Lifetime risk of breast cancer development

 

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.

 

Women's Age Risk of breast cancer
30 1 in 2000
40 1 in 233
50 1 in 53
60 1 in 22
70 1 in 13
80 1 in 9
overall 1 in 8

 

What jumps out at you from the above statistics is the exponential increase in probability between age 30 and 40. A woman is about 8 times more likely to get breast cancer at 40, than she was at 30. Between the age of 40 and 50, there is another large increase in probability; the 50 year old woman is about 4 times more likely than the 40 year old to get breast cancer.

About 1% of women have a 20% lifetime risk of breast cancer

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 are differences in breast cancer risk among different ethnic groups

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 Lifetime risk following 'in situ' breast cancer is considerably higher, but still relatively low

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.

References

  1. National Cancer Institute Surveillance, Epidemiology and End Results Program, USA, 1995-1997
  2. Graubard BI, Freedman AN, Gail MH. Five-year and lifetime risk of breast cancer among U.S. subpopulations: implications for magnetic resonance imaging screening. Cancer Epidemiol Biomarkers Prev. (Oct.2010) ;19(10):2430-6
  3. Feuer EJ, Wun LM, Boring CC, Flanders WD, Timmel MJ, Tong T, The lifetime risk of developing breast cancer. , Journal of the National Cancer Institute [1993, 85(11):892-7.
  4. Hebert-Croteau N, Goggin P, Kishchuk N. Estimation of breast cancer risk by women aged 40 and over (a population-based study). Can J Public Health. (1997);88:392–396
  5. Morris, CR., Wright, WE., SChlag, RD. The risk of developing breast cancer within the next 5, 10, or 20 years of a woman’s life. American Journal of Preventive Medicine (April 2001) Volume 20, Issue 3 , Pages 214-218
  6. Lloyd S, Watson M, Waites B, et al. Familial breast cancer (a controlled study of risk perception, psychological morbidity and health beliefs in women attending for genetic counseling). Br J Cancer. 1996;74:482–487
  7. Constantino JP, Gail MH, Pee D, et al. Validation studies for models projecting the risk of invasive and total breast cancer incidence. J Natl Cancer Inst. 1999;91:1541–1548
  8. Ready K, Arun B., Clinical assessment of breast cancer risk based on family history, J Natl Compr Canc Netw. (Oct. 2010) ;8(10):1148-55.
  9. Fraser, GE., Shavlik D. Risk factors, lifetime risk, and age at onset of breast cancer. Annals of Epidemiology,(Aug 1997) Volume 7, Issue 6, Pages 375-382.
  10. Paap, E., Broeders, MJM., van Schoor, G., Otten, JDM., Verbeek, ALM. Large increase in a Dutch woman’s lifetime risk of developing breast cancer. European Journal of Cancer (July 2008)Volume 44, Issue 11 , Pages 1485-1487.
  11. Bray F, McCarron P, Parkin DM. The changing global patterns of female breast cancer incidence and mortality. Breast Cancer Res. 2004;6(6):229–239
  12. Héry C, Ferlay J, Boniol M, Autier P. Changes in breast cancer incidence and mortality in middle-aged and elderly women in 28 countries with Caucasian majority populations. Ann Oncol (2008).
  13. Kurian AW, Fish K, Shema SJ, Clarke CA. Lifetime risks of specific breast cancer subtypes among women in four racial/ethnic groups. Breast Cancer Res. (Nov. 2010) ;12(6)

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Copyright Steven B. Halls, MD Last edited 07-July-2011

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