BREAST CANCER OVERVIEW

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.

This article will focus on the surgical treatment of breast cancer. An introduction to breast cancer and an overview of treatment for breast cancer is also available. (See "Patient information: Breast cancer guide to diagnosis and treatment (Beyond the Basics)".)

BREAST CANCER STAGING

In addition to removing the cancer from the breast and lymph nodes, surgery also provides important information about the "stage" of the cancer. The stage of the breast cancer (TNM) is based upon the size of the tumor in the breast (T), status of lymph nodes (N), and metastatic spread to distant sites (M).

Staging is discussed in detail in a separate article. (See "Patient information: Breast cancer guide to diagnosis and treatment (Beyond the Basics)".)

FACTORS AFFECTING SURGICAL TREATMENT

Several factors must be considered when choosing the best surgical treatment for your breast cancer. You should discuss these factors with your physician as you decide which treatment is best for you.

Microscopic findings — The surgeon must determine if a breast cancer is invasive or noninvasive (in situ). (See "Patient information: Breast cancer guide to diagnosis and treatment (Beyond the Basics)", section on 'Types of breast cancer'.)

Invasive breast cancer — Invasive breast cancers usually require surgical treatment (mastectomy or breast conserving therapy) as well as treatment after surgery (called adjuvant treatment). Adjuvant treatment can include radiation as well as systemic treatment such as chemotherapy or endocrine therapy.

Noninvasive (in situ) breast cancer — Noninvasive or in situ breast cancer is divided into two types: lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS).

• LCIS — Women with LCIS have an increased risk of developing breast cancer in the future. However, LCIS does not require treatment. Management of LCIS is discussed separately. (See "Atypia and lobular carcinoma in situ: High risk lesions of the breast".)
• DCIS — Women with DCIS require surgical treatment (mastectomy or breast conserving therapy) as well as treatment after surgery (called adjuvant treatment). Adjuvant treatment can include radiation as well as systemic treatment such as endocrine therapy. Chemotherapy is usually not necessary. (See "Ductal carcinoma in situ: Treatment and prognosis" and "Microinvasive breast carcinoma".)

Size of the breast tumor — Larger tumors are more likely to recur and usually require more aggressive treatment. Large tumors (5 cm or about the size of an egg) may require chemotherapy before surgery, which is called neoadjuvant chemotherapy. This is given in order to shrink the tumor and allow for lumpectomy. (See "Neoadjuvant therapy for breast cancer: Rationale, pretreatment evaluation, and therapeutic options".)

Tumors that invade the skin and inflammatory breast cancers also require chemotherapy and mastectomy is usually recommended for these more advanced cancers. This is discussed in a separate article. (See "Patient information: Locally advanced and inflammatory breast cancer (Beyond the Basics)".)

Spread to the lymph nodes — Lymph nodes (or glands) are usually the first place for breast cancer to spread. If a breast cancer has spread to lymph nodes, it is called node-positive; a cancer that has not spread to the lymph nodes is called node-negative. If a breast cancer has spread to the lymph nodes, it is twice as likely to have also spread elsewhere, and therefore, to recur.

However, even when cancer has spread to the lymph nodes, there is still a chance it has not spread anywhere else in the body. The goal of surgery is to remove cancer from both the breast and the lymph nodes. (See 'Management of axillary lymph nodes' below.)

SURGICAL TREATMENT

Surgical removal of the tumor is usually the first step in treating early stage breast cancer. If the breast tumor is large or more advanced, treatment with chemotherapy, trastuzumab, or sometimes anti-estrogen therapy may be recommended before surgery. (See "Patient information: Locally advanced and inflammatory breast cancer (Beyond the Basics)", section on 'Treatment of locally advanced breast cancer'.)

There are two options for breast surgery:

• Mastectomy involves removing the entire breast. (See 'Mastectomy' below.)
• Breast conserving surgery removes just the cancerous area and a small amount of surrounding normal tissue (also called lumpectomy). Breast conserving surgery plus radiation therapy is referred to as breast conserving therapy, or BCT. (See 'Breast conserving therapy (BCT)' below.)

