ASK THE DOCTOR:
Breast cancer risk: Many factors in equation
By DR. JIM MITTERANDO
Q Since I turned 50 I have been thinking more about breast cancer. My mother had breast cancer when she was 62. My doctor told me that because she had breast cancer after menopause that puts me at less of a risk then if she had breast cancer younger. What are my odds of getting breast cancer?
A Breast cancer is the second most common cancer in women; skin cancer is first. It is the second-leading cause of cancer deaths in women after lung cancer. Women often overestimate their risk of breast cancer and death because it is common and highly publicized. Many women have a friend or family member with breast cancer that further contributes to increased awareness and fear of breast cancer.
The risk of a healthy, 40-year-old woman dying of breast cancer over the next 10 years is low (one in 300). The risk of dying of breast cancer by age 80 is one in 33 (3 percent). This is lower than the one in 3 (30 percent) risk of dying of heart disease by age 80. Heart disease is a far greater killer but often does not get the publicity of cancer. Furthermore, most women with breast cancer do not die from the disease. Fortunately, nine out 10 women with early breast cancer can be cured.
With age, the risk for developing breast cancer increases with more than half of breast cancers occurring over the age of 60.
The risk of breast cancer for a 50-year old woman during the next 10 years is 2 percent (one in 50 women). A 70-year-old woman has a 3 percent (one in 33) risk of breast cancer over the next 10 years. These numbers are quite different from the frequently quoted lifetime risk of breast cancer diagnosis being one in eight women, which represents the cumulative lifetime risk for an infant who lives to be 90. It is more practical to know the risk of cancer at a given age. At age 50, your risk of breast cancer over the next 30 years is 8 percent (one in 12).
The chart below reviews the average risk of breast cancer for women at certain ages during the next 10 years and the risk of developing breast cancer by age 80(the average life expectancy).
1 in 76(1.3%) 1 in 11(9%) over next 40 years 1 in 50(2%) 1 in 12(8%) over next 30 years 1 in 43(2.3%) 1 in 20(5%) over next 20 years 1 in 33(3%) 1 in 33(3%) over next 10 years If you have a sister, mother or daughter with breast cancer, your risk of cancer almost doubles. Your risk is only slightly increased with an aunt, cousin or grandmother having breast cancer. If you have several family members with breast cancer your risk is even higher. Family members with breast cancer that occurs before menopause may increase your risk more than postmenopause breast cancer.
Family history, though, is often given too much exposure. Most women with breast cancer do no not have a family history and may falsely believe that breast cancer will not happen to them.
A small percentage of women have a breast cancer gene called BRCA that makes them very high risk for breast cancer. These women often have multiple family members with breast cancer and/or ovarian cancer.
A great web site for calculating your individual risk of developing breast cancer is www.halls.md/breast/risk.htm. I typed in your age and family history on this web site which calculated your 10-year risk of breast cancer to be 4.7 percent (one in 21) and your risk of getting breast cancer over the next 30 years to be 14.5 percent (one in 7). Your risk may be slightly lower than this estimate since your mother had breast cancer after menopause.
In two weeks: Ask the Doctor answers breast cancer screening questions.
Dr. Jim Mitterando is a family doctor at Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA 02269-9159, or by E-mail to his attention at features@ledger.com.
Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.
Copyright 2003 The Patriot Ledger
Transmitted Tuesday, October 21, 2003