Mammography is effective in the early diagnosis of breast cancer, and it is recommended that women age 40 and older have a mammogram every 1 to 2 years (USPSTF, 2002). Most (70 percent) women aged 40 and older reported in 2000 that they had a mammogram in the past 2 years (ACS, 2004b). The widespread use of mammographic screening has resulted in diagnosis at younger ages and with smaller tumors. The 20 to 30 percent decrease in mortality associated with mammographic screening (among women aged 50 and older) has also contributed to the growing population of breast cancer survivors, estimated at 2.3 million as of 2002 (NCI, 2005b). High screening rates have also resulted in more women being diagnosed with DCIS, a type of noninvasive breast cancer of uncertain clinical significance (IOM, 2005). In 2005, an estimated 58,490 women will be diagnosed with DCIS (ACS, 2005a). These women were not counted among the 211,240 cases of invasive breast cancer but, because women with DCIS usually receive the same treatment as women with invasive early breast cancer, the rise in DCIS detection has increased the use of breast-cancer-related services and created a new cohort of women who are worried about their future risk of invasive disease but for whom clear prognostic guidance is lacking.
Lower rates of use of screening among certain groups result in certain women being diagnosed at later stages when treatment is less effective. Rates of mammography use in 2000, for example, was significantly lower among American Indians and Alaskan Natives relative to women who are white (37 percent versus 57 percent, respectively) (ACS, 2004a). This lower rate of screening likely accounts for the relatively low percentage of American Indians and Alaskan Natives diagnosed with localized breast cancer as compared to whites (56 versus 66 percent, respectively) (Figure 2-21).
African-American women, despite having rates of mammography use similar to white women (53 versus 57 percent) and lower incidence rates, have higher rates of breast cancer death (Table 2-2) (ACS, 2005a). This anomaly persists even when adjusting for age, socioeconomic status, and disease stage. Recent research suggests that African-American women are more likely to be diagnosed at a younger age with aggressive breast cancer than are white women (Cross et al., 2002; Porter et al., 2004; Jones et al., 2004; Chlebowski et al., 2005).
African-American women are more likely to have later stage tumors (larger tumors and/or positive lymph nodes), tumors with higher histological and nuclear grades, and genetic characteristics that are associated with a poor outcome. While African-American women have tumors that are more aggressive biologically, socioeconomic status is also consistently associated with poor outcomes and is a better predictor of outcomes than race (Bradley et al., 2002). Breast cancer strikes African-American women at