Breast cancer affects more American women than any other cancer, except skin cancer. It's also the deadliest cancer for women after lung cancer. Breast cancer affects men too, but it's 100 times more common among women.
Age 40 or older - The risk for breast cancer increases as a woman ages. Most breast cancers occur in women over the age of 50; the risk is especially high for women over 55.
Family history - The risk of getting breast cancer increases for a woman whose mother, sister or daughter has had the disease. The risk increases if the relative's cancer developed before menopause or if it affected both breasts.
About 5-10% of breast cancers are thought to be hereditary due to genetic mutations in the BRCA 1 or 2 genes. There is a blood test available to see if you have this genetic difference. Women who have inherited one of these mutations are at risk for developing other cancers, especially ovarian cancer. There are other gene mutations that can lead to inherited breast cancers, but are much rarer.
Personal history - Women who have had breast cancer are at high risk for developing the disease again. There are also benign breast (glandular or ductal) conditions that increase a woman's risk of developing breast cancer.
Race and ethnicity - Overall, white women are slightly more likely to develop breast cancer, but African-American women are more likely to die of this cancer. African-American women are more likely to be diagnosed under the age of 45.
Never given birth, or birth after 30 - Estrogen levels in the breasts of these women are higher than in women who have had children, making their risk for breast cancer slightly higher. This is because estrogen increases the rate of cell division, which increases the risk of cancer developing. Higher estrogen leads to dense breasts (less fatty tissue in breasts) as well, which can make mammograms less accurate.
Long menstrual history - Women who began menstruating at an early age (before 12) and/or having a late menopause (after 55) are slightly more at risk for breast cancer, because of the level of estrogen in their bodies. Breastfeeding and loss of menstrual cycles may have a protective effect. The use of oral contraceptives and Depo-Provera also have a slightly greater risk while using the medications, but which reverses once discontinued.
Exposures - (1) Previous Chest radiation - women who had radiation therapy to the chest for other reasons as a child or young adult are at increased risk for breast cancer. (2) Women exposed to the drug diethylstilbestrol (DES) in the 1940’s to 1960’s have a slightly higher risk, as do their daughters. (3) Use of combined hormone therapy (conjugated estrogens and medroxyprogesterone acetate) is associated with a higher risk compared to estrogen alone. (4) Women who have more than one alcoholic drink a day on a regular basis are at higher risk. (5) Smoking tobacco increases a woman’s risk for breast cancer.
Signs and Symptoms
The most common sign of breast cancer is a lump or thickening. A lump that does not change in the way it feels is a sign of breast cancer. Other signs are swelling, puckering or dimpling, redness, or soreness of the skin. The nipple may change shape or become crusty. Although early breast cancers are usually painless, any pain or tenderness that lasts throughout the menstrual cycle should also be reported to a physician.
Detection of Breast Cancer
Most breast lumps are found by women themselves or by their sexual partners. It is important for a woman to know her own breasts and examine them monthly for signs of change. Any changes in the breasts should be reported to a physician immediately. Women over the age of 20 should examine their breasts once a month. The best time is seven to 10 days after the start of the period, when the breast swelling and tenderness is over. Post-menopausal women can perform breast self-examination any time of the month.
Mammography, a low-dose X-ray of the breast, is able to detect changes that even a specially trained examiner cannot find. A woman with a lump or other symptoms of breast cancer should have mammography of both breasts as soon as possible, while women with no symptoms should have a screening by the age of 40.
Edited by Carolyn Quist, DO