Treatments for Breast Cancer 

At Siteman Cancer Center and WashU Medicine, we have one of the largest programs in the country for breast cancer treatment and care. With an extensive team of experienced breast specialists, you can be confident that you will receive the most comprehensive evaluation of your specific cancer and recommendations on how best to treat it. From small, early breast tumors to more advanced cancer, we have a multidisciplinary approach that includes reviews by medical oncologists, radiologists, surgeons, and immunotherapy specialists. 

Staging Your Cancer 

Once you have been diagnosed with breast cancer, the next step is for doctors to determine if it is contained in a small area or if it has spread. This is called staging.  

Breast cancers can be Stage 0, Stage 1, Stage 2, Stage 3, or Stage 4. The lower the stage number, the less the cancer has spread. The staging number is based on a comprehensive evaluation of imaging scans, laboratory tests, and biopsies. It also takes into account genetic testing that determines if you have a gene mutation that increases your risk for specific types of breast cancer. 

Advanced imaging will measure your precise tumor size (T) and check to see if any cancer has spread to nearby lymph nodes (N).  CT, PET, or MRI imaging scans also will determine if your cancer has spread, or metastasized, to other places in your body (M). This TNM designation helps to determine staging for cancer.  

Lab tests will check for biomarkers and identify if your breast cancer cells contain receptors for hormones such as estrogen and/or progesterone. Pathologists will take a close look at the breast tissue samples taken during your biopsy. You also may undergo a sentinel lymph node biopsy (SLNB) to obtain a tissue sample from a nearby lymph node to check for cancer spread. 

When everything is reviewed, doctors will use imaging, lab and genetic tests, pathology reports, and TNM status to stage your cancer and guide recommended treatment options.  

Treatment Options 

At Siteman Cancer Center and WashU Medicine, we have a broad range of treatment options for breast cancer. We also offer multiple clinical trials evaluating new treatments for breast cancer, including many that have been initiated or pioneered by WashU Medicine physicians and researchers at Siteman. 

• Surgery 
• Radiation Therapy 
• Cryoablation 
• Hormone Therapy 
• Chemotherapy 
• Immunotherapy & Targeted Therapies 
• Clinical Trials 

Surgery

Your Siteman Cancer Center breast specialists will work together and help you choose what’s right for you based on your specific diagnosis and preferences.  

Our surgeons have played a key role in advancing innovative approaches to breast cancer surgery. In addition to developing novel surgical techniques to improve outcomes, we have published extensive research on nipple-sparing mastectomies. We also specialize in immediate, direct-to-implant reconstruction along with these sparing techniques to enhance the look of your breast after surgery. 

If surgery is recommended, you have several options: 

• Lumpectomy 
  • Breast-conserving surgery that removes only the tumor and a small amount of surrounding tissue. This surgical procedure is often followed by radiation therapy. 
• Multiple Lumpectomy/Breast Conservation  
  • If you have 2-3 small tumors, we offer a specialized procedure that can remove each tumor separately, sometimes preventing the need for a full mastectomy. 
• Skin- and Nipple-Sparing Mastectomy 
  • Removal of breast tissue, but this procedure keeps most of your skin and sometimes your own nipple intact. 
• Mastectomy 
  • Removal of one of both of your breasts. Lymph nodes under your arm may also be removed in some cases. 

Experts in Breast Surgery

WashU Medicine breast surgeons at Siteman Cancer Center like Julie Margenthaler, MD, FACS have long-standing expertise in skin- and nipple-sparing mastectomies, having performed 1000+ procedures. This makes us one of the largest volume centers in the United States for these procedures. 

Breast cancer surgeon and physician-scientist Rebecca Aft, MD, the Jeffrey Moley Professor of Endocrine and Oncologic Surgery, is a recognized leader in translational research to better understand why breast cancer spreads or returns after treatment. She investigates newer treatments, including next-generation hormone therapies, to improve outcomes for patients with ER-positive breast cancer. 

High-tech infrared Medical Vision Goggles

High-tech infrared Medical Vision Goggles, invented by WashU Medicine researchers, help surgeons see cancer cells in real time during surgery. 

Advanced Reconstructive Surgery 

We have the most comprehensive range of reconstructive surgeries to consider if you have breast cancer. Our team includes plastic and reconstructive surgeons who work closely with cancer surgeons to produce exceptional cosmetic results. 

