Trends in childhood acute lymphoblastic leukemia in Western Australia, 1960–2006

Abstract

Increases in the incidence of childhood acute lymphoblastic leukemia (ALL) have been reported in some countries, while other reports from similar geographical regions have indicated stable rates. The reasons for the discrepancies have been debated in the literature, with the focus on whether the observed increases are “real” or an artifact resulting from improvements in diagnosis, case ascertainment and population coverage over time. We used population‐based data from Western Australia to investigate trends in the incidence of childhood ALL between 1960 and 2006. Age‐standardized incidence rates (ASRs) and rate ratios (indicating annual percent change) were estimated using Poisson regression. Between 1960 and 2006, the ASR was 3.7 per 100,000 person‐years, with an annual percent increase of 0.40% (95% CI: −0.20, 1.00). Between 1982 and 2006, the ASR was 3.8, with an annual percent increase of 0.80% (95% CI = −0.70 to 2.30). This increased to 1.42% (95% CI: −0.30, 3.0) when a sensitivity analysis was undertaken to assess the effect of excluding the final 2 years of data. Annual increases of 3.7% (95% CI: −0.50, 8.00) among children aged 5–14 years, and of 3.10% (95% CI: 0.50, 5.70) in girls, were observed for this latter period. These results were supported by national Australian incidence data available for 1982–2003. There may have been a small increase in the incidence of ALL since 1982 among girls and older children, but an overall increase appears unlikely. No impact of folate supplementation or fortification is apparent. © 2007 Wiley‐Liss, Inc.

Hospital Admissions in Children with Down Syndrome: Experience of a Population-Based Cohort Followed from Birth

“…As did others [10], [11], [12], [13], we found that rates of leukaemia admission among young people with Down syndrome were much higher than in the general population [31], [43]. Each child with leukaemia was admitted an average of 13 times with the majority for chemotherapy treatment.…”

International long‐term trends and recent patterns in the incidence of leukemias and lymphomas among children and adolescents ages 0–19 years

“…For lymphoid leukemia, rates were stable during 1982–2001 in the Nordic countries, during 1974–1997 in Yorkshire in the United Kingdom and during 1973–2005 in Shanghai, China . Lymphoid leukemia incidence increased modestly (0.7–1.1% per year) during 1978–1997 in the multi‐country European Automated Childhood Cancer Information System, during 1982–2003 in western Australia and during 1954–1998 in Manchester, United Kingdom, but increased more notably (1.2–2.2%) during 1977–2001 in the Piedmont region in Italy, during 1968–1990 in New Zealand and during 1974–1991 in the United States before stabilizing in the U.S. during 1992–2004 . However, lymphoid leukemia declined during 1981–1996 in Costa Rica .…”

“…Several countries, particularly in Europe, described the increase in acute lymphocytic leukemia most pronounced in boys aged 1–4 (likely to be due to precursor B‐cell leukemia) and higher incidence of leukemias in western than in eastern Europe due to a more pronounced peak at ages 2–3 . Discrepancies in countries in proximity to each other and the lack of consistency of findings may reflect improvements over time in diagnostic criteria, level of mandatory reporting, completeness of ascertainment or duplication of reporting …”

Time and spatial trends in lymphoid leukemia and lymphoma incidence and survival among children and adolescents in Manitoba, Canada: 1984-2013

“…Overall leukemia incidence rates in Canadian boys increased by 0.8% annually during 1992–2010 [33], and this is largely driven by the increase (2.4% per year) during 1992–1999 [34]. Temporal trends in LL incidence varied by country: LL incidence rates increased 0.7% per year in children and adolescents in the United States (1975–2010) [1], 0.6% per year in children and 1.9% per year in adolescents in Europe (1978–1997) [40], but the increases in Western Australia (1960–2006) [41] and in Shanghai, China (1973–2005) [42] were not statistically significant. Rising incidence could be attributed to increased exposure to risk factors (e.g., environmental exposures) and/or diagnostic improvement.…”