Putative role of serum insulin-like growth factor–1 (IGF-1) and IGF binding protein-3 (IGFBP-3) levels in the development of prostate cancer in Arab men

Abstract

Introduction: The incidence of clinical prostate cancer in the Arab population is among the lowest in the world. High serum IGF-1 level has been implicated as a possible risk factor for the development of prostate cancer in Caucasians. The purpose of this study was to determine serum IGF-1 and IGFBP-3 levels in healthy Arab men and in Arab men with newly diagnosed benign prostatic hyperplasia (BPH) and prostate cancer, and to compare these values with values reported in Caucasians. Patients and Methods: Subjects were recruited in two groups: (a) indigenous, healthy Arab men aged 15-90 y (n ¼ 383); (b) Arab men with newly diagnosed prostate cancer (n ¼ 30) or BPH (n ¼ 40). Blood was obtained from fasting patients and volunteers, between 8:00 a.m. and 12:00 noon. The serum concentrations of IGF-1 and IGFBP-3 were determined using Immunoradiometric assay (IRMA) kits. Results: As in Caucasians, serum IGF-1 and IGFBP-3 levels declined with age in Arab men. The mean7s.d. of serum IGF-1 levels in healthy Arab men in the age group 15-20, 51-60, 61-70 y were lower (376.27153.2, 134.97105.7 and 89.6748.4 ng/ml, respectively), compared to values reported for similarly aged Caucasians. Arab men with newly diagnosed prostate cancer had significantly higher serum IGF-1 level (Po0.01) and lower IGFBP-3 levels (Po0.01) compared to age-matched Arabs without the disease. Conclusions: Arab men have lower serum IGF-1 levels compared to Caucasians and this may be an important factor in the explanation of the low incidence of prostate cancer in the Arab population.

Relationship of insulin-like growth factor (IGF) binding protein-3 (IGFBP-3) gene polymorphism with the susceptibility to development of prostate cancer and influence on serum levels of IGF-I, and IGFBP-3

“…Epidemiological studies regarding the circulating IGFBP-3 concentration revealed both positive and inverse associations of IGFBP-3 with PCa [28,30,31,41]. Association between serum IGF-I, and ILGFBP levels with precancerous lesions of the prostate has also been reported.…”

“…Evidence linking IGFBP-3 to PCa risk is inconsistent. The consequence of high circulating levels of IGFBP-3 on PCa risk in some studies is associated with increased PCa risk [28,29] whereas other studies report a protective role, concluding that high serum IGFBP-3 concentrations are associated with decreased cancer risk [30,31]. Additional studies report no association between IGFBP-3 concentrations and PCa [32,33].…”

Insulin-Like Growth Factor (IGF) family and prostate cancer

“…The incidence of PCa in the Arab population is among the lowest in the world. Incidentally, one study has demonstrated that healthy Arab men have significantly lower serum IGF-I levels compared to healthy Caucasians [60].…”

Combination of insulin-like growth factor-1, IGF binding protein-3, chromogranin A and prostate specific antigen can improve the detection of prostate cancer

“…[32] Previous study on Arab males indicated that IGF-1 and IGFBP-3 reached their peak levels during adolescence and gradually lowered with age. [33] IGFBP-3, the most prevalent form of the IGFBPs, has been linked with prostatic growth. About 75% of IGF-1 is bound to IGFBP-3, while 20-25% is bound to the other binding proteins (IGFBP-1, 2, 4 and 5), and less than 1% is carried in the unbound state in the circulation.…”