Table 2.

Odds ratios of cancer of the colorectum, colon, or rectum for quartiles of serum IGF-1 and IGFBP-3

	Quartile level
	1	2	3	4	p for trend
IGF-1
Colorectum
OR	1.00	1.17	1.19	1.27	0.51
95% CI	—	0.66–2.08	0.63–2.22	0.65–2.47
No of cases/controls	39/86	43/83	45/81	41/85
Mean exposure	109.86	172.71	222.79	293.14
Colon
OR	1.00	1.89	2.30	2.66	0.03
95% CI	—	0.89–4.04	1.02–5.17	1.09–6.50
No of cases/controls	21/64	30/57	30/46	29/53
Mean exposure	105.92	172.71	222.59	293.54
Rectum
OR	1.00	0.45	0.33	0.33	0.09
95% CI	—	0.13–1.53	0.09–1.14	0.09–1.13
No of cases/controls	18/22	13/26	15/35	12/32
Mean exposure	118.24	172.72	223.11	292.41
IGFBP-3
Colorectum
OR	1.00	0.80	1.25	1.23	0.24
95% CI	—	0.44–1.45	0.68–2.29	0.68–2.22
No of cases/controls	40/85	35/91	46/79	46/80
Mean exposure	1754	2394	2740	3456
Colon
OR	1.00	0.91	1.80	1.93	0.02
95% CI	—	0.42–1.94	0.82–3.98	0.92–4.06
No of cases/controls	23/55	23/64	30/50	34/51
Mean exposure	1761	2405	2738	3457
Rectum
OR	1.00	0.75	0.66	0.49	0.21
95% CI	—	0.27–2.06	0.23–1.87	0.16–1.49
No of cases/controls	17/30	12/27	16/29	12/29
Mean exposure	1743	2370	2743	3459

Conditional logistic regression analyses were matched for age, sex, date of blood sampling, and fasting status, and further adjusted for smoking status.

OR, odds ratio; CI, confidence interval; IGF-I, insulin-like growth factor 1; IGFBP, IGF binding protein.

Colorectum: IGF-1 measurements were missing for one control; IGFBP-3 measurements were missing for one case and one control.

Rectum: IGF-1 measurements were missing for one control; IGFBP-3 measurements were missing for one case and one control.

Cut off points: IGF-1, 146.35–197.59–252.64; IGFBP-3, 2176–2575–2948.