Summary
Worldwide, breast cancer is the most frequently diagnosed cancer. In the Netherlands, 1 in 7 women will be diagnosed with breast cancer at some point during life, corresponding with a cumulative lifetime risk of 12–13 %. Approximately 75 % of the newly diagnosed breast cancer patients are aged 50 or older. Approximately 7 % are less than 40 years. These young women with breast cancer comprise a particular subset due to the often more aggressive biology of their tumours as well as their unique psychosocial concerns. They are at a higher risk of carrying a high-risk allele for hereditary breast cancer and will be offered counselling by a clinical geneticist irrespective of their family history. Young women, who are often advised to have systemic chemotherapy, can be confronted with treatment-related infertility and/or premature ovarian failure. Therefore counselling by gynaecologists, in close collaboration with medical oncologists, is immediately offered after diagnosis if they want to have children in the future. Young women can suffer various other long-term physical and mental side effects of oncological treatment. Problems related to premature ovarian failure include menopausal symptoms such as hot flushes, genitourinary problems, psychological and psychosexual difficulties, and accelerated loss of bone mineral density. Premature menopause may contribute to increased cardiovascular morbidity.