Treatment-related mortality in children with cancer in low-income and middle-income countries: a systematic review and meta-analysis

Background: Approximately 90% of children with cancer live in low-income and middle-income countries (LMICs), where 5-year survival is lower than 20%. Treatment-related mortality in high-income countries is approximately 3-5%; however, in LMICs, treatment-related mortality has been reported in up to 45% of children with cancer. This study aimed to systematically explore the burden of treatment-related mortality in children with cancer in LMICs and to explore the association between country income level and treatment-related mortality.

Methods: For this systematic review and meta-analysis we identified articles published between Jan 1, 2010, and June 22, 2021, describing treatment-related mortality in paediatric patients (aged 0-21 years) with cancer in LMICs. We searched PubMed, Trip, Web of Science, Embase, and the WHO Global Metric Index databases. The search was limited to full-text articles and excluded case reports (<10 patients) and haematopoietic stem-cell transplantation recipients. Two reviewers independently screened studies for eligibility, extracted data from included publications, and evaluated data quality. Random and mixed-effects models were used to estimate treatment-related mortality burden and trends. The Cochran-Q statistic was used to assess heterogeneity between studies. This study is registered on PROSPERO (CRD42021264849).

Findings: Of 13 269 identified abstracts, 501 studies representing 68 351 paediatric patients with cancer were included. The treatment-related mortality estimate was 6·82% (95% CI 5·99-7·64), accounting for 30·9% of overall mortality (4437 of 14 358 deaths). Treatment-related mortality was inversely related to country income. Treatment-related mortality was 14·19% (95% CI 9·65-18·73) in low-income countries, 9·21% (7·93-10·49) in lower-middle-income countries, and 4·47% (3·42-5·53) in upper-middle-income countries (Cochran-Q 42·39, p<0·0001). In upper-middle-income countries, the incidence of treatment-related mortality decreased over time (slope -0·002, p=0·0028); however, outcomes remained unchanged in low-income (p=0·21) and lower-middle-income countries (p=0·16).

Interpretation: Approximately one in 15 children receiving cancer treatment in LMICs die from treatment-related complications. Although treatment-related mortality has decreased in upper-middle-income countries over time, it remains unchanged in LMICs. There is an urgent need for targeted supportive care interventions to reduce global disparities in childhood cancer survival.

Funding: American Lebanese Syrian Associated Charities and National Cancer Institute.