PIK3CA and MAP3K1 alterations imply luminal A status and are associated with clinical benefit from pan-PI3K inhibitor buparlisib and letrozole in ER+ metastatic breast cancer

Mellissa J. Nixon, Luigi Formisano, Ingrid A. Mayer, M. Valeria Estrada, Paula I. González-Ericsson, Steven J. Isakoff, Andrés Forero-Torres, Helen Won, Melinda E. Sanders, David B. Solit, Michael F. Berger, Lewis C. Cantley, Eric P. Winer, Carlos L. Arteaga, Justin M. Balko