• The incidence of childhood cancer in Australia, 1983-2015, and projections to 2035

      Youlden, DR; Baade, PD; Green, Adèle C; Valery, PC; Moore, AS; Aitken, JF; Cancer Council Queensland, Brisbane, QLD (2019)
      OBJECTIVES: To describe changes in childhood cancer incidence in Australia, 1983-2015, and to estimate projected incidence to 2035. DESIGN, SETTING: Population-based study; analysis of Australian Childhood Cancer Registry data for the 20 547 children under 15 years of age diagnosed with cancer in Australia between 1983 and 2015. MAIN OUTCOME MEASURES: Incidence rate changes during 1983-2015 were assessed by joinpoint regression, with rates age-standardised to the 2001 Australian standard population. Incidence projections to 2035 were estimated by age-period-cohort modelling. RESULTS: The overall age-standardised incidence rate of childhood cancer increased by 34% between 1983 and 2015, increasing by 1.2% (95% CI, +0.5% to +1.9%) per annum between 2005 and 2015. During 2011-2015, the mean annual number of children diagnosed with cancer in Australia was 770, an incidence rate of 174 cases (95% CI, 169-180 cases) per million children per year. The incidence of hepatoblastoma (annual percentage change [APC], +2.3%; 95% CI, +0.8% to +3.8%), Burkitt lymphoma (APC, +1.6%; 95% CI, +0.4% to +2.8%), osteosarcoma (APC, +1.1%; 95%, +0.0% to +2.3%), intracranial and intraspinal embryonal tumours (APC, +0.9%; 95% CI, +0.4% to +1.5%), and lymphoid leukaemia (APC, +0.5%; 95% CI, +0.2% to +0.8%) increased significantly across the period 1983-2015. The incidence rate of childhood melanoma fell sharply between 1996 and 2015 (APC, -7.7%; 95% CI, -10% to -4.8%). The overall annual cancer incidence rate is conservatively projected to rise to about 186 cases (95% CI, 175-197 cases) per million children by 2035 (1060 cases per year). CONCLUSIONS: The incidence rates of several childhood cancer types steadily increased during 1983-2015. Although the reasons for these rises are largely unknown, our findings provide a foundation for health service planning for meeting the needs of children who will be diagnosed with cancer until 2035.
    • Second primary cancers in people who had cancer as children: an Australian Childhood Cancer Registry population-based study

      Youlden, DR; Baade, PD; Green, Adèle C; Valery, PC; Moore, AS; Aitken, JF; Cancer Council Queensland, Brisbane, QLD (2019)
      OBJECTIVE: To investigate the incidence of second primary cancers in people diagnosed with cancer during childhood. DESIGN, SETTING: Retrospective, population-based study; analysis of Australian Childhood Cancer Registry data. PARTICIPANTS: People alive at least two months after being diagnosed before the age of 15 years with a primary cancer, 1983-2013, followed until 31 December 2015 (2-33 years' follow-up). MAIN OUTCOME MEASURES: Risks of second primary cancer compared with the general population, expressed as standardised incidence ratios (SIRs). RESULTS: Among 18 230 people diagnosed with cancer during childhood, 388 (2%) were later diagnosed with second primary cancers; the estimated 30-year cumulative incidence of second cancers was 4.4% (95% CI, 3.8-5.0%). The risk of a new primary cancer was five times as high as for the general population (SIR, 5.13; 95% CI, 4.65-5.67). Relative risk of a second primary cancer was greatest for people who had childhood rhabdomyosarcoma (SIR, 19.9; 95% CI, 14.4-27.6). Relative risk was particularly high for children who had undergone both chemotherapy and radiotherapy (SIR, 9.80; 95% CI, 8.35-11.5). Relative risk peaked during the 5 years following the first diagnosis (2 to less than 5 years: SIR, 10.3; 95% CI, 8.20-13.0), but was still significant at 20-33 years (SIR, 2.58; 95% CI, 2.02-3.30). The most frequent second primary cancers were thyroid carcinomas (65 of 388, 17%) and acute myeloid leukaemias (57, 15%). CONCLUSIONS: Survivors of childhood cancer remain at increased risk of a second primary cancer well into adulthood. As the late effects of cancer treatment probably contribute to this risk, treatments need to be refined and their toxicity reduced, without reducing their benefit for survival.
    • Stage at diagnosis for childhood solid cancers in Australia: a population-based study

