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

Complete prevalence and indicators of cancer cure: enhanced methods and validation in Italian population-based cancer registries

Objectives

To describe the procedures to derive complete prevalence and several indicators of cancer cure from population-based cancer registries.

Materials and methods

Cancer registry data (47% of the Italian population) were used to calculate limited duration prevalence for 62 cancer types by sex and registry. The incidence and survival models, needed to calculate the completeness index (R) and complete prevalence, were evaluated by likelihood ratio tests and by visual comparison. A sensitivity analysis was conducted to explore the effect on the complete prevalence of using different R indexes. Mixture cure models were used to estimate net survival (NS); life expectancy of fatal (LEF) cases; cure fraction (CF); time to cure (TTC); cure prevalence, prevalent patients who were not at risk of dying as a result of cancer; and already cured patients, those living longer than TTC at a specific point in time. CF was also compared with long-term NS since, for patients diagnosed after a certain age, CF (representing asymptotical values of NS) is reached far beyond the patient's life expectancy.

Results

For the most frequent cancer types, the Weibull survival model stratified by sex and age showed a very good fit with observed survival. For men diagnosed with any cancer type at age 65-74 years, CF was 41%, while the NS was 49% until age 100 and 50% until age 90. In women, similar differences emerged for patients with any cancer type or with breast cancer. Among patients alive in 2018 with colorectal cancer at age 55-64 years, 48% were already cured (had reached their specific TTC), while the cure prevalence (lifelong probability to be cured from cancer) was 89%. Cure prevalence became 97.5% (2.5% will die because of their neoplasm) for patients alive >5 years after diagnosis.

Conclusions

This study represents an addition to the current knowledge on the topic providing a detailed description of available indicators of prevalence and cancer cure, highlighting the links among them, and illustrating their interpretation. Indicators may be relevant for patients and clinical practice; they are unambiguously defined, measurable, and reproducible in different countries where population-based cancer registries are active.

Temporal trends in the proportion of "cure" in children, adolescents, and young adults diagnosed with chronic myeloid leukemia in England: A population-based study

BACKGROUND

Survival probability in children, adolescents, and young adults with chronic myeloid leukemia (CML) has dramatically improved during recent years. Tyrosine kinase inhibitors (TKI), targeted drugs developed for patients with CML, were introduced in 2001 in England. We here quantify the trends in the "cure" proportion according to the year of diagnosis.

METHODS

We included all children, adolescents, and young patients with CML (0 to 24 years) diagnosed in England during 1980 to 2005. We fitted mixture cure models to estimate the "cure" proportion and the median survival time among the "uncured" patients according to the year of diagnosis, adjusted for age at diagnosis.

RESULTS

The "cure" proportion increased dramatically between 1980 and 2005, from under 10% to over 80%, while conversely, the median survival time of "uncured" patients decreased slightly between 1980 and 1999, with the trend from 2000 being uncertain.

CONCLUSIONS

The striking improvement of the "cure" fraction in young patients with CML since the early 1980s is concomitant with improvement of treatment, especially the allogeneic hematopoietic stem-cell transplant and, later, the introduction of TKI. The trends over the last years (2000-2005) remain, however, uncertain and would benefit from further studies with more recent data and updated follow-up.

Sentinel Amenable Mortality: A New Way to Assess the Quality of Healthcare by Examining Causes of Premature Death for Which Highly Efficacious Medical Interventions Are Available

BACKGROUND

Amenable mortality, or premature deaths that could be prevented with medical care, is a proven indicator for assessing healthcare quality when adapted to a country or region's specific healthcare context. This concept is currently used to evaluate the performance of national and international healthcare systems. However, the levels of efficacy and effectiveness determined using this indicator can vary greatly depending on the causes of death that are included. We introduce a new approach by identifying a subgroup of causes for which there are available treatments with a high level of efficacy. These causes should be considered sentinel events to help identify limitations in the effectiveness and quality of health provision.

