A woman finds a lump in her breast or gets a phone call after her mammogram.

Instantly, her mind races to “Do I have breast cancer?  How could I, there isn’t any breast cancer in my family.”  

It is estimated that only 10-12% of breast cancers are related to a known genetic mutation. I often tell my patients that most breast cancers are bad luck, not bad family.  So, what are the various factors other than family history that influence a woman’s breast cancer risk?

One factor is how long she has been exposed to regular estrogen cycles without a break. A woman’s age when she has her at first menstrual period (less than 11), first child (over 30), and experiences the onset of menopause (over 55) all figure into breast cancer risk. 

Similarly, nulliparity (having no children), use of oral contraceptives for more than 10 years beginning at age 16 or younger, or more than 10 years of estrogen replacement therapy after hysterectomy or menopause are shown to influence breast cancer risk.

Personal medical history and lifestyle can also increase risk. Previous cancer history, especially uterine or ovarian cancer, increases risk. Previous breast biopsies, especially if some showed atypical cells, are associated with increased risk. Dense breasts on mammograms are associated with an increased rate of breast cancer as well as increased difficulty in detecting breast cancer on routine screening. Lifestyle factors, such as obesity, smoking, sedentary lifestyle, and taking two or more alcoholic beverages daily will increase risk as well.  

We use several models to assess risk, which have been developed through very large population-based studies to give a woman an estimate of her breast cancer risk.

Two of the most commonly used models are the modified Gail model (developed in 1989), and the Tyrer-Cuzick model (developed in 2004).  Both models can be accessed online, and allow a woman to calculate her own risk.

Both models assess basic information about age, race and ethnicity, height, and weight. Menstrual history, including age at first period, age of first live birth, and age at menopause is included. Also assessed is whether the woman has been tested for a mutation in one of the breast cancer genes, BRCA1 or BRCA2, her family history, number of prior breast biopsies and if any had atypical cells.  

The Gail model returns information about risk over the next five years, and during her lifetime. Tyrer-Cuzick will calculate ten-year and lifetime risk. Results are often very similar. The risk assessment model chosen depends on the provider’s personal preference and the availability of the information. 

If a woman’s lifetime risk of developing breast cancer is more than 20%, she is considered “high risk” and appropriate for more intense screening. 

Although monthly breast self-exam is no longer recommended as a routine part of breast cancer screening, we feel that breast self-awareness is important for all women, but especially those at high risk.  I tell my patients that they don’t have to come in and say they feel a two-centimeter mass in the upper outer quadrant of their left breast, for instance, but come in and say, “I know my breast, and this area doesn’t feel the same.” 

For high-risk women, annual or twice annual clinical breast exams are important.  Annual mammograms, even in women with dense breasts are important. These should begin at age 40, or 10 years younger than the youngest family member who developed breast cancer. 

Breast MRI should be considered in many high-risk women, often alternating with mammograms every six months. MRI is the most sensitive test for detecting breast cancers, however we must balance that with the expense, the time (and noise) of the exam, and a lack of specificity, which can lead to false-positive tests and additional tests or biopsies. Newer techniques are being explored, such as abbreviated MRI, which can perform the test when used for screening in a much shorter period of time, allowing more women to be screened at a lower cost.  

For a woman identified as at high risk for developing breast cancer, early detection through these increased screening methods is important, but it is just as important to look at what can be done to reduce her risk. 

Lifestyle modifications such as weight control, stopping smoking, limiting alcohol use, and a regular exercise program are important not just in reducing the risk of breast cancer, but also for general health. 

For some women, the overall risk of breast cancer may be high enough to consider some drug interventions for prevention, which can reduce risk by as much as 60%.  Most important is not to ignore the risk, or try to go it alone. 

Get to know the breast health team from Chestnut Hill Hospital at the next Pastorius Park concert on Wednesday, July 13. Clinical staff will be available at the hospital’s table in the back of the amphitheater at 7 p.m. until the concert begins. Hope to see you there.