摘要：Objectives. We examined the effect of routine screening on breast cancer staging by race/ethnicity. Methods. We used a 1990 to 1998 mammography database (N = 5182) of metropolitan Denver, Colo, women to examine each racial/ethnic cohort's incident cancer cases (n = 1902) and tumor stage distribution given similar patterns of routine screening use. Results. Regardless of race/ethnicity, women participating in routine screenings had earlier-stage disease by 5 to 13 percentage points. After control for possible confounding factors, White women were more likely to have early-stage disease compared with Black and Hispanic women. Conclusions. Lack of screening coverage in certain racial/ethnic populations has often been cited as a reason for tumor stage differences at detection. In this study, correcting for screening did not completely reduce stage differentials among Black and Hispanic women. (Am J Public Health. 2002;92:1144–1150) Breast cancer incidence rates have risen in the United States for the past 2 decades. Although the lifelong chance of developing breast cancer is higher for White women than for Black and Hispanic women, Black women and subgroups of Hispanic women have a lower breast cancer survival rate. 1– 6 In the United States, Black and Hispanic women disproportionately have poor breast cancer outcomes. Black women diagnosed with breast cancer are twice as likely to die from the disease within 5 years after diagnosis and Hispanic women are 1.5 times as likely to die as White women. 1, 3 Black and Hispanic women undergo fewer baseline and routine mammography screenings and have more advanced stage of disease at diagnosis, which in part explains the observed decreases in survival rates. Several investigators contend that race/ethnicity is in part a determinant of resource access and that it is a contributing factor in the racial/ethnic disparity. 7– 13 Racial/ethnic differentials in breast cancer incidence rates, staging, and survival seen nationwide are similar to those observed in the Colorado and the 6-county Denver metropolitan area study data. Non-Hispanic White (hereafter labeled White), Hispanic, and non-Hispanic Black (Black) women in the Denver metropolitan area demonstrated an 11- to 21-percentage-point increase in early-stage disease between the period 1985 to 1987 and the period 1996 to 1997. Although increases in early detection were seen in all groups, presumably as a result of screening, tumor stage differentials were still apparent among Black, Hispanic, and White women. In 1996 to 1997, more Black (48%) and Hispanic (46%) women than White women (40%) received a diagnosis of advanced-stage breast cancer. 1 Several randomized controlled trials of screening found significant decreases in mortality rates. Notably, the Stockholm and Malmo trials reported that 85% to 100% of breast cancer deaths occurred among women diagnosed with stage II, III, or IV breast cancer disease. 14– 16 Screening mammography for early breast cancer detection has been investigated quite thoroughly, but studies examining the association of screening with race/ethnicity have been limited. The current investigation was undertaken in light of the observational evidence regarding the association of race/ethnicity with breast cancer staging and survival and the public health importance attributed to showing that access to routine screening can reduce racial/ethnic differentials in tumor staging. Conducting a randomized controlled trial of sufficient size to answer these questions was not feasible in our environment. Thus, we elected to explore data from a 9-year observational study designed to examine mammography performance in a community setting. From these data, we assessed the effect of routine screening on the identification of primary breast cancer and examined whether routine screening would have eliminated the excess of late-stage breast cancer found in Black and Hispanic women.
