1

WSUS Women’s Health GuideHot Topics

Breast C

ancer 01

Deb

ra G. W

echter, M

D

Debra G. Wechter, MDVirginia Mason Medical CenterSeattle, WA

Breast cancer is the most commonly occurring cancer in women and will a� ect one in nine women in their lifetime. � e cause of the majority of breast cancers is unknown though risk factors which may be associated with the development of breast cancer include early age with � rst menstrual period, late age at menopause, late � rst pregnancy, nulliparity, no breastfeeding, and a family history of breast or ovar-ian cancer.

Only 5-10% of breast cancers are hereditary. � ere are two gene mutations, BRCA1 and BRCA2, which increase the lifetime risk of breast cancer up to 85% and ovarian cancer as high as 60% in a� ected wom-

en. Women (or men) who might be at risk of having a genetic mutation include those with:

• Early onset breast cancer

• Two primary breast cancers

• Family history of early onset breast cancer

• Personal or family history of male breast cancer

• Personal or family history of ovarian cancer

• Ashkenazi Jewish heritage

• Known BRCA mutation in the fam-ily.

In BRCA carriers, one of the options for prevention is prophylactic bilateral mas-tectomy. If not done, follow-up should include yearly mammogram, yearly breast MRI and twice yearly clinical breast exam. Prophylactic oophorectomy reduces the risk of ovarian cancer, and

WSU

S 2008

BREAST CANCER

2

WSUS Women’s Health GuideHot Topic #01

Breast C

ancer

Deb

ra G. W

echter, M

D

also reduces the risk of developing breast cancer by 50% in premenopausal women. Tamoxifen may also decrease the risk of breast cancer.

Screening for breast cancer includes breast self exam (BSE), clinical breast exam (CBE), and mammography. Although BSE is widely recommended, there is actually no compelling evidence to show that BSE a� ects prognosis. Although some women � nd it reassuring to become familiar with their breast exam, others may � nd it intimidating to try to assess a breast abnormality. Performing BSE is a personal choice that should be discussed with a woman’s primary care provider. CBE is recommended by the American Cancer Society every 3 years for women in their 20’s and 30’s, and annually for asymptomatic women who are 40 and older. Screening mammography is recommended yearly for women 40 and older by the Ameri-can Cancer Society. Screening breast MRI is reserved for women with a high lifetime risk of breast cancer and guidelines for its use have been published by the American Cancer Society (cancer.org; CA Cancer J Clin 2007;57:75-89).

If a breast mass is found on exam, mammogram and ultrasound may be used to assess the mass. If a mammogram is abnormal, additional mam-mographic views and ultrasound may be used. If

exam or imaging is suspicious, the preferred method of diagnosis is core needle biopsy which is performed under local anesthe-sia by a breast radiologist or surgeon using mammogram, ultrasound or palpation for guidance.

Once a diagnosis of cancer is made, a mul-tidisciplinary team including providers with expertise in radiation oncology, medical oncology, breast surgery, plastic surgery, and genetic counseling guides evaluation and treatment.

3

WSUS Women’s Health GuideHot Topic #01

Breast C

ancer

Deb

ra G. W

echter, M

D

� e clinical stage of the tumor is based on tumor size, lymph node status, and presence or absence of metastases. Lab tests and imag-ing such as chest x-ray, breast MRI, PET/CT scan, bone scan, and CT scan are chosen to help de� ne the stage based on NCCN guidelines (cancer.org).

Surgical options for treatment of the breast are partial mastectomy (lumpectomy) and mastec-tomy. Partial mastectomy is usually performed as an outpatient procedure and involves re-moving the cancer with a rim of normal tissue around it. If the mass is not palpable, either wire localization with mammogram or ul-trasound, or ultrasound alone, identi� es the cancer for the surgeon. With wire localization, a mammogram or ultrasound is performed to identify the cancer and a skinny wire is inserted through a needle toward the cancer under local anesthesia. In the operating room, an inci-sion is made using the wire as a guide and the cancer is removed with a rim of normal breast tissue around it. An x-ray is taken of the tissue to prove the cancer has been removed and that there is a clear margin.

A mastectomy removes the entire breast and nipple-areolar complex, but not the muscle un-derlying the breast. A skin-sparing mastectomy removes the entire breast and nipple, but leaves a small rim of skin around the nipple, allowing more skin to be used in reconstruction. Recon-struction by a plastic surgeon can be performed at the same time (immediate) or at any point in

the future (delayed). � e two primary options include implant reconstruction, or autologous reconstruction using one’s own tissue from the abdominal wall, buttock or back.

One of the � rst places that breast cancer can spread is to the lymph nodes under the arm. With invasive cancer, the lymph nodes are as-sessed with sentinel lymph node biopsy (SLNB) unless the lymph nodes have already been shown to have cancer by biopsy or imaging. � is technique removes the � rst node or nodes draining the cancer through microscopic lymph channels from the breast to the axillary nodes.

To � nd the sentinel node, a small amount of radioactive tracer is injected into the breast using local anesthesia the afternoon before or the day of the operation. In the operating room, sometimes a blue dye is injected into the breast as well. � e radioactive or blue sentinel node is removed using a gamma probe (a small Geiger counter) and evaluated by the pathologist. If the sentinel node has cancer, an axillary node dissection may be performed. � is involves removal of the lower level lymph nodes in the fatty tissue under the arm.

4

WSUS Women’s Health GuideHot Topic #01

Breast C

ancer

Deb

ra G. W

echter, M

D

Additional treatment after operation may include radiation therapy, chemotherapy and hormonal therapy. Women who under-go partial mastectomy also require radiation treatment to the breast to reduce the risk of recurrence. Without radiation, the chance of cancer coming back in the breast may be up to about 30%, though with radiation the risk is at most up to 10-15%. Whole breast radiation begins a few weeks after opera-tion and is given over approximately 6 weeks for a few minutes each weekday. A newer technique called accelerated partial breast radiation may be appropriate in selected patients. It is not yet considered the stan-dard of care because we do not know that the long term risk of breast recurrence is as low as with whole breast radiation. � e area of cancer is treated twice daily for � ve con-secutive working days using external beam radiation, placement of an intracavitary balloon catheter (MammoSite®), or, least commonly, insertion of interstitial wires through the breast tissue. Some women will require radiation therapy after mastectomy to reduce the risk of chest wall recurrence if the invasive cancer is 4 cm or larger in size, if there are 4 or more lymph nodes involved with cancer, or if the cancer is close to the skin or chest wall.

� e use of hormonal therapy may be consid-ered in women whose tumors test positive

for estrogen and/or progesterone receptors depending upon tumor size, lymph node sta-tus, and other factors. � ese oral medications are usually taken for up to 5 years.

� e primary purpose of chemotherapy is to treat or prevent metastasis (spread to lymph nodes, liver, lung, bone or other organs). Recommendations are based on tumor size, lymph node status and other factors such as age and coexisting medical conditions. Che-motherapy is usually given intravenously every one to three weeks for a period of 3-6 months. In women with “HER-2 positive” tumors, Herceptin (trastuzumab), a mono-clonal antibody, may be considered for treat-ment. HER-2/neu is a tumor oncogene that is “overexpressed” or positive in some tumors.

After initial treatment, women who have had breast cancer are followed with regularly scheduled exams and mammograms to look for evidence of recurrent cancer in the breast or elsewhere in the body. Follow-up guidelines may be found on the National Comprehensive Cancer Network website (nccn.org).

For additional information on this release, please contact:

Debi Johnsonwww.wsus.org