Acute lymphoblastic leukaemia (ALL) is the commonest cancer in children, with 450 children diagnosed each year in the UK. Treatment for childhood ALL is lengthy and complex and currently continues for two years for girls and three years for boys. The majority of the first nine months of treatment, which is designed to put the child’s disease into remission, is administered in hospital. Crucially, during this period the researchers found no evidence of a difference in survival by social group**.
The disparity appeared to begin 6-9 months after diagnosis and widened after treatment changed from being predominantly hospital administered to being largely the responsibility of parents or carers. This suggests that there may be problems in complying with the complicated home-based maintenance treatment regimens.
The treatment regimens are comprised of daily drug administrations in 12 week cycles, during which the frequency and timing of prescribed doses varies both with the drug and on a day to day basis.*** Keeping to these regimens over several years can be challenging, especially as the children generally appear to be well. However, maintenance drugs are absolutely essential to prevent children relapsing as survival rates for children who relapse remain poor.
The findings from this study provide the first clear evidence in the UK that social disparities exist in relation to childhood leukaemia survival
Dr Tracy Lightfoot
The study from the Epidemiology & Genetics Unit in the Department of Health Sciences at University of York is published online in the European Journal of Cancer. Researchers followed over 1,500 children diagnosed with acute lymphoblastic leukaemia (ALL) for almost 16 years. It found that death rates varied with socio-economic indicators, being higher in children from more deprived families. Importantly, the same study previously demonstrated that there were no differences between social groups with respect to the likelihood of whether or not a child would develop ALL in the first place.
Dr Tracy Lightfoot, of the Department of Health Sciences at the University of York, who led the research, said: “The findings from this study provide the first clear evidence in the UK that social disparities exist in relation to childhood leukaemia survival. Importantly this variation is not due to differential treatment across social groups and was the same when children who were not enrolled in clinical trials were excluded from the analysis.”
Dr David Grant, Scientific Director at the charity Leukaemia & Lymphoma Research, which funded the research, said: “We know every parent wants to do their best for their children. Managing the precise regimen of drugs in the home is stressful for any family caring for a child with leukaemia, especially as the child already appears to be completely cured. We need to do more work to find out what support parents or carers need during the two to three years after their child leaves hospital.
“Thanks to the work of Leukaemia & Lymphoma Research, over 90 per cent of children now survive the most common form of leukaemia. We need to make sure every child is cured and this research suggests that helping with treatment compliance will take us a step towards achieving this.”
The researchers followed the treatment outcome of children diagnosed with ALL from 1991 to 1996 ascertained as part of the United Kingdom Childhood Cancer Study (www.ukccs.org). Children were divided into different social classes, which were either determined by their post-code-based deprivation score at the time of their diagnosis, or by their father’s employment status as recorded at birth.
Notes to editors:
- The research is published online on 13 December in the European Journal of Cancer under the title ‘Survival from childhood acute lymphoblastic leukaemia: the impact of social inequality in the UK’. Principle author: Dr Tracy Lightfoot, Department of Health Sciences, University of York
- *Over the study’s follow-up period, 29.8 per cent of children in the most deprived category died, compared to a 23.2 per cent death rate in the most affluent category. Overall, those in quintiles 4 and 5 were at a greater risk of dying compared to those in quintiles 1 to 3. The, 10-year survival estimates differed by approximately 5% and the hazard ratio was 1.29 (95 per cent confidence interval 1.05-1.57) – meaning that the mortality rate among children from the most deprived areas was, on average, 1.29 times higher than that among those from the least deprived areas. When the analysis was repeated including only children treated in the UKALL XI clinical trial (86% of the total), the hazard ratio was 1.31 (95 per cent confidence interval 1.05-1.64).
- **The five social categories were derived by dividing the continuous deprivation score for national 1991 census enumeration areas into five equally-sized groups, with group one representing the most affluent and group five the least. Postcodes were used to allocate deprivation scores at both diagnosis and at birth (mother’s address taken from the child’s birth certificate). Individual measures of social class were also assigned using father’s employment status and occupation as stated at birth certification
- ***e.g. Mercaptopurine is daily one hour after evening meals, methotrexate weekly, dexamethasone twice daily after food for the first five days every 4 weeks, and co-trimoxazole morning and evening but only on Mondays and Tuesdays. While survival rates for childhood ALL have improved, the home-based maintenance regime has not changed in over a decade.
- Leukaemia & Lymphoma Research is the only UK charity solely dedicated to research into blood cancers, including leukaemia, lymphoma and myeloma. These cancers are diagnosed in around 30,000 children, teenagers and adults in the UK every year. Further information, including patient information booklets, is available from www.beatingbloodcancers.org.uk or on 020 7405 0101. Media information contact Henry Winter at Leukaemia & Lymphoma Research Press Office on 020 7269 9019, 07824 375880 or email: [email protected]
- The University of York’s Department of Health Sciences is a large, multidisciplinary Department with an international reputation for world-class research and high quality teaching. For further information visit www.york.ac.uk/healthsciences.