Patients with HER2-positive breast cancer may be eligible for a Baylor College of Medicine-led, multi-institutional clinical study evaluating a new approach to treatment using a combination of HER2-targeted therapies without chemotherapy.

The study is being done as a follow-up to a recent clinical trial that showed HER2-positive breast cancer patients using a combination of trastuzumab (Herceptin) and lapatinib (Tykerb) for 12 weeks – without chemotherapy – showed a significant benefit in the eradication of breast cancer tumors.

The study results were released in May 2011 by the American Society of Clinical Oncology.

"Certain subgroups in the study (those that were estrogen receptor positive or negative) showed different complete pathologic response rates (no cancer cells found in the tumor after treatment), so we hypothesized that longer treatment may be more effective for some," said Dr. Mothaffar Rimawi, medical director of the Lester and Sue Smith Breast Center at BCM and study chair. "There may be a group that does not need chemotherapy. It will still be helpful for some, but maybe not for all."

The study will randomize patients to receive 12 vs. 24 weeks of trastuzumab and lapatinib. Patients whose tumors are also estrogen receptor positive will receive anti-estrogen therapy. Eligible patients must be newly diagnosed with HER2-positive breast cancer and have tumors 2 cm or larger. Rimawi said they will use patient tissue samples to predict who may still need chemotherapy.

Other institutions involved in the study include The Sidney Kimmel Comprehensive Cancer Center at John’s Hopkins University; Dana-Farber Cancer Institute; The University of Texas MD Anderson Cancer Center; University of Alabama at Birmingham Comprehensive Cancer Center; Indiana University Melvin and Bren Simon Cancer Center ; The University of Chicago Comprehensive Cancer Center; the Mayo Clinic; The Vanderbilt-Ingram Cancer Center at Vanderbilt University, and the Duke Cancer Institute.

The study is being sponsored by the Translational Breast Cancer Research Consortium. Other sites may be added later.

At BCM, the study will be open at both sites of the Lester and Sue Smith Breast Center, the Baylor Clinic and the Harris County Hospital District’s Ben Taub General Hospital.

For more information on enrolling at the BCM sites, contact Anne Pavlick at or 713-798-7814.