Prognostic relevance of CD20 in adult B-cell precursor acute lymphoblastic leukemia

The different predictive effects of the intensity and proportion of CD20 expression on the prognosis of B-lineage acute lymphocyte leukemia

The prognostic effects of the CD20 positivity have been studied extensively in B-lineage acute lymphocyte leukemia (B-ALL) patients, but the results remain controversial. The aim of this study is to investigate the different predictive effects of the intensity and proportion of CD20 expression on the prognosis for B-ALL patients by retrospective analysis. The mean fluorescence intensity (MFI) and percentage of CD20 on B-ALL cells from 206 patients with B-ALL were dynamically measured by flow cytometry, and their optimal cut-off values were determined using the receiver operating characteristic curve. Changes in MFI and percentage of CD20 at various time points and their relationship with prognosis were analyzed. We found that a low baseline CD20 MFI or high CD20 proportion was significantly associated with shorter 5-year overall survival and progression-free survival, and the combination of these two factors could more accurately predict worse survival for B-ALL patients. Furthermore, low CD20 MFI or a high CD20 proportion had different predictive effects for ALL patients with different clinical characteristics and could serve as an independent risk factor for adverse prognosis. There were significant decreases in both the intensity and proportion of CD20 after recurrence in the absence of rituximab treatment, particularly with CD20 intensity. Notably, the decrease of CD20 intensity after recurrence indicated a more shortened survival time. Finally, we conclude that a low intensity or high proportion of CD20 expression may be used as an indicator for inferior prognosis for B-ALL patients. CD20 intensity is more likely to be a more universal biomarker for worse prognosis.

[CD20 is not a poor prognostic factor for childhood B-lineage acute lymphoblastic leukemia with high white blood cell count]

OBJECTIVE

To study the significance of CD20 combined with white blood cell (WBC) count at diagnosis in the prognosis assessment in children with B-lineage acute lymphoblastic leukemia (ALL).

METHODS

A retrospective analysis was performed on the medical data of 821 B-ALL children who were treated with CCLG-ALL2008 regimen from April 2008 to April 2015. Their survival status was followed up.

RESULTS

Among the 821 children, 547 (66.6%) were negative, while 274 (33.4%) were positive for CD20 expression. Among 694 children with WBC<50×10⁹/L (lower WBC count), the 5-year EFS rates were 65.9%±3.2% and 77.3%±2.0% for CD20 positive and negative patients respectively (P=0.001); the 5-year OS rates were 78.3%±2.9% and 87.5%±1.6% for CD20 positive and negative patients respectively (P=0.005); CD20 positive expression was an independent risk factor for EFS (HR=1.634, P=0.001) and OS (HR=1.761, P=0.005). Among 127 children with WBC>50×10⁹/L (higher WBC count), the 5-year EFS rates was 64.3%±7.7% and 53.7%±5.5% for CD20 positive and negative patients respectively (P=0.135); the 5-year OS rate was 81.4%±6.4% and 58.6%±5.6% for CD20 positive and negative patients respectively (P=0.022); CD20 positive expression was an independent protective factor for OS (HR=0.367, P=0.016).

CONCLUSIONS

In children with B-ALL who are treated with CCLG-ALL2008 regimen, those with CD20 positive expression in lower WBC count at diagnosis have a poor prognosis; however, those with CD20 positive expression in higher WBC count at diagnosis have a better long-time survival.

[CD20 is not a poor prognostic factor for childhood B-lineage acute lymphoblastic leukemia with high white blood cell count]

OBJECTIVE

To study the significance of CD20 combined with white blood cell (WBC) count at diagnosis in the prognosis assessment in children with B-lineage acute lymphoblastic leukemia (ALL).

METHODS

A retrospective analysis was performed on the medical data of 821 B-ALL children who were treated with CCLG-ALL2008 regimen from April 2008 to April 2015. Their survival status was followed up.

RESULTS

Among the 821 children, 547 (66.6%) were negative, while 274 (33.4%) were positive for CD20 expression. Among 694 children with WBC<50×109/L (lower WBC count), the 5-year EFS rates were 65.9%±3.2% and 77.3%±2.0% for CD20 positive and negative patients respectively (P=0.001); the 5-year OS rates were 78.3%±2.9% and 87.5%±1.6% for CD20 positive and negative patients respectively (P=0.005); CD20 positive expression was an independent risk factor for EFS (HR=1.634, P=0.001) and OS (HR=1.761, P=0.005). Among 127 children with WBC>50×109/L (higher WBC count), the 5-year EFS rates was 64.3%±7.7% and 53.7%±5.5% for CD20 positive and negative patients respectively (P=0.135); the 5-year OS rate was 81.4%±6.4% and 58.6%±5.6% for CD20 positive and negative patients respectively (P=0.022); CD20 positive expression was an independent protective factor for OS (HR=0.367, P=0.016).

