Table 2 Estimates of the cumulative incidence of thrombosis

From: Circulating tumour cells are associated with increased risk of venous thromboembolism in metastatic breast cancer patients

  N No of thrombosis events 12-Month estimate (percent) 95% Confidence interval P -value
All 290 25 8.5 (5.5, 12.4)
Baseline CTC
 0 108 3 3.0 (0.8, 7.9)  
1 182 22 11.7 (7.3, 17.3) 0.006
Baseline CTC
 <5 177 11 6.6 (3.3, 11.4)  
5 113 14 11.6 (6.3, 18.6) 0.076
Age (years)
 <50 100 10 8.9 (4.1, 15.9)  
 >50 190 15 8.3 (4.7, 13.2) 0.552
Line of therapy
 1 123 6 3.3 (1.1, 7.8)  
2 167 19 12.8 (7.8, 19.1) 0.027
Estrogen and progesteron receptor
 Positive for both 192 14 6.4 (3.4, 10.8)  
 Negative for either 98 11 12.8 (6.7, 21.0) 0.188
HER2/neu amplified
 No 227 20 8.4 (5.1, 12.8)  
 Yes 62 5 8.8 (3.2, 18.1) 0.900
Inflammatory breast cancer
 No 222 17 7.9 (4.7, 12.1)  
 Yes 68 8 11.1 (4.3, 21.3) 0.234
Visceral metastasis
 No 109 2 2.0 (0.4, 6.3)  
 Yes 181 23 12.3 (7.8, 18.0) 0.002
Bone metastasis
 No 88 6 8.6 (3.4, 16.9)  
 Yes 202 19 8.6 (5.1, 13.2) 0.547
Number of sites of metastasis
 1 100 3 3.53 (0.9, 9.2)  
 2 or 3 144 11 7.69 (3.9, 13.2)  
4 46 11 21.07 (10.2, 34.5) 0.002
Chemotherapy
 No 36 3 5.6 (1.0, 16.5)  
 Yes 254 22 8.8 (5.6, 13.0) 0.934
Bevacizumab-based therapy
 No 230 20 8.1 (4.9, 12.4)  
 Yes 60 5 10.0 (3.5, 20.5) 0.999
Hormonal therapy
 No 164 19 11.9 (7.2, 18.0)  
 Yes 126 6 4.2 (1.6, 8.9) 0.037
Tamoxifen
 No 101 10 10.4 (5.3, 17.5)  
 Yes 38 1 0.0 0.177
Aromatase inhibitors
 No 194 22 11.2 (7.0, 16.6)  
 Yes 96 3 3.2 (0.9, 8.3) 0.016
Erythropoetin-stimulating agents
 No 256 24 9.3 (5.9, 13.6)  
 Yes 34 1 2.9 (0.2, 13.2) 0.150
Port-a-catheter and/or central venous device
 No 211 17 7.9 (4.6, 12.4)  
 Yes 79 8 9.8 (4.2, 18.1) 0.747
History of DVT/PE
 No 274 23 8.0 (5.1, 11.9)  
 Yes 16 2 14.6 (2.0, 38.7) 0.672
Arterial hypertension
 No 188 19 9.1 (5.4, 13.9)  
 Yes 102 6 7.5 (3.0, 14.8) 0.242
Diabetes mellitus
 No 255 22 8.5 (5.3, 12.6)  
 Yes 35 3 8.9 (2.2, 21.6) 0.924
  1. Abbreviations: DVT=deep vein thrombosis; PE= pulmonary embolism, CTC=circulating tumour cells.