Table 2

Risk estimates [n (%)] for all SPTsa relative to IGF-I, IGFBP-3 levels, and smoking status in logistic regression analysis

No SPT (n = 173)SPT (n = 80)Univariate OR (95% CI)Multivariate OR (95% CI)b
Smoking status
 Never24 (13.9)6 (7.5)1.001.00
 Former100 (57.8)37 (46.3)1.48 (0.56–3.91)1.32 (0.47–3.74)
 Current49 (28.3)37 (46.3)3.02 (1.12–8.14)2.54 (0.88–7.38)
Treatment regimen
 Placebo88 (50.9)46 (57.5)1.001.00
 13 cRA85 (49.1)34 (42.5)0.77 (0.45–1.31)0.72 (0.40–1.32)
IGF-I (ng/ml)
 < 104.2598 (57.7)25 (31.6)1.001.00
 ≥ 104.2572 (42.3)54 (68.4)2.94 (1.67–5.16)3.66 (1.86–7.19)
IGFBP-3 (ng/ml)
 ≥ 2276, < 414091 (53.2)32 (40.5)1.001.00
 < 227674 (43.3)32 (40.5)1.23 (0.69–2.19)2.22 (1.11–4.45)
 ≥ 41406 (3.5)15 (19.0)7.11 (2.54–19.89)7.12 (2.32–21.80)
  • a SPT, second primary tumor; IGF-I, insulin-like growth factor-I; IGFBP-3, IGF binding protein 3; OR, odds ratio; CI, confidence interval; 13 cRA, 13-cis-retinoic acid.

  • b Multivariate logistic regression model was built to assess the predictive effects of IGF-I and IGFBP-3 for SPT risk. The model simultaneously includes IGF-I, IGFBP-3, smoking status at registration, and treatment regimen.