Drug may shrink breast cancers

HOUSTON, April 21 (UPI) -- A drug that targets cell surface receptors may shrink breast cancer tumors in six weeks, a U.S. scientist reports.

Dr. Angel Rodriguez of Baylor College of Medicine in Houston says the drug -- a tyrosine kinase inhibitor known as lapatinib -- could decrease tumor-causing breast cancer stem cells in women receiving treatment given before primary surgery.

Rodriguez and colleagues studied 45 patients with locally advanced breast cancer in which the gene HER-2 was over-expressed. The patients received lapatinib for six weeks, followed by a combination of weekly trastuzumab and thrice-weekly docetaxel, given over 12 weeks, before primary surgery. Biopsies were performed at the time of diagnosis and also after six weeks of lapatinib and cells from the tumors were obtained and analyzed.

"We saw significant tumor regression after six weeks of single-agent lapatinib," Rodriguez said in a statement. "Bi-dimensional tumor measurements showed a median decrease of minus 60.8 percent."

The findings are being presented at the sixth European Breast Cancer Conference in Berlin.