Of the total participants, 68.8 and 31.7% were pre- and post-menopausal, respectively, while 14.7% (n = 318) were nulliparous. The mean age of the participants was 49.26 years with a maximum and minimum age of 83 and 17 years, respectively. The majority of the subjects were in the 40−59-year age range (75.5%). The purpose of the visit to the clinic and mammography was primarily for screening (72.8%), followed by pain (19.3%), and lump (5.7%). Mammography showed scattered fibroglandular and extremely dense breasts in 38.6% and 5% of women, respectively. Most of the participants showed BI-RADS 2 (63%), while BI-RADS 5 was associated with 2.9% women (Table 1).
Table 1
Clinical and pathological characteristics of the subjects
Variable | Subjects (n) | Subjects (%) |
Age | < 40 | 272 | 12.6 |
40–49 | 854 | 39.6 |
50–59 | 774 | 35.9 |
> 59 | 258 | 12.0 |
Complain | Screening | 1570 | 72.8 |
Pain | 416 | 19.3 |
Lump | 122 | 5.7 |
Scar/Moles/Skin retraction | 3 | 0.1 |
Tissue thickening | 3 | 0.1 |
Nipple discharge | 22 | 1 |
Nipple inversion or retraction | 5 | 0.2 |
Other | 17 | 0.7 |
Breast density | A | 798 | 37.0 |
B | 834 | 38.6 |
C | 424 | 19.6 |
D | 102 | 4.7 |
BI-RADS assessment categories | 0 | 100 | 4.6 |
1 | 477 | 22.1 |
2 | 1348 | 62.5 |
3 | 70 | 3.2 |
4 | 85 | 3.9 |
5 | 63 | 2.9 |
6 | 15 | 0.7 |
Family history of breast cancer | No | 1789 | 82.9 |
Yes | 369 | 17.1 |
Age at first childbirth (n = 1840) | < 15 | 34 | 1.8 |
15–19 | 549 | 29.8 |
20–24 | 673 | 36.6 |
> 25 | 584 | 31.7 |
Menopause status | Pre | 1485 | 68.8 |
Post | 673 | 31.2 |
Breast cancer (by biopsy) | No | 2045 | 94.8 |
Yes | 113 | 5.2 |
BI-RADS, Breast Imaging Reporting and Data System |
Extremely dense (type D) breasts were the highest (52%) in the 40−49-year age group, while type A was more (40.6%) in the 50−59-year age group. Among women aged < 40 years, 35.66% and 32.72% showed type B and C breast densities, respectively (Table 2).
Table 2
Association between breast density and other variables
Variable | | | Age (years) | Age at first childbirth (years) | Menopause status | Breast cancer family history | Breast cancer |
Breast density | | | < 40 | 40–49 | 50–59 | > 59 | < 15 | 15–19 | 20–24 | > 25 | Pre | Post | Yes | No | Yes | No |
A | Count | 59 | 251 | 324 | 164 | 16 | 239 | 262 | 208 | 447 | 351 | 124 | 674 | 37 | 761 |
% | 7.4 | 31.5 | 40.6 | 20.6 | 2.2 | 33.0 | 36.1 | 28.7 | 56.0 | 44.0 | 15.5 | 84.5 | 4.6 | 95.4 |
B | Count | 97 | 339 | 315 | 83 | 13 | 224 | 263 | 222 | 594 | 240 | 142 | 692 | 41 | 793 |
% | 11.6 | 40.6 | 37.8 | 10.0 | 1.8 | 31.0 | 36.4 | 30.7 | 71.2 | 28.8 | 17.0 | 83.0 | 4.9 | 95.1 |
C | Count | 89 | 211 | 115 | 9 | 4 | 67 | 123 | 132 | 356 | 68 | 84 | 340 | 28 | 396 |
% | 21.0 | 49.8 | 27.1 | 2.1 | 1.2 | 20.6 | 37.7 | 40.5 | 84.0 | 16.0 | 19.8 | 80.2 | 6.6 | 93.4 |
D | Count | 27 | 53 | 20 | 2 | 1 | 19 | 25 | 22 | 88 | 14 | 19 | 83 | 7 | 95 |
% | 26.5 | 52.0 | 19.6 | 2.0 | 1.5 | 28.4 | 37.3 | 32.8 | 86.3 | 13.7 | 18.6 | 81.4 | 6.9 | 93.1 |
Total | Count | 272 | 854 | 774 | 258 | 34 | 549 | 673 | 584 | 1485 | 673 | 369 | 1789 | 113 | 2045 |
% | 12.6 | 39.6 | 35.9 | 12.0 | 1.8 | 29.8 | 36.6 | 31.7 | 68.8 | 31.2 | 17.1 | 82.9 | 5.2 | 94.8 |
| p-value | < 0.0005 | < 0.0005 | < 0.0005 | 0.291 | 0.516 |
In the 40−49-year age group, the most common breast density type was B (39.69%), while most 50−59 years participants had non-dense breasts (82.55%). More than half of the women aged > 59 years (63.56%) had type A breast density; breast density decreased with the increase in age (p < 0.0005) (Table 2).
