A woman’s breast is composed internally of multiple glandular lobules and ducts surrounded by fatty tissue, and therefore by the nature of its design is often of lobular texture. Most women notice irregularities or lumps in their breast from time to time. Fortunately, the overwhelming majority of these breast lumps (80-90%) are benign. Despite this, almost all women will, at some point in their lifetime, be confronted with breast cancer either personally or in a friend or relative. In the United States, the current statistics are that 1 in 8 women will develop breast cancer in her lifetime and that 1 in 30 women will die of breast cancer. This may become a more sobering statistic the next time you are in a room with 30 or more women. Though breast cancer survival is now actually improving as earlier breast cancer detection and improved cure rates take effect, for women, breast cancer remains the second leading cause of cancer-related deaths in the United States. It is important for each woman to have a good understanding of the changes in her breast and when and why it is important to see a medical professional early if a suspicious breast lump occurs.
Although normal changes and breast lumps can occur at any time, there are certain patterns that occur at specific times or ages in a woman’s life. Before puberty, breast bud development in a young girl may occur one side at a time or one side larger than the other. This lump asymmetry is generally normal development. After breast development and with menstruation, many women experience cyclical changes in their breasts as hormone levels fluctuate monthly. Young women may develop smooth, rubbery, mobile, oval lumps in their breast known as fibroadenomas. Fibroadenomas are the most common breast tumor in young women, found especially from age 15 to 30, though they may occur later in life as well. Fibroadenomas are benign and do not carry an increased risk of cancer but may increase rapidly in size. Pregnancy and lactation may also result in irregular breast changes as milk-producing glands become engorged. Occasionally a duct may become plugged or infected resulting in a painful, tender, red mass. Breast infection or abscess may also rarely occur when a woman is not breast-feeding and may require antibiotics or surgical drainage. Trauma to the breast can cause bruising and internal bleeding resulting in a hematoma, or later a residual lump effect known as fat necrosis. The most extreme examples of cyclical hormonal breast changes are often labeled as “fibrocystic changes.” These fibrocystic breast changes are worse 7-10 days before menses, may be painful, swollen, and tender, and often produce irregular ropey or granular lumps, which improve following menses. These lumps may be multiple and involve both breasts. Fibrocystic changes are more prominent from ages 30 to 50 and may become worse as menopause approaches. Treatment of severe, painful fibrocystic changes usually involves the use of salt restriction, avoiding caffeine, tea, and chocolate, and in some cases the use of hormone manipulation. These changes generally resolve after menopause if hormone replacement is not being used. Breast cysts, as a component of fibrocystic changes, are fluid-filled sacs that may become quite tense, firm, and painful and may mimic solid lumps. Breast cysts are most common from age 40 to menopause. After menopause, a breast lump may be any of the above benign conditions; however, the likelihood that it is cancer becomes much higher. Though breast cancer is more common as a woman grows older, it can occur even at a young age.
Any breast lump that persists through one menstrual cycle or any new lump in a postmenopausal woman should be brought to the attention of a medical professional. Workup usually consists of a thorough history, a clinical breast exam, and mammograms. This may be supplemented by ultrasound of the breast and/or fineneedle aspiration (withdrawal of fluid or solid cell material). Core biopsy (large-needle tissue sampling) or excisional biopsy (complete removal of the lump) is often indicated to rule out malignancy. Cysts often respond to simple needle aspiration. Recurrent or bloody cysts are generally an indication for excision. Only rarely are such imaging studies as magnetic resonance imaging (MRI) or positron emission tomography (PET) scanning indicated. Breast cancer can present as a lump (often painless) or as a suspicious finding on a mammogram. Other changes such as skin dimpling, bloody nipple discharge, new nipple retraction, or lumps under the armpit can occur with breast cancer. Some breast cancers are not detectable on physical examination and others are not seen on mammogram, thus both methods must be used to evaluate for the possibility of cancer.
Although some breast cancers (5-10%) are inherited (mutations in the BRCA1 and BRCA2 genes are identified examples), most breast cancers appear to occur sporadically. Certain conditions are associated with a higher incidence of cancer. These include risks related to family history such as breast cancer in more than one first-degree relative (sister or mother), breast cancer in a first-degree relative before age 50, bilateral breast cancer in a first-degree relative, or known BRCA1 or BRCA2 gene mutations in the family. Other risks are related to long-term unopposed estrogen exposure such as early onset of menses, lack of breastfeeding, no pregnancies or late pregnancies, obesity, or late menopause. The majority of benign fibrocystic lumps are not associated with any increased risk of breast cancer. However, certain benign diagnoses such as the hyperplasia seen with intraductal papilloma and sclerosing adenosis, and atypical hyperplasia are associated with an increased risk of breast cancer.
