ESO–ESMO fifth international consensus guidelines for breast cancer in young women (BCY5)

•Breast cancer in young women encompasses unique treatment and survivorship considerations.•Fertility, ovarian function suppression and premature menopause are major issues that need to be addressed.•The presence of a germline pathogenic variant impacts risk reduction measures, local management and systemic therapy.•Research on how new systemic therapies impact fertility and ovarian function is urgently needed. We dedicate this manuscript in memory of a dear friend and colleague Bella Kaufman.The fifth International Consensus Symposium for Breast Cancer in Young Women (BCY5) took place virtually in October 2020, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY4 with incorporation of new evidence to inform the guidelines. Areas of research priorities as well as specificities in different geographic and minority populations were identified. This manuscript summarizes the ESO–ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA). We dedicate this manuscript in memory of a dear friend and colleague Bella Kaufman. The fifth International Consensus Symposium for Breast Cancer in Young Women (BCY5) took place virtually in October 2020, organized by the European School of Oncology (ESO) and the European Society of Medical Oncology (ESMO). Consensus recommendations for the management of breast cancer in young women were updated from BCY4 with incorporation of new evidence to inform the guidelines. Areas of research priorities as well as specificities in different geographic and minority populations were identified. This manuscript summarizes the ESO–ESMO international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).