Development and validation of a pre- and intra-operative scoring system that distinguishes between non-advanced and advanced axillary lymph node metastasis in breast cancer with positive sentinel lymph nodes: a retrospective study

Table 3 Scoring system based on multivariate analysis in the training cohort

	Score	β-coefficient	Odds ratio	P value
Clinical tumor size (mm)
≥ 1 cm	0	–	1
1–2 cm	0	0.33	1.40	0.696
2–3 cm	0	0.19	1.20	0.828
3–4 cm	0	− 0.28	0.76	0.781
4–5 cm	2	1.60	4.94	0.086
> 5 cm	2	1.95	7.03	0.075
Histologic type
IDC-NST	0	–	1
Others	0	− 0.97	0.38	0.411
IMPC	0	0.84	1.84	0.492
ILC	1	0.61	2.31	0.068
No. of suspicious ALNs on US imaging^a
0	0	–	1
1 (solitary)	0	0.04	1.04	0.915
≥ 2 (multiple)	2	1.61	5.02	0.001
Size of SLN metastasis
ITC, micrometastasis	0	–	1
Macrometastasis	3	3.07	21.5	< 0.001
Ratio of no. of positive SLNs to total no. of SLNs
< 0.5	0	–	1
≥ 0.5	1	1.05	2.86	0.024
No. of positive SLNs
0 (ITC only), 1	0	–	1
2	1	1.12	3.05	0.003
3	3	2.75	15.7	< 0.001

IC invasive carcinoma, NST no special type, IDC infiltrating ductal carcinoma, ILC invasive lobular carcinoma, IMPC invasive micropapillary carcinoma, ALN axillary lymph node, US ultrasound, ITC isolated tumor cells, SLN sentinel lymph node
^aAxillary lymph nodes were considered suspicious if at least one of the following were noted: diffuse cortical thickness > 5 mm, focal cortical thickness > 3 mm, and effacement or replacement of the fatty hilum on US imaging

ISSN: 1477-7819