Breast Cancer Treatment

Developing Your Personalized Cancer Treatment Plan

A diagnosis of breast cancer is a life-changing experience and Mercy has the focused, expert care you need. At Mercy you’ll be guided by a breast cancer Nurse Navigator, who works with patients and their families to assist in coordinating cancer care and support resources. They advocate for patients by helping translate complex medical information into understandable language, while making the overwhelming more manageable.

We understand that each patient's breast cancer outlook differs, depending on the cancer’s stage and other factors such as hormone receptors, general state of health and treatment. The breast itself is treated by surgery, often in combination with radiation. To reach cancer cells that may have spread beyond the breast and nearby tissues, drugs can be given by pills or by injection. This type of treatment is called systemic therapy. Examples of systemic treatment include chemotherapy, hormone therapy, and other types of targeted therapy.

Breast Cancer Surgery

Mercy provides many options for surgical treatment of breast cancer. We’ll help you understand all the options and work with you to develop a personalized treatment plan.


Lumpectomy, also called a partial mastectomy or wide local excision, is for the technique of excising cancerous tissue while preserving the rest of the breast. The goal is to remove the cancer and minimal normal tissue around it to ensure all the cancer is gone. Lumpectomy is generally used in conjunction with radiation to obtain the lowest recurrence rate possible, usually with success rates similar to mastectomy. Lumpectomy can also be performed in conjunction with a breast reduction in some cases. This is called oncoplasty  and would be performed by a Mercy breast surgeon and plastic surgeon working together.


Mastectomy is procedure to remove the entire breast, also called a total mastectomy and simple mastectomy. Radiation is often not needed with mastectomy. The option of breast reconstruction is available in most cases and can be performed at the same time as the mastectomy. If you choose mastectomy without reconstruction you may have a prostheses and special bras following your surgery.

Axillary Lymph Node Evaluation

If breast cancer spreads, it travels first to axillary lymph nodes under the arm. We routinely look at these lymph nodes as part of your surgical evaluation, in conjunction with a lumpectomy or mastectomy. There are two main surgical options to evaluate and treat the spread of cancer. A sentinel lymph node biopsy is performed by removing 2-4 lymph nodes for analysis. If cancer is detected in the biopsy, a more thorough lymph node axillary dissection is performed.   

Breast Reconstruction

Breast reconstruction can be done at the time of lumpectomy or mastectomy or in a delayed fashion. Your Mercy care team will guide you through your options and develop a personalized treatment plan. We also provide second opinions and revision procedures if you’ve had issues related to breast reconstruction.

Breast reconstruction by Mercy’s board-certified plastic surgeons is performed at both Mercy Hospital St. Louis and Mercy Outpatient Surgery Center - Clayton-Clarkson.

Please contact our office for more information and for scheduling appointments (314) 251-8750.

Possible breast reconstruction treatments include:

Oncoplastic Surgery and Reconstruction

Performed at the same time as a lumpectomy, a breast lift or reduction can be used to improve the shape and contour of the breast. This can improve long-term symmetry.

Implant-Based Reconstruction

Tissue-expander-based reconstruction is done in two steps. The tissue expander is placed at the time of the mastectomy or it can be done after the mastectomy. A biological mesh may be placed above or below the muscle during the procedure. Your Mercy plastic surgeon will describe the differences for you in detail. After cancer treatment is complete, the implant can be placed. This is the most common form of breast reconstruction.

Direct to implant reconstruction can occur in certain circumstances. The implant is placed at the time of the mastectomy. A biological mesh is typically used to help hold the implant in place.

Latissimus Flap Reconstruction

This is a hybrid procedure involving the use of your own tissue and an implant. It is not commonly done as a primary form of reconstruction but can be done in cases of a complications, open wound or previous radiation. Skin and muscle from the mid to lower back is rotated through the axillary area and secured in the front for reconstruction. The tissue flap can be done by itself or used in conjunction with a tissue expander or implant.

Abdominal Flap Reconstruction

Pedicled TRAM flap reconstruction is done with the reclusive muscle from the abdomen as well as the skin and tissue above it. It can be done in a unilateral or bilateral reconstruction and does not involve the use of an implant or microsurgery. Your Mercy doctor can discuss the risks associated with this type of procedure.

Deep Inferior Epigastric artery Perforator (DIEP) flap uses the same skin and tissue as the pedicled TRAM flap, but the muscle is saved. The tissue is removed from the abdomen attached to blood vessels, and those blood vessels are reconnected in the chest. This minimizes the morbidity to the abdomen and provides a soft supple reconstruction without the use of an implant.

