Table 3.
OR (and 95% CI) for prostate cancer associated with quartile concentrations of IGF-I or a doubling in IGF-I concentration in the European Prospective Investigation into Cancer and Nutrition
| Fourth of circulating IGF-I concentrationa |
||||||||
|---|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | ORdoublingb | P trend c | P heterogeneity d | ||
| Overall prostate cancerb |
Cases/ controls (N) |
297/386 | 375/385 | 419/386 | 451/385 | 1,542/1,542 | ||
| OR (95% CI) | 1 (ref) | 1.31 (1.05, 1.62) | 1.51 (1.21, 1.88) | 1.69 (1.35, 2.13) | 1.38 (1.17, 1.64) | 0.0002 | ||
| Prostate cancer stageb,e | ||||||||
| Localized stage | Cases/ controls (N) |
146/196 | 186/195 | 208/174 | 205/180 | 745/745 | ||
| OR (95% CI) | 1 (ref) | 1.29 (0.95, 1.76) | 1.69 (1.24, 2.30) | 1.65 (1.19, 2.27) | 1.40 (1.10, 1.78) | 0.01 | ||
| Advanced stage | Cases/ controls (N) |
57/83 | 84/68 | 71/77 | 97/81 | 309/309 | 0.84 | |
| OR (95% CI) | 1 (ref) | 2.05 (1.22, 3.44) | 1.58 (0.95, 2.63) | 2.15 (1.26, 3.68) | 1.46 (1.01, 2.12) | 0.04 | ||
| Histological gradeb,f | ||||||||
| Low grade | Cases/ controls (N) |
165/208 | 197/212 | 218/196 | 268/232 | 848/848 | ||
| OR (95% CI) | 1 (ref) | 1.19 (0.89, 1.59) | 1.46 (1.09, 1.96) | 1.57 (1.17, 2.10) | 1.36 (1.09, 1.69) | 0.01 | ||
| High grade | Cases/ controls (N) |
37/45 | 46/34 | 40/36 | 36/44 | 159/159 | 0.19 | |
| OR (95% CI) | 1 (ref) | 1.79 (0.90, 3.56) | 1.48 (0.75, 2.94) | 1.05 (0.52, 2.10) | 0.95 (0.58, 1.55) | 0.84 | ||
| Time to diagnosisb | ||||||||
| <4 y | Cases/ controls (N) |
93/136 | 88/90 | 107/90 | 169/141 | 457/457 | ||
| OR (95% CI) | 1 (ref) | 1.57 (1.03, 2.39) | 1.96 (1.29, 2.99) | 2.01 (1.35, 2.99) | 1.39 (1.08, 1.80) | 0.01 | ||
| 4–7 y | Cases/ controls (N) |
122/145 | 135/139 | 154/139 | 149/137 | 560/560 | ||
| OR (95% CI) | 1 (ref) | 1.13 (0.80, 1.61) | 1.33 (0.94, 1.90) | 1.37 (0.94, 2.00) | 1.29 (0.96, 1.71) | 0.08 | 0.77 | |
| >7 y | Cases/ controls (N) |
82/105 | 152/156 | 158/157 | 133/107 | 525/525 | ||
| OR (95% CI) | 1 (ref) | 1.30 (0.89, 1.89) | 1.39 (0.95, 2.05) | 1.80 (1.17, 2.77) | 1.50 (1.04, 2.16) | 0.03 | ||
| Age at diagnosisb | ||||||||
| <65 y | Cases/ controls (N) |
106/139 | 166/165 | 176/185 | 255/214 | 703/703 | ||
| OR (95% CI) | 1 (ref) | 1.33 (0.95, 1.86) | 1.29 (0.92, 1.81) | 1.67 (1.19, 2.34) | 1.26 (0.99, 1.60) | 0.06 | ||
| ≥65 y | Cases/ controls (N) |
191/247 | 209/220 | 243/201 | 196/171 | 839/839 | 0.33 | |
| OR (95% CI) | 1 (ref) | 1.28 (0.96, 1.70) | 1.67 (1.25, 2.22) | 1.67 (1.22, 2.28) | 1.50 (1.18, 1.92) | 0.001 | ||
| Age at blood collectionb | ||||||||
| <60 y | Cases/ controls (N) |
113/144 | 185/184 | 194/215 | 262/211 | 754/754 | ||
| OR (95% CI) | 1 (ref) | 1.29 (0.93, 1.79) | 1.18 (0.86, 1.64) | 1.67 (1.21, 2.32) | 1.34 (1.05, 1.70) | 0.02 | ||
| ≥60 y | Cases/ controls (N) |
184/242 | 190/201 | 225/171 | 189/174 | 788/788 | 0.73 | |
| OR (95% CI) | 1 (ref) | 1.28 (0.96, 1.72) | 1.87 (1.38, 2.53) | 1.65 (1.19, 2.28) | 1.43 (1.12, 1.81) | 0.003 | ||
| Assay typeb | ||||||||
| IDS-iSYS immunoassay |
Cases/ controls (N) |
35/48 | 47/48 | 36/48 | 74/48 | 192/192 | ||
| (Umeaå, Sweden only) | OR (95% CI) | 1 (ref) | 1.35 (0.75, 2.42) | 1.01 (0.54, 1.88) | 2.19 (1.21, 3.97) | 1.64 (0.97, 2.76) | 0.06 | |
| DSL-10-5600 ACTIVE ELISA |
Cases/ controls (N) |
262/338 | 328/337 | 383/338 | 377/337 | 1,350/1,350 | 0.46 | |
| (All centers except Umeaå ) |
OR (95% CI) | 1 (ref) | 1.30 (1.03, 1.65) | 1.57 (1.24, 1.98) | 1.61 (1.26, 2.07) | 1.35 (1.13, 1.62) | 0.001 | |
Quartile cutoff points (16.5, 20.6, and 25.3 nmol/L) were defined among control participants for all cohorts combined except Umeaå , Sweden where country specific cutoff points (13.2,16.0, and 18.8 nmol/L) were used to account for variation in IGF-I concentrations attributable to the assay method.
Conditioned by matching factors: study center, age at recruitment, time of blood collection, and duration of fasting at blood collection and adjusted for age at blood collection.
P values for trend were obtained by replacing the categorical variable with the logarithm of IGF-I concentration; with adjustment for age at blood collection.
P for heterogeneity values relate to likelihood ratio χ2 tests of heterogeneity between trends (using the logarithm of IGF-I); with adjustment for age at blood collection.
Localized stage includes T0 or T1 or T2 and N0 or NX and M0, or stage coded in the recruitment center as localized and advanced stage includes T3 or T4 and/or N1+ and/or M1, or stage coded in the recruitment center as metastatic.
Low grade includes Gleason score ≤7, or cases coded as well differentiated or moderately differentiated according to the WHO grading system and high grade includes Gleason score >7, or cases coded as poorly differentiated or undifferentiated according to the WHO grading system.