Although the precise causes of breast cancer are unclear, we know the main risk factors. Still, most women considered at high risk for breast cancer do not get it, while many with no known risk factors do develop breast cancer. Among the most significant factors are advancing age and a family history of breast cancer. Risk increases for a woman who has certain types of benign breast lumps and increases significantly for a woman who has previously had cancer of the breast or the ovaries.
A woman whose mother, sister, or daughter has had breast cancer is two to three times more likely to develop the disease, particularly if more than one first-degree relative has been affected. Researchers have now identified two genes responsible for some instances of familial breast cancer. These genes are known as BRCA1 and BRCA2. About one woman in 200 carries the genes. Having one of them predisposes a woman to breast cancer but does not ensure that she will get it.
Generally, women over 50 are more likely to get breast cancer than younger women, and African-American women are more likely than Caucasians to get breast cancer before menopause. A link between breast cancer and hormones is gradually becoming clearer. Researchers think that the greater a woman's exposure to the hormone estrogen, the more susceptible she is to breast cancer. Estrogen tells cells to divide; the more the cells divide, the more likely they are to be abnormal in some way, possibly becoming cancerous. (WebMD)
Under certain circumstances, people with breast cancer have the opportunity to choose between total removal of a breast (mastectomy) and breast-conserving surgery (lumpectomy) followed by radiation. Lumpectomy followed by radiation is likely to be equally as effective as mastectomy for people with only one site of cancer in the breast and a tumor under 4 centimeters. Clear margins are also a requirement (no cancer cells in the tissue surrounding the tumor). (Breastcancer.org 1)...