Longitudinal enumeration and cluster evaluation of circulating tumor cells improve prognostication for patients with newly diagnosed metastatic breast cancer in a prospective observational trial

Table 3 Prognostic information of CTC count and CTC clusters in a clinicopathological model

Model 1	Model 1 C-index	Model 2	Model 2 C-index	LRχ²	df	P value
PFS at baseline^a
CP	0.690	CP + CTC_BL	0.707	11.46	1	0.0007
CP	0.690	CP + cluster	0.706	9.47	1	0.0021
CP	0.690	CP + CTC_BL + cluster	0.714	14.46	2	0.0007
OS at baseline^a
CP	0.752	CP + CTC_BL	0.786	18.96	1	< 0.0001
CP	0.752	CP + cluster_BL	0.777	13.16	1	0.0003
CP	0.752	CP + CTC_BL + cluster_BL	0.799	23.54	2	< 0.0001
PFS at 1 month^b
CP + CTC_BL	0.697	CP + CTC_BL + CTC_1M	0.709	6.69	1	0.0097
CP + CTC_BL	0.697	CP + CTC_BL + cluster_1M	0.712	7.56	1	0.0060
CP + CTC_BL	0.697	CP + CTC_BL + CTC_1M+cluster_1M	0.713	10.56	2	0.0051
OS at 1 month^b
CP + CTC_BL	0.766	CP + CTC_BL + CTC_1M	0.812	15.73	1	0.0001
CP + CTC_BL	0.766	CP + CTC_BL + cluster_1M	0.788	12.01	1	0.0005
CP + CTC_BL	0.766	CP + CTC_BL + CTC_1M+cluster_1M	0.817	20.57	2	< 0.0001
PFS at 3 months^b
CP + CTC_BL	0.695	CP + CTC_BL + CTC_3M	0.701	7.31	1	0.0068
CP + CTC_BL	0.695	CP + CTC_BL + cluster_3M	0.711	6.22	1	0.0126
CP + CTC_BL	0.695	CP + CTC_BL + CTC_3M+cluster_3M	0.710	9.01	2	0.0110
OS at 3 months^b
CP + CTC_BL	0.774	CP + CTC_BL + CTC_3M	0.806	14.76	1	0.0001
CP + CTC_BL	0.774	CP + CTC_BL + cluster_3M	0.806	7.02	1	0.0081
CP + CTC_BL	0.774	CP + CTC_BL + CTC_3M+cluster_3M	0.806	15.16	2	0.0005
PFS at 6 months^b
CP + CTC_BL	0.694	CP + CTC_BL + CTC_6M	0.732	11.14	1	0.0008
CP + CTC_BL	0.694	CP + CTC_BL + cluster_6M	0.709	7.14	1	0.0075
CP + CTC_BL	0.694	CP + CTC_BL + CTC_6M+cluster_6M	0.727	12.14	2	0.0023
OS at 6 months^b
CP + CTC_BL	0.758	CP + CTC_BL + CTC_6M	0.804	15.88	1	0.0001
CP + CTC_BL	0.758	CP + CTC_BL + cluster_6M	0.813	13.24	1	0.0003
CP + CTC_BL	0.758	CP + CTC_BL + CTC_6M+cluster_6M	0.818	20.66	2	< 0.0001

Abbreviations: BL baseline, 3M 3 months, 6M 6 months, df degrees of freedom, LRχ² likelihood ratio chi-square, CP clinicopathological model, CTC circulating tumor cell, PFS progression-free survival, OS overall survival
^aAdjusted for subtype, histologic grade, performance status (Eastern Cooperative Oncology Group (ECOG)), age, metastasis-free interval (MFI), visceral metastases, and number of metastatic locations
^bAdjusted for baseline CTC count ≥ 5, subtype, histologic grade, performance status (ECOG), age, MFI, visceral metastases, and number of metastatic locations. Analyses at 1, 3, and 6 months were performed by landmark analysis

ISSN: 1465-542X