Patient information: Adjuvant chemotherapy and trastuzumab (Herceptin) for early stage breast cancer

INTRODUCTION

Breast cancer is the most common female cancer in the United States. Finding and treating breast cancer in the early stages allows many women to be cured.

After breast cancer is removed with surgery, there is still a risk that cancer cells have broken away from the tumor and spread to other parts of the body. Adjuvant therapy is given after surgery to get rid of any tumor cells that remain. Adjuvant therapy improves the chance of curing breast cancer and decreases the risk of dying of breast cancer. Thus, adjuvant therapy is a very important part of modern breast cancer treatment.

There are three different types of adjuvant therapy for breast cancer: endocrine therapy, chemotherapy, and trastuzumab (Herceptin®). This article will focus on chemotherapy and trastuzumab. An introduction to breast cancer and an overview of available treatments is also available. (See "Patient information: Breast cancer guide to diagnosis and treatment".) More detailed information is available by subscription. (See "Adjuvant systemic therapy for older women with early stage breast cancer".)

CHEMOTHERAPY

Chemotherapy is a treatment given to slow or stop the growth of cancer cells. Even after a cancer has been removed with surgery, cancer cells can remain in the body, increasing the risk of a relapse (increasing the risk that the cancer comes back). Chemotherapy can eliminate these cancer cells and increase the chance of cure. This type of chemotherapy is called "adjuvant", which means that it is given after surgery.

Chemotherapy is not given every day but instead is given in cycles. A cycle of chemotherapy (which is typically 21 or 28 days) refers to the time it takes to give the treatment and then allow the body to recover from the side effects of the medicines. This treatment usually involves a combination of several chemotherapy drugs (called regimens).

Chemotherapy is usually started within four to six weeks after surgery and is given for three to six months. Most women who undergo breast-conserving treatment (lumpectomy) will need radiation treatment after surgery. Chemotherapy is usually given after surgery, before the start of radiation. (See "Patient information: Surgery for breast cancer: Mastectomy and breast conserving therapy".)

Your doctor can describe which chemotherapy drugs will be needed, how long treatment will last, and what side effects are expected from your treatment.

Do I need chemotherapy? — Not all women with breast cancer need chemotherapy. Two tools are available to help decide if chemotherapy is needed. Ask your doctor or nurse if these tools would be helpful in deciding whether chemotherapy is needed in your case.

• Adjuvant! (www.adjuvantonline.com) is a program available online that can help to determine your risk of a breast cancer relapse and the possible benefits of chemotherapy and endocrine therapy.
• Oncotype DX assay™, also known as 21 gene recurrence score assay, can help to estimate your risk of a breast cancer relapse (and the possible benefits of chemotherapy and endocrine therapy).

Side effects of chemotherapy — Chemotherapy can cause side effects during and after treatment. The type and severity of these side effects depends upon which chemotherapy drugs are used.

Side effects that occur during chemotherapy are usually temporary and reversible. The most common side effects are nausea, vomiting, mouth soreness, temporary lowering of the blood counts, and hair loss.

Long term side effects can include premature menopause (ovarian failure), damage to the heart, and a small risk of leukemia.

TRASTUZUMAB (HERCEPTIN)

Trastuzumab (Herceptin®) is drug that targets a protein called HER2, which is found in high levels in some breast cancers. Trastuzumab may be recommended, in addition to chemotherapy, if your breast cancer is lymph node positive, HER-positive, or node-negative but at a high-risk of recurring. (See "Adjuvant chemotherapy and trastuzumab for HER2-positive early breast cancer".)

Trastuzumab is given by IV once per week (or once every three weeks), usually for one year. It is generally given after chemotherapy has been completed. The most common side effect of trastuzumab is fever and/or chills. Heart failure develops in about 3 to 5 percent of women treated with trastuzumab. Trastuzumab-related heart damage may not be permanent.

WHICH TREATMENT IS RIGHT FOR ME?

There are many options for the adjuvant therapy of breast cancer, and deciding which is best can be confusing. Expert guidelines help clarify which treatments are most appropriate for large groups of women. However, individual factors (your preferences, cancer stage) are also important to consider. You should discuss your options for adjuvant therapy with your doctor to determine which therapy is best.

FOLLOW UP AFTER TREATMENT

A summary of the American Society of Clinical Oncology's recommendations for follow up after breast cancer treatment is provided in the following table (table 1).

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Breast cancer guide to diagnosis and treatment
Patient information: Surgery for breast cancer: Mastectomy and breast conserving therapy

Professional Level Information:
Adjuvant chemotherapy and trastuzumab for HER2-positive early breast cancer
Adjuvant chemotherapy for early stage HER2-negative breast cancer
Adjuvant endocrine therapy for postmenopausal women with early stage breast cancer
Adjuvant endocrine therapy for premenopausal women with early stage breast cancer
Adjuvant systemic therapy for older women with early stage breast cancer
An overview of breast cancer and treatment for early stage disease
Diagnostic evaluation of women with suspected breast cancer
Follow-up for breast cancer survivors: Recommendations for surveillance after therapy
General principles of management of early breast cancer in older women

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Cancer Institute

       1-800-4-CANCER
       (www.nci.nih.gov)

• American Society of Clinical Oncology

      (www.cancer.net/portal/site/patient)

• National Comprehensive Cancer Network

      (www.nccn.com)

• American Cancer Society

       1-800-ACS-2345
      (www.cancer.org)

• Adjuvant! Online

       (www.adjuvantonline.com)

• Susan G. Komen Breast Cancer Foundation

       (www.komen.org)

Patient support — There are a number of online forums where patients can find information and support from other people with similar conditions.

• About.com Breast Cancer Forum

      (http://breastcancer.about.com/forum)

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