CONCLUSIONS

In children with B-ALL who are treated with CCLG-ALL2008 regimen, those with CD20 positive expression in lower WBC count at diagnosis have a poor prognosis; however, those with CD20 positive expression in higher WBC count at diagnosis have a better long-time survival.

Outcome of CD20-positive Adult B-cell Acute Lymphoblastic Leukemia and the Impact of Rituximab Therapy

BACKGROUND

In adult B cell precursor acute lymphoblastic leukemia (BCP-ALL), CD20 expression has generally been associated with an adverse prognosis. Incorporating rituximab to standard of care is found to improve the outcome of CD20⁺ BCP-ALL. The aim of this study is to estimate the prognostic effect of CD20 expression and the impact of rituximab in BCP-ALL in Saudi Arabia.

PATIENTS AND METHODS

We performed a retrospective study of 55 Saudi adult patients with BCP-ALL in King Fahad Specialist Hospital in Dammam from 2008 to 2017.

RESULTS

The proportion of CD20⁺ cases was approximately 55%. Excluding rituximab-treated patients, the 5-year overall survival (OS) rate of CD20⁺ patients was lower than CD20^- patients (56% vs. 66%; P = .62). Among CD20⁺ patients, the proportion that received rituximab was approximately 27%. Comparing CD20⁺ patients with and without rituximab, all patients who received rituximab achieved complete remission (CR) 4 weeks post-induction. The 3-year OS rate (88% vs. 63%; P = .35) and the 2-year event-free survival rate (70% vs. 68%; P = .75) were in favor of rituximab. In univariate and multivariate analyses, CR 4 weeks post-induction is recognized as an independent predictor of outcome. However, differences in survival rates did not have a statistical significance.

CONCLUSION

CD20 expression in adult patients with BCP-ALL seems to be higher in Saudi Arabians than in Caucasians, and it seems to have a tendency towards an inferior outcome in terms of OS. Incorporating rituximab to standard of care seems to improve the outcome in terms of CR, OS, and event-free survival.

Prognostic Effect of CD20 Expression in Adult B-cell Acute Lymphoblastic Leukemia

INTRODUCTION

The expression of the CD20 on adult B-cell acute lymphoblastic leukemia (ALL-B) has generally been associated with a poor prognosis, and several studies have explored the incorporation of rituximab into the therapeutic regimen for adult ALL-B patients, with a positive effect on event-free survival (EFS).

PATIENTS AND METHODS

We analyzed the prognostic value of CD20 expression and the effect of rituximab for the treatment of Hispanic adult ALL-B patients. We performed a retrospective study of 152 ALL-B patients treated from 2009 to 2016. The patient characteristics and treatment outcomes were analyzed according to CD20 expression (CD20⁺ vs. CD20^-), age group, and treatment with rituximab.

RESULTS

CD20 expression was positive for 47.7% of patients (n = 72). Excluding the patients who had received rituximab, the overall survival (OS) was greater for the CD20^- patient subgroup than for the CD20⁺ subgroup (11.2 vs. 6.9 months; 95% confidence interval [CI], 7.43-14.9; P = .008). In the CD20⁺ subgroup, 10 patients (7.2%) received treatment with rituximab, with 100% reaching complete remission (CR) 4 weeks after treatment. In the 18- to 39-year age group, CD20⁺ patients treated with rituximab had EFS and OS that was not reached. In addition, for CD20⁺ patients who received with chemotherapy, EFS was 3.9 months (95% CI, 0.6-7.2 months; P = .025) and OS was 7.2 months (95% CI, 3.37-11.0; P = .013). Multivariate analysis showed that the use of rituximab was independently associated with OS and CR at 4 weeks after induction.

CONCLUSION

CD20 expression in adult ALL-B is associated with decreased OS. Treatment with rituximab can increase OS, EFS, and CR in the 18- to 39-year age group.

