Advanced Burkitt Lymphoma in Sub-Saharan Africa Pediatric Units: Results of the Third Prospective Multicenter Study of the Groupe Franco-Africain d'Oncologie Pédiatrique

The feasibility of implementing Toronto childhood cancer stage guidelines and estimating the impact on outcome for childhood cancers in seven pediatric oncology units in sub-Saharan Africa. A study from the Franco-African Pediatric Oncology Group

BACKGROUND

The improvement of childhood cancer outcome is determined by early diagnosis, effective treatment, supportive care, and adequate medical follow-up. Stage at diagnosis may reflect timeliness of diagnosis, therefore standardized registration of stage is essential for interpretation of regional differences and time trends in survival. Here, we describe the feasibility of implementing the Toronto Childhood Cancer Stage Guidelines (hereafter Toronto Guidelines [TG]) in the hospital-based cancer registry of the Franco-African Pediatric Oncology Group (GFAOP), and assess the impact of TG stage on outcome in pediatric oncology units (POUs) in seven low- and middle-income countries in sub-Saharan Africa (SSA).

METHODS

All cancer patients diagnosed before 15 years of age with one of the 15 cancer types defined in TG, resident in one of the participating countries, and attending one of the selected POUs in 2017-2019 were included. Stage was assigned according to TG. Patients were followed-up for vital status for at least 12 months post diagnosis. Survival at 3, 6, and 12 months was calculated using Kaplan-Meier method and compared between POUs and tumor groups using log-rank test.

RESULTS

TG stage was assigned to 1772 of 2446 (89%) cases diagnosed with one of 11 cancer types. It was not possible to assign TG stage to acute lymphoblastic leukemia (ALL) and the three types of the central nervous system tumors included in the TG. One-year overall survival (OS) was 58% [95% confidence interval: 55-60] and varied between POUs. Survival declined with increasing stage for four tumor types and was statistically significant for two.

CONCLUSION

Except for ALL and brain tumors, we demonstrated feasibility of TG implementation for childhood solid cancers in participating POUs in SSA, and provided a baseline assessment of childhood cancer outcomes against which future stage distribution and survival can be measured as timelines of diagnosis improve over time within the GFAOP network.

Infection-Associated Mortality During Induction Chemotherapy in Group B Intermediate-Risk Pediatric Burkitt's Lymphoma

Background Burkitt's lymphoma (BL) in the pediatric population has significant burden in developing countries. Infection-related complications during the induction chemotherapy phase pose a major challenge and contribute to high mortality rates due to a severely immunocompromised state. However, there is scarce data on the etiologies and optimal management strategies for infection-related mortality in pediatric BL patients, especially in developing countries like Pakistan. Methods This is a cross-sectional study that included a total of 116 pediatric patients with intermediate-risk BL. All patients were treated based on the Children's Cancer and Leukaemia Group (CCLG) 2020 guidelines. Data on patient demographics, presenting symptoms, diagnosis, infectious etiologies, and outcomes were collected. Infection-related complications and mortality were monitored during the induction chemotherapy period. The results of relevant culture reports were tabulated and data were analyzed. Results Among the 116 included patients, 61.1% were males with a mean age of 4.83 ± 2.12 years. Abdominal BL was the most common anatomical location. During the induction period, 66 patients (56.9%) had culture-proven infections, resulting in 33 deaths (28.4%). Fever was the predominant presenting symptom in all patients, followed by vomiting (57.6%), loose stools (42.4%), and cough (18.2%). Neutropenic colitis, sepsis, pneumonia, and meningitis were among the diagnosed infections. Hospital-acquired bacterial infections, including multi-drug resistant gram-negative and gram-positive organisms, were the main cause of mortality, with fungal infections and cytomegalovirus viremia also identified in a few patients. Conclusions This study highlights the urgent need for improved management strategies in pediatric BL patients in Pakistan to reduce infection-related complications and mortality rates, emphasizing the importance of context-specific approaches for infection prevention and management.

Outcomes of Wilms tumor therapy in Lilongwe, Malawi, 2016-2021: Successes and ongoing research priorities

INTRODUCTION

Wilms tumor therapy in low- and middle-income countries (LMICs) relies on treatment protocols adapted to resource limitations, but these protocols have rarely been evaluated in real-world settings. Such evaluations are necessary to identify high-impact research priorities for clinical and implementation trials in LMICs. The purpose of this study was to identify highest priority targets for future clinical and implementation trials in sub-Saharan Africa by assessing outcomes of a resource-adapted treatment protocol in Malawi.

