Table 2.

Association between survival and CTC response^a

	n (%)	Median OS, mo (95% CI)	HR (95% CI)b	p valueb
Week 4
All patients	440	11.4 (10.5–12.4)
Response	283 (64.3)	14.4 (12.8–15.9)	0.45 (0.36–0.56)	<0.001
Non-response	157 (35.7)	7.9 (6.9–8.9)
IMMC-38	113	11.2 (9.7–12.6)
Response	75 (66.4)	12.3 (8.2–16.3)	0.46 (0.29–0.74)	0.001
Non-response	38 (33.6)	6.8 (4.4–9.2)
COU-AA-301	327	11.7 (10.3–13.1)
Response	208 (63.6)	14.4 (13.2–15.5)	0.44 (0.34–0.57)	<0.001
Non-response	119 (36.4)	7.9 (6.9–9)
Week 8
All patients	380	12.5 (11.1–13.9)
Response	248 (65.3)	15.4 (13.9–16.8)	0.41 (0.33–0.53)	<0.001
Non-response	132 (34.7)	7.9 (15.4–12.5)
IMMC-38	84	12.3 (9.4–15.1)
Response	56 (66.7)	17.2 (9.7–24.6)	0.42 (0.24–0.74)	0.003
Non-response	28 (33.3)	10.2 (5.5–14.9)
COU-AA-301	296	12.6 (11.1–14.2)
Response	192 (64.9)	15.4 (14.1–16.7)	0.4 (0.31–0.53)	<0.001
Non-response	104 (35.1)	7.7 (6.7–8.5)
Week 12
All patients	351	13.8 (12.3–15.3)
Response	226 (64.4)	16.1 (14.6–17.7)	0.39 (0.3–0.5)	<0.001
Non-response	125 (35.6)	9.7 (8.3–11.1)
IMMC-38	79	13.6 (10.6–16.6)
Response	55 (69.6)	18.2 (11.7–24.7)	0.35 (0.19–0.63)	<0.001
Non-response	24 (30.4)	13.6 (10.6–16.6)
COU-AA-301	272	13.9 (12.2–15.6)
Response	171 (62.9)	15.9 (14.5–17.4)	0.41 (0.3–0.54)	<0.001
Non-response	101 (37.1)	9.7 (7.7–11.7)

CTC = circulating tumor cell; OS = overall survival; HR = hazard ratio; CI = confidence interval.

^aResponse was defined as a 30% decline in CTC count relative to baseline at each of the landmark time points.

^bUnivariable Cox regression.