Breast cancer molecular subtypes: What is at stake to improve breast cancer screening in France

Molecular subtypes are essential for understanding the epidemiology, natural history and management of breast cancer. Tumours of the basal-like (triple negative) subtype affect younger women and are overrepresented in interval cancers. In case of metastatic evolution, it is mainly a visceral evolution, with a higher risk of recurrence during the first 3 years. Luminal A subtype cancers affect slightly older women, after menopause, and are the preferred target for screening. Their prognosis is more favourable. If there is one, the metastatic evolution is preferably bony. The risk of recurrence is low but constant and lasts for 10 to 15 years after diagnosis. HER2-like cancers have a similar evolution to basal-like tumours, the reference treatment being the targeted anti-HER2 adjuvant therapy. Luminal B subtype cancers are intermediate, with a metastatic evolution, preferably bony, but with a poorer prognosis thanluminal A subtypes. The different profiles benefit from screening, with a poorer representation of the basal like subtypes but a greater gain in survival if diagnosed early. Better knowledge of the molecular subtypes and their epidemiology will allow the type of screening to be adapted to the type of cancer to which the woman is more exposed. Large epidemiological studies are underway to clarify these points and to propose an adaptation of screening. (C) 2021 Elsevier Masson SAS. All rights reserved.