Effect of parity and age of first full term pregnancy on age of BC diagnosis in different ER and HER2 subtypes

Professor Patrick Neven presents an investigation examining the correlation between parity, age at the first full-term pregnancy (FTP1), and the age of BC diagnosis, as well as the prevalence of the triple-negative subtype of BC in an extensive cohort of nearly 10,000 patients at UZ Leuven over 20 years.

Women initiating their FTP1 at a young age (<27 years) tend to a later age of BC diagnosis, particularly in cases where the cancer is HER2+. No disparity in the age of BC onset was identified based on low versus high parity. In premenopausal women, the combination of low parity and late FTP1 is associated with an advanced age at diagnosis for ER+/HER2- BC, relative to nulliparous women. Comparisons between parous patients and their nulliparous counterparts revealed a reduction in the odds of developing ER-/HER2- BC with increased age at FTP1, particularly in the ER+/HER2- subtype.

In postmenopausal patients with low parity, a tendency was observed towards reduced odds of ER-/HER2- BC and increased odds of ER+/HER2+ BC, relative to ER+/HER2- BC. Finally, when contrasted with nulliparous women, postmenopausal women with >3 children and an early pregnancy displayed heightened odds of developing ER-/HER2- tumours in comparison to ER+/HER2- tumours.

Reference:

Zhang J, Parity and age first full term pregnancy affects the age of breast cancer diagnosis in breast cancer subtypes defined by ER and HER2.  SABCS 2023, #PO4-02-14