In centers that specialize in breast cancer treatment, approximately 75 percent of women with early stage breast cancer are candidates for BCT. In 25 to 50 percent of women, there are medical, cosmetic and/or social and emotional reasons for having a mastectomy rather than BCT. Survival outcomes are the same whether BCT or mastectomy is performed.

MASTECTOMY

Mastectomy may be necessary because of the location of your tumor, the size or shape of your breast, findings on your imaging examination (mammogram or MRI), whether radiation may be used, or it may be your preference. (See "Mastectomy".)

Simple mastectomy — A total or simple mastectomy involves removing the entire breast without removing the axillary lymph nodes. A technique called sentinel lymph node biopsy is performed to be sure that the cancer has not spread to the lymph nodes.

Skin-sparing mastectomy — In a skin-sparing mastectomy, the nipple and areola are usually removed but the rest of the skin over the breast is preserved. This is done in conjunction with immediate reconstruction with a plastic surgeon.

Nipple sparing mastectomy and areola-sparing mastectomy — Because there is breast tissue extending to the nipple areolar complex (NAC), standard mastectomies (both simple and skin-sparing) usually involve removing the NAC. However, for certain subsets of patients, it may be safe to preserve either the entire NAC (the nipple sparing mastectomy, NSM) or remove the nipple with the breast tissue but preserve the areola (areola-sparing mastectomy, ASM). As with the skin-sparing mastectomy, these are done in conjunction with immediate reconstruction with a plastic surgeon.

Modified radical mastectomy — During a modified radical mastectomy (MRM), the breast tissue and the lymph nodes in the armpit (the axillary lymph nodes) are removed. An axillary node dissection is necessary only if the cancer has spread to the lymph nodes. (See 'Management of axillary lymph nodes' below.)

Breast reconstruction — Reconstruction of the breast is an important option for women who undergo mastectomy. You may choose to have breast reconstruction immediately after the mastectomy or at a later time. The nipples may also be reconstructed to allow the breast to appear more natural. There are several options for reconstruction, and all women planning to undergo mastectomy should see a plastic or reconstructive surgeon to discuss these options before having breast surgery. (See "Breast reconstruction in women with breast cancer".)

Complications of mastectomy — Mastectomy is generally a safe surgery, although complications can occur, including bleeding, collection of fluid, wound infection, and arm problems. (See "Patient information: Lymphedema after breast cancer surgery (Beyond the Basics)".)

Radiation therapy after mastectomy — Radiation therapy is sometimes recommended after a mastectomy to decrease the chance of a recurrence, especially in women who have large tumors (5 cm in size or larger), have tumors close to the chest wall, or who have four or more positive lymph nodes [1]. The benefit of radiation after mastectomy for women with smaller tumors or fewer involved lymph nodes is controversial.

More information about radiation therapy is available below. (See 'Radiation therapy' below.)

BREAST CONSERVING THERAPY (BCT)

Breast conserving therapy refers to surgical removal of the tumor and a small portion of normal surrounding breast tissue. BCT is almost always followed by radiation therapy to the remaining breast tissue. Breast conserving surgery is also called a partial mastectomy, and less accurately, a lumpectomy. A partial mastectomy is the most commonly performed BCT procedure in the United States and Canada.

A quadrantectomy, which is more often used outside of North America, refers to removal of the tumor and about one-fourth of the breast tissue on that side. The remainder of this article will use the word lumpectomy, although the information also applies to women who have had a quadrantectomy. (See "Breast conserving therapy".)

Radiation therapy

Invasive breast cancer — Radiation therapy (RT) refers to the exposure of a tumor to high-energy x-rays in order to slow or stop its growth. Exposure to x-rays damages cells. Unlike normal cells, cancer cells cannot repair the damage caused by exposure to x-rays over several days. This prevents the cancer cells from growing further and causes them to eventually die.

RT for breast cancer is mostly given as external beam RT, meaning that the radiation beam is generated by a machine that is outside the patient. Exposure to the beam typically takes only a few seconds (similar to having an x-ray). In general, RT is given daily, five days per week, for approximately five to six weeks. Some patients may be candidates for an accelerated course of RT, which is only given to the part of the breast where the cancer was removed. This is called “accelerated partial breast irradiation”.

