As reported by Prevention, December 2004.

Breast Cancer Prevention Strategies

Read about the risks associated with breast cancer and preventive measures you can take to lower those risks

By Carolyn D. Runowicz, M.D., and Sheldon H. Cherry, M.D., with Dianne Partie Lange

Among cancers that affect women, breast cancer has held the number one spot for many years. It's far ahead of lung cancer, which ranks number two. In 2003, breast cancer accounted for 32 percent of cancer diagnoses among women, compared with 12 percent for lung cancer.

The American Cancer Society predicts that in 2004, 215,990 women will learn that they have invasive breast cancers. This figure does not include noninvasive, or in situ, breast cancers, which occur at a much lower rate, with an estimated 59,390 cases in 2004.

The good news in all of the statistics is that fewer women are dying from breast cancer. In fact, in 1987, breast cancer fell behind lung cancer as the leading cause of cancer deaths among women. Still, the number of deaths remains high, with the disease expected to claim the lives of as many as 40,580 women this year (2004).

One possible explanation for the declining number of breast cancer deaths is the increasing availability of mammography, coupled with the growing awareness among women of the need for periodic mammograms. Consequently, we're able to detect breast cancer at an earlier stage, when most forms of the disease are more curable. The rise in mammography screening also is a likely explanation for the surge in the number of breast cancer diagnoses in the 1980s, when the incidence rate jumped by 32 percent.

Of course, improvements in treatment are another important factor in the gradually declining death rate. For example, the number of women who survive early, localized breast cancers for at least 5 years has increased from 27 percent in the 1940s to 97 percent today.

You probably are familiar with the statistic about the average woman's having a one-in-eight or one-in-nine chance of developing breast cancer. While these numbers are disconcerting, what most women don't realize is that they reflect cumulative risk over an entire lifetime--that is, from birth to age 85. Perhaps a more accurate way to assess risk is to compare the actual incidence of breast cancer among various age groups.

Age Incidence
25-29: 8.2 women per 100,000
40-44: 120.1 women per 100,000
50-54: 200.8 women per 100,000
65-69: 352 women per 100,000

Excerpted from The Answer to Cancer (Rodale Inc., 2004) by permission of the publisher.

Are You at Risk?

Are you over age 50?
Age is the most important risk factor for breast cancer. About 77 percent of women who develop the disease are over age 50. Fewer than 20 percent are in their forties.

Do you have a family history of breast cancer?
In fact, most women who develop cancer do not have a family history of the disease. Fewer than 10 percent of cases are inherited. Nevertheless, if you have breast cancer in your family, you are at above-average risk.

Has any member of your family, female or male, been found to carry a mutated BRCA1 or BRCA2 gene?
BRCAs are tumor suppressor genes; any damage to them can increase a woman's risk of breast cancer. If you have this gene, you have a 50 percent chance of inheriting the mutation, which means that you may want to consider genetic counseling and testing. Should testing reveal that you also carry the mutation, you have a 50 to 85 percent chance of developing breast cancer. But remember that BRCA gene mutations account for just up to 10 percent of breast cancers. Most cases are sporadic--that is, they are not inherited.

Has anyone in your family had ovarian cancer?
This could signal the presence of a BRCA gene mutation, which also raises breast cancer risk. With a BRCA2 mutation, the lifetime risk of ovarian cancer is 16 percent. It climbs as high as 40 percent with a BRCA1 mutation.

Have you had cancer of the ovary, uterus, or colon?
Ovarian cancer slightly increases the risk of breast cancer, particularly in those who carry BRCA1 or BRCA2 gene mutations. The risk doubles with a personal history of uterine (endometrial) or colorectal cancer.

Are you of Ashkenazi Jewish heritage?
About one in every 40 Ashkenazi Jewish women carries a BRCA1 or BRCA2 gene mutation. A study involving more than 200 of these women--all of whom had breast cancer--found the mutation in 30 percent of those diagnosed before age 40. Among those over 40, the figure declined to 10 percent. Women of Ashkenazi Jewish descent can develop sporadic (noninherited) breast cancers as well.

Does your mammogram reveal that you have dense breasts?
While younger women normally have dense breasts, this tends to diminish with age as fat replaces some of the breast tissue. Still, some older women have dense breasts, which can make spotting abnormalities on mammograms more difficult.

