1. Baseline characteristics of patients according to type of first-line therapy.

Characteristics	NPCT (n=129) [n (%)]	PBCT (n=91) [n (%)]	P
DFS, disease-free survival; 95% CI, 95% confidence interval; NPCT, non-platinum-based chemotherapy; PBCT, platinum-based chemotherapy; *, Including digestive tract, pancreatic and prostate cancer and blood system tumors; **, Including lung, liver and brain metastases.
Age (year)
Median (range)	51 (25−75)	46 (21−66)	0.001
≤50	64 (49.6)	62 (68.1)	0.006
>50	65 (50.4)	29 (31.9)
Family history
Breast/ovarian cancer	12 (9.3)	9 (9.9)	0.416
Other cancers*	16 (12.4)	17 (18.7)
No	101 (78.3)	65 (71.4)
Histology of primary tumor
Invasive ductal carcinoma	113 (87.6)	79 (86.8)	0.063
Invasive lobular carcinoma	8 (6.2)	1 (1.1)
Others	8 (6.2)	11 (12.1)
Diagnosed triple negative
Primary tumor	111 (86.0)	79 (86.8)	0.870
Metastatic sites	18 (14.0)	12 (13.2)
Tumor grade
I	1 (0.8)	0 (0)	0.624
II	49 (38.0)	30 (33.0)
III	44 (34.1)	33 (36.3)
Unknown	35 (27.1)	28 (30.8)
Ki67 index
≤14%	12 (9.3)	9 (9.9)	0.459
15%−50%	50 (38.8)	26 (28.6)
>50%	45 (34.9)	39 (42.9)
Unknown	22 (17.1)	17 (18.7)
DFS (month)
Median (95% CI)	24.3 (20.6−28.0)	14.3 (11.9−16.7)	0.002
≤24	66 (51.2)	69 (75.8)	0.000
>24	63 (48.8)	22 (24.2)
Metastatic site
Node	56 (43.4)	43 (47.3)	0.573
Bone	31 (24.0)	20 (22.0)	0.722
Chest wall	23 (17.8)	18 (19.8)	0.714
Lung	41 (31.8)	30 (33.0)	0.853
Liver	24 (18.6)	13 (14.3)	0.399
Brain	6 (4.7)	2 (2.2)	0.554
Other sites	13 (10.1)	20 (22.0)	0.015
Number of metastases
1	88 (68.2)	52 (57.1)	0.153
2	22 (17.1)	25 (27.5)
≥3	19 (14.7)	14 (15.4)
Visceral metastasis**
No	72 (55.8)	51 (56.0)	0.973
Yes	57 (44.2)	40 (44.0)