Breast cancer causes one death a week in women aged 20 to 39 years, a new report looking at the impact of the disease on young women says.

"These young women are at a life stage in which they are building careers, establishing relationships and planning for a family. Issues such as infertility, early menopause and body image as well as time away from work and family can have a substantial impact, with long term physical, psychological and social effects," the chief executive officer of Cancer Australia, Professor Helen Zorbas, said.

"Although the number of young women diagnosed with breast cancer has increased over time, the incidence rate has remained stable over the past three decades."

The report, by the Australian Institute of Health and Welfare, is the first report to look at the situation facing young women with breast cancer.