Survival following relapse in childhood haematological malignancies diagnosed in 1974-2003 in Yorkshire, UK

Relapse and survival after relapse among children with cancer in Denmark: 2001-2021

BACKGROUND

In recent decades, new first and subsequent lines of anticancer treatment and supportive care have improved survival for children with cancer. We investigated recent temporal changes in the incidence of relapse and survival after relapse among children with cancer in Denmark.

PROCEDURE

This register-based study included 2890 children diagnosed before age 15 years with haematological cancers and solid tumours (2001-2021) and central nervous system (CNS) tumours (2010-2021). We used the Aalen-Johansen and Kaplan-Meier estimators to assess cumulative incidence of relapse-defined as cancer recurrence or progression-and survival probability after relapse.

RESULTS

Comparing the periods 2001-2010 and 2011-2021, the 5-year cumulative incidence of relapse decreased from 14% to 11% among children with haematological cancers (p = .07), and from 21% to 18% among children with solid tumours (p = .26). Concurrently, the 5-year survival after relapse increased among children with haematological cancers (from 44% to 61%, p = .03) and solid tumours (from 38% to 46%, p = .25). Among children with malignant CNS tumours, the 5-year cumulative incidence of relapse and the 5-year survival after relapse remained stable (49% and 51%, p = .82; and 20% and 18%, p = .90) comparing 2010-2015 and 2016-2021.

CONCLUSIONS

In recent decades in Denmark, improvements were observed in reducing relapse incidence and increasing survival after relapse in children with haematological cancers and solid tumours. However, the persistent survival gap between children who relapse and those who do not across all childhood cancers underlines the need for intensified and highly targeted treatments for children at high risk of relapse.

Incidence and survival of childhood bone cancer in northern England and the West Midlands, 1981-2002

There is a paucity of population-based studies examining incidence and survival trends in childhood bone tumours. We used high quality data from four population-based registries in England. Incidence patterns and trends were described using Poisson regression. Survival trends were analysed using Cox regression. There were 374 cases of childhood (ages 0-14 years) bone tumours (206 osteosarcomas, 144 Ewing sarcomas, 16 chondrosarcomas, 8 other bone tumours) registered in the period 1981-2002. Overall incidence (per million person years) rates were 2.63 (95% confidence interval (CI) 2.27-2.99) for osteosarcoma, 1.90 (1.58-2.21) for Ewing sarcoma and 0.21 (0.11-0.31) for chondrosarcoma. Incidence of Ewing sarcoma declined at an average rate of 3.1% (95% CI 0.6-5.6) per annum (P=0.04), which may be due to tumour reclassification, but there was no change in osteosarcoma incidence. Survival showed marked improvement over the 20 years (1981-2000) for Ewing sarcoma (hazard ratio (HR) per annum=0.95 95% CI 0.91-0.99; P=0.02). However, no improvement was seen for osteosarcoma patients (HR per annum=1.02 95% CI 0.98-1.05; P=0.35) over this time period. Reasons for failure to improve survival including potential delays in diagnosis, accrual to trials, adherence to therapy and lack of improvement in treatment strategies all need to be considered.

Childhood leukaemia: long-term excess mortality and the proportion 'cured'

Survival from childhood leukaemia has increased, but the proportion of children cured is unknown. The proportion 'cured' is defined as the proportion of survivors for whom, as a group, there is no longer excess mortality compared to the general population. Average time to cure is defined as the time since diagnosis at which the excess mortality rate has declined to or below a predetermined small value. Data on children diagnosed with leukaemia during 1971-2000 in Great Britain were used to estimate trends in survival, the proportion cured and the average time to cure. Five-year survival for all types of leukaemia combined rose from 33 to 79% by 2000. The percentage cured rose from 25 to 68% by 1995; it is predicted to increase to 73% for those diagnosed more recently. Average time to cure increased from 12 years (95% confidence interval (CI): 11-14) to 19 years (95% CI: 14-26) for lymphoid leukaemia (average annual increase of 0.3 years; P<0.001), but remained at about 5 years for acute nonlymphoblastic leukaemia. The proportion of children cured of leukaemia has risen dramatically, but the period of excess mortality associated with lymphoid leukaemia has also increased, possibly because of late relapse, secondary malignancy and toxicity from treatment.