The Margie Petersen Breast Center / Breast Oncology

The Margie Petersen Breast Center at Providence Saint John’s Health Center brings you some of the finest breast cancer care in Southern California. We focus on caring for the whole person: mind, body, and spirit. Here, you can benefit from innovative and compassionate care along with an array of support services to support your emotional wellbeing to complement your medical treatment. Our unique partnership with the Saint John’s Cancer Institute offers an environment which combines clinical excellence with novel research, to provide all our patients exceptional care.

Margie Petersen Breast Team Group photo of doctors from the breast center team Five women in front of the Margie Petersen Breast Center sign

A One-Stop, Comprehensive, Multidisciplinary Clinic

Breast Health Clinic

Breast Cancer Clinic

A New Way to Approach Breast Health

The Margie Petersen Breast Center wants to change the way women look at breast health. We have a complete diagnostic center to help immediately identify and treat breast issues. We take an integrated approach to breast health. Throughout their course of care, our patients are surrounded by a team of healthcare professionals who focus on the whole person. Our physicians provide tools to improve overall health, in a place women can trust.

Services Provided:

  • Onsite advanced imaging, including 3-D mammography
  • Innovative surgical and non-surgical treatments
  • Genetic risk assessment and prevention, especially for BRCA1 and 2 gene mutations
  • Access to the latest clinical trials and research
  • Complementary therapies including nutrition, mindfulness, and yoga
  • Breast cancer prevention and survivorship strategies
  • Complete care teams including breast radiologists, radiation oncologists, pathologists, genetic specialists, nurse navigators, and nurse practitioners
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A Team of Experts on Your Side

We take into account your condition, medical history, lifestyle and personal preferences. Then our experts prepare a personalized plan, giving you the most effective, gentlest treatment options. Every breast cancer is different, and not all options are appropriate for everyone.

Once treatment is over, we help you transition back to normal life and keep a close watch on you. Together, our dedicated team helps you achieve the best outcomes possible. In addition to our experienced breast surgeons, our collaborative team includes:

  • Breast radiologists
  • Radiation oncologists
  • Pathologists (specialist physicians who analyze tissue specimens)
  • Breast health specialist nurse practitioners
  • RNs who provide education and support
  • Genetic specialists who focus on risk assessment and prevention
  • Licensed clinical social workers who offer counseling and connect you to resources
Meet Our Team
Breast Cancer Team of doctors

Quick Appointments & Results

Finding a breast lump can be unsettling for both women and men, alike. Fortunately, most mammographic calcifications and painful breast lumps are not cancer, which is why we offer the peace of mind that comes with quickly securing an appointment.

Schedule an Appointment
Doctors looking at mammogram results

The Latest Clinical Trials and Research

Clinical trials help doctors and scientists find better ways to diagnose, treat, and prevent disease. Individuals who volunteer for clinical trials play an active role in their own health care and help others by advancing medicine. Our doctors make clinical trials a regular part of cancer care to increase overall cancer survival and expedite the development of a cure. At the Saint John’s Cancer Institute you can participate in studies led by internationally renowned researchers. If you are interested in a clinical trial, please speak with your provider.


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Research lab for breast center

Our History

In the early 1990’s the leaders of the Saint John’s Cancer Institute raised the idea of creating a center dedicated to the treatment and research of breast cancer. An extraordinary gift from Joyce Eisenberg Keefer, a dedicated champion for cancer research and treatment, allowed them to bring their vision to fruition and, in 1993, they opened the multidisciplinary breast center at Saint John’s Health Center. Unfortunately, the building that housed the breast center was damaged beyond repair in the 1994 Northridge earthquake. Once again a generous philanthropist, Margie Petersen, stepped in to provide the financial support necessary to rebuild the breast center.

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Five women in the Margie Petersen Breast Center building


Thank you Dr. Grumley for accepting me as a patient at the Margie Petersen Breast Cancer Center. I am forever blessed and grateful to have been referred to you. Your breast cancer specialty has given me quality of life. Thank you for your gentleness, kindness, and caring spirit. My family and I thank you from the bottom of our hearts.

Breast Cancer Patient

I went to see Dr. Fischer about a breast cancer returning. He had returned from a breast cancer conference a week before and shared some recent insight about my cancer. He has a wonderful bedside manner and is respectful and patient.

Breast Cancer Patient

I am now days away from chemo #2 of 8 and I want to thank Dr. Grumley, my incredible breast surgeon. I was fearful at every step, but I trusted Dr. Grumley and her team. She saved my life!

Breast Cancer Patient

Dr. Fischer is always available by cell and stayed in constant contact throughout the winter holidays. He and his team are true professionals and I highly recommend him.

Breast Cancer Patient

I have been coming to the Margie Petersen Breast Center for years for my mammograms and I have never encountered anything except great service by competent and knowledgeable staff. Everyone is always warm and friendly.

Breast Health Patient