• Direct-to-implant reconstruction: This allows patients to receive permanent implants at the same time as their mastectomy, avoiding the common intermediate step of using tissue expanders and undergoing a second surgery later. 
• Pre-pectoral implant reconstruction: We are leaders in this newer procedure that places the implant above the pectoral muscle, which can lead to a more natural appearance, less pain, and faster recovery than under-the-muscle placement later. 
• Partial Breast Reconstruction (oncoplastic surgery): During this procedure, surgeons not only can remove large tumors, but they also reshape the breast to minimize dimpling or distortion. The procedure can be done immediately after a lumpectomy or after several months. In some cases, “fat grafting,” or volume replacement filler, is used to cosmetically improve the look and feel of your breast. 
• Advanced Flap Procedures: If you prefer not to use synthetic implants, our specialists can rebuild your breast using your body’s own natural tissue. These advanced, microsurgical, muscle-sparing surgeries transfer healthy skin and fat from another part of your body — such as the abdomen, thighs or back — to rebuild your breast.  
• Non-Surgical Reconstruction option: 3D-printed breast prostheses: If you choose not to have reconstructive surgery, we have the expertise with 3D printing and specialized photography to create highly customized, natural-fitting external prostheses that matchy our own breasts prior to treatment. Our 3D imaging simulator can also show you how your post-surgery breast will look before actual reconstruction surgery.

Radiation Therapy  

Radiation therapy for breast cancer has evolved rapidly in recent years, with shorter treatment plans, more precise radiation techniques, and personalized treatment plans. 

Siteman Cancer Center offers a wide range of radiation therapies for breast cancer, specializing in procedures that minimize damage to healthy tissue. Because we have precise technology for pinpointing the location of your tumors, radiation treatment plans are safer and more effective. 

MRI-Guided External Beam Radiation Therapy (EBRT): This is the most common form of radiation used after breast cancer surgery. It is used to destroy any microscopic cancer cells that may remain after surgery. It is considered standard practice after a lumpectomy. 

Brachytherapy: Siteman Cancer Center is a Center of Excellence for brachytherapy, which is ideal for treating small tumors in the breast. It involves placing small radiation “seeds” in the breast for about 5 days.  

Accelerated Partial Breast Irradiation (APBI):  This is a shorter course of treatment (one week or less) that is focused only on the area where a tumor was removed, rather than the entire breast.   

Hypofractionated Breast Radiation: This treatment plan uses fewer treatment sessions with slightly higher doses of radiation. It has been shown to be effective and safe, and some patients can receive just a handful of treatments versus multiple treatments over several weeks. 

Intensity-Modulated Radiation Therapy: These are advanced radiation procedures that can carefully shape the beams of radiation to minimize damage to healthy tissue and organs. 

Adaptive Radiation Therapy (ART): This makes radiation treatments more precise during the course of treatment. Based on daily CT scans, our radiologists adjust the treatment plan to account for changes in the tumor size. 

Whole Breast Radiation: If you need whole breast radiation, we have several methods to protect you during treatments, including the use of intensity-modulated radiation therapy (IMRT), which can carefully sculpt beams of radiation to protect the heart and minimize exposure to non-target areas. 

Radiation Procedures for Advanced Breast Cancer: We offer specialized procedures that deliver radiation directly into the lymph nodes under the arm, near the collarbone, or behind the breastbone. We also have radiation procedures that can shrink painful tumors in advanced (Stage 4) cases as part of a palliative care treatment plan. 

Cryoablation 

Cryoablation is a minimally invasive treatment that destroys cancer cells by exposing them to extremely cold temperatures. The procedure was approved by the FDA in 2025 for select patients with low-risk breast cancer. The American Society of Breast Surgeons also updated guidelines for breast cancer treatment in 2026 to include cryoablation as an option for certain patients. 

We are National Leaders in Cryoablation for Breast Cancer 

At Siteman Cancer Center and WashU Medicine, our physicians are pioneers in the use of cryoablation. We developed and started national clinical trials studying cryoablation as a potential alternative to surgery. We serve as the nation’s lead institution for the COOL-IT clinical trials now under way at several centers across the country. It is because of early promising results from these studies that the FDA approved cryoablation for select individuals with breast cancer. 

Who Can Get Cryoablation for Breast Cancer? 

Cryoablation could be an option if you have 

• Small, early-stage, low-risk breast tumors 
• Hormone receptor-positive, HER2-negative tumors 
• Are age 70 or older 

It also may be an option if you have a medical condition that makes surgery more difficult or risky. 

Benefits of Cryoablation 

• Minimally invasive 
• Outpatient procedure 
• Less pain and scarring  
• Fast recovery 

How It Works 

Cryoablation is a team-based procedure that involves interventional radiologists and breast surgeons.  

