TEST:

Prosigna™ Breast Cancer Prognostic Gene Signature Assay

...prospective translational research study in stage I-IIIA HER2+ breast cancer designed to evaluate the ability of the PAM50 intrinsic subtypes to predict pCR in the breast (pCRB; in situ allowed) following 18 weeks of neoadjuvant lapatinib and trastuzumab...6 year DFS and DDFS were 91.7% and 93.7%, respectively....Of the 12 patients who did not receive CT, 6 (50%) pts achieved a pCRB, and no relapse events were observed....Despite the small sample size, PAMELA opens the door to study dual HER2 blockade without chemotherapy in selected pts.

The LETLOB phase II trial randomized 92 postmenopausal women with clinical stage II-IIIA HR+/HER2- BC to receive neoadjuvant letrozole + lapatinib or letrozole + placebo for 6 months….The highest response rate (90%) was observed in luminal patients treated with letrozole + lapatinib.

This was a phase II trial that randomized 184 patients with HR+ MBC in premenopausal women to palbociclib plus exemestane with GNRH agonist (Arm A, n=79) versus capecitabine (Arm B, n=62)....RB1 loss, known as a resistant biomarker of CDK4/6 inhibitor was found in 4% of Arm A, and was associated with shorter PFS (log2 HR=2.26, 95% CI 0.51 to 4.01, p=0.011)....The alteration of a few genes including Rb1 loss may be associated with resistance of palbociclib in HR-positive premenopausal population with MBC.