Women interact with cancer in complex ways, as healthy individuals participating in cancer prevention and screening activities, as individuals living with and beyond a cancer diagnosis, as caregivers for family members and friends, as patient advocates, as health workers and health-care professionals, and as cancer researchers and policy makers. The topic of women and cancer spans broad terrain, beyond women's cancers and the biomedical aspects of any type of cancer that women in all their diversities might experience. It is inclusive of the ways in which sex and gender influence exposures to cancer risk factors, interactions with the cancer health system, and specific challenges faced by health-care professionals, advocates, and caregivers. In all these domains, women experience gender bias, and are subject to overlapping forms of discrimination, such as due to age, race, ethnicity, socio-economic status, sexual orientation, and gender identity, that render them structurally marginalised. These myriad factors can intersect and restrict a woman's rights and opportunities to avoid modifiable cancer risks and impede their ability to seek and obtain a prompt diagnosis and quality cancer care. At the same time, they serve to unfairly burden and perpetuate an unpaid cancer caregiver workforce that is predominantly female, and hinder women's professional advancement as leaders in cancer research, practice, and policy making. However, we believe that much can be achieved if actions are urgently taken.