The relationship between age at first childbirth and breast density revealed a statistically significant correlation (p < 0.0005). Participants aged 20−24 years were found to have highest type A, B, and D breast densities, while type C was highest in participants who had their first childbirth at > 25 years (Table 2).
Menopausal status such as, premenopausal and postmenopausal stage, and its relationship with breast density were also statistically significant (p < 0.0005). Type A and B (non-dense) breasts were observed in 87.8% of postmenopausal as compared with 70.1% of pre-menopausal women. Similarly, extremely dense breasts were seen in 5.9 and 2% of pre- and post-menopausal women, respectively.
Breast density did not show any association with a family history of breast cancer (p = 0.291). A total of 94.8% of women had benign findings on biopsy results, while 5.2% were diagnosed with breast cancer. Among the women who developed breast cancer, 36.3 and 6.2% had type B and type D densities, respectively (Table 2).
Based on BI-RADS assessment categories, a higher incidence of benign (category 2) and probably benign (category 3) cases were found in the 40−49-year age group, whereas suspicious (category 4) and highly suggestive of malignancy (category 5) cases were more frequent in the 50−59-year age group (p < 0.0005) (Table 3). In pre-menopausal patients, the frequency was higher in all BI-RADS categories than that of post-menopausal patients (p = 0.01). The majority of BI-RADS category 1 (99%) and 5 (74.6%) cases were tested negative and malignant, respectively (p < 0.0005).
Table 3
Association of BI-RADS assessment categories with other variables
Variable | | | Age (years) | Age at first childbirth (years) | Menopause status | Breast cancer Family history | Breast cancer |
BI-RADS Assessment Categories | | | < 40 | 40–49 | 50–59 | > 59 | < 15 | 15–19 | 20–24 | > 25 | Pre | Post | Yes | No | Yes | No |
0 | Count | 19 | 35 | 30 | 16 | 0 | 26 | 26 | 33 | 71 | 29 | 23 | 77 | 8 | 92 |
% | 19.0 | 35.0 | 30.0 | 16.0 | 0.0 | 30.6 | 30.6 | 38.8 | 71.0 | 29.0 | 23.0 | 77.0 | 8.0 | 92.0 |
1 | Count | 71 | 219 | 155 | 32 | 8 | 122 | 153 | 134 | 349 | 128 | 75 | 402 | 5 | 472 |
% | 14.9 | 45.9 | 32.5 | 6.7 | 1.9 | 29.3 | 36.7 | 32.1 | 73.2 | 26.8 | 15.7 | 84.3 | 1.0 | 99.0 |
2 | Count | 121 | 527 | 524 | 176 | 23 | 348 | 415 | 350 | 892 | 456 | 240 | 1108 | 16 | 1332 |
% | 9.0 | 39.1 | 38.9 | 13.1 | 2.0 | 30.6 | 36.5 | 30.8 | 66.2 | 33.8 | 17.8 | 82.2 | 1.2 | 98.8 |
3 | Count | 22 | 28 | 16 | 4 | 1 | 14 | 22 | 21 | 56 | 14 | 11 | 59 | 8 | 62 |
% | 31.4 | 40.0 | 22.9 | 5.7 | 1.7 | 24.1 | 37.9 | 36.2 | 80.0 | 20.0 | 15.7 | 84.3 | 11.4 | 88.6 |
4 | Count | 23 | 24 | 26 | 12 | 0 | 23 | 32 | 18 | 65 | 20 | 10 | 75 | 18 | 67 |
% | 27.1 | 28.2 | 30.6 | 14.1 | 0.0 | 31.5 | 43.8 | 24.7 | 76.5 | 23.5 | 11.8 | 88.2 | 21.2 | 78.8 |
5 | Count | 12 | 14 | 19 | 18 | 2 | 14 | 19 | 22 | 40 | 23 | 8 | 55 | 47 | 16 |
% | 19.0 | 22.2 | 30.2 | 28.6 | 3.5 | 24.6 | 33.3 | 38.6 | 63.5 | 36.5 | 12.7 | 87.3 | 74.6 | 25.4 |
6 | Count | 4 | 7 | 4 | 0 | 0 | 2 | 6 | 6 | 12 | 3 | 2 | 13 | 11 | 4 |
% | 26.7 | 46.7 | 26.7 | 0.0 | 0.0 | 14.3 | 42.9 | 42.9 | 80.0 | 20.0 | 13.3 | 86.7 | 73.3 | 26.7 |
Total | Count | 272 | 854 | 774 | 258 | 34 | 549 | 673 | 584 | 1485 | 673 | 369 | 1789 | 113 | 2045 |
% | 12.6 | 39.6 | 35.9 | 12.0 | 1.8 | 29.8 | 36.6 | 31.7 | 68.8 | 31.2 | 17.1 | 82.9 | 5.2 | 94.8 |
| p value | < 0.0005 | 0.916 | 0.01 | 0.382 | < 0.0005 |
BI-RADS, Breast Imaging Reporting and Data System |