Cross-sectional study of association of reproductive history with molecular subtype of breast cancer in women aged ≤ 50 years

Prof. Jonine Figueroa

The etiology of breast cancer diagnosed at ≤ 50 years of age is unclear. A cross-sectional study in Scotland compared reproductive risk factors between molecular subtypes of breast cancer. The study included 4108 women aged ≤ 50 years with primary breast cancer diagnosed between 2009 and 2016. Luminal A-like was the most common subtype. Number of births and time since last birth differed by molecular subtype. There was limited evidence for differences by subtype with age at first birth.