Benefit of screening mammography in reducing the rate of late-stage breast cancer diagnoses (United States).

Center for Clinical Epidemiology and Biostatistics and Department of Biostatistics and Epidemiology, University of Pennsylvania, 801 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104-6021, USA. snorman@cceb.med.upenn.edu

OBJECTIVE: We studied the benefit of modern mammography screening in community settings, evaluating age-related differences in rates of late-stage breast cancer detection. METHODS: Our multicenter population-based case-control study included 931 black and white women with incident breast cancer (American Joint Commission on Cancer Stage IIB or higher) diagnosed 1994-1998 and 4,016 randomly sampled controls never diagnosed with breast cancer. Adjusted odds ratios (ORs) estimated the relative rate of late-stage diagnosis in screened and non-screened women. RESULTS: Women aged 50-64 at diagnosis with at least one screening mammogram in the previous 2 years were significantly less likely to have late-stage diagnosis (OR = 0.41, 95% CI 0.33-0.52). Results for women aged 40-49 were consistent with a screening benefit, although the confidence interval marginally overlapped the null (OR = 0.81, 95% CI 0.64-1.02). Mammography screening was associated with lower rates of late-stage breast cancer among both premenopausal (OR = 0.64, 95% CI 0.50-0.81) and postmenopausal (OR = 0.44, 95% CI 0.35-0.56) women. CONCLUSIONS: With modern mammography in the community, rates of late-stage breast cancer diagnoses are lower in screened compared to non-screened women ages 40 and older, but age-related differences persist.

PMID: 16841259 [PubMed - indexed for MEDLINE]