Breast Cancer

BREAST CANCER A cancer that has no single, specific cause rather, a combination of hormonal, genetic, and possibly environmental events may contribute to its development. Etiology The two ovarian hormones, estradiol and progesterone, have an important role in breast cancer and are altered in the cellular environment by a variety of factors, and these may affect growth factors for breast cancer. Hormones Laboratory studies shows that tumors grow much faster when exposed to estrogen, and epidemiologic research suggests that women who have longer exposure to estrogen have a higher risk for breast cancer, while early menarche, nulliparity, childbirth after 30 years of age, and late menopause are considered as minor risks. Genetics Growing evidence indicates that genetic alterations are associated with the development of breast cancer. These genetic alterations include changes or mutations in normal genes and the influence of proteins that either promote or suppress the development of breast cancer. Two gene mutations are identified that may play a role in the development of breast cancer. These two gene mutations are BRCA-1 which is a gene on chromosome 17 that, when damaged or mutated, places a woman at greater risk for breast or ovarian cancer, or both, compared with women who do not have the mutation, and BRCA-2 which is a gene on chromosome 17 that, when damaged or mutated, places a woman at greater risk for breast cancer (though less so than BRCA-1) compared with women who do not have the mutation. Risk Factors  BRCA-1 or BRCA-2 Women with gene mutation have a 50% to 90% chance of developing breast cancer and a 50/50 possibility of developing breast cancer before 50 years of age  Increasing age Greatest risk for breast cancer occurs after age 50.  Personal or family history of breast cancer Risk of developing breast cancer in the other breast increases about 1% per year. Risk increases twofold *if first-degree female relatives (sister, mother, or daughter) had breast cancer. Risk increases four to six times if breast cancer occurred in two first-degree relatives.

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Risk increases if the mother was affected with cancer before 60 years of age. Early menarche Menses beginning before 12 years of age. Nulliparity and late maternal age at first birth Women having their first child after 30 years of age have twice the risk for breast cancer as women having first child before 20 years of age. Late menopause Menopause after 55 years of age but women with bilateral oophorectomy before 35 years of age have one third the risk. Obesity Weak risk among obese postmenopausal women: estrogen is stored in the body adipose tissue, and dietary fat increases pituitary prolactin, thus increasing estrogen production. Obese women diagnosed with breast cancer have a higher mortality rate, which may be related to these hormonal influences or perhaps a delayed diagnosis. Alcohol intake As a risk factor, alcohol use remains controversial; however, a slightly increased risk is found in women who consume even one drink daily. The risk doubles among women drinking three drinks daily. Some research findings suggest that young women who drink alcohol are more vulnerable in later years.

Protective Factors Certain factors may be protective in relation to the development of breast cancer. Regular, vigorous exercise has been shown to decrease risk, suppress menstruation, and like pregnancy, reduce the number of ovulatory menstrual cycles. Exercise can also decrease body fat, where estrogens are stored and produced from other steroid hormones. Breast feeding is also thought to decrease risk because it prevents the return of menstruation and having had a full-term pregnancy before the age of 30 years is also thought to be protective. Clinical Manifestations Breast cancer can occur anywhere in the breast, but most are found in the upper outer quadrant. The lesions are non-tender rather than mobile, and hard with irregular borders rather than encapsulated and smooth. Diffused breast pain and tenderness with menstruation are usually associated with benign breast disease. Dimpling or a peu d’orange (orange-peel appearance of the skin, and nipple retraction and lesions fixed to the chest wall may also be evident. Assessment and Diagnosis Assessment to determine the histology and tissue diagnosis of breast cancer includes Fine-needle aspiration (FNA), the removal of fluid for diagnostic analysis from a cyst or cells from a mass using a needle and syringe; excisional (or open) biopsy, incisional biopsy, needle localization, core biopsy, and stereotactic biopsy.

Surgical Management The procedures most often used for the local management of invasive breast cancer are mastectomy with or without reconstruction and breastconserving surgery combined with radiation therapy which typically begins about 6 weeks after the surgery to allow the incision to heal.  Breast-Conserving Surgery Consists of lumpectomy, wide excision, partial or segmental mastectomy, or quadrantectomy and removal of the axillary nodes for tumors with an invasive component, followed by a course of radiation therapy to treat residual, microscopic disease. The goal of breast conservation is to remove the tumor completely with clear margins while achieving an acceptable cosmetic result.  Axillary lymph node dissection Removal of some or all fat-enmeshed axillary lymph nodes for determination of extent of disease spread: the single most important determinant for prognosis and for need for adjuvant treatment.  Total mastectomy removal of the breast tissue only; this procedure is generally done for the treatment of carcinoma in situ, typically ductal.  Modified radical mastectomy Removal of the breast tissue and an axillary lymph node dissection; the pectoralis major and minor muscle remain intact.  Radical mastectomy Removal of the breast tissue along with pectoralis major and minor muscles inn conjunction with an axillary lymph node dissection.