Mammographic densities of Aboriginal and non-Aboriginal women living in Australia’s Northern Territory

Objectives To compare the mammographic densities and other characteristics of Aboriginal and non-Aboriginal women screened in Australia. Methods Population screening programme data of Aboriginal ( n = 857) and non-Aboriginal women ( n = 3236) were used. Mann–Whitney U test compared ages at screening and Chi-square tests compared personal and clinical information. Logistic regression analysis was used for density groupings. OR and 95% CI were calculated for multivariate association for density. Results Mammographic density was lower amongst Aboriginal women ( P < 0.001). For non-Aboriginal women, higher density was associated with younger age (OR 2.4, 95% CI 2.1–2.8), recall to assessment (OR 2.2, 95% CI 1.6–3.0), family history of breast cancer (OR 1.4, 95% CI 1.2–1.6), English-speaking background (OR 1.4, 95% CI 1.2–1.6), and residence in remote areas (OR 1.2, 95% CI 1.1–1.4). For Aboriginal women, density was associated with younger age (OR 2.7, 95% CI 2.0–3.5; P < 0.001), and recall to assessment (OR 2.3, 95% CI 1.4–3.9; P < 0.05). Conclusions Significant differences between Aboriginal and non-Aboriginal women were found. There were more significant associations for dense breasts for non-Aboriginal women than for Aboriginal women.