Breast Cancer Statistics

From the 1940's until recently, the rate of new cases of breast cancer in the United States increased by a little over one percent a year. In the 1980's, the rate of new cases rose markedly (likely due to increased screening) and during the 1990's, the rate of new cases leveled off. Since 2003 there has been a marked decline in the rate of new breast cancer cases. [American Cancer Society. Cancer Facts and Figures 2008. Atlanta, Georgia, American Cancer Society, 2008., Ravdin PM, Cronin KA, Howlander N, et al. The decrease in breast-cancer incidence in 2003 in the United States. N Engl J Med. 356(16):1670-4, 2007.]. This decline appears to be relatd to the drop in use of postmenopausal hormones that occurred after the Women's Health Initiative study showed that their use increased risk of breast cancer and heart disease. [American Cancer Society. Cancer Facts and Figures 2008. Atlanta, Georgia, American Cancer Society, 2008., Ravdin PM, Cronin KA, Howlander N, et al. The decrease in breast-cancer incidence in 2003 in the United States. N Engl J Med. 356(16):1670-4, 2007, Kerlikowske K, Miglioretti DL, Buist DSM, Walker R, Carney PA for the National Cancer Institute-Sponsored Breast Cancer Surveillance Consortium. Declines in invasive breast cancer and use of postmenopausal hormone therapy in a screening mammography population. J Natl Cancer Inst. 99(17):1335-9, 2007.]

Although these statistics are encouraging, an estimated 182,460 new cases of breast cancer will be diagnosed in American women in 2008 alone [American Cancer Society. Cancer Facts and Figures 2008. Atlanta, Georgia, American Cancer Society, 2008.]. In 1975, the incidence (the number of new cases) of breast cancer was 107 per 100,000 for white women and 94 per 100,000 for black women. Twenty-nine years later in 2004, the number of new cases per year had risen to 128 per 100,000 for white women and 119 per 100,000 for black women [U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999—2004 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute, 2007.].

Even though incidence increased during that 29-year period, mortality (the rate of death) for white women decreased. In 1975, 32 per 100,000 white women died of breast cancer, but by 2003, the figure* had declined to 24.6. For black women, though, mortality increased over the same period, rising from 30 per 100,000 black women in the population in 1975 to 34.1 per 100,000 in 2003 [U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999—2004 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute, 2007.]. (Figure 1 shows this trend).

Figure 1. Breast Cancer Incidence and Mortality, White Females vs.
Black Females. Age-adjusted to the 2004 U.S. standard population.
U.S. Cancer Statistics Working Group, 2007

As screening programs have become more common, more cases of breast cancer are being detected in the earlier stages of disease, when they are more easily and successfully treated. During the 1980s and 1990s, diagnoses of early stage cancer and precancerous conditions have increased considerably Since the late 1990s these rates have remained steady. At the same time, diagnoses of cases at the advanced stages have remained stable or dropped slightly. [American Cancer Society. Cancer Facts and Figures 2008. Atlanta, GA, American Cancer Society, 2008.].

Rates of male breast cancer have changed little over the past 29 years and are quite a bit lower than rates for female breast cancer [U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999—2004 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute, 2007.]. In 2004, the overall incidence of breast cancer in women was 124 per 100,000. In men, it was 1.4 per 100,000. Differences in mortality were equally wide: 24 per 100,000 for women, and 0.3 per 100,000 for men [U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999—2004 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute, 2007.].

World and Domestic Variations in Rates

Rates of breast cancer around the world vary a great deal, with industrialized countries generally having higher rates than non-industrialized countries (Figure 2 below shows this). And, although all the factors responsible for this variation aren't known, differences between such countries in lifestyle and reproductive factors are thought to play a large role.

Figure 2. Breast Cancer Incidence Worldwide

Even within the United States, breast cancer rates vary both geographically (see Figure 3) and racially/ethnically (see Figure 4). Whites have the highest incidence, while American Indian and Alaskan Natives have the lowest. Of note, immigrants in the United States usually mimic their country of origin's breast cancer risk, but over successive generations, the daughters and granddaughters of immigrants take on a risk more similar to that of this country.

Estimated Rate of New Invasive Breast Cancer
(per 100,000 women) by State, 2000-2004

Figure 4. Incidence of Invasive Breast Cancer by Racial/Ethnic Group,