Radiation is generally recommended for most women who have had breast conserving surgery for invasive breast cancer, even if the tumor is very small. The goal of this treatment is to kill any remaining cancer cells. Some women, particularly those with many other medical conditions, may be safely treated without radiation.

In situ breast cancer — Most women with ductal carcinoma in situ (DCIS) will be advised to have radiation therapy after breast conserving surgery. This will depend on the size and grade of the DCIS, your age, and whether the DCIS is hormone receptor positive. (See "Breast ductal carcinoma in situ: Epidemiology, clinical manifestations, and diagnosis" and "Ductal carcinoma in situ: Treatment and prognosis" and "Microinvasive breast carcinoma".)

Cosmetic outcomes — With modern surgical techniques, cosmetic results are good to excellent in most women after breast conserving therapy (ie, the treated and untreated breast are almost identical or there are only slight differences). The effects of BCT on the appearance of the breast take about three years to stabilize. Factors such as weight gain and the normal age-related sagging of breast tissue also affect the shape and size of the breasts.

Complications following BCT — Following breast conserving surgery or radiation, complications can sometimes occur, including bleeding, pain, infection or collection of fluid.

MASTECTOMY VERSUS BREAST CONSERVING THERAPY

Studies show that women with localized breast cancer are equally likely to survive their cancer whether they are treated with BCT or a mastectomy [1,2].

Factors to consider — Although cancer outcomes are similar, there are several factors that you should consider when trying to decide between BCT and mastectomy.

• Tumor size — Some women who have a large tumor and small breasts are advised to undergo mastectomy rather than BCT. However, chemotherapy may be given before surgery to shrink the tumor; this may allow the woman to have breast conserving surgery, if she desires it.
• Extensive DCIS ─ Extensive ductal carcinoma in situ (DCIS), a very early cancer, does not respond well to chemotherapy and therefore may necessitate a mastectomy in order to make sure that all the disease is removed.
• Tumor margins ─ After lumpectomy, it is important to have a margin of normal breast tissue around the tumor. If cancer cells are found at or near the edges of the tissue removed, additional surgery may be necessary. If a large amount of tissue has been removed and the margins are still involved, mastectomy may be recommended.
• Tumor location ─ Tumors that are in the center of the breast or involve the nipple or the skin, may be treated with a mastectomy or breast conserving surgery, depending upon the expected cosmetic results.
• Need for radiation ─ BCT involves both lumpectomy and radiation. In addition, while radiation does allow for preservation of the breast, there are both immediate and long-term side effects. (See "Techniques of breast and chest wall irradiation for early stage breast cancer".)
• Risk reduction ─ Some patients will opt to have a mastectomy (often on both sides) to reduce the risk of future breast cancers.  This is particularly the case in women who carry a breast cancer gene mutation or those with significant risk factors (eg, lobular carcinoma in situ or a significant family history)
• Individual needs and preferences — You should discuss your preferences and concerns about preserving your breast with your doctor.

Reasons to avoid BCT — Certain factors clearly favor mastectomy over BCT. These include:

• Multiple tumors ─ Having two or more separate tumors in different areas of the breast. Some patients have more than one cancer in the breast and it may not be possible to remove all of the tumors and still save the breast.
• Extensive tumor ─ If tumor is spread throughout the breast tissue, it will not be possible to remove the entire tumor without a mastectomy.
• Contraindication for radiation ─ Some women are not candidates for radiation, such as women who are pregnant, have already had radiation to the area, or with conditions that make radiation dangerous, such as lupus skin disease.
• Risk of a second breast cancer ─ Some women may be candidates for BCT but may be at a high risk of developing another breast cancer. These include very young women, women with a known breast cancer gene mutation or women with a very strong family history of breast cancer. These women may consider bilateral mastectomy to not only treat the known cancer, but prevent a second cancer in the future.