METHODS

We conducted a retrospective cohort study of children treated for Wilms tumor with an adapted SIOP-backbone protocol in Lilongwe, Malawi between 2016 and 2021. Survival analysis assessed variables associated with poor outcome with high potential for future research and intervention.

RESULTS

We identified 136 patients, most commonly with stage III (n = 35; 25.7%) or IV disease (n = 35; 25.7%). Two-year event-free survival (EFS) was 54% for stage I/II, 51% for stage III, and 13% for stage IV. A single patient with stage V disease survived to 1 year. Treatment abandonment occurred in 36 (26.5%) patients. Radiotherapy was indicated for 55 (40.4%), among whom three received it. Of these 55 patients, 2-year EFS was 31%. Of 14 patients with persistent metastatic pulmonary disease at the time of nephrectomy, none survived to 2 years. Notable variables independently associated with survival were severe acute malnutrition (hazard ratio [HR]: 1.9), increasing tumor stage (HR: 1.5), and vena cava involvement (HR: 3.1).

CONCLUSION

High-impact targets for clinical and implementation trials in low-resource settings include treatment abandonment, late presentation, and approaches optimized for healthcare systems with persistently unavailable radiotherapy.

Evaluating the baseline survival outcomes of the "six Global Initiative for Childhood Cancer index cancers" in Africa

Limited survival data for the six Global Initiative for Childhood Cancer (GICC) priority cancers are available in Africa. Management of pediatric malignancies in Africa is challenging due to lack of resources, setting-specific comorbidities, high rates of late presentation and treatment abandonment. Reporting of outcome data is problematic due to the lack of registries. With the aim of evaluating the feasibility of baseline outcomes for the six index cancers, we present a descriptive analysis of respective survival rates in Africa. The survival rates were between 18% (lower middle-income countries) to 82.3% (upper middle-income countries) for acute lymphoblastic leukemia, between 26.9% (low-income countries) to 77.9% (upper middle-income countries) for nephroblastoma, between 23% (low-income countries) to 100% (upper middle-income countries), for retinoblastoma, 45% (low-income countries) to 95% (upper middle-income countries) for Hodgkin lymphoma and 28% (low-income countries) to 76% (upper middle-income countries) for Burkitt lymphoma. Solutions to improve survival rates and reported outcomes include establishing and funding sustainable registries, training and to actively include all countries in consortia from different African regions.HighlightsContinental differences in childhood cancer management such lack of resources, setting-specific comorbidities, high rates of late presentation and treatment abandonment, present challenges to the achievement of Global Initiative for Childhood Cancer goals.The available data registries do not adequately inform on the true incidences and outcomes of childhood cancers in Africa.The pathophysiology of some childhood cancers in Africa are associated with high-risk prognostic factors.Outcomes can be improved by greater regional collaboration to manage childhood cancer based on local resources and tumor characteristics.Some individual countries have reached the Global Initiative for Childhood Cancer goals for single cancers and it should be possible for more African countries to follow suit.

Pediatric Oncology Clinical Trials and Collaborative Research in Africa: Current Landscape and Future Perspectives

PURPOSE

Adequate clinical services have yet to be established in the majority of African countries, where childhood cancer survival rates vary from 8.1% to 30.3%. The aim of this review is to describe the landscape of pediatric oncology trials in Africa, identify challenges, and offer future opportunities for research collaborations.

METHODS

The study includes data from the International Pediatric Oncology Society (SIOP) global mapping survey, meta-research identifying trials in Africa in ClinicalTrials.gov, and a literature overview of publications on the subject of pediatric oncology clinical research supported by expert opinions on the current situation and challenges.

RESULTS

The SIOP global mapping survey received responses from 47 of 54 African countries, of which 23 have active clinical research programs. A preliminary search of ClinicalTrials.gov showed that only 105 (12.1%) of 868 African oncology studies included children and adolescents. Of these, 53 (50.5%) were interventional trials according to the registry’s classification. The small number of African trials for children and adolescents included palliative care and leukemia trials. In African oncology journals and international pediatric oncology journals, < 1% of the pediatric oncology publications come from Africa. Services and research were strengthened by international collaboration. National studies focused on clinical needs, local challenges, or interventional priorities. Both the literature review and the expert opinions highlight the need to expand clinical research in Africa, despite ongoing regional instability and lack of resources.

