BREAST CANCER

Breast cancer occurs when the cells in the breast begin to grow out of control and then invade nearby tissues or spread throughout the body. Large collections of these tissues are called tumors. However, some tumors do not necessarily become cancerous and are called benign tumors. The tumors that can spread throughout the body or invade nearby tissues are considered cancer and are called malignant tumors. Any of the types of tissue in the breast can form a cancer, but usually it comes from either the ducts or the glands. Because it may take months to years for a tumor to get large enough to feel in the breast, tumors are screened for with mammograms, which can sometimes identify the disease before it can be felt.

Breast Cancer Risks
Breast cancer is the most common cancer affecting women in North America and Europe. Every woman is at risk for breast cancer, and is the second leading cause of cancer death in American women behind lung cancer. The lifetime risk of a woman getting breast cancer is about 1 in 8, although the lifetime risk of dying from breast cancer is much lower at 1 in 28. Some factors that increase your risk of breast cancer that cannot be altered by a woman like getting older, having a family history (having a mother, sister, or daughter with breast cancer doubles your risk), having a previous history of breast cancer, having had radiation therapy to the chest region, being Caucasian, getting your periods young (before 12 years old), having your menopause late (after 50 years old), never having children or having them when you are older than 30, and having a genetic mutation that increases your risk. However there are certain factors which increase a woman's risk of breast cancer can be altered including taking hormone replacement therapy (long term use of estrogens with progesterone for menopause symptoms slightly increases your risk), taking birth control pills (a very slight increased risk that disappears in women who have stopped them for over 10 years), not breastfeeding, drinking 2 to 5 alcoholic drinks a day, being overweight (especially after menopause), and not exercising. All of these modifiable risk factors are not nearly as important as gender, age, and family history, but they are things that a woman can control that may reduce her chances of developing a breast malignancy. All risk factors are based on probabilities, and even someone without any risk factors can still get breast cancer. Proper screening and early detection are our best weapons in reducing the mortality associated with this disease.

Breast Cancer Prevention
There are a few risk factors that may be modified by a woman that potentially could influence the development of breast cancer. If possible, a woman should avoid long-term hormone replacement therapy, have children before age 30, breastfeed, avoid weight gain through exercise and proper diet, and limit alcohol consumption to 1 drink a day or less. For women already at a high risk, their risk of developing breast cancer can be reduced by about 50% by taking a drug called Tamoxifen for five years. Tamoxifen has some common side effects (like hot flashes and vaginal discharge), which are not serious and some uncommon side effects (like blood clots, pulmonary embolus, stroke, and uterine cancer) which are life threatening. Tamoxifen isn't widely used for prevention, but may be useful in some cases. There are limited data suggesting that vitamin A may protect against breast cancer but further research is needed before it can be recommended for prevention. Other things being investigated include phytoestrogens (naturally occurring estrogens that are in high numbers in soy), vitamin E, vitamin C, and other drugs. Further testing of these substances is also needed before they can be recommended for breast cancer prevention. The most important thing any woman can do to decrease her risk of dying from breast cancer is to have regular mammogram screening, learn how to perform breast self exams, and have a regular physical examination by their physician.

National Breast Cancer Foundation

Breast Cancer Self-Exam