Factors that do not affect your decision — Several factors do not play a role in the choice between BCT and mastectomy:

• The spread of cancer cells to lymph nodes in the armpit
• A family history of breast cancer
• A high likelihood that cancer will metastasize or spread to other locations in your body

MANAGEMENT OF AXILLARY LYMPH NODES

Most women with invasive cancer will have an operation to check for cancer cells in the axillary lymph nodes. Women with ductal carcinoma in situ (DCIS) have a very small chance of having cancer cells spreading to the axillary lymph nodes. In general, SLN biopsy is not recommended for women with DCIS unless a mastectomy is being performed. In that case, SLN is done since, if invasive cancer is found in the mastectomy specimen, the surgeon cannot go back and do a SLN procedure after a mastectomy.

Axillary lymph node dissection — This procedure involves removing most of the lymph nodes in the axilla (armpit) to examine them for cancer cells and to help prevent the spread of the cancer to distant sites (such as the lung). This operation was commonly performed for women with invasive breast cancer in the past and is associated with complications such as pain and arm swelling (lymphedema). An axillary lymph node dissection is now usually performed only when the sentinel node or another lymph node in the axilla contain cancer cells.

Sentinel lymph node biopsy — The idea of a sentinel lymph node (SLN) is based on the fact that breast tumor cells first involve one or a few lymph nodes before involving lymph nodes in other areas or spreading (metastasizing) to distant organs. To identify this sentinel node, the surgeon injects blue dye, a radioactive material, or a combination of both into the breast. The dye enters the lymphatic channels and flows to the sentinel lymph node or nodes, which helps the surgeon identify and remove the appropriate lymph nodes.

The sentinel node or nodes are removed and examined under the microscope. If these nodes do not contain any cancer cells, there is only a small chance that other axillary nodes will be positive; removal of additional axillary lymph nodes is not necessary [1]. Most patients do not have cancer in their sentinel lymph nodes and will not need additional surgery. (See "Sentinel lymph node dissection for breast cancer: Indications and outcomes".)

TREATMENT AFTER SURGERY

Treatment after surgery, called adjuvant treatment, is often recommended for women with invasive breast cancer. Adjuvant treatment is discussed in a separate article. (See "Patient information: Early stage breast cancer treatment in postmenopausal women (Beyond the Basics)" and "Patient information: Early stage breast cancer treatment in premenopausal women (Beyond the Basics)".)

SURVEILLANCE AFTER INITIAL TREATMENT

After being treated for breast cancer, there is a risk that breast cancer will recur. Breast cancer survivors are advised to see their oncologist every three to six months for the first three years after treatment, every 6 to 12 months for the next two years, and then annually.

Women who have undergone BCT are advised to continue breast self-exams and mammography. Screening mammography after mastectomy and breast reconstruction is usually not recommended. (See "Approach to the long-term survivor of breast cancer".)

A summary of the American Society of Clinical Oncology's recommendations for surveillance after breast cancer treatment is provided in the 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.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient information: Breast cancer (The Basics)
Patient information: Breast reconstruction after mastectomy (The Basics)
Patient information: Choosing treatment for early-stage breast cancer (The Basics)
Patient information: Ductal carcinoma in situ (DCIS) (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient information: Breast cancer guide to diagnosis and treatment (Beyond the Basics)
Patient information: Lymphedema after breast cancer surgery (Beyond the Basics)
Patient information: Locally advanced and inflammatory breast cancer (Beyond the Basics)
Patient information: Early stage breast cancer treatment in postmenopausal women (Beyond the Basics)
Patient information: Early stage breast cancer treatment in premenopausal women (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Professional Level Information:

Overview of the treatment of newly diagnosed, non-metastatic breast cancer
Atypia and lobular carcinoma in situ: High risk lesions of the breast
Breast conserving therapy
Breast ductal carcinoma in situ: Epidemiology, clinical manifestations, and diagnosis
Ductal carcinoma in situ: Treatment and prognosis
Breast reconstruction in women with breast cancer
Hormone receptors in breast cancer: Clinical utility and guideline recommendations to improve test accuracy
Mastectomy
Microinvasive breast carcinoma
Sentinel lymph node dissection for breast cancer: Indications and outcomes
Techniques of breast and chest wall irradiation for early stage breast cancer
Approach to the long-term survivor of breast cancer

The following organizations also provide reliable health information.

• 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.org)

• American Cancer Society

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

• National Library of Medicine

     (www.nlm.nih.gov/medlineplus/healthtopics.html)

• 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)