CONCLUSION

While a low number of pediatric clinical treatment trials are open to African children and adolescents, clinical research of high quality is being done in Africa. Several initiatives are stimulating the development of the research capacity across the continent, which should increase the publication output.

Five decades of low intensity and low survival: adapting intensified regimens to cure pediatric Burkitt lymphoma in Africa

Long-term cure of childhood Burkitt lymphoma (BL) in sub-Saharan Africa after treatment with single-agent cyclophosphamide has been documented for more than half of a century. Contemporary cure rates for the highest-risk patients with BL in high-income countries exceed 90% using intensive multiagent chemotherapy. By contrast, the majority of African children with BL still die. Data spanning 5 decades in Africa have repeatedly shown that the children most likely to achieve cure with limited cyclophosphamide regimens are those with lower-stage disease isolated to the jaw. Attempts to intensify the cyclophosphamide monotherapy backbone with the addition of vincristine, low-dose methotrexate, prednisone, doxorubicin, and/or low-dose cytarabine have not yielded significant improvement. High-dose methotrexate is a critical component in the treatment of childhood BL worldwide. Although initial efforts in Africa to incorporate high-dose methotrexate resulted in high treatment-related mortality, more recent collaborative experiences from North and West Africa, as well as Central America, demonstrate that it can be administered safely and effectively, despite limitations in supportive care resources. Recognizing the unacceptable disparity in curative outcomes for BL between the United States/Europe and equatorial Africa, there is a critical need to safely adapt contemporary treatment regimens to optimize curative outcomes amid the resource limitations in regions where BL is endemic. Here, we critically review reports of BL treatment outcomes from low- and middle-income countries, in addition to data from high-income countries that predated modern intensified regimens, to identify potential strategies to improve the therapeutic approach for children suffering from BL in sub-Saharan Africa.

Immune landscape in Burkitt lymphoma reveals M2-macrophage polarization and correlation between PD-L1 expression and non-canonical EBV latency program

BACKGROUND

The Tumor Microenviroment (TME) is a complex milieu that is increasingly recognized as a key factor in multiple stages of disease progression and responses to therapy as well as escape from immune surveillance. However, the precise contribution of specific immune effector and immune suppressor components of the TME in Burkitt lymphoma (BL) remains poorly understood.

METHODS

In this paper, we applied the computational algorithm CIBERSORT to Gene Expression Profiling (GEP) datasets of 40 BL samples to draw a map of immune and stromal components of TME. Furthermore, by multiple immunohistochemistry (IHC) and multispectral immunofluorescence (IF), we investigated the TME of additional series of 40 BL cases to evaluate the role of the Programmed Death-1 and Programmed Death Ligand-1 (PD-1/PD-L1) immune checkpoint axis.

RESULTS

Our results indicate that M2 polarized macrophages are the most prominent TME component in BL. In addition, we investigated the correlation between PD-L1 and latent membrane protein-2A (LMP2A) expression on tumour cells, highlighting a subgroup of BL cases characterized by a non-canonical latency program of EBV with an activated PD-L1 pathway.

CONCLUSION

In conclusion, our study analysed the TME in BL and identified a tolerogenic immune signature highlighting new potential therapeutic targets.

Burkitt lymphoma: bridging the gap between advances in molecular biology and therapy

Genomic studies have revealed molecular mechanisms involved in the pathogenesis of Burkitt's lymphoma, including the ID3/TCF3-dependent centroblast gene expression program, tonic PI3K-AKT-mTOR signaling, and deregulation of cell cycle and apoptosis through mutations in cyclin D3, CDKN2A, or TP53. Unfortunately, these advances have not been translated into treatment, which relies on dose-intense cytotoxic chemotherapy. While most patients achieve long-term survival, options for relapsed/refractory disease are lacking, as Burkitt lymphoma is often excluded from clinical trials of novel approaches. The lower-intensity, dose-adjusted EPOCH plus rituximab (DA-EPOCH-R) regimen constitutes a major advance allowing for treatment of older and HIV-positive patients but needs augmentation to better address the central nervous system involvement. Furthermore, DA-EPOCH-R provides a platform for the study of targeted or immunotherapeutic approaches while de-escalating cytotoxic agents and their associated adverse effects. In this review we discuss the epidemiology and molecular genetics of BL, first-line treatment considerations, and potential novel treatment strategies.