Diagnosis and Treatment of Breast Cancer
Breast cancer is characterized by the growth of malignant tumors in the glandular tissues of the breast. Today, more women are surviving breast cancer than ever before. Over two million women are breast cancer survivors. With early detection and prompt and appropriate treatment, the outlook for women with breast cancer can be positive.
No one knows why some women develop breast cancer and others do not. Although the disease may affect younger women, 75% of all breast cancer occurs in women age 50 or older. Some of the noted risks factors include familial or genetics, exposure to estrogen, demographic factors (age, race, ethnicity, and socioeconomic status), nutrition and lifestyle, and smoking.
Symptoms of breast cancer are hardly noticeable when it first develops but as the cancer grows, it can cause changes that women should watch for. The most common symptom is an abnormal lump or swelling in the breast, but lumps may also appear beside the breast or under the arm. Other symptoms may include unexplained breast pain, abnormal nipple discharge, changes in breast texture, or changes in the skin on or around the breast.
Breast Cancer Screening
To screen or not to screen – that is the dilemma. The problem is not simply medical but also a matter of economics. Diagnosis of cancer, whether initial or recurrence, is the period of greatest acute stress for a cancer patient. This crisis is defined by sadness (depression), fear (anxiety), confusion, and occasional anger.
The goal of screening women for breast cancer is to detect cancer in its earliest stage when surgery and medical treatment can be most effective in reducing mortality. Screening is only beneficial when an earlier diagnosis results in a reduction in mortality and morbidity and when the risks of the screening test are low. There are three methods for breast cancer screening that are currently practiced: X-ray mammography, clinical breast examination and breast self-examination.
Of the three screening methods, the most reliable by far is mammography. However, in women with very dense breast tissue, both ultrasound and mammograms may miss tumors, which, however, can be detected by a Magnetic Resonance Imager (MRI). MRI is also more accurate for detecting cancer in women who carry the breast cancer genes BRCA1 and BRCA2. However, the principal means of diagnosis – and many believe the only definitive one – is biopsy – a minor surgical procedure in which the lump or part of the lump is removed and examined under a microscope for cancer cells. A doctor might perform fine needle aspiration, a needle or core biopsy, or a surgical biopsy.
A mammogram is a special x-ray of the breast that often can detect cancers that are too small for a woman or her doctor to feel. Screening aims to detect breast cancer at a very early stage when cure is more likely. The amount of radiation needed to produce a clear mammogram (picture) varies 乳房手術推薦 with breast size and density. To avoid undue exposure it is highly desirable to use the lowest possible dose of radiation needed.
A mammogram cannot distinguish between a benign or malignant tumor and thus is not 100% accurate. However, mammography detects over 90% of all breast cancer though a negative mammography does not necessarily indicate its absence. Mammography and clinical examination are complementary and if there is strong suspicion of a palpable lesion, the only way to make a positive diagnosis is by having a biopsy.
The results of several large studies have convincingly demonstrated that breast cancer screening by mammography reduces mortality by approximately 30% in women older than 50 years. The American Cancer Society states that women of 40 to 49 years of age should receive screening mammograms every one to two years. Yearly mammography screening is recommended for women of 50 years and older.
However the risks of any screening intervention need to be evaluated as closely as the benefits. The risks associated with mammography screening for breast cancer include, radiation exposure, false positives, and over-diagnosis. The risk of radiation-induced breast cancer from screening mammography is estimated to be minimal. The excess risk for breast cancer caused by radiation is increased with a younger age of the woman at exposure and increasing cumulative radiation dose. However, the benefits of mammography still significantly outweigh the risk of radiation-induced breast cancer.