      Youlden, DR; Frazier, AL; Gupta, S; Pritchard-Jones, K; Kirby, ML; Baade, PD; Green, Adèle C; Valery, PC; Aitken, JF; Cancer Council Queensland, Brisbane, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia (2019)
      BACKGROUND: Stage of cancer at diagnosis is one of the strongest predictors of survival and is essential for population cancer surveillance, comparison of cancer outcomes and to guide national cancer control strategies. Our aim was to describe, for the first time, the distribution of cases by stage at diagnosis and differences in stage-specific survival on a population basis for a range of childhood solid cancers in Australia. METHODS: The study cohort was drawn from the population-based Australian Childhood Cancer Registry and comprised children (<15 years) diagnosed with one of 12 solid malignancies between 2006 and 2014. Stage at diagnosis was assigned according to the Toronto Paediatric Cancer Stage Guidelines. Observed (all cause) survival was calculated using the Kaplan-Meier method, with follow-up on mortality available to 31 December 2015. RESULTS: Almost three-quarters (1256 of 1760 cases, 71%) of children in the study had localised or regional disease at diagnosis, varying from 43% for neuroblastoma to 99% for retinoblastoma. Differences in 5-year observed survival by stage were greatest for osteosarcoma (localised 85% (95% CI?=?72%-93%) versus metastatic 37% (15%-59%)), neuroblastoma (localised 98% (91%-99%) versus metastatic 60% (52%-67%)), rhabdomyosarcoma (localised 85% (71%-93%) versus metastatic 53% (34%-69%)), and medulloblastoma (localised 69% (61%-75%) versus metastases to spine 42% (27%-57%)). CONCLUSION: The stage-specific information presented here provides a basis for comparison with other international population cancer registries. Understanding variations in survival by stage at diagnosis will help with the targeted formation of initiatives to improve outcomes for children with cancer.
    • Stage at diagnosis for children with blood cancers in Australia: application of the Toronto Paediatric Cancer Stage Guidelines in a population-based national childhood cancer registry

      Youlden, DR; Gupta, S; Frazier, AL; Moore, AS; Baade, PD; Valery, PC; Green, Adèle C; Aitken, JF; Cancer Council Queensland, Brisbane, Queensland, Australia (2019)
      BACKGROUND: Information on stage at diagnosis for childhood blood cancers is essential for surveillance but is not available on a population basis in most countries. Our aim was to apply the internationally endorsed Toronto Paediatric Cancer Stage Guidelines to children (<15 years) with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), or non-Hodgkin lymphoma (NHL) and to assess differences in survival by stage at diagnosis. PROCEDURE: Stage was defined by extent of involvement of the central nervous system (CNS) for ALL and AML and using the Ann Arbor and St Jude-Murphy systems for HL and NHL, respectively. The study cohort was drawn from the population-based Australian Childhood Cancer Registry, consisting of children diagnosed with one of these four blood cancers between 2006 and 2014 with follow-up to 2015. Five-year observed survival was estimated from the Kaplan-Meier method. RESULTS: Stage was assigned to 2201 of 2351 eligible patients (94%), ranging from 85% for AML to 95% for ALL, HL, and NHL. Survival following ALL varied from 94% (95% CI = 93%-95%) for CNS1 disease to 89% (95% CI = 79%-94%) for CNS2 (P = 0.07), whereas for AML there was essentially no difference in survival between CNS- (77%) and CNS+ disease (78%; P = 0.94). Nearly all children with HL survived for five years. There was a trend (P = 0.04) toward worsening survival with higher stage for NHL. CONCLUSIONS: These results provide the first population-wide picture of the distribution and outcomes for childhood blood cancers in Australia by extent of disease at diagnosis and provide a baseline for future comparisons.