Clinical information and pathological findings
A total of 90 patients with 54 benign and 36 malignant breast lesions were included. Of these, there were 19 gynecomastia, 13 fibroadenoma, 11 inflammation, 6 epithelial cysts, 3 intraductal papilloma, 1 lipoma and 1 hemangioma in benign nodules, and there were 30 IDC, 2 encapsulated papillary carcinoma (EPC), 2 intraductal papillary carcinoma (IPC), 1 lymphoma and 1EPC with IDC in malignant nodules.
The ages and size of the onset of male breast cancer were markedly higher than those of benign breast cancer (P < 0.05). The general information of the patients was summarized in Table 1.
Table 1
Basic characteristics of patients in all breast nodules
Basic characteristics
|
Benign (n = 54)
|
Malignant (n = 36)
|
P
|
Age(y)
|
46.240 ± 17.186
|
56.580 ± 13.179
|
0.003
|
Size(cm)
|
2.271 ± 1.122
|
1.489 ± 0.898
|
0.000
|
Age(y) and Size(cm)were represented as median ± SD. |
P < 0.05 was statistically significant. |
Table 2 Interobserver Agreement for Ultrasonographic features
US Features
|
Group I
|
P
value
|
Group II
|
P
value
|
Group III
|
P value
|
ICC
|
Benign
(n=54)
|
Malignant
(n=36)
|
Benign
(n=54)
|
Malignant
(n=36)
|
Benign
(n=54)
|
Malignant(n=36)
|
Mass shape
|
|
|
0.040
|
|
0.011
|
|
|
0.007
|
0.677(0.580,0.762)
|
Irregular
|
17(31.5)
|
20(55.6)
|
|
20(37.0)
|
24(66.7)
|
|
15(27.8)
|
21(58.3)
|
|
0.677(0.580,0.762)
|
regular
|
37(68.5)
|
16(44.4)
|
|
34(63.0)
|
12(33.3)
|
|
39(72.2)
|
15(41.7)
|
|
0.677(0.580,0.762)
|
Echo pattern
|
|
|
0.177
|
|
0.152
|
|
|
0.106
|
0.923(0.893,0.946)
|
Hypoechoic
|
44(81.6)
|
31(86.1)
|
|
44(81.6)
|
32(88.9)
|
|
45(81.6)
|
33(91.7)
|
|
0.829(0.769,0.878)
|
Complex
|
5(9.2)
|
4(11.1)
|
|
5(9.2)
|
3(8.3)
|
|
4(9.2)
|
2(5.6)
|
|
0.718(0.629,0.794)
|
Hyperechoic
|
0(0)
|
1(2.8)
|
|
0(0)
|
1(2.8)
|
|
0(0)
|
1(2.7)
|
|
1.000(1.000,1.000)
|
echoless
|
5(9.2)
|
0(0)
|
|
5(9.2)
|
0(0)
|
|
5(9.2)
|
0(0)
|
|
1.000(1.000,1.000)
|
Mass orientation
|
|
|
0.350
|
|
0.087
|
|
|
0.173
|
0.651(0.548,0.741)
|
Parallel
|
46(85.2)
|
27(75)
|
|
51(94.4)
|
29(80.6)
|
|
51(94.4)
|
30 (83.3)
|
|
0.651(0.548,0.741)
|
Not parallel
|
8(14.8)
|
9(25)
|
|
3(5.6)
|
7(19.4)
|
|
3(5.6)
|
6(16.7)
|
|
0.651(0.548,0.741)
|
Boundary
|
|
|
0.007
|
|
0.025
|
|
|
0.025
|
0.674(0.578,0.759)
|
Circumscribed
|
39(72.2)
|
15(41.7)
|
|
38 (70.4)
|
16(44.4)
|
|
38(70.4)
|
16(44.4)
|
|
0.674(0.578,0.759)
|
No- circumscribed
|
15(27.8)
|
21(58.3)
|
|
16(29.6)
|
20(55.6)
|
|
16(29.6)
|
20(55.6)
|
|
0.674(0.578,0.759)
|
Margin
|
|
|
0.000
|
|
0.000
|
|
|
0.000
|
0.826(0.764,0.875)
|
Smooth
|
32(59.3)
|
6(16.7)
|
|
34(63.0)
|
9(25.0)
|
|
38(70.4)
|
11(30.6)
|
|
0.793(0.722,0.851)
|
Angular
|
6(11.1)
|
18(50)
|
|
7(13.0)
|
18(50.0)
|
|
5(9.2)
|
14(38.8)
|
|
0.646(0.543,0.737)
|
Indistinct
|
16(29.6)
|
12(33.3)
|
|
13(24.0)
|
9(25.0)
|
|
11(20.4)
|
11(30.6)
|
|
0.790(0.718,0.849)
|
Posterior features
|
|
|
0.157
|
|
0.237
|
|
|
0.217
|
0.805(0.738,0.860)
|
None
|
30(55.6)
|
22(61.2)
|
|
24 (44.4)
|
14(38.9)
|
|
33(61.2)
|
23(64.5)
|
|
0.706(0.664,0.816)
|
Enhancement
|
19(35.2)
|
7(19.4)
|
|
23 (42.6)
|
12(33.3)
|
|
16(29.6)
|
6(12.9)
|
