Estrogen receptor–positive (ER+) breast cancers adapt to hormone deprivation and become resistant to antiestrogen therapy. Here, we performed deep sequencing on ER+ tumors that remained highly proliferative after treatment with the aromatase inhibitor letrozole and identified a D189Y mutation in the inhibitory SH2 domain of the SRC family kinase (SFK) LYN. Evaluation of 463 breast tumors in The Cancer Genome Atlas revealed four
Luis J. Schwarz, Emily M. Fox, Justin M. Balko, Joan T. Garrett, María Gabriela Kuba, Mónica Valeria Estrada, Ana María González-Angulo, Gordon B. Mills, Monica Red-Brewer, Ingrid A. Mayer, Vandana Abramson, Monica Rizzo, Mark C. Kelley, Ingrid M. Meszoely, Carlos L. Arteaga