METHODS

We conducted an extensive literature review using a list of amenable causes of death compiled by Spanish researchers. We complemented this approach by assessing the time trends of amenable mortality in two high-income countries that have a similar quality of healthcare but very different systems of provision, namely, Spain and the United States. This enabled us to identify different levels of efficacy of medical interventions (high, medium, and low). We consulted a group of medical experts and combined this information to help make the final classification of sentinel amenable causes of death.

RESULTS

Sentinel amenable mortality includes causes such as surgical conditions, thyroid diseases, and asthma. The remaining amenable causes of death either have a higher complexity in terms of the disease or need more effective medical interventions or preventative measures to guarantee early detection and adherence to treatment. These included cardiovascular diseases, diabetes, hypertension, all amenable cancers, and some infectious diseases such as pneumonia, influenza, and tuberculosis.

CONCLUSIONS

Sentinel amenable mortality could act as a good sentinel indicator to identify major deficiencies in healthcare quality and provision and detect inequalities across populations.

Childhood cancer research in Oxford II: The Childhood Cancer Research Group

BACKGROUND

We summarise the work of the Childhood Cancer Research Group, particularly in relation to the UK National Registry of Childhood Tumours (NRCT).

METHODS

The Group was responsible for setting up and maintaining the NRCT. This registry was based on notifications from regional cancer registries, specialist children's tumour registries, paediatric oncologists and clinical trials organisers. For a large sample of cases, data on controls matched by date and place of birth were also collected.

RESULTS

Significant achievements of the Group include: studies of aetiology and of genetic epidemiology; proposals for, and participation in, international comparative studies of these diseases and on a classification system specifically for childhood cancer; the initial development of, and major contributions to, follow-up studies of the health of long-term survivors; the enhancement of cancer registration records by the addition of clinical data and of birth records. The Group made substantial contributions to the UK government's Committee on Medical Aspects of Radiation in the Environment.

CONCLUSION

An important part of the ethos of the Group was to work in collaboration with many other organisations and individuals, both nationally and internationally: many of the Group's achievements described here were the result of such collaborations.

Improving access to novel agents for childhood leukemia

Leukemia is the most common pediatric cancer. Despite great progress in the development of curative therapy, leukemia remains a leading cause of death from disease in childhood, and survivors are at life-long risk of complications of treatment. New agents are needed to further increase cure rates and decrease treatment-associated toxicities. The complex biology and aggressive nature of childhood leukemia, coupled with the relatively small patient population available for study, pose specific challenges to the development of new therapies. In this review, the authors discuss strategies and initiatives designed to improve access to new agents in the treatment of pediatric leukemia.

Recruitment of childhood leukaemia patients to clinical trials in Great Britain during 1980-2007: variation by birth weight, congenital malformation, socioeconomic status and ethnicity

OBJECTIVE

To assess recruitment of children to national clinical trials for acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in Great Britain during 1980-2007 and describe variation by some factors that might influence trial entry.

DESIGN AND SETTING

Records of leukaemia patients aged 0-14 years at diagnosis were identified in the National Registry of Childhood Tumours and linked to birth registrations, Children's Cancer and Leukaemia Group records, Hospital Episode Statistics and Medical Research Council clinical trial registers. Trial entry rates were compared between categories of birth weight, congenital malformation, socioeconomic status and ethnicity.

RESULTS

9147 ALL and 1466 AML patients were eligible for national clinical trials during 1980-2007. Overall recruitment rates were 81% and 60% respectively. For ALL, rates varied significantly with congenital malformation (Down syndrome 61%, other malformations 80%, none 82%; p<0.001) and ethnicity (South Asian 78%, other minority groups 80%, white 85%; p<0.001). For AML, rates varied with birth weight (< 2500 g 48%, 2500-4000 g 69%, >4000 g 67%; p=0.001) and congenital malformation (Down syndrome 28%, other malformations 56%, none 63%; p<0.001).

CONCLUSIONS

Although recruitment rates to clinical trials for childhood leukaemia are high, future trials should monitor possible variation by birth weight, ethnicity and presence of congenital malformations.

