Who's At Risk of Breast Cancer

The exact causes of breast cancer are not known. However, studies show that the risk of breast cancer increases as a woman gets older.

This disease is very uncommon in women under the age of 35. Most breast cancers occur in women over the age of 50, and the risk is especially high for women over age 60. Also, breast cancer occurs more often in white women than African-American or Asian women.

Research has shown that the following conditions increase a woman's chances of getting breast cancer:

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Personal history of breast cancer. Women who have had breast cancer face an increased risk of getting breast cancer in their other breast.

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Family history. A woman's risk for developing breast cancer increases if her mother, sister, or daughter had breast cancer, especially at a young age.

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Certain breast changes. Having a diagnosis of atypical hyperplasia or lobular carcinoma in situ (LCIS) may increase a woman's risk for developing cancer.

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Genetic alterations. Changes in certain genes (BRCA1, BRCA2, and others) increase the risk of breast cancer. In families in which many women have had the disease, gene testing can sometimes show the presence of specific genetic changes that increase the risk of breast cancer. Doctors may suggest ways to try to delay or prevent breast cancer, or to improve the detection of this disease in women who have these changes in their genes.

Other factors associated with an increased risk for breast cancer include:

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Estrogen. Evidence suggests that the longer a woman is exposed to estrogen (estrogen made by the body, taken as a drug, or delivered by a patch), the more likely she is to develop breast cancer. For example, the risk is somewhat increased among women who began menstruation at an early age (before age 12), experienced menopause late (after age 55), never had children, or took hormone replacement therapy for long periods of time. Each of these factors increases the amount of time a woman's body is exposed to estrogen.

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DES (diethylstilbestrol) is a synthetic form of estrogen that was used between the early 1940s and 1971. Women who took DES during pregnancy to prevent certain complications are at a slightly higher risk for breast cancer. This does not appear to be the case for their daughters who were exposed to DES before birth. However, more studies are needed as these daughters enter the age range when breast cancer is more common.

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Late childbearing. Women who have their first child late (after about age 30) have a greater chance of developing breast cancer than women who have a child at a younger age.

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Breast density. Breasts that have a high proportion of lobular and ductal tissue appear dense on mammograms. Breast cancers nearly always develop in lobular or ductal tissue (not fatty tissue). That's why cancer is more likely to occur in breasts that have a lot of lobular and ductal tissue (that is, dense tissue) than in breasts with a lot of fatty tissue. In addition, when breasts are dense, it is more difficult for doctors to see abnormal areas on a mammogram.

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Radiation therapy. Women whose breasts were exposed to radiation during radiation therapy before age 30, especially those who were treated with radiation for Hodgkin's disease, are at an increased risk for developing breast cancer. Studies show that the younger a woman was when she received her treatment, the higher her risk for developing breast cancer later in life.

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Alcohol. Some studies suggest a slightly higher risk of breast cancer among women who drink alcohol.

Most women who develop breast cancer have none of the risk factors listed above, other than the risk that comes with growing older.

Doctors can seldom explain why one woman gets breast cancer and another doesn't. It is clear, however, that breast cancer is not caused by bumping, bruising, or touching the breast. And this disease is not contagious; no one can "catch" breast cancer from another person.

Scientists are trying to learn more about factors that increase the risk of developing this disease. For example, they are looking at whether the risk of breast cancer might be affected by environmental factors. So far, scientists do not have enough information to know whether any factors in the environment increase the risk of this disease.

Some aspects of a woman's lifestyle may affect her chances of developing breast cancer. For example, recent studies suggest that regular exercise may decrease the risk in younger women. Also, some evidence suggests a link between diet and breast cancer. Ongoing studies are looking at ways to prevent breast cancer through changes in diet or with dietary supplements. However, it is not yet known whether specific dietary changes will actually prevent breast cancer. These are active areas of research.

A considerable amount of research has been conducted to determine whether having an abortion or a miscarriage affects a woman's chance of developing breast cancer later on. Until the mid-1990s, studies produced inconsistent results, but most of those studies were small and had scientific flaws. Since then, larger, better-designed studies have consistently shown no link between abortion or miscarriage and the development of breast cancer.

Basic, clinical, and population research will continue to investigate how hormones, in general and during pregnancy, influence the development of breast cancer.

Research has led to the identification of changes (mutations) in certain genes that increase the risk of developing breast cancer. Women with a strong family history of breast cancer may choose to have a blood test to see if they have inherited a change in the BRCA1 or BRCA2 gene. Women who are concerned about an inherited risk for breast cancer should talk to their doctor. The doctor may suggest seeing a health professional trained in genetics. Genetic counseling can help a woman decide whether testing would be appropriate for her. Also, counseling before and after testing helps women understand and deal with the possible results of a genetic test. Counseling can also help with concerns about employment or about health, life, and disability insurance.

Scientists are looking for drugs that may prevent the development of breast cancer. In one large study, the drug tamoxifen reduced the number of new cases of breast cancer among women at an increased risk for the disease. Doctors are now studying how another drug called raloxifene compares to tamoxifen.

source:www.nbc6.net