• IGF-1;
  • serum;
  • prostate cancer;
  • androgen deprivation

Objectives To compare the serum levels of insulin-like growth factor-1 (IGF-1) in patients with prostate cancer and in control patients with no malignancy, and to evaluate any possible influence of testicular androgen withdrawal on the level of IGF-1 in patients with prostate cancer.

Patients and methods IGF-1 was measured in serum samples from 238 patients using both a chemiluminescence method and a radio-immunoassay. From a subgroup of 19 patients presenting with newly diagnosed carcinoma of the prostate, IGF-1 and testosterone values were measured before and during the course of testicular androgen with-drawal, achieved by the administration of luteinizing hormone-releasing hormone (LHRH) analogues combined with anti-androgens.

Results There were no significant differences in the mean serum levels of IGF-1 patients with and without prostate cancer (158.6 and 159.1 ng/mL, respect-ively). There were no significant differences in mean IGF-1 levels before and after antiandrogen therapy; the mean (median, sd, range) levels of testosterone (µg/L) and IGF-1 (ng/mL) before androgen withdrawal were 4.81 (4.84, 1.26, 3.11–6.93) and 157.1 (152.5, 26.7, 122.8–195.1). After androgen withdrawal the corresponding values were 0.303 (0.218, 0.24, 0.13–0.81) and 169.7 (31.7, 168.6, 124.9–227.6). A linear regression analysis (P = 0.76) and Spearman rank order correlation test (correlation coefficient –0.0613, P = 0.64) showed no association between levels of testosterone and IGF-1. Freeze and thaw cycles applied to the samples had no effect on the IGF-1 values measured.

Conclusions There was no significant association between IGF-1 serum levels and prostate cancer. Short-term androgen withdrawal using LHRH anal-ogues combined with anti-androgens had no effect on the levels of IGF-1.