Antibody therapies for lymphoma in children

Use of rituximab in mature, high-grade and advanced-stage pediatric B-lineage non-Hodgkin lymphomas: a systematic review, meta-analysis and the Brazilian reality

Objectives

Rituximab is a valuable agent for treating adult B-cell non-Hodgkin lymphoma (B-NHL), and several studies have tested its efficacy in children with mature, high-grade B-NHL. The aim of the present study was to systematically review the use of rituximab in children and adolescents with high-grade mature B-NHL and to conduct a meta-analysis of the evidence. Since access to this medication in public health systems in low- and middle-income countries is complex, we were also interested in mapping access to it in Brazil.

Methods

We conducted a systematic review and meta-analysis on the survival of pediatric patients with mature, high-grade and advanced-stage B-NHL treated with rituximab in combination with chemotherapy in first-line treatment or later. Patients' access to the medication was evaluated through a questionnaire sent to oncologists in Brazilian pediatric oncology centers.

Results

We selected 17 trials, which were subsequently grouped by disease type and line of therapy. In patients receiving first-line treatment, excluding those with primary mediastinal B-cell lymphoma (PMBL), the use of rituximab resulted in (1) better event-free survival [Hazard Ratio of 0.37 (0.22, 0.61); p < 0.01]; (2) a reduced risk of events [odds ratio of 0.44 (0.26-0.76); p = 0.003]; and (3) a reduced risk of death [odds ratio of 0.44 (0.21-0.89); p = 0.02]. In refractory or relapsed (R/R) patients, rituximab use was associated with a decreased chance of death [odds ratio of 0.25 (0.09-0.75); p = 0.01]. Additionally, our survey included 31 Brazilian centers, 63% of which reported bearing the cost of rituximab.

Conclusion

Rituximab improves outcomes in pediatric patients receiving first-line treatment for high-grade B-NHL (except PBML) and overall survival in R/R patients. However, access to rituximab in Brazilian hospitals is currently dependent on centers supporting its economic burden.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42021292912).

WNT974 Inhibits Proliferation, Induces Apoptosis, and Enhances Chemosensitivity to Doxorubicin in Lymphoma Cells by Inhibiting Wnt/β-Catenin Signaling

Background

Upregulation of the Wnt/β-catenin pathway has been demonstrated to promote tumor proliferation and chemoresistance in lymphoma. Our objective was to evaluate the effect of the Wnt/β-catenin pathway inhibitor WNT974 in lymphoma cells.

Material/Methods

Human lymphoma cell lines HUT-78 and BJAB were treated with or without 1 μM WNT974±0.15 μg/L doxorubicin (Dox). Cell viability and proliferation were evaluated by CCK-8 and colony formation assay. Expression of proliferating cell nuclear antigen (PCNA), KI67, and apoptotic-related proteins including Bcl-2, Bax, cleaved-caspase3, and cleaved-caspase9, together with Wnt pathway proteins Wnt, β-catenin, Axin2, and c-Myc, were detected by Western blot analysis. Flow cytometry was used to calculate the ratio of apoptotic cells.

Results

In HUT-78 and BJAB cells, 1 μM WNT974 significantly reduced viability and colony formation. The expression of 2 markers of tumor cell proliferation, protein PCNA and KI67, was also reduced by WNT974. Treatment with 1 μM WNT974 for 48 h increased the rate of cell apoptosis, inhibited the expression of anti-apoptotic protein Bcl-2, and enhanced pro-apoptotic proteins Bax, cleaved-caspase3, and cleaved-caspase9 expression in both cell lines. After treatment with WNT974 plus Dox, cell viability was markedly decreased compared with Dox treatment alone. Mechanistically, WNT974 prevented the expression of Wnt, Axin2, β-catenin, and its target gene c-Myc.

Conclusions

WNT974 effectively treats lymphoma by inhibiting cell proliferation, inducing cell apoptosis, and enhancing chemosensitivity to Dox, and these effects are dependent on blocking Wnt/β-catenin signaling.

Mortality and survival patterns of childhood lymphomas: geographic and age-specific patterns in Southern-Eastern European and SEER/US registration data

Childhood (0-14 years) lymphomas, nowadays, present a highly curable malignancy compared with other types of cancer. We used readily available cancer registration data to assess mortality and survival disparities among children residing in Southern-Eastern European (SEE) countries and those in the United States. Average age-standardized mortality rates and time trends of Hodgkin (HL) and non-Hodgkin (NHL; including Burkitt [BL]) lymphomas in 14 SEE cancer registries (1990-2014) and the Surveillance, Epidemiology, and End Results Program (SEER, United States; 1990-2012) were calculated. Survival patterns in a total of 8918 cases distinguishing also BL were assessed through Kaplan-Meier curves and multivariate Cox regression models. Variable, rather decreasing, mortality trends were noted among SEE. Rates were overall higher than that in SEER (1.02/106 ), which presented a sizeable (-4.8%, P = .0001) annual change. Additionally, remarkable survival improvements were manifested in SEER (10 years: 96%, 86%, and 90% for HL, NHL, and BL, respectively), whereas diverse, still lower, rates were noted in SEE. Non-HL was associated with a poorer outcome and an amphi-directional age-specific pattern; specifically, prognosis was inferior in children younger than 5 years than in those who are 10 to 14 years old from SEE (hazard ratio 1.58, 95% confidence interval 1.28-1.96) and superior in children who are 5 to 9 years old from SEER/United States (hazard ratio 0.63, 95% confidence interval 0.46-0.88) than in those who are 10 to 14 years old. In conclusion, higher SEE lymphoma mortality rates than those in SEER, but overall decreasing trends, were found. Despite significant survival gains among developed countries, there are still substantial geographic, disease subtype-specific, and age-specific outcome disparities pointing to persisting gaps in the implementation of new treatment modalities and indicating further research needs.