Other microsurgical reconstructions are available at Mercy involving the tissue of the medial thigh for patients who are not good candidates for abdominal flap reconstruction.

Medical Treatment for Breast Cancer Treatment

A medical oncologist will help you determine what oral or IV medicines can be used to help treat your cancer. Standard options are a pill or chemotherapy. Not everyone needs chemotherapy to have a good outcome. This is also an area where there are often clinical trials.

Additional Breast Cancer Testing

Whenever a breast biopsy shows cancer, Mercy pathologists test the tumor for three standard biomarkers:

  • Estrogen receptor (ER)
  • Progesterone receptor (PR)
  • HER2

Most breast cancers do express ER and/or PR. This means they grow in response to female hormones. We can use endocrine therapy (estrogen blocking medication) to treat these cancers.

HER2 is found in about 25 percent of breast cancers. This is a marker of a more aggressive type of cancer. However, it also means that we can use very effective targeted anti-HER2 therapy to treat the cancer.

In women with Stage IV breast cancer that has spread to other parts of the body, the goal for Mercy doctors is to maximize efficacy while minimizing toxicity. For example, we now have FDA-approved medications (PARP inhibitors) to treat BRCA(+) HER2- metastatic breast cancer. Targeted treatment therapy is typically paired with more traditional treatments, such as chemotherapy and radiation.

Breast cancer that does not express any of these markers is called “triple negative.” This cancer is more difficult to treat but we have several good options, including clinical trials, for patients with triple negative breast cancer.

Subtyping of Tumors

Dr. Cara Hahs

Endocrine Therapy

If your cancer is ER positive (estrogen receptor positive), part of your treatment may be a pill. Examples are Tamoxifen, Femara, and Arimidex. These pills block or decrease hormonal stimulation to the breast and can lower recurrence rates.


Chemotherapy (chemo) delivers targeted anti-cancer drugs to wipe out or slow the growth of cancerous cells. Not all breast cancer patients will need chemo. Mercy specialists will determine the optimal course of treatment based on each patient’s unique needs.

Breast cancer patients needing chemo can receive treatment at our infusion centers. All of Mercy’s St. Louis-area infusion centers are connected via MyMercy’s Electronic Health Record system, allowing patients to receive chemo where it’s most convenient at the time. This flexibility can be a big time-saver for our patients.    

As side effects to chemo arise, we still want patients to feel confident and comfortable. For breast cancer patients undergoing chemo treatments, Mercy offers a wide range of healing services to reduce and manage side effects.

Mercy’s integrative approach to managing chemo side effects during chemo includes:

  • Pain Management, including Calmare® treatments
  • Healing Touch therapy during chemo
  • Cold Capping Support
  • Acupuncture
  • Nutrition Therapy
Cold Caps for Chemotherapy Patients

For many people, hair loss from chemo can be reduced by wearing a cold cap, or scalp-cooling device, during treatment. Special coolants in the cold cap work to limit the amount of chemotherapy delivered to the hear follicle, reducing the risk of hair loss.

Radiation Therapy for Breast Cancer Treatment

The Mercy Radiation Oncology treatment team utilizes a variety of treatment planning and delivery techniques, and different treatment machines to deliver external beam radiation.

3D Conformal Radiation Therapy (3DCRT)

This the most commonly used treatment technique for breast cancer. This technique uses a few radiation beams custom-shaped to the area being treated, often with the beams broken up into several smaller beams of varying intensity throughout the target area.

Intensity Modulated Radiation Therapy (IMRT)

This differs from 3D treatment in that it uses a larger number of beams and intensity levels within each beam. IMRT can be used to deliver extremely precise treatment to tumors close to critical normal tissues, and often at higher doses than typically employed, such as for unresectable tumor.

TomoTherapy and VMAT

These are types of “volumetric arc” IMRT therapy delivered on specialized machines that rotate around the patient in an arc. Built-in CT imaging capability on these machines allow precise alignment of treatment to tumors inside the body, such as enlarged lymph nodes and recurrent tumors.

Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT)

These are used for breast cancer that has spread to other organs, such as the brain, lung, liver or bone. This type of treatment is delivered using several beams or arcs of varying intensities in 1-5 sessions on an outpatient basis. Because there is no surgical incision, patients are able to return to their normal activities usually within hours of treatment.