Table 2

RR and 95% CI of colorectal cancer, intermediate/late-stage colorectal adenoma, and early-stage colorectal adenoma according to tertiles of IGF-1 and IGFBP-3 in the NHS, 1989–1994

Tertile 1Tertile 2Tertile 3P, trend
Colorectal cancer
IGF-1
No. of Cases212731
No. of controls525353
RRa1.00.801.21
RRb1.00.912.18
95% CI0.42–1.990.94–5.080.10
IGFBP-3
No. of cases293218
No. of controls535352
RRa1.01.150.53
RRb1.00.970.28
95% CI0.48–1.960.10–0.830.05
Intermediate/Late-stage adenomac
IGF-1
No. of cases323820
No. of controls372825
RRa1.01.140.82
RRb1.02.102.78
95% CI0.92–4.830.76–9.760.24
IGFBP-3
No. of cases303921
No. of controls292833
RRa1.01.130.47
RRb1.01.040.28
95% CI0.46–2.320.09–0.850.04
Early-stage adenomac
IGF-1
No. of cases353141
No. of controls283841
RRa1.00.640.99
RRb1.00.540.65
95% CI0.24–1.240.27–1.580.52
IGFBP-3
No. of cases373535
No. of controls383633
RRa1.00.981.02
RRb1.01.281.41
95% CI0.58–2.830.59–3.360.68
  • a Adjusted for alcohol intake and BMI. Cutpoints for IGF-1 and IGFBP-3 tertiles for cancer and adenoma matched pairs were determined separately. For cancers, mediums and ranges for increasing tertiles of IGF-1 (ng/ml) are 108 (56–132), and 159 (133–182), and 223 (183–401); and for IGFBP-3 (ng/ml), these are 3140 (939–3465), 3809 (3466–4212), and 4543 (4213–5753). For adenomas, for IGF-1 these are 96 (44–116), 139 (117–165), and 199 (166–387); and for IGFBP-3, these are 2834 (1628–3230), 3694, (3231–4063), and 4602 (4064–6790).

  • b Adjusted for alcohol intake and BMI; IGF-1 and IGFBP-3 are mutually adjusted for each other.

  • c Intermediate/late-stage adenomas include those ≥1 cm in diameter or that have a tubulovillous/villous histology, and early-stage adenomas are those <1 cm in diameter and with a tubular histology.