT was performed at diagnosis in 181 Rai 0 patients enrolled in the O-CLL1-GISL trial (clinicaltrial.gov ID:NCT00917549).

RESULTS

Fifty-five patients showed an abnormal aCT. Patients with an abnormal aCT showed a significantly shorter TTFT than those with normal aCT (P < 0.0001). At multivariate analysis, aCT (P = 0.011), β-2 microglobulin (P = 0.019), and CD38 expression (P = 0.047) correlated with TTFT. Following IWCLL 2008 criteria, 112 (61.9%) cases remained at Rai 0, while 69 (38.1%) satisfied the criteria of clinical monoclonal B-cell lymphocytosis (cMBL). Reclassified Rai 0 patients with an abnormal aCT showed a significantly shorter TTFT than those with a normal aCT (P < 0.0001). At multivariate analysis, only aCT (P = 0.011) correlated with TTFT. Eleven cMBL cases (15.9%) showed an abnormal aCT and were reclassified as small lymphocytic lymphomas (SLL); nonetheless, TTFT was similar for cMBLs and SLLs.

CONCLUSION

Our results confirm the ability of the abnormal aCT to predict progression in early stage cases.

Prospective validation of a risk score based on biological markers for predicting progression free survival in Binet stage A chronic lymphocytic leukemia patients: results of the multicenter O-CLL1-GISL study

A risk score based on three biological features (CD38, ZAP-70, and IGHV mutational status) was previously developed to predict progression-free survival (PFS) in untreated Binet A CLL patients. Here we perform a score validation analysis in a prospective and independent cohort of patients. Biological markers (CD38, ZAP-70, and IGHV mutational status) and gene expression profiles (GEP) of leukemic cells from CLL patients included in a prospective multicenter observational study (O-CLL1-GISL protocol, clinicaltrial.gov ID:NCT00917549) were used to assess the value and reproducibility of this score. To date, 468 Binet A patients were classified as low- (0 positive marker), intermediate- (1 positive marker), or high-risk (2 or 3 positive markers) using the progression risk score. The 3-year PFS probability was 91.7%, 82.9%, and 57.4% for low-, intermediate-, and high-risk (P < 0.0001) cases, respectively. These values were similar to those found in the original cohort. At Cox multivariate analysis, Rai stage, absolute lymphocyte count, progression risk score, and β-2 microglobulin maintained an independent prognostic impact on PFS. This score remained a predictor of progression when analysis was limited to 371 Rai 0 cases (P < 0.0001). Finally, the cells from the different CLL risk groups showed differences in their gene expression patterns. These results confirm the ability of this progression risk score to predict PFS among Binet A patients. The utility of the score was also extended by demonstrating that it retains prognostic value when applied exclusively to Rai 0 patients. Specific transcriptional patterns were significantly associated with risk groups.