breast cancer, a malignant neoplastic disease of breast tissue, a common malignancy in women and very rarely in men. The incidence increases with age from the third to the fifth decade and reaches a second peak at age 65. Known risk factors include age, certain genetic abnormalities, a family history of breast cancer, nulliparity or late parity (over age 30 years), exposure to ionizing radiation, early menarche, and late menopause. Women who take postmenopausal combined estrogen and progesterone therapy are also at increased risk. The diagnosis may be established by a careful physical examination, mammography, and cytological examination of tumor cells obtained by biopsy. Infiltrating ductal carcinomas are found in about 75% of cases, and infiltrating lobular, infiltrating medullary, colloid, comedo, or papillary carcinomas in the others. Inflammatory carcinomas account for approximately 1% of cases. Metastasis through the lymphatic system to axillary lymph nodes and to bone, lung, brain, and liver is common, but there is evidence that primary carcinomas of the breast may exist in multiple sites and that tumor cells may enter the bloodstream directly without passing through lymph nodes. See also lumpectomy, mastectomy, scirrhous carcinoma. ▪ OBSERVATIONS: A mass detected by breast self-examination, clinical breast examination, or mammogram requires follow-up. Increasing numbers of breast cancers are found on mammogram. Definitive diagnosis is made by incisional, excisional, fine needle, or stereotactic core biopsy of the mass. Pain, tenderness, changes in breast shape, dimpling, and nipple retraction rarely occur until the disease reaches an advanced stage. Prognosis dims markedly as the number of involved lymph nodes increases. Pleural effusion, ascites, pathological fracture, and spinal compression can occur with advanced disease. ▪ INTERVENTIONS: Surgical treatment may consist of a mastectomy or a lumpectomy, with dissection of axillary nodes, or sentinel lymph node biopsy for women without palpable lymph nodes. Postoperative radiotherapy, chemotherapy, or both are often prescribed. Chemotherapeutic agents frequently administered in various combinations are cyclophosphamide, methotrexate, 5-fluorouracil, phenylalanine mustard (L-PAM), thiotepa, DOXOrubicin, vinCRIStine, paclitaxel, and predniSONE. The presence of estrogen receptors in breast tumors is considered an indication for hormonal manipulation such as the administration of antiestrogens. Implantation of a prosthesis after mastectomy is optional and does not appear to decrease survival probability. Reconstructive surgery is common, with few complications. Adjunct systemic multidrug chemotherapy is used primarily for premenopausal node-positive women. Adjunct hormone therapy (estrogens, androgens, and progestins) is used primarily for postmenopausal node-positive or receptor-positive women. Antiestrogen therapy (Tamoxifen and aromatase inhibitors) is used as first-line therapy; biological therapy with trastuzumab (Herceptin) is used in select patients for treatment of metastatic disease. Emotional needs, such as fear over a cancer diagnosis, grieving over loss of a breast, and altered body image, must be addressed. Counseling may be needed. Referrals can be made for age-specific recovery support groups. Referral may also be made for fitting and construction of a breast prosthesis or surgical reconstruction of the breast. The need for long-term follow-up of physical and emotional sequelae is stressed. ▪ PATIENT CARE CONSIDERATIONS: Nurses, physicians and primary health care providers have responsibilities for patient care at all levels of the care continuum, from primary care and screening to acute and long-term follow-through after diagnosis and medical treatment for breast cancer. Health professionals play a major role in early detection and should educate and instruct women age 50 and older to get a biannual mammogram and clinical breast exam. Women at increased risk (i.e., family history, known genetic mutation, prior thoracic radiation) should talk with their health care provider about more frequent and earlier screening. All women should practice breast awareness (know how their breasts normally look and feel) and report any breast change promptly to their health care provider. Breast self-exam (BSE) is an option for women, starting in their 20s; however, several large-scale studies suggest that BSE is of minimal value in the early detection of breast cancer.
