Preoperative Chemotherapy With Paclitaxel, Gemcitabine, and Lapatinib (Tykerb®) (PGT)

Primary objectives : 1\. To evaluate the recommended dose of the combination of paclitaxel, gemcitabine, and lapatinib (Tykerb®) (PGT) as preoperative chemotherapy in patients with HER2 positive operable breast cancer Secondary objectives : 1. To evaluate the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of PGT 2. To determine the safety profile 3. To assess pCR in primary tumor and axillary LN 4. To evaluate clinical response rate, disease free survival (DFS), and overall survival (OS) 5. To assess breast conserving rate after preoperative PGT