Have you ever had a breast biopsy that detected abnormal cells?
This condition, known as atypical hyperplasia, raises the risk of developing breast cancer about fivefold. Fewer than 20 percent of women under age 50 undergo breast biopsies for benign breast disease, but studies show that those with such conditions are more likely to develop breast cancer. The biopsy itself doesn't increase risk. Rather, the fact that the procedure is necessary is a marker for what physicians call an active breast.

Have you already had breast cancer?
The risk of developing a new cancer in the same breast if you had a lumpectomy, or in the opposite breast, increases slightly each year.

Have you received radiation therapy to your chest for any other type of cancer?
Women who've undergone radiation therapy for Hodgkin's disease, for example, are significantly more likely to develop breast cancer. In fact, some experts recommend early mammography screening after Hodgkin's.

Did you begin menstruating at or before age 12?
Early onset of menstruation means longer lifetime exposure to estrogen, which could increase your risk of breast cancer.

Did you have your first child after age 30?
Never having children or giving birth at a later age nearly doubles the risk of breast cancer. (On the other hand, breastfeeding at any age lowers risk.)

Are you taking oral contraceptives, or have you in the past?
Although overall the incidence of breast cancer is not higher among women taking the Pill, the risk does rise slightly for young women, especially for those who went on oral contraceptives before age 21 and continued with it for more than 10 years. For women who carry BRCA1 gene mutations, taking the Pill also may increase risk.

Did you go through menopause at or after age 51?
Breast cancer risk rises by about 3 percent for each year of delayed menopause. "Delayed" means onset after age 51, the average age of menopause for women in the United States.

Have you used hormone replacement therapy, or are you on it now?
According to several studies, women who are on HRT for more than 5 years have a higher risk of breast cancer. The risk declines over time once HRT stops.

Are you overweight?
Women who gain weight after age 18 are twice as likely to develop breast cancer after menopause as women who maintain their weight throughout their lives. Regardless of when the extra pounds begin to appear, being overweight increases breast cancer risk. Where the body stores the extra fat can be a risk factor, too. For instance, research has shown that women whose waistlines exceed 36 inches are 34 percent more likely to develop breast cancer than those whose waistlines are less than 28 inches.

Do you drink more than two alcoholic beverages a day?
Moderate alcohol consumption can cause a modest increase in breast cancer risk. With heavy drinking, defined as four or more alcoholic beverages a day, risk nearly doubles. Some researchers believe that even a small amount of alcohol--say, one drink a day--can elevate risk slightly, by about 3 to 4 percent. According to one analysis, the lifetime risk of breast cancer is 1 in 7 for heavy drinkers, 1 in 11 for nondrinkers.

What You Can Do Now

Find Out Your Risk
At your next annual gynecologic exam, ask your doctor to calculate your breast cancer risk. Several Web sites now offer risk assessment calculators; one is the official Web site of the National Surgical Adjuvant and Bowel Project (NSABP) Breast Cancer Prevention Trial.

Examine Your Breasts
If you are at average risk, do a breast self-exam every month, ideally starting at age 20. Follow up with a clinical breast exam at least every 3 years between ages 20 and 39, then every year starting at age 40. Also get a mammogram every year starting at age 40.

Get Screened
If you are at high risk, talk with your doctor about which screening tests you need and at what intervals.

Discuss Preventive Options
If you are at high risk, ask your doctor whether you'd be a candidate for tamoxifen therapy. Or you may want to consider enrolling in a clinical trial of another chemopreventive drug.

Maintain a Healthy Weight
Make every effort to maintain a healthy weight. As you get older, this may mean eating fewer calories and getting more exercise.

Eat Nine a Day
Eat at least five servings of fruits and vegetables a day, and do your best to get nine.

Stay Fit
Find ways to become more physically active in every aspect of your life--on the job, at home, and in your leisure time.

Stop Smoking
If you smoke, stop.

Take Your Genes into Account
If your mother, sister, or daughter has breast cancer, seek genetic counseling before deciding whether to undergo genetic testing. If genetic testing reveals that you carry the BRCA1 or BRCA2 gene mutation, talk with your doctor about your options for managing your breast cancer risk. You could take tamoxifen or enroll in a clinical trial. Another possibility is preventive surgery (prophylactic mastectomy and/or oophorectomy).

Carolyn D. Runowicz, M.D., is director of the University of Connecticut Cancer Center in Farmington. Shelton H. Cherry, M.D., is clinical OB/GYN professor at Mt. Sinai School of Medicine in NYC. Dianne Partie Lange is a Prevention deputy editor.