Acute lymphoblastic leukaemia (ALL) is rare. It is estimated that 6100 new cases of ALL, and 1400 associated deaths, will occur in the US in 2025.[10]National Cancer Institute. Cancer stat facts: leukemia - acute lymphocytic leukemia (ALL). 2025 [internet publication].
https://seer.cancer.gov/statfacts/html/alyl.html
Median age at diagnosis is 17 years.[10]National Cancer Institute. Cancer stat facts: leukemia - acute lymphocytic leukemia (ALL). 2025 [internet publication].
https://seer.cancer.gov/statfacts/html/alyl.html
More than half of all new cases (52.7%) occur in those aged under 20 years.[10]National Cancer Institute. Cancer stat facts: leukemia - acute lymphocytic leukemia (ALL). 2025 [internet publication].
https://seer.cancer.gov/statfacts/html/alyl.html
Peak incidence occurs at age 1-4 years (7.7 per 100,000 [2018-2022 data]).[11]National Cancer Institute. All cancer sites combined: recent trends in SEER age-adjusted incidence rates, 2000-2022. 2025 [internet publication].
https://seer.cancer.gov/statistics-network/explorer/application.html?site=1&data_type=1&graph_type=2&compareBy=sex&chk_sex_3=3&chk_sex_2=2&rate_type=2&race=1&age_range=1&hdn_stage=101&advopt_precision=1&advopt_show_ci=on&hdn_view=0&advopt_show_apc=on&advopt_display=2#resultsRegion0
Incidence decreases to 2.6 per 100,000 by age 10-14 years (2018-2022 data).[11]National Cancer Institute. All cancer sites combined: recent trends in SEER age-adjusted incidence rates, 2000-2022. 2025 [internet publication].
https://seer.cancer.gov/statistics-network/explorer/application.html?site=1&data_type=1&graph_type=2&compareBy=sex&chk_sex_3=3&chk_sex_2=2&rate_type=2&race=1&age_range=1&hdn_stage=101&advopt_precision=1&advopt_show_ci=on&hdn_view=0&advopt_show_apc=on&advopt_display=2#resultsRegion0
Incidence of ALL is slightly higher in males than females.[10]National Cancer Institute. Cancer stat facts: leukemia - acute lymphocytic leukemia (ALL). 2025 [internet publication].
https://seer.cancer.gov/statfacts/html/alyl.html
Incidence in the US is highest in Hispanic people (3.1 per 100,000 and 2.4 per 100,000 for males and females, respectively [2018-2022 data]) and lowest in non-Hispanic black people (1.1 per 100,000 and 0.9 per 100,000 for males and females, respectively [2018-2022 data]).[10]National Cancer Institute. Cancer stat facts: leukemia - acute lymphocytic leukemia (ALL). 2025 [internet publication].
https://seer.cancer.gov/statfacts/html/alyl.html
B-ALL (arising from B lymphoid progenitors) accounts for approximately 75% of adult cases, with the remainder being predominantly T-ALL (arising from T lymphoid progenitors).[3]Terwilliger T, Abdul-Hay M. Acute lymphoblastic leukemia: a comprehensive review and 2017 update. Blood Cancer J. 2017 Jun 30;7(6):e577.
https://www.nature.com/articles/bcj201753
http://www.ncbi.nlm.nih.gov/pubmed/28665419?tool=bestpractice.com
Mixed-phenotype (B-cell and T-cell) ALL may occur, but is exceptionally rare.