|
0.707(0.615,0.785)
|
Shadowing
|
5(9.2)
|
7(19.4)
|
|
7(13)
|
10(27.8)
|
|
5(9.2)
|
7(22.6)
|
|
0.835(0.775,0.882)
|
Microcalcifications
|
|
|
1.00
|
|
0.821
|
|
|
1.00
|
0.773(0.697,0.836)
|
Yes
|
7(12.9)
|
5(13.9)
|
|
4(7.4)
|
4(11.1)
|
|
6(11.1)
|
4(11.1)
|
|
0.773(0.697,0.836)
|
None
|
47(87.1)
|
31 (86.1)
|
|
50(92.6)
|
32(88.9)
|
|
48 (88.9)
|
32(88.9)
|
|
0.773(0.697,0.836)
|
Numbers in parentheses are percentages except ICC. Data in parentheses in ICC are 95% CIs.
P<0.05 was statistically significant.
Interobserver agreement for ultrasonographic features
In seven kinds of ultrasound features with all nodules, the mass shape, boundary and margin characteristics showed an obvious difference (P < 0.05) between benign and malignant nodules other than echo, orientation, posterior features and microcalcifications in the judgment of the reader for each group.
For reader performance, the descriptions of echo (0.923), margin (0.826), posterior (0.805) and microcalcifications (0.773) showed excellent ICCs across the three groups. By contrast, the ICC of the boundary, mass shape and orientation had good levels, and the ICC of the boundary was lower than else (0.651 vs 0.674, 0.677). Furthermore, the echo descriptions as hyperechoic and echoless had the best ICC of 1.00 contrary to the margin described as angular had the lowest ICC at 0.646 among all features (Table 2).
Interobserver agreement for BI-RADS classifications
The three groups expressed excellent concordance in BIRADS 2 category and good concordance in BIRADS 3 category. Three groups showed fair concordance in the BIRADS 4b,4c and 5 categories and poor concordance in the BIRADS 4a category. In all BIRADS classifications, three groups had good performance (Table 3).
Table 3
Interobserver Agreement for BI-RADS classifications
BI-RADS
|
Group I
|
Group II
|
Group III
|
ICC
|
2
|
6
|
5
|
5
|
0.934(0.908,0.954)
|
3
|
30
|
23
|
30
|
0.677(0.579,0.761)
|
4a
|
20
|
19
|
21
|
0.379(0.249,0.509)
|
4b
|
13
|
14
|
14
|
0.483(0.358,0.601)
|
4c
|
14
|
19
|
11
|
0.521(0.401,0.634)
|
5
|
7
|
10
|
9
|
0.491(0.368,0.608)
|
All
|
|
|
|
0.709(0.617,0.786)
|
Note—Data in parentheses are 95% CIs. |
Comparison of diagnostic efficiency for the prediction of malignant nodules based on the three groups
In group I, the ROC curve demonstrated that the best cutoff was 4a with an AUC for the ROC was 0.779 (95% CI: 0.681, 0.876), for which the sensitivity, specificity, and accuracy were 88.3%, 55.6%, and 66.7%. In group II, the ROC curve demonstrated that the best cut-off was 4a with the AUC was 0.838 (95% CI: 0.756, 0.920), for which the sensitivity, specificity, and accuracy were 83.3%, 75.9%, and 71.1%. In group III, the ROC curve showed that the best cut-off was 4a with an AUC of 0.904 (95% CI: 0.842, 0.966), which the sensitivity, specificity, and precision were 97.2%, 62.9%, and 76.7% (Fig. 1). Moreover, the comparison of the AUCs between two groups, group I had significant differences from group III (z = 3.226, P = 0.0013); others were not (for group III vs. group II: z = 1.548, P = 0.121; for group II vs. group I: z = 0.136, P = 0.256).