Tim Eden

An infectious aetiology for childhood acute leukaemia: a review of the evidence

There are three current hypotheses concerning infectious mechanisms in the aetiology of childhood leukaemia: exposure in utero or around the time of birth, delayed exposure beyond the first year of life to common infections and unusual population mixing. No specific virus has been definitively linked with childhood leukaemia and there is no evidence to date of viral genomic inclusions within leukaemic cells. The case–control and cohort studies have revealed equivocal results. Maternal infection during pregnancy has been linked with increased risk whilst breast feeding and day care attendance in the first year of life appear to be protective. There is inconclusive evidence from studies on early childhood infectious exposures, vaccination and social mixing. Some supportive evidence for an infectious aetiology is provided by the findings of space‐time clustering and seasonal variation. Spatial clustering suggests that higher incidence is confined to specific areas with increased levels of population mixing, particularly in previously isolated populations. Ecological studies have also shown excess incidence with higher population mixing. The marked childhood peak in resource‐rich countries and an increased incidence of the childhood peak in acute lymphoblastic leukaemia (ALL) (occurring at ages 2–6 years predominantly with precursor B‐cell ALL) is supportive of the concept that reduced early infection may play a role. Genetically determined individual response to infection may be critical in the proliferation of preleukaemic clones as evidenced by the human leucocyte antigen class II polymorphic variant association with precursor B‐cell and T‐cell ALL.

Baseline status of paediatric oncology care in ten low-income or mid-income countries receiving My Child Matters support: a descriptive study.

BACKGROUND Childhood-cancer survival is dismal in most low-income countries, but initiatives for treating paediatric cancer have substantially improved care in some of these countries. The My Child Matters programme was launched to fund projects aimed at controlling paediatric cancer in low-income and mid-income countries. We aimed to assess baseline status of paediatric cancer care in ten countries that were receiving support (Bangladesh, Egypt, Honduras, Morocco, the Philippines, Senegal, Tanzania, Ukraine, Venezuela, and Vietnam). METHODS Between Sept 5, 2005, and May 26, 2006, qualitative face-to-face interviews with clinicians, hospital managers, health officials, and other health-care professionals were done by a multidisciplinary public-health research company as a field survey. Estimates of expected numbers of patients with paediatric cancer from population-based data were used to project the number of current and future patients for comparison with survey-based data. 5-year survival was postulated on the basis of the findings of the interviews. Data from the field survey were statistically compared with demographic, health, and socioeconomic data from global health organisations. The main outcomes were to assess baseline status of paediatric cancer care in the countries and postulated 5-year survival. FINDINGS The baseline status of paediatric oncology care varied substantially between the surveyed countries. The number of patients reportedly receiving medical care (obtained from survey data) differed markedly from that predicted by population-based incidence data. Management of paediatric cancer and access to care were poor or deficient (ie, nonexistent, unavailable, or inconsistent access for most children with cancer) in seven of the ten countries surveyed, and accurate baseline data on incidence and outcome were very sparse. Postulated 5-year survival were: 5-10% in Bangladesh, the Philippines, Senegal, Tanzania, and Vietnam; 30% in Morocco; and 40-60% in Egypt, Honduras, Ukraine, and Venezuela. Postulated 5-year survival was directly proportional to several health indicators (per capita annual total health-care expenditure [Pearsons r(2)=0.760, p=0.001], per capita gross domestic product [r(2)=0.603, p=0.008], per capita gross national income [r(2)=0.572, p=0.011], number of physicians [r(2)=0.560, p=0.013] and nurses [r(2)=0.506, p=0.032] per 1000 population, and most significantly, annual government health-care expenditure per capita [r(2)=0.882, p<0.0001]). INTERPRETATION Detailed surveys can provide useful data for baseline assessment of the status of paediatric oncology, but cannot substitute for national cancer registration. Alliances between public, private, and international agencies might rapidly improve the outcome of children with cancer in these countries.

Three distinct subgroups of hypodiploidy in acute lymphoblastic leukaemia

This study of children and adults with acute lymphoblastic leukaemia (ALL) is the largest series of patients with hypodiploidy (<46 chromosomes) yet reported. The incidence of 5% was independent of age. Patients were subdivided by the number of chromosomes; near‐haploidy (23–29 chromosomes), low hypodiploidy (33–39 chromosomes) and high hypodiploidy (42–45 chromosomes). The near‐haploid and low hypodiploid groups were characterized by their chromosomal gains and a doubled hyperdiploid population. Structural abnormalities were more frequent in the low hypodiploid group. Near‐haploidy was restricted to children of median age 7 years (range 2–15) whereas low hypodiploidy occurred in an older group of median age 15 years (range 9–54). Patients with 42–45 chromosomes were characterized by complex karyotypes involving chromosomes 7, 9 and 12. The features shared by the few patients with 42–44 chromosomes and the large number with 45 justified their inclusion in the same group. Survival analysis showed a poor outcome for the near‐haploid and low hypodiploid groups compared to those with 42–45 chromosomes. Thus cytogenetics, or at least a clear definition of the modal chromosome number, is essential at diagnosis in order to stratify patients with hypodiploidy into the appropriate risk group for treatment.