Metabolic syndrome and cardiovascular risk among long-term survivors of acute lymphoblastic leukaemia - From the St. Jude Lifetime Cohort

Adult survivors of childhood acute lymphoblastic leukaemia (ALL) have a four-fold excess risk of mortality from cardiovascular disease. This cardiovascular risk has not been fully characterized. ALL survivors [n = 784, median age 31·7 years (18·9-59·1)] in the St. Jude Lifetime Cohort Study underwent evaluation for cardiovascular risk and metabolic syndrome (MetS) according to National Cholesterol Education Program - Adult Treatment Panel III criteria. Comparisons were made to 777 age-, sex-, and race-matched controls from the National Health and Nutrition Examination Survey (NHANES). MetS was identified in 259 survivors (33·6%) and associated with older age in 5-year increments (relative risk [RR] 1·13, 95% confidence interval [CI] 1·06-1·19) and prior cranial radiotherapy (CRT) (with craniospinal radiation: RR 1·88, 95%CI 1·32-2·67; without: RR 1·67, 95%CI 1·26-2·23). Measures of obesity were highly prevalent among female survivors and CRT recipients. Compared to NHANES controls, ALL survivors had a higher risk of MetS (RR 1·43, 95%CI 1·22-1·69), hypertension (RR 2·43, 95%CI 2·06-2·86), low high-density lipoprotein (RR 1·40, 95%CI 1·23-1·59), obesity (RR 1·47, 95%CI 1·29-1·68) and insulin resistance (1·64, 95%CI 1·44-1·86). This large study of clinically evaluated ALL survivors identified a high prevalence of MetS, obesity and cardiovascular risk, particularly in CRT recipients, underscoring the need for screening and aggressive reduction of modifiable risks.

Cancer survival: global surveillance will stimulate health policy and improve equity

Millions of people will continue to be diagnosed with cancer every year for the foreseeable future. These patients all need access to optimum health care. Population-based cancer survival is a key measure of the overall effectiveness of health systems in management of cancer. Survival varies very widely around the world. Global surveillance of cancer survival is needed, because unless these avoidable inequalities are measured, and reported on regularly, nothing will be done explicitly to reduce them.

Site-specific proportion cured models applied to cancer registry data

PURPOSE

Proportion-cured models were applied to evaluate their applicability on data from a relatively small cancer registry and to assess the up-to-date survival level of major cancer types in Tyrol, Austria.

METHODS

In total, the 25 most common types of cancer were analyzed with mixture cure models using the period approach for estimation of the proportion cured and median survival time of the fatal cases.

RESULTS

For several of the cancer types, no estimates could be obtained. The models converged for 14 sites among females and for 15 among males. The highest estimate of the proportion cured was found for cervix cancer (74.0 %; 95 % CI 64.4-83.6) and the lowest for male pancreas cancer (4.6 %; 95 % CI 0.2-9.0). The highest median survival of the uncured was 2.7 years (95 % CI 1.2-6.0) for male larynx cancer and the lowest 0.3 years (95 % CI 0.1-0.6) for male acute myeloblastic leukemia (AML).

CONCLUSIONS

The estimates seem reliable for stomach, colon, rectum, pancreas, lung, cervix, ovary, central nervous system/brain and AML cancer and among men also for head/neck, esophagus, liver and kidney cancer. Altogether, it is demonstrated that even data from a regional cancer registry covering a rather small region can be utilized to derive up-to-date survival estimates of various cancer types, enabling monitoring of the development and changes in cancer treatment. Moreover, potentially this methodology is advantageously employable in any situation where the number of cancer cases is limited.

Survival and cure trends for European children, adolescents and young adults diagnosed with acute lymphoblastic leukemia from 1982 to 2002

Proportion cured is a potentially more informative cancer outcome measurement than 5-year survival. We present population-based estimates of cure for young patients diagnosed with acute lymphoblastic leukemia in Europe from 1982 to 2002. Thirty-five European cancer registries provided data. Survival was estimated by age, period of diagnosis and European region, and used as input for parametric cure models, which assume cured patients have the same mortality as the general population. For acute lymphoblastic leukemia diagnosed in 1-14 year olds in 2000-2002, over 77% were estimated cured. The proportion cured improved significantly over the study period: an impressive 26-58% in infants (up to 1 year), 70-90% in 1-4 year olds, 63-86% in 5-9 year olds, 52-77% in 10-14 year olds, and 44-50% in 15-24 year olds. Regional variations in proportion cured reduced over time for 1-14 year-olds, but persisted in infants and 15-24 year olds. Five-year survival was always slightly higher than proportion cured. Considerable proportions of young patients were estimated cured of acute lymphoblastic leukemia. Nevertheless, a small excess risk of death persisted beyond five years after diagnosis when patients remained at risk for late treatment effects, late relapses and second primaries.

