Table 3

Location of the points of highest density within the breast, by level of overall PD

Overall PD value at left exit MLO screen

Number of women

Proportion of highest-density points located in highest-density regions^a

Mean entry-exit change in the location of the point of highest density^b

All

165

0.9 (0.9, 0.9)

1.3 (1.2, 1.5)

< 20%

41

1.0 (0.9, 1.0)

1.4 (1.1, 1.7)

20 to 39%

43

1.0 (0.9, 1.0)

1.0 (0.7, 1.3)

40 to 59%

38^c

0.9 (0.8, 1.0)

1.3 (1.0, 1.6)

60 to 79%

38

0.8 (0.7, 0.9)

1.6 (1.3, 1.9)

≥ 80%

5

0.8 (0.3,1.2)

2.4 (1.7, 3.1)

P value^d

< 0.01

< 0.01

^aThe highest-density regions in each woman were those in the top quarter of her distribution of regional percent density (PD) values at the left exit medio-lateral oblique (MLO) screen. ^bExpressed as the mean number of regions between the points of highest density between the entry and exit left MLO screens (see Methods) and accounting for clustering within women. ^cOnly 37 women in the change in location analysis. ^dWald's test.

Pinto Pereira et al. Breast Cancer Research 2009 11:R33   doi:10.1186/bcr2318