Mammographic parenchymal patterns and breast cancer risk in N ew S outh W ales N orth C oast A boriginal and T orres S trait I slander women

The objective of the study was to document the distribution of mammographic parenchymal patterns ( MPP ) of Indigenous Australian women attending BreastScreen New South Wales ( NSW ) North Coast, to profile breast cancer risk as it relates to breast density and to explore the correlation between MPP , breast size as described by the posterior nipple line ( PNL ) and age. Methods Ethics was granted from CQU niversity Human Research Ethics Committee, NSW Population Health Services Research Ethics Committee and the Aboriginal Health and Medical Research Council Ethics Committee. A quantitative retrospective analysis reviewed 502 screening mammograms against the Tabár I–V MPP classification system. The PNL was measured in millimetres (mm) and the age of the patient documented. Results A statistically significant variation in the distribution of MPP ( P  < 0.0001) was demonstrated, with patterns of I (23.9%), II (45.6%), III (10.4%), IV (15.9%) and V (4.2%). Statistically significant differences were noted in the age of subjects between patterns ( P  = 0.0002). Patterns I and V demonstrated statistically significant lower ages than II, III and IV (all P  < 0.05). Pattern V demonstrated a statistically significant lower age than pattern I ( P  = 0.0393). Pattern V demonstrated a statistically significant lower PNL value than all other patterns (all P  < 0.001/ P  < 0.0002); pattern II was statistically significantly higher in PNL value than all other patterns ( P  < 0.002/ P  < 0.001). No significant relationship was noted between PNL and age. Conclusion The study demonstrated that no identifiable or unique distribution of MPP was noted in this snapshot of Indigenous women. A larger study of Indigenous Australian women is required for validation.