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

Abstract

To enhance understanding of etiology, we examined international population-based cancer incidence data for lymphoid leukemia, non-Hodgkin lymphoma, Hodgkin lymphoma and myeloid leukemia among children aged 0-19. Based on temporal trends during 1978-2007 in 24 populations, lymphoid leukemia and myeloid leukemia incidence rates generally have not changed greatly and differences in rates for non-Hodgkin and for Hodgkin lymphoma have diminished in some regions. Lymphoid leukemia rates during 2003-2007 in 54 populations varied about 10-fold, with rates highest in US white Hispanics (50.2 per million person-years) and Ecuador (48.3) and lowest in US blacks (20.4), Tunisia (17.7) and Uganda (6.9). Non-Hodgkin lymphoma rates varied 30-fold, with very high rates in sub-Saharan Africa (146.0 in Malawi and 54.3 in Uganda) and low rates (≤ 10) in some Asian populations (China, Japan, India, the Philippines and Thailand) and U.S. Asian-Pacific Islanders, eastern and northern European populations and Puerto Rico. Hodgkin lymphoma rates varied 15-fold, with rates highest in Italy (21.3) and lowest in China (1.7). Myeloid leukemia rates varied only about fivefold, with rates highest in the Philippines and Korea (exceeding 14.0) and lowest in Eastern Europe (5.9 in Serbia and 5.3 in the Czech Republic) and Uganda (2.7). The boy/girl average incidence rate ratios were 2.00 or lower. Age-specific patterns differed among the four hematopoietic malignancies, but were generally consistent within major categories world-wide, except for non-Hodgkin lymphoma. A systematic world-wide approach comparing postulated etiologic factors in low- versus high-risk populations may help clarify the etiology of these childhood malignancies.

Keywords: Hodgkin lymphoma; childhood; incidence; lymphoid leukemia; myeloid leukemia; non-Hodgkin lymphoma; trends.

Figure 1.

Temporal trends in international childhood lymphoid leukemia, non-Hodgkin lymphoma, Hodgkin lymphoma and myeloid leukemia incidence (age-adjusted, world standard) for ages 0–19, both sexes combined, 1978–1982 to 2003–2007. Data for the SEER 9 whites and blacks were used for 1978–1992. From Ferlay et al., Cancer Incidence in Five Continents, CI5plus: IARC CancerBase No. 9 International Agency for Research on Cancer, 2014. Available at: http://ci5.iarc.fr; SEER 9 and SEER 13.^,,,

Figure 2.

International variation in childhood lymphoid leukemia, non-Hodgkin lymphoma, Hodgkin lymphoma and myeloid leukemia incidence (age-adjusted, world standard) for ages 0–19 by sex, 2003–2007. Rates based on <10 cases indicated by an X. Note the broken axes for non-Hodgkin lymphoma rates in Uganda and Malawi. From Forman et al, 2013, Cancer Incidence in Five Continents, Vol. X. International Agency for Research on Cancer and SEER 18 database.^,

Figure 3.

International variation in age-specific childhood lymphoid leukemia, non-Hodgkin lymphoma, Hodgkin lymphoma and myeloid leukemia incidence by racial/ethnic group for ages 0–19, both sexes combined, 2003–2007. Figure 3 (Supporting Information Table 7) compares age-specific incidence rates among populations by ethnic group. Since 72% of the inhabitants of Israel are Jews and most have migrated from and/or were born to immigrants from Eastern Europe, we grouped Israelis with Eastern European populations in contrast to the more traditional geographic grouping of Israel with Asia (Fig. 1: Supporting Information Table 5) or Asia-Western (Fig. 2: Supporting Information Table 6). From Forman et al., 2013, Cancer Incidence in Five Continents, vol. X. International Agency for Research on Cancer and SEER 18 database.^,