Correlation of the BI-RADS assessment categories of Papua New Guinean women with mammographic parenchymal patterns, age and diagnosis.

introductionWomen with increased breast density are at increased risk of breast cancer. The aim of this research is to evidence for the first time the mammographic breast findings of Papua New Guinean (PNG) women and the relationship between Breast Imaging-Reporting and Data System (BI-RADS) assessment, mammographic parenchymal patterns (MPPs) and age.

methodsA retrospective analysis of 1357 mammograms of women imaged at the Pacific International Hospital (PIH) from August 2006 to July 2010 was undertaken. Mammographic findings were categorised using the BI-RADS Atlas® 5th Edition. MPPs were recorded for each woman using the Tabár Pattern I-V classification system. Age was recorded in years. Statistical analysis was by descriptive analysis and Kruskal-Wallis with Dunn's post-test and Spearman's rho correlation for inferential analysis.

resultsTrue pathological findings (benign and malignant); BI-RADS 2-5 were noted in 111 women (8.2%); 1242 (91.5%) were negative. BI-RADS categories for malignancy were reported in 16 (88.9%) of women aged 30 to 60 years. The lower risk Tabár Type I, II and III MPPs were associated with 94.4% (n = 17) of malignancies. Linear correlations between variables were weak and not statistically significant: age and Tabár pattern r = 0.031, P = 0.0261; age and BI-RADS r = 0.018, P = 0.517; Tabár pattern and BI-RADS r = 0.020, P = 0.459 (n = 1357).

conclusionThere was no correlation demonstrated between BI-RADS category, age and MPP. Importantly, there was no correlation demonstrated between BI-RADS categories 4 and 5 for breast malignancy and high-risk Tabár Type IV and V MPPs. The results of this study again reflect that the incidence of breast cancer in PNG cannot be explained by breast density and suggest that any formalised screening program in PNG has a target age group aimed at women younger than that of Western screening programs.