CD20 expression sub-stratifies standard-risk patients with B cell precursor acute lymphoblastic leukemia

Patients with standard-risk adult acute lymphoblastic leukemia (ALL) treated with chemotherapy do not have satisfactory outcomes. To more precisely classify ALL patients and optimize treatment, we re-evaluated the risk stratification system by examining CD20 expression and other classic risk factors at diagnosis. We retrospectively analyzed response to induction chemotherapy of 217 consecutive patients with newly diagnosed Philadelphia-negative B cell precursor-ALL. Survival analyses were conducted for the 136 patients who were intended to be treated with chemotherapy alone. Among the 217 patients, 69 (31.8%) were considered standard risk based on age <35 years, white blood cell count <30 × 10⁹/L, absence of central nervous system involvement, and high-risk cytogenetic abnormalities. Seventy-four patients (34.1%) expressed CD20 on ≥20% of leukemia blasts and were considered CD20 positive. We found that fewer CD20-positive than CD20-negative patients achieved durable first complete responses (CR1 ≥3 months) (81.1% vs. 94.9%, P=0.002). Within the standard-risk group, more CD20-negative than CD20-positive patients achieved CR (100% vs. 83.3%, P=0.003) and durable CR1 (100% vs. 82.4%, P=0.014). For patients in the CD20-negative standard-risk, CD20-positive standard-risk, CD20-negative high-risk, and CD20-positive high-risk groups, the 3-year cumulative incidence of relapse was 42.6%, 70.0%, 59.3%, and 69.5%, respectively (P=0.118); the 3-year disease-free survival rates were 52.1%, 0%, 20.7%, and 13.7%, respectively (P=0.006); and the 3-year overall survival rates were 55.8%, 13.8%, 23.6%, and 16.9%, respectively (P=0.006). Our results suggest that patients with CD20-negative standard-risk B cell precursor-ALL have favorable prognosis compared with CD20-positive standard-risk or CD20-negative or -positive high-risk patients. CD20-positive standard-risk ALL patients may need other therapeutic modalities bridging to allogeneic hematopoietic stem cell transplantation.

[Clinical analysis of adult Philadelphia chromosome-positive acute lymphoblastic leukemia with p16 gene deletion]

Objective: To investigate the clinical implications of p16 gene deletion in adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) . Methods: Retrospective analysis of clinical, immunophenotypic, cytogenetics, molecular characteristics and prognosis of 80 newly diagnosed Ph(+) ALL patients with p16 deletion. Results: Of 80 adult Ph(+) ALL, the prevalence of p16 gene deletion was 31.3%. p16 gene deletion carriers frequently accompanied with high WBC counts (WBC≥30×10(9)/L) and CD20 expression. The incidence of complex chromosome abnormality in p16 gene deletion group was higher than that in non-deletion group, with alternations in chromosome 7, 8, 19 and der (22) more frequently observed. There was no difference occurred between patients with or without p16 gene deletion in complete remission (CR) rate following induction chemotherapy combined with tyrosine kinase inhibitors (TKIs) . However, after three cycles of chemotherapy, the MMR and CMR rate in the p16 gene deletion group was lower than patients with wild-type p16 gene (P=0.034, P=0.036) . The p16 gene deletion patients showed no significant differences in MMR, CMR and relapse rate between Imatinib or Dasatinib plus chemotherapy (P>0.05) . Deletion of p16 gene was significantly associated with poor outcomes including worse overall survival (OS) (37.1% vs 54.1%, P=0.037) , lower disease free-survival (DFS) (12.4% vs 45.9%, P=0.026) , and increased cumulative incidence of relapse (P=0.033) . Among the 25 patients with p16 deletion, 14 underwent allo-HSCT and the median survival was 21 months, better than that of patients received chemotherapy alone (12 months) (P=0.030) . Conclusion: This study indicated that deletion of p16 was associated with poor prognosis in adult Ph(+) ALL, and the utility of second-generation TKI (Dasatinib) does not necessarily have an edge on efficacy over Imatinib, but allo-HSCT has the potential of elongating life expectancy. It is an important significance to define the status of p16 in Ph(+) ALL for predicting prognosis and guiding therapy decision-making.

Prognostic stratification improvement by integrating ID1/ID3/IGJ gene expression signature and immunophenotypic profile in adult patients with B-ALL

Background

Survival of adults with B-Acute Lymphoblastic Leukemia requires accurate risk stratification of patients in order to provide the appropriate therapy. Contemporary techniques, using clinical and cytogenetic variables are incomplete for prognosis prediction.

