Incidence of Breast Cancer
Rates of breast cancer have declined since the early 1990’s, largely due to participation in breast cancer screening programs, and quite likely due to decreased use of hormone supplementation therapy. The chances of a woman developing breast cancer in her 20’s or 30’s is really very very low. It is estimated that only 21% of all new cases of breast cancer occur in women under age 50. But as she reaches menopause, the chances of developing breast cancer are significantly increased.
I just want to let you know that I have created a newer version of this page with more up-to-date information on Incidence of Breast Cancer. However, even though this page is pretty short, it is still very useful for research!
Estimated incidence of breast cancer by 10 year age group for women in Canada (2005)
As the above chart indicates, the incidence of breast cancer for women ages 20-29 is very very low. There is a small increase in breast cancer incidence for women in their 30’s, then a significant jump for women in their 40’s.
For women aged 50-59, one notices a large increase in the number of breast cancer cases, about double women in their 40’s. The breast cancer incidence rate more or less levels off for women in their 60’s to eighties, but remains rather high.
General Probability of New Breast Cancer Diagnosis
The following graphs gives a general indication of the probability of new breast cancer diagnosis for women of different age groups in the United States. The results are quite similar to the Canadian statistics, with perhaps a slightly higher diagnosis rate for women in their 60’s.
For women aged 30-39 the rate and chances of breast cancer diagnosis is very low, at approximately 0.44%.
For women 40-49 the breast cancer rate jumps to about 1.46%, also very low.
For women 50-59 the percentage chance of breast cancer development jumps to about 2.73%.
For women 60-69 the diagnosis rate is approximately 3.82%. In the United States that translates to a rate of 1 in 229 for women aged 30-39, 1 in 68 for women age 40-49, 1 in 37 for women aged 50-59, and 1 in 26 for women in their 60’s.
Mortality risk from Breast Cancer and all causes
It is of some reassurance to not that the mortality rate due to breast cancer is proportionally very low compared to the incidence rate. Most breast cancers are curable, and the most significant factor in breast cancer mortality is a late stage of breast cancer development at the time of diagnosis.
The following graphic presents the relative mortality risk due to breast cancer for the USA, as compared to mortalities from all causes.
The risk of death from breast cancer for women aged 40-49 is 0.35%, or 1 in 291. By comparision the risk for death from all causes in about 2.7%, or 1 in 39. For women aged 50-59 the mortality risk from breast cancer is about 0.65 %, or 1 in 155, compared to an all-cause mortality risk of 6.6%, or 1 in 16. Women aged 60-69 have appromixately a 0.9% chance of mortality from breast cancer, or 1 in 112. This compares to a mortality risk from all causes at about 15% or 1 in 7. For women over 70 the risk of death due to breast cancer is about 1.15% or 1 in 87, while the risk of death from all causes is about 34%, or 1 in 3. So, while the chances of a woman developing some form of breast cancer during her entire lifetime is relatively high at approximately 1 in 8 or 1 in 9, breast cancer does not account for high mortality rates compared to death by all causes.
This means that for women aged 40-49, the death due to breast cancer accounts for perhaps 15% to 16% of all mortalities. For women aged 50-59 breast cancer accounts for perhaps 14% of all mortality risk. For women aged 60-69 breast cancer is about 10% of the overall mortality risk, while for women over 70 the risk of mortality due to breast cancer is only about 5%.
For further reading, I suggest you visit this page with information on breast cancer incidence and mortality rates in Canada, UK and the US.
- National Cancer Institute of Canada, Canadian Cancer Statistics Toronto, Canada. May 2005.
- Altekruse SF, Kosary CL, Krapcho M, Neyman N, Aminou R, Waldron W, Ruhl J, Howlader N, Tatalovich Z, Cho H, Mariotto A, Eisner MP, Lewis DR, Cronin K, Chen HS, Feuer EJ, Stinchcomb DG, Edwards BK (eds). SEER Cancer Statistics Review, 1975-2007, National Cancer Institute. November 2009 SEER data submission,
- Mettlin C. Global breast cancer mortality statistics. CA Cancer J Clin. 1999 May-Jun;49(3):138-44.
- Marshall SF, Clarke CA, Deapen D, Henderson K, Largent J, Neuhausen SL, Reynolds P, Ursin G, Horn-Ross PL, Stram DO, Templeman C, Bernstein L. Recent breast cancer incidence trends according to hormone therapy use: the California Teachers Study cohort. Breast Cancer Res. (2010);12(1):R4
- Zahl, PH., Strand, BH., Maehlen, J. Incidence of breast cancer in Norway and Sweden during introduction of nationwide screening: prospective cohort study. BMJ 2004; 328 : 921