Neoadjuvant lapatinib decreases tumorigenic breast cancer stem cells

Neoadjuvant lapatinib (Tykerb) decreased tumorigenic stem cells in primary breast cancers, Jenny Chang, MD, of Baylor College of Medicine, Houston, reported at the 6th European Breast Cancer Conference. In the study, 45 patients with locally advanced HER2-overexpressing breast cancer received single-agent lapatinib for 6 weeks followed by lapatinib plus weekly trastuzumab (Herceptin) and thrice-weekly docetaxel (Taxotere) for 12 weeks.

Biopsy results showed significant tumor regression from baseline (median decrease of 60.8%, P = .001) after 6 weeks of single-agent lapatinib. Unlike treatment with chemotherapy, lapatinib decreased tumorigenic breast cancer stem cells from 10.6% to 4.7%. The pathological complete response rate after combination treatment was 63%, Dr. Chang and colleagues reported.