Risk Factors

Reducing Your Risk of Breast Cancer

By Dennis R. Holmes, M.D. USC Norris Cancer Center,1-800-5-CANCER

Every woman is at risk of developing breast cancer. However, the risk is not equal among all women. Some breast cancer risk factors, such as gender and family history, are not changeable. Other risk factors, like age, become more important as a woman grows older. Fortunately, there are some risk factors that can be changed. The Women’s Health Initiative Cohort Study of 100,000 women found that the following lifestyle factors could reduce the risk of developing breast cancer.

Exercise
Women who exercised for at least 1 1/2 hours a week have fewer breast cancers compared to women who are sedentary. Women who exercise even more often, or who exercised regularly during their teens, had an even lower risk of breast cancer.

Body Weight
In general, lean women have fewer breast cancers than obese women. The reason is that body fat produces estrogen, which increases the risk of developing breast cancer. Lean and moderately overweight women who exercise more than 11/4 hours a week cut their risk of breast cancer by a third. Exercising and maintaining normal or near-normal body weight will significantly lower your chances of developing breast cancer.

Aspirin or Ibuprofen
Women who take 2 or more tablets of aspirin or ibuprofen each week for at least 5 year have a significant lower risk of developing breast cancer. The best dose and frequency of aspirin or ibuprofen have not been determined. However, based on these findings, you should consider taking a low dose of aspirin (81mg) or ibuprofen (200mg) twice a week. Please talk with your doctor before taking aspirin or ibuprofen regularly, especially if you have a history of heartburn, stomach ulcers, or bleeding problems.

Hormone Replacement Therapy
For many years, hormone replacement therapy (HRT) has been recommended to post-menopausal women to reduce the risk of heart attack and stroke, prevent bone loss, and to reduce the symptoms of menopause. Numerous studies have evaluated the risk of breast cancer in women taking HRT. Although these studies have produce often confusing and sometimes contradictory results, several findings are quite clear:

1) HRT does not reduce the risk of heart attack or stroke and

2) HRT taken for more than 5 years does increase the risk of breast cancer. If you are now taking HRT or if you are considering starting HRT, consider limiting your use to less than 5 years.

Alcohol
Research has shown that daily alcohol consumption more than doubles the risk of breast cancer in women who have a mother, sister, or daughter with breast cancer. There is also a slightly increased risk in women who have no family history of breast cancer.

Smoking
A study of over 100,000 California teachers found that cigarette smoking increases the risk of breast cancer. Stopping smoking reduced breast cancer risk. Stopping smoking will also reduce the risk of cardiovascular disease, the major cause of illness and death among women.