Mammography screening rates and breast cancer mortality by race across SEER sites

Background: Racial and geographic disparities in breast cancer mortality may be partially due to differing utilization of Medicare-reimbursed annual screening mammography which became effective in 1998. Objective: Determine the association between mammography screening rates and breast cancer mortality by race across SEER sites for time periods pre- and post-Medicare-reimbursement of annual screening mammography. Methods: Categorize mammography screening rates across SEER sites in 1995-1997 (time 1) and 2000-2002 (time 2) among black and white women ages 67-74 in the 5% SEER-Medicare non-cancer sample as low vs. high (approximate median split). Examine the association between mammography screening rates and 5-year breast cancer mortality among black and white cases diagnosed with non-metastatic disease in the same time periods. Results: After adjustment for stage at diagnosis and treatment, black women living in low mammography screening rate areas were at slightly reduced, but identical, risk of death in time 1 (hazard ratio [HR] 0.9, 95% confidence interval [CI] 0.5-1.6) and in time 2 (HR 0.9, 95% CI 0.5-1.6) relative to women living in areas with high mammography screening rates. In contrast, white women in low mammography screening rate areas were at no greater risk of death in time 1 (HR 1.0, 95% CI 0.9-1.3), but slightly reduced risk of death in time 2 (HR 0.8, 95% CI 0.6-1.0). Conclusions: There was little effect of low mammography screening rates on breast cancer mortality evidenced by slight reductions in risk of death, which appeared to be more pronounced among whites than among blacks in time 2.