Site of primary tumor has a prognostic role in operable breast cancer: The International Breast Cancer Group experienceM. Colleoni, D. Zahrieh, R.D. Gelber, S.B. Holmberg, J.E. Mattsson, C.-M. Rudenstam, J. Lindtner, D. Erzen, R. Snyder, J. Collins, et al. JCO 2005;23(7):1390–1400