Table 1.

Clinical characteristics of patients in the training and test sets.

Characteristic	Training cohort (127)			Test cohort (43)
	Resistance (N = 61)	Non-resistance (N = 66)	P	Resistance (N = 21)	Nonresistance (N = 22)	P
Age (mean, SD)	46.80 ± 10.66	48.58 ± 10.22	.341	48.14 ± 10.70	46.00 ± 10.04	.502
Volume (cm3)	13.05 ± 12.57	9.15 ± 8.82	.044	8.43 ± 9.96	7.09 ± 5.24	.581
ER			.019			.001
Positive	43	33		17	7
Negative	18	33		4	15
PR			.476			.087
Positive	25	23		10	5
Negative	36	43		11	17
Ki67			.282			.066
Positive	43	52		13	19
Negative	18	14		8	3
Her2			.046			.650
Positive	19	32		11	10
Negative	42	34		10	12
Molecular subtype			.023			.502
HR+ and HER2−	31	18		8	7
HER2+	19	32		11	10
Triple-negative	11	16		2	5

	Non-PCR (N = 80)	PCR (N = 47)	P	Non-PCR (N = 27)	PCR (N = 16)	P
Age (mean, SD)	47.29 ± 10.26	48.47 ± 10.78	.540	48.78 ± 11.03	44.13 ± 8.47	.155
Volume (cm3)	11.67 ± 11.50	9.93 ± 9.87	.388	7.91 ± 9.01	7.47 ± 5.56	.861
ER			.022			<.001
Positive	54	22		22	2
Negative	26	25		5	14
PR			.295			.295
Positive	33	15		11	4
Negative	47	32		16	12
Ki67			.104			.025
Positive	56	39		17	15
Negative	24	8		10	1
Her2			.001			.454
Positive	23	28		12	9
Negative	57	19		15	7
Molecular subtype			.001			.185
HR+ and HER2−	40	9		12	3
HER2+	23	28		12	9
Triple-negative	17	10		3	4

Abbreviations: PCR: pathological complete response; Non-PCR: nonpathological complete response; ER: estrogen receptor; PR: progesterone receptor; HR: hormone receptor; HER2: human epidermal growth factor receptor 2.