Clinical stage of breast cancer by parity, age at birth, and time since birth: a progressive effect of pregnancy hormones?

Albrektsen G, Heuch I, Thoresen S, Kvale G. Clinical stage of breast cancer by parity, age at birth, and time since birth: a progressive effect of pregnancy hormones? Cancer Epidemiol Biomarkers Prev 2006; 15(1):65-69.