Table 4.

Multivariable proportional hazards model for disease-free survival and overall survival for different circulating tumor cell cutoff values*

Variable	HRs (95% CI) adjusted for treatment
	0 vs ≥1 CTC per 30mL blood	0–1 vs ≥2 CTC per 30mL blood	0–4 vs ≥5 CTC per 30mL blood
DFS
CTCs in blood, negative vs positive	2.11† (1.487 to 2.986)	3.19† (2.141 to 4.763)	4.51† (2.586 to 7.864)
Hormone receptor status, positive vs negative	1.97† (1.36 to 2.85)	1.98† (1.366 to 2.861)	1.98† (1.365 to 2.869)
Lymph node involvement, N0 vs N1–3	2.94† (1.92 to 4.51)	2.77† (1.807 to 4.241)	2.84† (1.859 to 4.349)
Grading, G1 vs G2–3	3.25† (2.15 to 4.94)	3.39† (2.236 to 5.145)	3.32† (2.186 to 5.026)
Tumor size, T1 vs T2–4	2.08† (1.41 to 3.08)	2.13† (1.440 to 3.159)	2.19† (1.485 to 3.246)
Menopausal status, pre vs post	1.02 (0.88 to 2.63)	1.00 (0.705 to 1.423)	0.99 (0.699 to 1.410)
Histology, lobular/mixed vs ductal	0.93 (0.58 to 1.51)	0.91 (0.559 to 1.466)	0.94 (0.579 to 1.516)
OS
CTCs in blood, negative vs positive	2.18† (1.32 to 3.59)	2.57† (1.416 to 4.659)	3.60† (1.564 to 8.445)
Hormone receptor status, positive vs negative	3.0† (1.76 to 5.10)	3.04† (1.786 to 5.163)	3.05† (1.790 to 5.190)
Lymph node involvement, N0 vs N1–3	4.25† (2.18 to 8.29)	4.07† (2.085 to 7.947)	4.19† (2.149 to 8.161)
Grading, G1 vs G2–3	3.55† (1.86 to 6.76)	3.65† (1.920 to 6.954)	3.66† (1.924 to 6.977)
Tumor size, T1 vs T2–4	2.67† (1.44 to 4.93)	2.74† (1.479 to 5.058)	2.85† (1.548 to 5.255)
Menopausal status, pre vs post	1.52 (0.88 to 2.63)	1.49 (0.856 to 2.580)	1.49 (0.859 to 2.583)
Histology, lobular/mixed vs ductal	1.26 (0.56 to 2.85)	1.23 (0.546 to 2.779)	1.25 (0.556 to 2.823)

* CI = confidence interval; CTC = circulating tumor cell; DFS = disease free survival; HR = hazard ratio; OS = overall survival. Cox proportional hazards models. All statistical tests were two-sided.

† Statistically significant.