Breast cancer usually arises from two normal cell types in the breast, ductal cells that form the tubes that carry milk out to the nipple, and lobular cells that form the actual milk-producing glands of the breast. Breast cancer can either be noninvasive, so-called ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS), or it can be invasive, so-called ductal carcinoma or lobular carcinoma. All of these are classified in the broad category of glandular cancers or so-called adenocarcinomas. DCIS is felt to be precancerous with a high likelihood of becoming invasive cancer with time. It thus requires aggressive treatment. LCIS behaves differently and while its presence is associated with a higher risk of cancer in either breast, it does not appear to become invasive cancer itself. Close monitoring or very rarely more aggressive prophylactic bilateral mastectomy is used. Ductal invasive carcinoma and lobular invasive carcinoma are malignant cancers that can potentially metastasize (spread to other parts of the body) and are treated similarly with aggressive therapy.
Breast cancer treatment occurs at two very different levels. The first is local treatment that involves treatment to the affected breast and its draining lymph nodes in the adjacent armpit (axilla). The second is systemic treatment that involves treatment to the rest of the body away from the breast, where cancer cells may spread in advanced cases. Surgery and radiation are both local treatments to treat only the breast and axilla. Chemotherapy and hormonal therapy are systemic treatments and are used to treat the rest of the body, if the risk of metastasis outside the breast is high enough.
Local breast cancer treatment generally involves two options. The first option is breast conservation treatment that consists of surgical lumpectomy and axillary node excision combined with radiation to the breast and axilla. This conserves most of the breast. The second option is mastectomy that involves removal of the entire breast and axillary node excision. Mastectomy may be accompanied by immediate or delayed reconstruction of the breast with plastic surgery. Radiation is often not required with mastectomy. In either option an important principle is the treatment of the entire affected breast, including the breast tissue that is away from the cancer itself, by either removing it (mastectomy) or irradiating it (radiation). The axillary node excision with either of the two above options can be accomplished in several ways depending on the clinical situation. One option is sentinel node biopsy where one or two axillary lymph nodes identified in a special technique as the first (or sentinel) node(s) to drain the breast are removed and inspected. If no cancer is found in the sentinel node the procedure is over. If the sentinel node is found to contain cancer, more axillary nodes are then removed. Axillary node excision may also be accomplished by axillary node sampling, in which at least 10 nodes are removed, or by formal axillary node dissection, in which most of the axillary nodes are removed. In many situations breast conservation treatment with axillary node excision and mastectomy with axillary node excision may be equivalent treatment in terms of both overall survival and local recurrence rates.
The prognosis and severity of breast cancer depends on whether the tumor has spread to the axillary lymph nodes or other areas of the body and on the original size of the tumor. The term grade refers to the microscopic appearance and aggressiveness of the cancer cells themselves and ranges from grade 1 (best) to grade 3 (worst). The term stage refers to the extent of the spread of the cancer and ranges from stage I (small tumor with no spread to the lymph nodes or elsewhere: excellent prognosis with proper local treatment) to stage IV (distant metastases: very poor prognosis even with aggressive local and systemic treatment). Other factors such as the patient’s age and menopausal status, total number of lymph nodes involved with cancer, vascular or lymphatic invasion, estrogen and progesterone receptor status, DNA ploidy, S phase fraction, and HER-2/neu and p53 status also affect prognosis and the need for possible systemic treatment.
Systemic treatment, if indicated, is either chemotherapy or hormonal therapy or both. Chemotherapy is usually given primarily intravenously using a combination of different drugs in cycles often as an outpatient usually for 4-6 cycles lasting from 3 to 6 months. Recently, newer medications used to treat the side effects of chemotherapy have dramatically improved the tolerance for this type of treatment. Hormonal therapy in oral pill form (tamoxifen or aromatase inhibitors) is often indicated as systemic treatment for certain tumors or age groups.
The key to better breast cancer cure rates is early detection and treatment. For early breast cancer detection and as part of a healthy lifestyle, all women should practice a triple approach: monthly breast self-examination (beginning at age 20 and taught by a medical professional), yearly breast clinical examinations (beginning at age 25-30 and performed by a qualified medical professional), and routine screening mammography (beginning at age 35-40). Women at higher risk for breast cancer should seek and follow the advice of a breast care specialist for lifetime surveillance.