Titles and Affiliations

Professor of Medicine, Hematology and Oncology
Dudley and Tina Sharp Chair for Cancer Research
Founding Director Dan L. Duncan Comprehensive Cancer Center
Baylor College of Medicine
Houston, Texas

Research area

Identifying and treating drivers of resistance in advanced estrogen receptor-positive and HER2-positive breast cancers.


While effective treatments for estrogen receptor (ER)-positive and HER2-positive breast cancers are available, many tumors are or become resistant to these therapies. Drs. Osborne, Schiff, and their teams conduct laboratory and clinical studies to understand resistance to endocrine and anti-HER2 therapy and develop new treatment strategies to overcome it. They have a growing panel of experimental models of drug resistance and metastasis, as well as data from clinical specimens—valuable resources to advance the understanding of the molecular drivers of drug resistance that can be shared with the wider research community.

Progress Thus Far

The team developed a variety of experimental models, including organoids—a three-dimensional sphere of cultured tumor cells grown in conditions that more closely mimic tissue architecture—and patient-derived models in order to study tumor growth and response to drugs. Using these innovative model systems, the team discovered a potential role of the immune system in resistance to CDK4/6 inhibitors in ER-positive breast cancer, which may be overcome by repurposing existing drugs. They also revealed a cholesterol producing pathway that plays a role in anti-HER2 resistance. 

What’s next

Based on findings to date, the team will further expand their panel of drug-resistant breast cancer models, in particular, those that are resistant to endocrine, CDK4/6, and anti-HER2 therapies to test new drug combinations. 


Dr. Osborne was born in St. Louis, Missouri and received his AB and his MD from the University of Missouri, both with honors. He completed his internship and residency at Johns Hopkins and followed this with three years as a Clinical Associate at the Medicine Branch of the National Cancer Institute. He was a faculty member at the University of Texas Health Science Center from 1977 until 1999 and became Chief of Medical Oncology in 1992. In 1999, Dr. Osborne moved to Baylor College of Medicine to direct a new Breast Center and in 2004 was named Director of the Dan L. Duncan Comprehensive Cancer Center at Baylor.

Dr. Osborne's research interests have focused on the biology and treatment of breast cancer. He has published extensively on the role of growth factors in breast cancer pathogenesis, and has also investigated the mechanisms of action and resistance to ER and HER2 targeted therapies in breast cancer. Dr. Osborne currently directs the Baylor Breast Cancer Specialized Program of Research Excellence Grant. Dr. Osborne has authored more than 400 manuscripts dealing with the biology and treatment of breast cancer.

BCRF Investigator Since


Donor Recognition

The Macy's Award

Areas of Focus