Methods

To improve the classification of adult patients diagnosed with B-ALL into prognosis groups, two strategies were examined and combined: the expression of the ID1/ID3/IGJ gene signature by RT-PCR and the immunophenotypic profile of 19 markers proposed in the EuroFlow protocol by Flow Cytometry in bone marrow samples.

Results

Both techniques were correlated to stratify patients into prognostic groups. An inverse relationship between survival and expression of the three-genes signature was observed and an immunophenotypic profile associated with clinical outcome was identified. Markers CD10 and CD20 were correlated with simultaneous overexpression of ID1, ID3 and IGJ. Patients with simultaneous expression of the poor prognosis gene signature and overexpression of CD10 or CD20, had worse Event Free Survival and Overall Survival than patients who had either the poor prognosis gene expression signature or only CD20 or CD10 overexpressed.

Conclusion

By utilizing the combined evaluation of these two immunophenotypic markers along with the poor prognosis gene expression signature, the risk stratification can be significantly strengthened. Further studies including a large number of patients are needed to confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0506-4) contains supplementary material, which is available to authorized users.

New monoclonal antibodies for the treatment of acute lymphoblastic leukemia

Monoclonal antibodies represent a major advance in treatment of acute lymphoblastic leukemia (ALL). Targeted delivery of these agents based on leukemic cell-surface receptor recognition, improves efficacy and minimizes off-target toxicity. The antigens CD19, CD20, CD22 and CD52, are the most common antigens to which monoclonal antibodies in B-cell ALL have been directed. Rituximab, an anti-CD20 antibody, in combination with conventional chemotherapy has been shown to improve survival in newly diagnosed CD20 positive B-cell ALL. Blinatumomab, a bispecific T-cell engager, as monotherapy in relapsed and refractory B-cell ALL resulted in prolonged relapse free survival. Inotuzumab ozogamicin, an anti-CD22 antibody, alone and in combination with chemotherapy has been promising in relapsed and refractory B-cell ALL. The effectiveness and safety of several newer monoclonal antibodies including ofatumumab, obinutuzumab, epratuzumab, denintuzumab mafodotin and moxetumomab pasudotox as single agents or in combination with a chemotherapeutic back bone are currently under investigation.

Correlation between deletion of the CDKN2 gene and tyrosine kinase inhibitor resistance in adult Philadelphia chromosome-positive acute lymphoblastic leukemia

BACKGROUND

Frequency relapses are common in Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukemia (ALL) following tyrosine kinase inhibitors (TKIs). CDKN2A/B is believed to contribute to this chemotherapy resistance.

METHODS

To further investigate the association between CDKN2 status and TKI resistance, the prevalence of CDKN2 deletions and its correlation with a variety of clinical features was assessed in 135 Ph-positive ALL patients using interphase fluorescence in situ hybridization (I-FISH).

RESULTS

Results showed that no difference occurred between patients with CDKN2 deletion (44/135) and wild-type patients in sex, age, and complete remission (CR) rate following induction chemotherapy combined with tyrosine kinase inhibitors (TKIs). However, CDKN2 deletion carriers demonstrated higher white blood cell (WBC) count, enhanced rates of hepatosplenomegaly (P = 0.006), and upregulation of CD20 expression (P = 0.001). Moreover, deletions of CDKN2 resulted in lower rates of complete molecular response (undetectable BCR/ABL), increased cumulative incidence of relapse, short overall survival (OS), and disease-free survival (DFS) time (P < 0.05) even though these patients received chemotherapy plus TKIs followed by allogenic hematopoietic stem cell transplantation (Allo-HSCT). In the case of 44 patients who presented with CDKN2 deletion, 18 patients were treated with dasatinib treatment, and another 26 patients were treated with imatinib therapy, and our study found that there were no differences associated with OS (P = 0.508) and DFS (P = 0.555) between the two groups.

CONCLUSIONS

CDKN2 deletion is frequently acquired during Ph-positive ALL progression and serves as a poor prognostic marker of long-term outcome in Ph-positive ALL patients with CDKN2 deletion even after the second-generation tyrosine kinase inhibitor treatment.

