Table 1.

Association of the systemic immune-inflammation index (SII) with the patient and tumor characteristics.

	Total	Low SII	High SII	P value
Age	784	562	222	0.037
≤40	170 (21.7%)	111 (19.8%)	59 (26.6%)
>40	614 (78.3%)	451 (80.2%)	163 (73.4%)
ER				0.416
−	293 (37.4%)	215 (38.3%)	78 (35.1%)
+	491 (62.6%)	347 (61.7%)	144 (64.9%)
PR				< 0.001
−	334 (42.6%)	273 (48.6%)	61 (27.5%)
+	450 (57.4%)	289 (51.4%)	161 (72.5%)
HER2				0.035
−	588 (75.0%)	433 (77.0%)	155 (69.8%)
+	196 (25.0%)	129 (23.0%)	67 (30.2%)
Ki-67 status				0.396
−	289 (36.9%)	202 (35.9%)	87 (39.2%)
+	495 (63.1%)	360 (64.1%)	135 (60.8%)
pT Stage				0.949
1	249 (31.8%)	178 (31.7%)	71 (32.0%)
2	450 (57.4%)	321 (57.1%)	129 (58.1%)
3	60 (7.7%)	45 (8.0%)	15 (6.8%)
4	25 (3.2%)	18 (3.2%)	7 (3.2%)
pN Stage				0.377
0	381 (48.6%)	283 (50.4%)	98 (44.1%)
1	276 (35.2%)	188 (33.5%)	88 (39.6%)
2	100 (12.8%)	71 (12.6%)	29 (13.1%)
3	27 (3.4%)	20 (3.6%)	7 (3.2%)
Histological grade				0.337
I-II	549 (70.0%)	388 (69.0%)	161 (72.5%)
III	235 (30.0%)	174 (31.0%)	61 (27.5%)
Surgery type				0.538
Mastectomy	621 (79.2%)	442 (78.6%)	179 (80.6%)
BCS	163 (20.8%)	120 (21.4%)	43 (19.4%)
Chemotherapy				0.369
Yes	281 (35.8%)	196 (34.9%)	85 (38.3%)
No	503 (64.2%)	366 (65.1%)	137 (61.7%)
Radiotherapy				0.627
Yes	285 (36.4%)	205 (36.5%)	80 (36.0%)
No	499 (63.6%)	357 (63.5%)	142 (64.0%)
Hormonal therapy				0.054
Yes	510 (65.1%)	354 (63.0%)	156 (70.3%)
No	274 (34.9%)	208 (37.0%)	66 (29.7%)
Target therapy				0.220
Yes	156 (19.9%)	118 (21.0%)	38 (17.1%)
No	628 (80.1%)	444 (79.0%)	184 (82.9%)

PR, progesterone receptor; ER, estrogen receptor; TNBC, triple-negative breast cancer; BCS, breast conserving surgery.