Declining treatment-related and overall mortality in children with newly diagnosed advanced-stage non-Hodgkin lymphoma treated in a paediatric cancer centre during 2013-2024, Shanghai, China.

Little is known about overall and treatment-related mortality (TRM) in children with non-Hodgkin lymphoma (NHL) in upper-middle-income countries (UMICs). A retrospective cohort of children with advanced-stage NHL diagnosed and treated in a large paediatric cancer centre in Shanghai, China, was analysed. The 3-year overall mortality and TRM cumulative incidence were 11.20% ± 1.44% and 2.11% ± 0.65% respectively. Patients diagnosed in the late period (2020-2024) had lower overall mortality (7.18% ± 1.88% vs. 14.45% ± 2.12%, p = 0.006) and TRM (0.46% ± 0.46% vs. 3.60% ± 1.12%, p = 0.019) rates compared with those diagnosed in the early period (2013-2019), primarily driven by the progress in supportive care. The outcome for patients suffering disease relapse/refractory remained poor (18-month overall mortality: 45.60% ± 10.69% during 2020-2024 vs. 57.07% ± 8.18% during 2013-2019, p = 0.162). However, the growing availability of novel therapies may motivate curative salvage treatment, leading to less treatment abandonment (0.0% vs. 26.1%, p = 0.042) and lower 3-month overall mortality (4.35% ± 4.25% vs. 34.36% ± 7.47%, p = 0.007) in the late period. The increasing trend of salvage TRM in this subgroup (13.26% ± 7.34% vs. 2.74% ± 2.74%, p = 0.107) suggested that the survival benefits of salvage treatment may be offset by treatment toxicity. These findings indicate that children with NHL in UMICs can achieve comparable overall mortality and TRM to those in high-income countries with standard treatment and appropriate supportive care.