The overall lifetime risk of a woman developing breast cancer during her lifetime is now thought to be about 1 in 8. In 1989, a womans lifetime risk for developing breast cancer was about 1 in 10. That risk increased to about 1 in 7 by 2003. Even though it may seem that breast cancer risk has increased in recent years, the actual risk of mortality has decreased significantly. The table below demostrates the probability of breast cancer diagonis in 10 year intervals.
Recent studies estimate that about 1% of women in the United states have about a 20% lifetime risk of developing breast cancer between the ages of 30 and 84. This small segment of increased risk is based on models that primarily consider a 'family history' or genetic predisposition to cancer or breast cancer. Taking the population as a whole, young women (less than 30) with a maternal history of breast cancer, or a parental history of any kind of cancer, may have a considerably increased lifetime risk of breast cancer development.
There is some evidence to support different breast cancer risks among women from different ethnic backgrounds. The 5-year risks for breast cancer development is generally highest for white non-Hispanics and lowest for Hispanics. As women get older, the breast cancer risk becomes highest among white non-Hispanics, lowest for hispanics, with African American non-Hispanic women somewhere in between.
|Women's Age||Caucasion||Afrrican American||Asian/Pacific Islander||Hispanic|
|50-55||1.3%||1 in 75||0.8%||1 in 133|
|50-60||2.9%||1 in 34||2.3%||1 in 43||2.0%||1 in 51||1.6%||1 in 63|
|50-70||6.6%||1 in 15||5.0%||1 in 20||3.9%||1 in 26||3.7%||1 in 27|
The risk of developing breast cancer within five years for women over 50 has been shown to vary among different ethnic groups, from as low as 0.8% for Hispanic women ( 1 in 133) to 1.3% among Caucasian women (1 in 75). Over 10 years the breast cancer risk for women over 50 is about 2.9% (1 in 34) for Caucasion women, and about 2.3% or 1 in 43 among African American women. During the same period the breast cancer risk among Asian and Pacific Island women is about 2.0% or 1 in 51, and only 1.6% or about 1 in 63 among Hispanics. For women during the next 20 years after 50 the estimated breast cancer risk among Caucasion women is about 1 in 15 or 6.6%, 1 in 20 or 5.0% among African American women, 3.7% or about 1 in 27 for Hispanics, and about 3.9% or 1 in 26 among Asian/Pacifc Islander women.
The risk of breast cancer where there has already been treatment for 'in situ' breast cancer tumors (DCIS) increases from between 8% to 20%. The point of all of this is to remind us that even though some overall statistics place the lifetime risk of breast cancer development at 1 in 8, that is actually quite a misleading statistic. As evident from the discussion above, the risk for developing breast cancer for a women between 50 and less than 70 can vary considerably.