Background: The pattern of cancer among young adults aged 20-49 years is different than that observed in other age groups, most notably women present higher rates than those observed among men. Estimations of the burden of cancer disease among women of this age group, however, rarely include both invasive and non-invasive disease.

Methods: We calculated incidence rates of invasive and non-invasive cancers for women and men aged 20-49 years and by cancer site for the period 2014-2018 in the canton of Geneva, Switzerland using data from the population-based cancer registry.

Results: Between 2014 and 2018, the incidence rates of invasive and non-invasive cancers among women were 177.6/100,000 and 166.4/100,000, respectively. The rates among men of the same age were 110.6/100,000 and 31.8/100,000, respectively. Just three cancers, breast, thyroid and melanoma accounted for 70% of all invasive cancers among women. In situ cervical cancer represented over 70% of non-invasive disease.

Conclusion: Cancer among women aged 20-49 years is quite frequent. This is primarily a result of increasing risk, increased diagnosis or both and highlights the need for better primary prevention strategies, personalized risk assessment and tailored screening, as well as increased awareness of women and health professionals about health risks in young adults.