Table 4. Sensitivity, specificity and accuracy of our model in low-risk predictive patients in validation group.

Predicted risk	Patient number and percentage (%)	Number of patients with ALN metastasis	Sensitivity (%)	Specificity (%)	Accuracy (%)	FNR (%)
<7.1%	6 (2.6)	0	100	6	100	0
<13.8%	19 (8.1)	1	99.2	17.8	94.7	5.3
<18.2%	23 (9.8)	2	98.5	20.8	91.3	8.7
<20%	29 (23.1)	5	96.2	23.8	82.8	17.2
<30%	55 (23.5)	14	89.5	40.6	74.5	25.5
<40%	78 (33.3)	16	88	61.4	79.5	20.5

Validation group (n = 234): patients with positive lymph node (n = 133, 56.8%); patients with negative lymph node (n = 101, 43.2%).

ALN: axillary lymph node; FNR: false negative rate.