Medical Breast Cancer Treatment


Medical treatments for breast cancer continue to advance, offering more ways to fight cancer and keep it from coming back. At Mercy, your multispecialty team includes a medical oncologist—a doctor with training and expertise in non-surgical treatments for all types and stages of breast cancer. Your Mercy medical oncologist will help determine, plan and provide the treatment that’s right for you.

Medical Treatment for Breast Cancer

Depending on your age, along with the type and stage of your cancer, your treatment plan may include systemic therapies such as hormone therapy, chemotherapy, targeted therapy or bone-modifying drugs.

Hormone Therapy for Breast Cancer

Some types of breast cancer use hormones to grow and spread. If your breast cancer is hormone-sensitive or hormone-dependent, you may be treated with hormone therapy. Types of hormone therapy include:

  • Drugs that prevent hormones from attaching to cancer cells. These medications include the long-used drug Tamoxifen.
  • Drugs that stop hormone production. These include a class of drugs called aromatase inhibitors (AIs). They’re only used in women who have gone through menopause.
  • Treatments to remove the ovaries or prevent them from working. Before menopause, your ovaries produce most of your estrogen and progesterone. Pre-menopausal women with breast cancer may have their ovaries surgically removed. Or they may receive injections to shut down their ovaries.


The type of hormone therapy you’ll need depends on the kind of breast cancer you have, your age and whether you’ve completed menopause. You may use one drug or a combination of drugs. For example, some women take Tamoxifen for several years then switch to an AI after menopause. Hormone therapy is often used before or after other breast cancer surgeries, such as lumpectomy or mastectomy.

Treating breast cancer with hormone therapy can help:

  • Prevent cancer recurrence
  • Keep cancer from growing and spreading
  • Shrink a tumor before surgery
  • Lower risk if you’re at high risk of developing breast cancer

Your Mercy care team will make sure you understand what to expect before, during and after hormone therapy. For example:

  • You may need to take hormone therapy for 5-10 years.
  • Common side effects include hot flashes, vaginal dryness, mood changes, weight gain and night sweats.


Like all medications, hormone therapy drugs have risks. Drugs like Tamoxifen may slightly increase your risk of blood clots or uterine cancer. 

At Mercy, we’ll take time to answer your questions, address your concerns and make sure you feel comfortable and informed before starting any new therapy.  Your Mercy doctor can help you find ways to manage the side effects of hormone therapy.

Chemotherapy for Breast Cancer

Chemotherapy (chemo) uses drugs to stop or slow the growth of cancer cells. Not all breast cancer patients need chemo. Mercy medical oncologists determine the best course of treatment based on individual needs.

Chemo treatment can be delivered orally or directly into the veins by IV. Mercy Infusion Centers provide outpatient infusion services in a warm and comforting environment. Patients have the flexibility to receive chemo where it’s most convenient while keeping their electronic medical records centralized.

Many patients are anxious about the side effects of chemo. Your Mercy doctor can help prevent and manage them. Mercy also offers complementary treatments and therapies to reduce and manage side effects.

Biomarker Testing in Breast Cancer Treatment

Mercy Clinic oncologist Dr. Bethany Sleckman explains biomarker testing in breast cancer and how it’s used in treatment planning.

Targeted Therapy for Breast Cancer

Targeted therapy directs treatment to specific breast cancer cells, causing less damage to surrounding tissues. Targeted therapy identifies specific sites or processes (targets) that are important to the function of cancer cells. For example, drugs can target HER2 on breast cancer cells, a protein that helps them grow and spread.

Radiation therapy can also deliver targeted therapy to breast cancer tumors. The Mercy radiation oncology team uses a variety of techniques with different equipment to deliver targeted radiation therapy. The types of radiation therapy used for breast cancer include:


3D Conformal Radiation Therapy (3DCRT)

This technique makes three-dimensional (3D) images of cancer tumors and surrounding areas. Radiation beams are custom-shaped to treat tumors precisely.


Intensity-Modulated Radiation Therapy (IMRT)

IMRT is similar to 3DRT, but it varies the intensity levels of beams, allowing stronger doses to reach specific areas of cancer tumors.


Tomotherapy & Volumetric Modulated Arc Therapy (VMAT)

Tomotherapy and VMAT are delivered on machines that rotate around the body in an arc, targeting tumors from many directions. Built-in imaging systems provide precise tumor treatment. VMAT also offers shortened treatment times.



Brachytherapy, internal radiation therapy, is delivered internally through a catheter into the lumpectomy cavity.  


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

SRS and SBRT are used when breast cancer spreads to other parts of the body, such as the brain, lung, liver or bone. They deliver high-dose radiation to extremely precise locations in up to five outpatient sessions. No surgical incisions are required. 

Bone-Modifying Drug Treatment for Breast Cancer

Bone-modifying drugs are used in breast cancer treatment to protect and strengthen bones that have been weakened by invading breast cancer cells. These medications can also be used to treat or prevent osteoporosis due to AI therapy.

Talk with your doctor about whether one of these medications is right for you.

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