Treatment of Monomorphic Posttransplant Lymphoproliferative Disorder in Pediatric Solid Organ Transplant: A Multicenter Review.

Posttransplant lymphoproliferative disorder (PTLD) is the most common posttransplant malignancy in children. We reviewed data from 3 Canadian pediatric centers to determine patient characteristics, treatment approaches, and outcomes for children with monomorphic PTLD. There were 55 eligible children diagnosed between January 2001 to December 2021. Forty-eight patients (87.2%) had B-cell PTLD: Burkitt lymphoma (n = 25; 45.4%) and diffuse large B-cell lymphoma (n = 23; 41.2%), the remainder had natural killer (NK)/T-cell lymphoma (n = 5; 9.1%), Hodgkin lymphoma (n = 1;1.8%), or other (n = 1;1.8%). Thirty-nine (82.1%) patients with B-cell PTLD were treated with rituximab and chemotherapy with or without a reduction in immunosuppression (reduced immune suppression). The chemotherapy used was primarily one of 2 regimens: Mature Lymphoma B-96 protocol in 22 patients (56.4%) and low-dose cyclophosphamide with prednisone in 14 patients (35%). Most patients with T/NK-cell lymphoma were treated with reduced immune suppression + chemotherapy (n = 4; 80%). For all patients with monomorphic PTLD, the projected 3-year event-free survival/3-year overall survival was 62% and 77%, respectively. Of the patients, 100% with T/NK-cell PTLD 100% progressed or relapsed and, subsequently, died of disease. For patients with B-cell PTLD, there was no significant difference in outcome between the two main chemotherapy regimens employed.

Comparison of Sodium Bicarbonate and Lactated Ringers Hydration for High-dose Methotrexate Chemotherapy in Children.

BACKGROUND: High-dose methotrexate is part of the treatment of pediatric cancers. To reduce the risk of toxicity, supportive measures, including hydration and alkalinization, are recommended. At our institution, we switched from intravenous sodium bicarbonate to Lactated Ringers during a worldwide shortage. PROCEDURE: This was a retrospective cohort of children who received high-dose methotrexate from January 1, 2016 to August 31, 2018. The primary outcome was the prevalence of delayed methotrexate clearance. Secondary outcomes were proportion of cycles with delayed methotrexate clearance, time to methotrexate clearance, adverse events, risk factors for delayed clearance, and association between hydration type and delayed clearance. RESULTS: Eighty-two patients, with a total of 325 methotrexate cycles, were included. Forty-four patients received sodium bicarbonate, 31 received Lactated Ringers, and 7 received both. There was no difference in the prevalence of delayed methotrexate clearance between those who received sodium bicarbonate and Lactated Ringers (64% vs. 68%). The proportion of cycles with delayed methotrexate clearance, time to methotrexate clearance, and adverse events were similar between groups. Cancer type, methotrexate dose, and vomiting were associated with delayed clearance. CONCLUSIONS: Our study suggests that Lactated Ringers may be used in place of sodium bicarbonate for intravenous hydration during high-dose methotrexate.

Incidence of childhood cancer in Namibia: the need for registries in Africa.

INTRODUCTION: Childhood cancer is rare and comprises only 1% of all cancers. The current incidence of childhood cancer in Namibia, as in many other African countries, is not known. The aim of this research was to assess the paediatric cancer incidence between 2003-2010 at Windhoek Central Hospital, the only pediatric oncology-referring centre in Namibia and to compare with the previous calculated incidence in the country 20 years ago. METHODS: A retrospective, descriptive review of the paediatric oncology cases presenting to Windhoek Central Hospital between 2003 and 2010 was undertaken, and data regarding age, sex, cancer type, area of residence were extrapolated. In this study due to the appearance of the HIV epidemic, an HIV incidence was also calculated. RESULTS: The incidence rate of all paediatric recorded cancers was 29.4 per million. Leukaemias (22.5%) and retinoblastomas (16.2%) were the most common tumours, with renal tumours, soft tissue sarcomas and lymphomas following in frequency. HIV incidence of children with malignancy was 6.8%. CONCLUSION: The incidence rates of cancers in this study are remarkably lower compared to a similar study done in the country 20 years ago. Many cancers are still not diagnosed or reported, and others are not treated in the country. The institution of a "twinning programme" between the paediatric haematological/oncological departments in Windhoek and Tygerberg Hospital in Cape Town, South Africa, will contribute to improvement of childhood cancer cases. This twinning programme includes the formation of a cancer registry.