The Guiding Significance of the Number of Positive Sentinel Lymph Nodes in Frozen Section for Intraoperative Axillary Dissection in Early Breast Cancer

Figures & data

Table 1 Clinicopathological Characteristics of Patients

Characteristics (n = 3303)
Ages, years	51.57 ± 10.89
Mean numbers of SLNs	3.55 ± 2.56
Histologic type, no. (%)
Invasive ductal	2989 (90.49)
Invasive lobular	77 (2.33)
Other	237 (7.18)
Histologic grade, no. (%)
I	176 (5.33)
II	1710 (51.77)
III	850 (25.73)
Missing	567 (17.17)
Pathological tumor (T) stage, no. (%)
T1a (>1 mm, ≤5 mm)	332 (10.05)
T1b (>5 mm, ≤10 mm)	403 (12.20)
T1c (>10 mm, ≤20 mm)	1397 (42.29)
T2 (>20 mm, ≤50 mm)	1171 (35.45)
HR status, no. (%)
Negative	898 (27.19)
Positive	2361 (71.48)
Missing	44 (1.33)
HER2 status, no. (%)
Negative	2313 (70.03)
Positive	856 (25.92)
Missing	134 (4.06)
Ki67 status, no. (%)
Low expression	1263 (38.24)
High expression	2040 (61.76)

Abbreviations: SLNs, Sentinel lymph nodes; HR, hormone receptor; HER2, Human epidermal growth factor receptor 2.

Table 2 Accuracy of SLNs Detection via Frozen Section

Frozen Section	Final Paraffin Section		Total
	Negative	Positive
Negative	2485	188	2673
Positive	8	622	630
Total	2493	810	3303
False negative rate, %			23.21
False positive rate, %			0.32
Sensitivity, %			76.79
Accuracy, %			94.07

Abbreviation: SLNs, sentinel lymph nodes.

Table 3 FNR and Sensitivity of Frozen Sections in SLNs by Size of SLNs Metastases (n = 810)

List	True Positive	False Negtive	Total	Sensitive Rate, %	FNR, %	OR, % (95% CI)	P value
Macrometastasis	567	78	645	87.91	12.09	1	<0.001
Micrometastasis	43	71	114	37.72	62.28	12.00 (7.68 to 18.76)
Isolated tumor cells	12	39	51	23.53	76.47	23.63 (11.86 to 47.05)
Total	622	188	810	76.79	23.21	–	–

Abbreviations: FNR, False negative rate; SLNs, sentinel lymph nodes.

Table 4 Comparison of SLNs Number Between Frozen Section and Final Paraffin Section (n = 420)

Frozen Section	Final Paraffin Section
	Negative	Macrometastasis		Micrometastasis	Isolated Tumor Cells	Total
		1 to 2 Positive	>2 Positive
Macrometastasis	0 (0.00%)	291 (80.17%)	62 (17.08%)	9 (2.48%)	1 (0.28%)	363 (100%)
1 to 2 positive	0 (0.00%)	290 (87.88%)	30 (9.09%)	9 (2.72%)	1 (0.30%)	330 (100%)
>2 positive	0 (0.00%)	1 (3.03%)	32 (96.97%)	0 (0.00%)	0 (0.00%)	33 (100%)
Micrometastasis	3 (6.98%)	15 (34.88%)	0 (0.00%)	21 (48.84%)	4 (9.30%)	43 (100%)
Isolated tumor cells	3 (21.43%)	3 (21.43%)	0 (0.00%)	2 (14.29%)	6 (42.86%)	14 (100%)

Abbreviation: SLNs, sentinel lymph nodes.

Table 5 Comparison of Clinicopathological Characteristics Between SLNs Metastasis Coincidence Group and Non-Coincidence Group

Characteristics	Non-Coincidence Group (n=31)	Coincidence Group (n=389)	P value
Ages, years	52.57 ± 10.76	49.91±10.18	0.30
Histologic type			0.56
Invasive ductal	30	362
Invasive lobular	1	13
Other	0	14
Histologic grade			0.35
I	1	16
II	21	237
III	9	100
Missing	0	36
Pathological tumor (T) stage			0.77
T1a (>1 mm, ≤5 mm)	0	6
T1b (>5 mm, ≤10 mm)	1	25
T1c (>10 mm, ≤20 mm)	15	168
T2 (>20 mm, ≤50 mm)	15	190
HR status			0.64
HR negative	5	76
HR positive	26	313
HER2 status			0.03
HER2 negative	16	285
HER2 positive	14	91
Missing	1	13
Ki67 status			0.02
Low expression	5	144
High expression	26	245

Abbreviations: SLNs, Sentinel lymph nodes; HR, hormone receptor; HER2, Human epidermal growth factor receptor 2.

Table 6 Rate of Non-Sentinel Lymph Node Metastasis in Different Sizes and Numbers of Metastatic SLNs (n= 420)

Frozen Section	Non-Sentinel Lymph Node			Total
	Negative	Positive	Without ALND
Macrometastasis	238 (65.56%)	123 (33.88%)	2 (0.55%)	363 (100%)
1 to 2 positive	227 (68.79%)	101 (30.61%)	2 (0.61%)	330 (100%)
>2 positive	11 (33.33%)	22 (66.67%)	0 (0.00%)	33 (100%)
Micrometastasis	30 (69.77%)	4 (9.30%)	9 (20.93%)	43 (100%)
Isolated tumor cells	5 (35.71%)	1 (7.14%)	8 (57.14%)	14 (100%)

Abbreviations: ALND, axillary lymph node dissection; SLNs, sentinel lymph nodes.