Hormonal therapy for young-onset breast cancer: current understanding and lessons
Menée à partir de données internationales portant sur 459 476 femmes âgées de 16 à 54 ans (durée médiane de suivi : 7,8 ans), cette étude analyse l'association entre un traitement hormonal et le risque de cancer du sein chez les jeunes femmes (8 455 cas)
The relationship between hormone therapy (oestrogen with or without progestogen) and breast cancer risk has been widely investigated in numerous studies and meta-analyses, mainly on hormone replacement therapies for postmenopausal women. However, scarce data have been published around the impact of hormone exposure on the risk of young-onset breast cancer in premenopausal women. The study by Katie O’Brien and colleagues,1 published in this issue of The Lancet Oncology, is relevant in this context and explores more than ten prospective cohorts in a large, pooled analysis. The main results of this study show no overall association of hormone therapy with the incidence of young-onset breast cancer (HR 0·96 [95% CI 0·88 to 1·04]), and highlight different associations according to the treatment. A favourable safety profile was seen for oestrogen hormone therapy, whereas the combination of oestrogen plus progestogen hormone therapy showed a positive association with breast cancer risk for the triple-negative subtype, for long-term users, and for women with no history of gynaecological surgery.
The Lancet Oncology , commentaire, 2025