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Steffi Oesterreich, PhD

Professor of Pharmacology and Chemical Biology
Professor & Vice Chair for Precision and Translational Pharmacology
Director of Education, Women's Cancer Research Center
Magee Women's Research Institute
University of Pittsburgh Cancer Institute
Pittsburgh, Pennsylvania

Current Research

  • Seeking to characterize the unique biology of invasive lobular breast cancer (ILC) for the development of personalized treatment strategies for this group of patients.
  • Laboratory studies are ongoing to understand mechanisms of drug resistance in ILC.
  • This work will provide valuable insight into an understudied type of breast cancer and may lead to potential new druggable targets to improve outcomes for ILC patients.

Invasive lobular breast cancer (ILC) is the second most common type of breast cancer, but its unique disease characteristics are just beginning to be understood. Resistance to anti-hormone drugs is a common characteristic and better treatments are needed. Dr. Oesterreich is leading laboratory studies to understand the causes of drug resistance in ILC so that personalized treatments can be developed to improve outcomes for women with this disease.

Full Research Summary

Invasive lobular carcinoma (ILC) is the second most common histological subtype of breast cancer. Although the majority of ILCs are estrogen receptor positive (ER+) and typically have a better prognosis than other invasive breast cancers, ILC is clearly very different from invasive ductal carcinoma, and its unique biology is poorly understood. 

Recent studies, including the analysis of ILC within The Cancer Genome Atlas, have shown that ILC is not only visibly distinct but also a molecularly distinct disease. The focus of Dr. Oesterreich's BCRF research is to better understand resistance to anti-estrogen therapies and to develop more personalized treatment strategies for this group of patients. 

Previous work from the Oesterreich group suggests that the estrogen receptor regulates a unique set of molecular programs in ILC, making this type of breast cancer more resistant to anti-estrogen therapy. The team identified other protein signaling factors that may be targets to improve response to treatment and are continuing to pursue these studies.

In the coming year, they will use a combination of approaches, including analysis of ILC clinical samples, mechanistic studies using ILC cell lines, and computational approaches to identify genes and pathways that may be responsible for resistance. They are further investigating previous observations regarding cellular metabolism and expression of immune genes in laboratory models. These efforts are leading to a better understanding of a relatively understudied type of breast cancer.

With increasing national and international awareness of and interest in ILC, these studies are very timely, and will provide critical insight and will serve as invaluable resources for the ILC (and general breast cancer) research community.


The main interest of Dr. Oesterreich’s research is to further our understanding of hormone action in women’s cancer in order to use this knowledge for improved diagnosis and endocrine treatment. Her studies have focused on breast cancer and in receptor action in ovarian cancer. Her lab studies how the estrogen receptor (ER) functions, how its activity is regulated by diverse signaling pathways and through coregulator proteins, and if and how these mechanisms are perturbed in cancer cells. The Oesterreich lab is interested in novel concepts of ER action, such as its role in repression of gene transcription and its role in epigenetic marks in the genome. Dr. Oesterreich’s lab has also a strong interest in situ and invasive lobular disease, with a focus on estrogen and antiestrogen response. In her role as Director of Training in the Women's Cancer Research Center, she is interested in providing outstanding training opportunities to the next generation of women's cancer researchers.

Large Researcher Headshot - Oesterreich Steffi

BCRF Investigator Since


Donor Recognition

The Citrone 33 Foundation Award

Area(s) of Focus