Outcome of B-Cell Acute Lymphoblastic Leukemia in Brazilian Children: Immunophenotypical, Hematological, and Clinical Evaluation

The aim of this study is to investigate the clinical, hematological, and immunophenotypic characteristics of Brazilian children with B-cell acute lymphoblastic leukemia (B-ALL) to identify prognostic biomarkers of the disease. Thirty-three children newly diagnosed with B-ALL were followed between March 2004 and December 2009. Information about the demographic profile, diagnosis, immunophenotype, clinical manifestations, and disease outcome were gathered from the patients' medical records. Of the 33 patients with B-ALL, 18 were male and 15 female. Eighteen patients were classified as high risk; 13 as low risk, and 2 as true low risk. The frequencies of cluster of differentiation (CD)10, CD19, and CD20 antigens were 69.7%, 81.8%, and 18.2%, respectively. Six patients (18.2%) had aberrant expression of myeloid antigens. At diagnosis, patients immunopositive for CD20 had elevated white blood cell counts (P = 0.018) and lower platelet counts (P = 0.017). The 6-year overall survival was 67.5%± 3.47%. Our results demonstrate the distinct immunophenotypic and prognostic characteristics of patients with B-ALL, which can be related to the Brazilian racial admixture. Consequently, these results will most likely aid in the selection of additional prognostic markers and their use in monitoring the clinical manifestations and treatment response among B-ALL patients.

[Clinical features and survival analysis of patients with CD20 positive adult B-lineage acute lymphoblastic leukemia]

OBJECTIVE

To explore the clinical and survival significance of CD20 positive adult patients with B-lineage acute lymphoblastic leukemia (B-ALL).

METHODS

The clinical features and survival of 168 adult patients with B-ALL diagnosed and treated in our department from May 2007 to July 2011 were analyzed retrospectively, 58 expressed CD20 and 110 not.

RESULTS

The sex, distribution of age, anemia, thrombocytopenia, infiltration of liver, spleen and lymph nodes, the expression of myeloid lineage marker, incidence of Ph chromosome, complete remission within 4 weeks showed no significant differences in CD20 positive and negative groups (P>0.05); median white blood cell count at diagnosis and the rate of patients with high white blood cell count in CD20 positive group were 19.2×10⁹/L and 37.9% respectively, which were significantly higher than those of 6.93 × 10⁹/L and 20.9% in CD20 negative group (P<0.05); cumulative incidence of relapse between two groups showed significant difference (P<0.05); multivariable analysis for overall survival and progress-free survival identified CD20 positivity as independent predictor.

CONCLUSION

The expression of CD20 in adult patients with B-ALL appeared to be associated with high white blood cell count and poor prognosis.

Treatment of acute lymphoblastic leukemia in adolescents and young adults

Treatment approaches for adolescents and young adults with acute lymphoblastic leukemia (ALL) have evolved considerably in the past 5-7 years. One of the major changes has been the widespread adoption of pediatric-based protocols, which appears to have significantly improved survival and probably renders allogeneic hematopoietic stem cell transplantation (HSCT) unnecessary in most standard-risk patients. However, high-risk patients, such as those with BCR-ABL or MLL rearrangements or high white count presentations, should still be referred for HSCT in CR-1. Minimal residual disease positivity has also been identified as a high-risk feature. Patients with BCR-ABL-positive ALL should receive combined therapy with a tyrosine kinase inhibitor and chemotherapy prior to HSCT. The adoption of pediatric-based regimens has been associated with significant additional toxicities, including venous thromboembolism, osteonecrosis, other steroid-related changes, and neuropathy, which can potentially have a major adverse impact on the quality of life of these young ALL patients.

CD20 expression has no prognostic role in Philadelphia-negative B-precursor acute lymphoblastic leukemia: new insights from the molecular study of minimal residual disease

The prognostic significance of CD20 expression in acute lymphoblastic leukemia has been investigated in children and adults but is still a subject of debate. The aim of our study was to correlate CD20 expression with clinical-biological characteristics and outcome in 172 Philadelphia chromosome negative patients prospectively treated in a multicenter trial introducing the molecular evaluation of minimal residual disease for therapeutic purposes. We considered 20% as the threshold for CD20 positivity. Complete remission rate, minimal residual disease negativity rate at weeks 10, 16 and 22, and disease-free and overall survival were similar among CD20-positive and -negative patients, even considering minimal residual disease results and related therapeutic choices. Our study failed to demonstrate any prognostic significance for CD20 expression in Philadelphia chromosome negative acute lymphoblastic leukemia. This conclusion is supported for the first time by a comparable minimal residual disease response rate among CD20-positive and -negative and positive patients.