Breast Cancer Screening and Radiology
Wessam Bou-Assaly, MD
The goal of screening is to detect disease at its earliest and most treatable stage.
In breast cancer screening, a woman who has no signs or symptoms of breast cancer, undergoes a breast examination such as:
- Clinical breast exam: A physical examination of the breast by a doctor or other health professional
- Mammography: A low-dose x-ray exam that produces images of the breast called a mammogram.
Ultrasound and magnetic resonance imaging (MRI) can help supplement mammography by detecting breast cancers that may not be visible with mammography, or their characteristics are not well defined by mammogram and need better assessment. Neither MRI nor ultrasound is meant to replace mammography. Rather, they are used in conjunction with mammography in selected women.
Breast Cancer is cancer that forms in tissues of the breast, usually in the ducts and lobules (glands that make milk). It can occur in both men and women, although male breast cancer is rare.
Breast cancer is the second leading cause of death from cancer in American women. About one woman in eight will be diagnosed with the disease over the course of her lifetime.
Risks:
A woman’s risk of developing breast cancer increases with:
· age
· a family history of the disease
· a known BRCA1 or BRCA2 gene mutation
· beginning menstruation at an early age
· older age at birth of first child or never having given birth
· breast tissue that is dense
· the use of hormones such as estrogen and progesterone
· obesity
· the consumption of alcoholic beverages
The Screening Recommendations:
· Screening mammography is recommended every year for women beginning at age 40 by the U.S. Department of Health and Human Services (HHS) and the American College of Radiology (ACR).
· The National Cancer Institute (NCI) advises women who have had breast cancer and those who are at increased risk due to a family history of breast cancer to seek expert medical advice about the frequency of screening and whether they should begin screening before age 40. According to American Cancer Society guidelines, most women at high risk should begin screening with MRI and mammography at age 30 and continue for as long they are in good health.
· Women should see their radiologist or primary care doctor to determine when to begin and how often to undergo breast cancer screening.
Breast cancer screening
-Clinical Breast Exam
Physician carefully examines the breasts and underarm area for nodules, masses or lymph nodes. Women may also perform a breast self-exam by checking their own breasts for lumps or changes in size or shape. The clinical breast exam and breast self-exam can help women become more familiar with the regular look and feel of their breasts and more readily identify changes.
-Screening Mammography
Mammography is a type of x-ray examination used to examine the breasts. This type of imaging involves exposing the breasts to a small amount of radiation to obtain pictures of the inside of the breasts.
During mammography, the breast is placed on a special platform and compressed with a paddle. The technologist will gradually compress the breast and while you hold still, an image will be taken producing a top-to-bottom view of the breast. You will be asked to change positions so the side view of the breast can be produced.
-Breast Ultrasound
Breast ultrasound uses sound waves to create pictures of the inside of the breast. Breast ultrasound can capture images of areas of the breast that may be difficult to see with mammography. It can also help to determine whether a breast lump is a solid mass or a fluid-filled cyst.
-Breast MRI
During breast MRI, a powerful magnetic field, radio frequency pulses are used to produce detailed pictures of the inside of the breasts. MRI is helpful in finding abnormalities that are not visible with mammography or ultrasound. In general, MRI is used only in women at high risk for breast cancer.
Benefit of Mammography
· Imaging the breast improves a physician's ability to detect small tumors. When cancers are small, the woman has more treatment options.
· The use of screening mammography increases the detection of small abnormal tissue growths confined to the milk ducts in the breast, called ductal carcinoma in situ (DCIS). These early tumors cannot harm patients if they are removed at this stage, and mammography is the only proven method to reliably detect these tumors. It is also useful for detecting all types of breast cancer, including invasive ductal and invasive lobular cancer.
· Mammography has been shown to decrease the number of deaths from breast cancer when it is used for screening.
· No radiation remains in a patient's body after an x-ray examination.
Risks
· There is always a slight chance of cancer from excessive lifetime exposure to radiation. However, the amount of radiation from a mammogram is very small and the benefit of an accurate diagnosis far outweighs the risk.
· False positive mammograms may occur. Five to 15 percent of screening mammograms require more testing such as additional mammograms or ultrasound. Most of these tests turn out to be normal. If there is an abnormal finding, a follow-up or biopsy may have to be performed. Most biopsies are done with a needle and confirm that no cancer was present. It is estimated that a woman who has yearly mammograms between ages 40 and 49 has about a 30 percent chance of having a false positive mammogram at some point in that decade and about a seven to eight percent chance of having a breast biopsy within the 10-year period.
