Table 1.

Patient demographics and clinical characteristics (N = 88)

nMedian OS (95% CI), monthsHR (95% CI), univariable analysisPHR (95% CI), multivariable analysisaPa
Age, y0.140.31
 <451438.6 (4.7–44.1+)1 (reference)1 (reference)
 45–645110.3 (8.4–19.3)1.95 (0.82–4.60)1.35 (0.54–3.38)
 ≥652310.0 (7.6–17.4)2.26 (0.92–5.56)1.92 (0.75–4.92)
Sex0.620.86
 Male4810.3 (8.0–16.9)1 (reference)1 (reference)
 Female4014.5 (8.6–21.5)0.88 (0.52–1.49)1.05 (0.61–1.79)
Race0.0960.43
 White5615.6 (10.0–26.5)1 (reference)1 (reference)
 African American38.9 (7.7–10.2)1.66 (0.38–7.16)1.71 (0.37–7.96)
 Asian119.2 (3.6–14.5)2.28 (1.11–4.67)1.55 (0.74–3.23)
 Hispanic188.0 (5.1–21.1)1.54 (0.80–2.93)1.57 (0.80–3.09)
Primary tumor site0.410.49
 Right colon2416.7 (7.2–21.5)1 (reference)1 (reference)
 Left colorectal cancer6111.4 (8.4–19.3)0.88 (0.50–1.56)0.93 (0.52–1.65)
 Unspecified310.0 (5.4–10.0)1.87 (0.54–6.54)1.91 (0.55–6.65)
Liver-only metastases0.200.092
 Yes1616.9 (6.4–33.2+)1 (reference)1 (reference)
 No7210.0 (8.0–16.7)1.61 (0.76–3.41)1.93 (0.90–4.15)
ECOG0.490.086
 03214.5 (7.7–23.8)1 (reference)1 (reference)
 1–25610.4 (8.6–17.4)1.20 (0.69–2.07)1.63 (0.93–2.85)
Number of prior treatments0.0010.11
 0–12033.3 (16.7–38.6)1 (reference)1 (reference)
 2236.6 (4.5–11.0)4.45 (1.90–10.43)3.09 (1.13–8.44)
 32510.0 (7.8–21.1)2.63 (1.11–6.23)2.23 (0.84–5.91)
 4–52010.3 (7.7–14.5)2.72 (1.12–6.61)1.74 (0.61–5.00)
Therapy initiated after CTC collection<0.001<0.001
 Standard therapy3133.3 (15.6–38.6)1 (reference)1 (reference)
 Experimental578.6 (6.9–10.3)3.65 (1.93–6.89)4.47 (2.28–8.76)
Baseline CEA0.0000.016
 ≤364121.1 (10.3–35.5)1 (reference)1 (reference)
 >36428.0 (6.9–10.0)2.59 (1.45–4.64)2.16 (1.15–4.05)
Baseline LDH0.0010.048
 ≤3005317.4 (10.0–33.3)1 (reference)1 (reference)
 >300158.0 (3.6–11.0)3.20 (1.43–7.18)2.44 (1.01–5.88)
  • aOn the basis of the multivariable Cox regression model adjusting for the current treatment (experimental vs. standard therapy) and the primary tumor site (right colon vs. left colorectal cancer vs. unspecified).