Radiologists use ultrasound to guide a thin, hollow needle direct into the tumor. Gas then moves through the probe to create a frigid cold temperature at the tip of the needle that then freezes and destroys cancer cells.  

Clinical Trials

A national clinical trial led by WashU Medicine physicians is under way to compare cryoablation to lumpectomy, a standard surgical treatment option for small, early-stage, localized breast cancer. Studies began in 2024. 

• The COOL-IT Trial: The first study to directly compare outcomes between cryoablation and the “gold standard” of lumpectomy surgery for early-stage tumors. 
  • Status: Actively enrolling patients 
• COOL-IT-PRO Registry: A multicenter registry to help assess long-term safety and follow-up for patients who receive cryoablation. 
  • Status: Actively adding patients 

Hormone Therapy

Hormone therapy is a treatment for certain types of breast cancer that grow in response to hormones like estrogen. It may be recommended for you before or after surgery and/or long-term treatment. It is also often combined with other treatments, such as targeted drug therapy or immunotherapy. 

Who Can Take Hormone Therapy? 

You may be given this treatment if you are diagnosed with hormone receptor-positive (HR+) breast cancer. It can be used if you have early or a more advanced stage cancer. 

Benefits of Hormone Therapy 

• Before surgery: Can shrink tumors to make surgery easier 
• After surgery: Reduces the risk of breast cancer recurrence  
• Long Term: Helps control cancer if it has spread 
• Easy to take — usually a pill 
• Can be taken if you are premenopausal or postmenopausal  

How it Works 

Hormone therapy is designed to lower the amount of hormones in your body or by blocking the cancer cells from using those hormones. 

Chemotherapy

Chemotherapy uses strong drugs to destroy cancer cells. It may be given to you in pill form or intravenously (IV) into a vein in periodic cycles over 3-6 months. 

Chemotherapy is used to shrink tumors prior to surgery (neoadjuvant therapy) or used after surgery (adjuvant therapy) to destroy any remaining cancer cells and reduce the risk of recurrence.  

Hair Loss Prevention During Chemotherapy 

One of the concerns that you may have while undergoing chemotherapy is potential hair loss. Because the drugs are powerful, you may experience hair loss during your chemotherapy treatment. An innovative technique called scalp cooling can help.  

We were the first in St. Louis to offer automated scalp cooling technology. 

Call our Care Coordination Center to learn more about scalp cooling at Siteman Cancer Center.

Immunotherapy and Targeted Therapies for Breast Cancer 

Immunotherapy uses your body’s own immune system to help find and destroy cancer cells. Some treatments help immune cells recognize cancer better, while others deliver medicine directly to cancer cells. 

At Siteman Cancer Center, our doctors and researchers are recognized leaders in breast cancer research and are studying new immunotherapies and cancer vaccines. Some immunotherapy treatments have become part of standard care practices for certain aggressive breast cancers, especially triple-negative breast cancer (TNBC). Other immunotherapies are available only through clinical trials. 

Personalized Cancer Vaccines 

One of the most promising areas of research is personalized cancer vaccines, sometimes called neoantigen vaccines. Every breast cancer tumor has its own unique genetic fingerprint. Doctors can analyze the DNA of your tumor to identify special proteins, called neoantigens, that appear on your cancer cells. We can then create a vaccine that will help your immune system better recognize and attack your cancer. Such cancer vaccines are not yet FDA-approved but are available in clinical trials for eligible patients at Siteman Cancer Center. 

We have leaders in the field of personalized cancer vaccines. In an early clinical trial for people with triple-negative breast cancer initiated here at WashU Medicine and Siteman: 

• Most patients who received a personalized vaccine remained cancer-free several years after treatment. 
• Researchers here and elsewhere are now studying whether combining cancer vaccines with other immunotherapies can further lower the risk of cancer returning. 
  

Immune Checkpoint Inhibitors 

Cancer cells can sometimes “hide” from the immune system. Checkpoint inhibitors are medicines that help unmask the cancer cells so that your immune cells can “see” and then attack the cancer. 

Checkpoint inhibitors may be used for: 

• High-risk, early-stage triple-negative breast cancer 
• Metastatic breast cancer (cancer that has spread) 
• Combination treatment with chemotherapy or other immunotherapies 
  

Antibody-Drug Conjugates (ADCs) 

Antibody-drug conjugates, or ADCs, are a newer type of targeted cancer treatment. 

These medicines combine: 

• An antibody that recognizes your particular breast cancer cells 
• A chemotherapy drug attached to the antibody 

The antibody acts like a guide, bringing the chemotherapy directly to cancer cells. This helps target cancer more precisely and may reduce damage to nearby healthy tissue. 

