Understanding age and sex differentials in cancer incidence and mortality: an international population-based study

Researchers from the International Agency for Research on Cancer (IARC) studying the differences in cancer incidence and mortality by sex have uncovered four distinct age periods, common to all 60 countries included in the study, when the sex ratios of cancer incidence and mortality peak, before a shift occurs to an excess in the other sex. The study was published in the International Journal of Cancer.

Using data from IARC’s Cancer Incidence in Five Continents for 2013–2017 and the IARC GLOBOCAN online tool for mortality in 2022, the research team estimated ages when the male-to-female ratio of cancer incidence and the male-to-female ratio of cancer mortality peaked and reversed from a male excess to a female excess or vice versa. Period 1 showed an early-life male excess up to about age 21 years. Period 2 had a multi-fold female excess lasting until about age 59 years and peaking at a female-to-male ratio of 2.4:1 at about age 41 years. Period 3 had a large male excess peaking at a male-to-female ratio of 1.5:1 at about age 73 years. For the absolute burden alone (not rates), in countries with long life expectancies there was a fourth period, with a female excess of cancers and cancer deaths at ages ≥ 85 years.

In lower-income countries, the period with a female excess of cancers (period 2) was found to last longer and be more extreme than in higher-income settings. This study characterized the four age periods of alternating sex differentials in the cancer burden, providing essential information to support sex-appropriate allocation of cancer prevention and oncology resources.

Rodet N, Zahed H, Colombet M, Bray F, McCormack V
Understanding age and sex differentials in cancer incidence and mortality: an international population-based study
Int J Cancer. Published online 10 November 2025;
https://doi.org/10.1002/ijc.70244

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