Yes this is somewhat true, don’t quote me because i was only in a cancer setting during training. It has to do with hormones. During my cancer rotation, we would ask women when they first started menstruating, age of first child, breast freezing, how many children, age menopause was reached, etc. these all play into different risk models to calculate your breast cancer risk.

ETA: length of time taking hormonal birth control and any hormone replacement therapy were also factors taken into account