Associate Professor, Department of Pathology,
University of Colorado Anschutz Medical Campus
Areas of Focus: Treatment and Tumor Biology
Co-Investigator: Kathryn Horwitz, PhD, University of Colorado Denver, Denver, Colorado
- Seeking to identify new treatment approaches for recurrent luminal breast cancers.
- Laboratory studies are conducted to explore the potential benefit of progestin-based therapies for patients whose breast cancer has come back.
- This research will help to determine whether drugs used for birth control may provide a less-toxic approach for women with estrogen-driven breast cancers.
Most breast cancers require estrogen to grow. These are treatable and often curable with anti-estrogen therapies, but for some women the breast cancer will come back, sometime many years later. When breast cancers recur, they are often resistant to the treatment that the patient initially received. The standard therapy then is a combination treatment that works well for many, but not all women. Dr. Sartorius is conducting studies to test an alternative and less toxic approach for women with recurrent estrogen-drive breast cancers.
Full Research Summary
Approximately 75 percent of all breast cancers fall into the luminal classification. These tumors are characterized by having both estrogen and progesterone receptors. Most patients with luminal breast cancer have a very good five-year prognosis when treated with anti-estrogen therapies, like the anti estrogen tamoxifen or aromatase inhibitor after breast cancer surgery. While these therapies can be curative, luminal breast cancer survivors face an unsettling lifelong risk of recurrence.
Current treatments for recurrent breast cancer include an aromatase inhibitor plus newer drugs called CDK4/6 inhibitors (palbociclib, ribociclib and abemaciclib). These drugs prolong survival, but are not curative, have serious side effects, and not all patients receive benefit.
Luminal tumors also have progesterone receptors (PRs), which are natural inhibitors of estrogen receptors. Dr. Sartorius and her team propose that progestin-based therapies may be a less-toxic option for some patients with luminal disease.
Progestin-based birth control is widely used for healthy women. However, the role of progestin as a breast cancer treatment has been controversial, with both “beneficial” and “harmful” effects widely reported. This year, Dr. Sartorius’ team will conduct laboratory studies to shed new light on the controversy so that patients with luminal breast cancer may benefit from these drugs.
Dr. Sartorius earned her bachelor’s degree from the University of Michigan and PhD from the University of Colorado Health Sciences Center, both in Molecular Biology. She did her postdoctoral work at the University of Colorado Boulder and is currently an Associate Professor at the University of Colorado Anschutz Medical Campus (UC-AMC).
Dr. Sartorius’s research studies the biology, progression, and endocrine resistance of hormone receptor positive breast cancer. Her laboratory seeks to understand the molecular basis of transcriptional regulation by progesterone receptors (PR) and how this impacts estrogen receptors (ER) and tumor cell phenotype. Current research topics include hormone regulation of cancer stem cells and tumor heterogeneity, hormone regulation of metastasis, hormone control of translation and protein synthesis, and how host obesity and metabolic syndrome specifically affect ER+ breast cancer and endocrine resistance. Dr. Sartorius’s team also specializes in developing hormone-dependent breast cancer models. She is the co-founder and co-director (with Dr. Peter Kabos) of the breast cancer patient-derived xenograft (PDX) bank at UC-AMC. Their collection emphasizes ER+PR+ tumors. These tumor models are being characterized by genomic and proteomic techniques to discover novel hormone receptor interactions that can be leveraged for treatment. The goal is to improve hormone-directed therapies for breast cancer.
She is an active member of the Cancer Biology Training Program at UC-AMC with an interest in training the next generation of scientists in the field of hormones and cancer. Her laboratory trains predoctoral students, and postdoctoral and clinical fellows.