Treatment non-adherence in teenage and young adult patients with cancer

Adhering to treatment can be a significant issue for many patients diagnosed with chronic health conditions and this has been reported to be greater during the adolescent years. However, little is known about treatment adherence in teenage and young adult (TYA) patients with cancer. To increase awareness of the adherence challenges faced by these patients, we have reviewed the published work. The available evidence suggests that a substantial proportion of TYA patients with cancer do have difficulties, with reports that up to 63% of patients do not adhere to their treatment regimens. However, with inconsistent findings across studies, the true extent of non-adherence for these young patients is still unclear. Furthermore, it is apparent that there are many components of the cancer treatment regimen that have yet to be assessed in relation to patient adherence. Factors that have been shown to affect treatment adherence in TYA patients include patient emotional functioning (depression and self-esteem), patient health beliefs (perceived illness severity and vulnerability), and family environment (parental support and parent-child concordance). Strategies that foster greater patient adherence are also identified. These strategies are multifactorial, targeting not only the patient, but the health professional, family, and treatment regimen. This review highlights the lack of interventional studies addressing treatment adherence in TYA patients with cancer, with only one such intervention being identified: a video game intervention focusing on behavioural issues related to cancer treatment and care. Methodological issues in measuring adherence are addressed and suggestions for improving the design of future adherence studies highlighted, of which there is a great need.

Comparative incidence patterns and trends of gonadal and extragonadal germ cell tumors in England, 1979 to 2003

It is believed that gonadal and extragonadal germ cell tumors (GCTs) arise from primordial germ cells and may have similar etiopathogenesis. Unlike testicular GCTs, there has been limited comprehensive population‐based analysis of ovarian and extragonadal GCTs.

Changes in cancer incidence in teenagers and young adults (ages 13 to 24 years) in England 1979‒2003

Cancer for teenagers and young adults represents a major source of morbidity and mortality. Trends in cancer incidence can provide pointers concerning how changes in the environment and in personal behavior affect cancer risks.

The impact of risk stratification by early bone-marrow response in childhood lymphoblastic leukaemia: results from the United Kingdom Medical Research Council trial ALL97 and ALL97/99

The 1997 acute lymphoblastic leukaemia (ALL) trial (ALL97) was a randomised comparison of prednisolone versus dexamethasone and of 6‐mercaptopurine versus 6‐thioguanine. During the first 2 years of the trial, review of survival data showed the preceding trial, UKALL XI, was no better than its predecessor and that survival for childhood ALL in the UK had not improved in the fashion witnessed by other cooperative treatment groups. The therapy template was therefore altered to an American Children’s Cancer Group (CCG) style regimen, including stratification by age, white cell count and early response to therapy by assessment of the bone marrow. This phase of the trial was designated ALL97/99. Comparison of the two phases showed that the event‐free survival (EFS) for both ALL97 and ALL97/99 was better than previous UKALL trials, as was overall survival (OS) for ALL97/99. Both EFS and OS were significantly better in ALL97/99 than in ALL97 (at five years, 80·0% vs. 74·0%, P = 0·002; and 88·0% vs. 83·5%, P = 0·005, respectively). Isolated central nervous system (CNS) relapse for patients in ALL97/99 was half that in ALL97 (3·0% vs. 4·9%), P = 0·03) and the overall CNS relapse rate was halved in ALL97/99 (4·4% vs. 9·6%, P < 0·00005). There were no significant differences for non‐CNS relapse, induction deaths or deaths in remission between the two phases of the trial.

Optimal care for the child with cancer: A summary statement from the SIOP working committee on psychosocial issues in pediatric oncology†

Since its foundation in 1991, the SIOP Working Committee on Psychosocial Issues in Paediatric Oncology 1 has developed and published 12 sets of Guidelines for health‐care professionals treating children with cancer and their families. Those elements considered essential in the process of cure and care of children with cancer are summarized in this document as a formal statement, developed at the 2007 SIOP annual meeting in Mumbai. Elaboration of the concepts with detailed strategies for practice can be found in the referenced guidelines [1–12] and in a companion publication [13]. This article is a summary of what practitioners considered critical elements in the optimal care of the child with cancer, with the goal of stimulating a broader application of these elements throughout the SIOP membership. Pediatr Blood Cancer 2009;52:904–907.

Are reported increases in incidence of primary CNS tumours real? An analysis of longitudinal trends in England, 1979–2003

Reported increases in the incidence of CNS tumours in the developed world in the 1970s to 1990s have been a cause for concern and debate. It still remains to be adequately answered whether these increases are true or an artefact of changes in diagnostic and registration practices. Using high-quality national cancer registration data, we have analysed incidence trends for each major histological subgroup of CNS tumour (2000 World Health Organisation (WHO) classification) registered in those aged 0-84 years for the whole of England during the period 1979 through 2003. 134,509 primary CNS tumours of malignant, benign and uncertain behaviour located in the brain, meninges, spinal cord, cranial nerves, other parts of the central nervous system and in the pituitary and pineal glands were registered. In summary, we present the single largest nationwide study on the longitudinal incidence trends of CNS tumours. The increase in incidence observed in the 1970s and 1980s was mainly in the young and the elderly and has now plateaued and may even be decreasing. There is however variation in trends by histology. The incidence of some histological sub-groups has continued to increase until the most recent period of analysis. Much of the initial increase can be attributed to the emergence of much more widely available neuroimaging, while the most recent incidence changes for specific sub-groups of CNS tumours appear to be due to greater diagnostic specificity leading to a shift in registered categories. However, the trends for high-grade astrocytomas and other gliomas need further observation and investigation.

Access to Care

Rapid diagnosis, timely initiation of optimal treatment and good supportive care should be the gold standard for all patients who develop cancer, irrespective of age and where they live. This article reviews the evidence that teenagers/adolescents and young adults may be disadvantaged with regard to access to care. Delays in diagnosis and the reasons for them (patient and professional), low enrolment into clinical trials, suboptimal treatment strategies and place of care are addressed. We must access the voice of the young, address their needs, and involve them more in decisions concerning their own health. Progress is being made slowly in several countries and international collaboration linking patients, health care professionals, governmental and non‐governmental agencies is essential. Such international collaboration and focus, with specific research goals are suggested in order to make variation in access to optimal care become a thing of the past. Pediatr Blood Cancer 2008:50:1094–1098.