Cancer in childhood, adolescence, and young adults: a population-based study of changes in risk of cancer death during four decades in Norway

PURPOSE

Cancer is one of the most common causes of death among young individuals. The purpose of this study was to explore the risk of early death (the first five years after diagnosis) among children (0-14 years), adolescents (15-19 years), and young adults (20-24 years) with cancer in Norway, born during 1965-1985.

METHODS

The overall and cancer-specific early deaths were explored by linking population-based national registers (including the Cancer Registry of Norway and the Cause of Death Registry) that include the entire population of Norway (approximately 1.3 million individuals). Hazard and sub-hazard ratios were estimated using Cox regression analyses and competing risk models.

RESULTS

A total of 5,828 individuals were diagnosed with cancer (56.3 % males). During follow-up, 1,415 individuals died from cancer (60.2 % males) within five years after diagnosis. The hazard ratio (HR) of overall death of the cancer patients relative to the general population decreased from 1965 (from HR, 385.8 (95 % confidence interval (CI): 335.3, 443.4) in 1965-74 to HR, 19.7 (CI: 9.3, 41.5) in 2005-09). Over all, there were fewer cancer-related deaths among female compared with male patients (sub-hazard ratio (SHR), 0.83 (CI: 0.74, 0.92)). Except for all hematopoietic malignancies, adolescents and young adult patients had lower risk of cancer death than children.

CONCLUSION

The difference in risk of cancer and overall deaths between the cancer patients and the general population has been substantially reduced since 1965.

Place of death and hospital care for children who died of cancer in England, 1999-2006

AIM

To describe patterns of hospital care and to evaluate factors influencing place of death for children who died after a diagnosis of cancer in England during 1999-2006.

MATERIALS AND METHODS

Registrations of children on the National Registry of Childhood Tumours (NRCT) who were diagnosed with cancer and died during 1999-2006 in England were linked to the Hospital Episode Statistics (HES) and to death certificates. Multivariable logistic modelling was used to assess factors that influence dying at home or in hospital.

RESULTS

1864 (96%) of children with cancer registrations were linked to HES records. The validation of hospital as a place of death and ethnicity between data sources was good, although anomalies within HES data exist. Similar proportions of children are dying at home (45%) and in hospital (47%), and the percentage dying in a hospice or care home increased from 2% to 10%. Of the children who died in hospital, 74% were admitted as emergencies or as a transfer from another hospital. Greater proportions of children were diagnosed with a leukaemia or lymphoma, those dying within six months of diagnosis, Asian and Black children, those from a deprived background and those not treated in a CCLG centre died in a hospital.

CONCLUSIONS

Patterns of hospital care varied considerably by type of cancer, death within six months of diagnosis, ethnicity and deprivation. Further research is required to elucidate explanations for these patterns and to evaluate methods to increase the proportion of children dying at home who wish to do so.

Adverse effects of treatment in childhood acute lymphoblastic leukemia: general overview and implications for long-term cardiac health

Survival of childhood acute lymphoblastic leukemia (ALL) is one of the greatest medical success stories of the last four decades. Unfortunately, childhood ALL survivors experience medical late effects that increase their risk of morbidity and premature death, often due to heart and vascular disease. Research has helped elucidate the mechanisms and trajectory of direct damage to the heart from treatment exposure, particularly to anthracyclines, and has also contributed knowledge on the influences of related chronic conditions, such as obesity and insulin resistance on heart health in these survivors. This article summarizes the key issues associated with early morbidity and mortality from cardiac-related disease in childhood ALL survivors and suggests directions for interventions to improve long-term outcomes.