The significance of serum levels of insulin‐like growth factor‐1 in patients with prostate cancer

Abstract

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 in¯uence 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 withdrawal, achieved by the administration of luteinizing hormone-releasing hormone (LHRH) analogues combined with anti-androgens. Results There were no signi®cant differences in the mean serum levels of IGF-1 patients with and without prostate cancer (158.6 and 159.1 ng/mL, respectively). There were no signi®cant differences in mean IGF-1 levels before and after antiandrogen therapy; the mean (median, SD, range) levels of testosterone (mg/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 coef®cient ±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 signi®cant association between IGF-1 serum levels and prostate cancer. Short-term androgen withdrawal using LHRH analogues combined with anti-androgens had no effect on the levels of IGF-1.

Growth hormone-releasing hormone (GHRH) antagonists inhibit the proliferation of androgen-dependent and -independent prostate cancers

“…Chan et al (32) reported an association between serum IGF-I levels and the risk of prostate cancer. However, in other studies, a direct correlation between prostate cancer and serum IGF-I could not be found (33,34). IGF-II also plays a critical role in the autocrine and paracrine stimulation of prostatic neoplasms.…”

“…There is a lack of consensus regarding the influence of IGF-I on the etiology of prostate cancer (29)(30)(31)(32)(33)(34). Chan et al (32) reported an association between serum IGF-I levels and the risk of prostate cancer.…”

IGF1 (CA)19 Repeat and IGFBP3 -202 A/C Genotypes and the Risk of Prostate Cancer in Black and White Men

“…However, a growing body of evidence suggests that serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) levels may play a role in prostate cancer risk and/or severity (5,6). Previous findings relating circulating levels of IGF-1 and IGFBP-3 to prostate cancer risk and severity have been intriguing, although not entirely consistent (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Of note, a positive association between increased IGF-1 levels and prostate cancer was found in three prospective studies (12)(13)(14).…”

Insulin-like growth factor-I and prostate cancer: a meta-analysis

“…Some studies have reported that IGF-I levels were higher in prostate cancer patients than in the control subjects (Cohen, 1993;Ho and Baxter, 1997;Mantzoros et al, 1997;Chan et al, 1998;Wolk et al, 1998;Djavan et al, 1999;Signorello et al, 1999;Stattin et al, 2000;Harman et al 2000), whereas others showed the opposite (Kanety et al, 1993;Finne et al, 2000;Kurek et al, 2000).…”