Treatment of postmenopausal women with locally advanced or metastatic breast cancer with letrozole alone or in combination with temsirolimus: a randomized, 3-arm, phase 2 study - J Baselga; H Roche; P Fumoleau; M Campone; R Colomer; H Cortes-Funes; M Gil; S Chan; J Boni; S Kong; M Cincotta; L Moore (Breast Cancer Research And Treatment, 2005)