> Distribution of Breast Cancer Stages in the Population
Over the past 30 years, the distribution of breast cancer stages at diagnosis in the United States has changed. The diagnosis of ductal in situ carcinoma (DCIS), or stage 0, and very early stage breast cancer (stage I) has increased. And, the diagnosis of stage II, III and IV breast cancer has either dropped or stayed about the same (see Figure 4.11).
Figure 4.11
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Most recent Surveillance, Epidemiology, and End Results (SEER) Program Results for U.S. breast cancer incidence reported by stage.
Source: Ries et al, 2001 [93].
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Diagnosis of DCIS has increased by more than 350 percent in white women over 50 and by more than 400 percent in African American women over age 50 (see Figure 4.12). Large increases have been seen in diagnosis of DCIS and stage I breast cancer in women under age 50 as well [93]. These changes suggest higher screening rates and better screening tools allow more breast cancer cases to be caught at early stages [93].
Figure 4.12 (see a larger image)
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Most recent Surveillance, Epidemiology, and End Results (SEER) Program Results for U.S. breast cancer incidence reported by stage.
Source: Ries et al. [93].
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Race and breast cancer stages
Early stage cancers make up over half of breast cancer diagnoses in both white and African American women (see Figure 4.13). However, white women are more likely to be diagnosed with early stage breast cancer than African American women [94-98].
Although racial differences in stage at diagnosis are decreasing, African American women are still more likely than white women to be diagnosed with cancer at advanced stages (stage III and IV) (see Figure 4.13) [94-99].
Figure 4.13 (see a larger image)
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Most recent Surveillance, Epidemiology, and End Results (SEER) Program Results for U.S. breast cancer incidence reported by stage.
Source: Ries et al. [93].
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Differences in access to care
Differences in stage at diagnosis make up a large part of the racial difference in breast cancer survival (learn more). Because African American women tend to be diagnosed with more advanced cases (when breast cancer is not as easily treated), chances for survival are lower.
Access to good care and a lack of health insurance make it more likely women of some ethnic groups and those with low income will be diagnosed at more advanced stages [94-96]. Efforts to improve breast cancer screening rates among women with low income and those who lack insurance, by addressing the barriers to screening, may help improve breast cancer survival [100].
Differences in tumor biology
There also appear to be differences in the biology of breast cancers that tend to occur in white and African American women. Studies show African American women are more likely to have breast cancers with factors linked to a poorer prognosis including [29,101-102]:
African American women (especially those who are premenopausal) also appear more likely than other women to have basal-like/triple negative breast cancer [29,49-51,58-60]. These tumors tend to have a poor prognosis compared to other subtypes of breast cancer. Triple negative breast cancers are:
Although the reasons for this are not clear, some lifestyle factors including breastfeeding and body weight might play a role [49,57,61-64].
Learn more about tumor grade.
Learn more about hormone receptor status.
Learn more about triple negative breast cancer.
Learn more about molecular subtypes of breast cancer.
Learn more about race, ethnicity and breast cancer risk.
Learn more about race, ethnicity and breast cancer screening.
Future research
Biologic differences may explain part of the racial differences in survival rates. However, later stage at diagnosis among African American women remains a major factor in these differences. Disparities in breast cancer diagnosis and survival are under active study.
Updated 10/26/12
