Screening mammography performance and cancer detection among black women and white women in community practice.

BACKGROUND

Despite improvement in mammography screening attendance, black women continue to have poorer prognosis at diagnosis than white woman. Data from the Carolina Mammography Registry were used to evaluate whether there may be differences in mammography performance or detected cancers when comparing black women with white women who are screened by mammography.

METHODS

Prospectively collected data from community-based mammography facilities on 468,484 screening mammograms (79,397 in black women and 389,087 in white women) were included for study. Mammograms were linked to a pathology data base for identification of cancers. Sensitivity, specificity, positive predictive value, and cancer detection rates were compared between black women and white women. Logistic regression methods were used to control for covariates associated with performance characteristics. Differences in cancer characteristics were compared between black women and white women using chi-square statistics.

RESULTS

Screening mammography performance results for black women compared with white women were as follows: sensitivity, odds ratio (OR) = 1.07 (95% confidence interval [95% CI], 0.83-1.39); specificity, OR = 1.02 (95% CI, 0.98-1.06); and positive predictive value, OR = 1.07 (95% CI, 0.94-1.23). Among women with no previous screening, black women had a larger proportion of invasive tumors that measured > or = 2 cm (38% vs. 26%; P = 0.04). The cancer detection rate was highest among black women who reported symptoms at screening (13.9 per 1000 black women vs. 7.9 per 1000 white women). Invasive cancers in black women were poorer grade (P = 0.001), and more often had negative estrogen receptor status and progesterone receptor status (P < 0.001).

CONCLUSIONS

Overall, screening mammography performed equally well in black women and white women controlling for age, breast density, and time since previous mammogram. Black women who reported symptoms had larger and higher grade tumors compared with white women. Educational efforts need to be strengthened to encourage black women to react sooner to symptoms, so that the tumors detected will be smaller and black women will have a better prognosis when they appear for mammography.