Aggressive Breast Cancers 

Aggressive breast cancers are treated by a multidisciplinary team that oversees a collaborative approach to chemotherapy, radiation, and surgery treatment. We have expertise in treating aggressive breast cancers with a multi-pronged approach that may include chemotherapy, radiation, surgery, targeted therapies, and immunotherapy. We also have several clinical trials under way. Among the aggressive cancers we see: 

• Triple-Negative Breast Cancer (TNBC): This type of cancer does not respond to hormone therapy or HER2-targeted therapy, so immunotherapy has become an important treatment option. 
• Inflammatory Breast Cancer (IBC): This is a rare and aggressive form of breast cancer that requires well-coordinated, intensive therapy. IBC is a specialized area at Siteman for both clinical care and research. Our researchers are actively studying new immunotherapies as well as heat-based therapies (hyperthermia) that may help your immune system respond better to treatment. 

Clinical Trials Focused on Breast Cancer

Clinical trials are a crucial part of breast cancer care at Siteman. These studies investigate new surgical procedures, radiation techniques, chemotherapy regimens, immunotherapies, targeted therapies (including vaccines), and lifestyle factors associated with breast cancer. 

We have more clinical trials than any other cancer center in the region, with around 350 studies currently underway. Some of these clinical trials were created by WashU Medicine  physician-scientists at Siteman and other breast cancer specialists. Several new drugs have emerged from our clinical studies and now have a promising impact on breast cancer,; including metastatic breast cancer. 

Learn more about Siteman’s breast cancer clinical trials. 

Breast Cancer Genetic Screening and Counseling

Know your risk for developing cancer or learn about the specific type of cancer you have with genetic screening.  

Why come to us for a genetic screening?  

We are leaders in the field. WashU Medicine breast cancer specialists helped to pioneer and patent the development of a 50-gene genomic test, ProSigna, that reliably identifies the four known types of breast cancer, thereby enabling oncologists to better personalize and better target you breast cancer treatment. 

Who should schedule a genetic screening? 

Anyone that has been diagnosed with breast cancer should schedule a genetic screening. Genetic screenings can tell you if your cancer was caused by an inherited mutation, which then guides the direction of your treatment options.  

Genetic screenings are also used for risk prediction. If there are family members or several close relatives that have had cancer, a screening will tell you if you carry an inherited gene that may increase the chance that you could develop cancer. 

Read more about the genetic testing and counseling process at Siteman. 

Support and Resources for You 

At Siteman Cancer Center, we understand that truly excellent cancer care requires compassion, expertise, and a personal touch tailored specifically to your life and your cancer type. 

From the moment you walk through our doors, you are surrounded by a team dedicated to addressing your needs and supporting your well-being. 

• Your Personal Guide: When you come to the Joanne Knight Breast Health Center, you will have a Care Coordinator by your side every step of the way. You can reach out to them at any point to get answers and information about your cancer care journey. 
• Your Mental Health: You and your family can receive free, specialized care from our dedicated psychologists who specialize in oncology care. They are here to help you through the emotional journey that cancer often creates. 
• Your Nursing Team: You will be cared for by experienced registered oncology nurses specially trained to support you. They are your partners in care, helping you manage symptoms and navigate treatments. 
• Your Personalized Nutrition: You have direct access to our registered dietitians. They are sub-specialists in oncology care and work with you to find meals and snacks that actually taste good and provide the strength you need during each phase of your treatment and beyond. 
• Your Comfort: We have palliative care specialists who are focused on helping you manage pain and any side effects so you can stay as comfortable as possible. 
• Your Life After Treatment: Through our Survivorship Program, we maintain a lifelong connection with you. We are committed to helping you embrace life to the fullest, long after your initial treatment ends. We also have breast cancer support groups that meet regularly. 

Get more information about supportive services at Siteman. 

We Make It Easy 

We have a one-stop location for you to get all the information and help you need. The Barnard Health & Cancer Information Center (BHCIC), located in the lobby of the Center for Advanced Medicine on the Washington University Medical Campus, can provide information about parking and nearby short- and long-term lodging accommodations. We also can connect you to free lodging facilities available for patients and caregivers who travel to St. Louis for treatment and meet certain criteria. 

BHCIC staff also can offer concierge or interpreter services. A Business Center also is on- site. 

Learn more about the services offered in our Barnard Health and Cancer Information Center on Floor 1 of the Center for Advanced Medicine on Washington University Medical Campus.