Table 3

IGF-I and multivariate relative risk (RR) of prostate cancer by prediagnostic PSA levels.

PSA level RR* associated with IGF-I quartile
1 23 4
≤4 ng/ml 1.00 1.66 2.07 4.57
(0.70 to 3.92) (0.84 to 5.09) (1.79 to 11.6)
>4 ng/ml 3.9211.0 16.0 17.5
(1.01 to 15.3)(1.84 to 65.4) (4.08 to 62.6) (3.83 to 80.1)
  • * Multivariate RR adjusted for age (40 to 44, 45 to 49, 50 to 54, 55 to 59, 60 to 64, 65 to 69, 70 to 74, and 75 to 80), smoking (never, past, and current), and IGFBP-3 (quartiles).

  • Reference group: men in first quartile of IGF-I and with PSA ≤ 4 ng/ml.

  • Ninety-five percent confidence intervals.