Prostate cancer is the second most frequent malignancy diagnosed in adult men. Androgens are considered the primary growth factors for prostate normal and cancer cells. However, other non-androgenic growth factors are involved in the growth regulation of prostate cancer cells. The association between IGF-I and prostate cancer risk is well established. However, there is no evidence that the measurement of IGF-I enhances the specificity of prostate cancer detection beyond that achievable by serum prostate-specific antigen (PSA) levels. Until now, there is no consensus on the possible association between IGFBP-3 and prostate cancer risk. Although not well established, it seems that high insulin levels are particularly associated with risk of aggressive prostatic tumours. This review describes the physiopathological basis, epidemiological evidence, and animal models that support the association of the IGFs family and insulin with prostate cancer. It also describes the potential therapies targeting these growth factors that, in the future, can be used to treat patients with prostate cancer. RESUMOO câncer de próstata é a segunda neoplasia mais frequentemente diagnosticada em homens adultos. Os androgênios são considerados fatores de crescimento primários para células prostáticas normais e malignas. Entretanto, outros fatores de crescimento não androgênicos estão envolvidos na regulação do crescimento das células prostáticas malignas. Associação entre IGF-I e risco de câncer de próstata é bem estabelecida. No entanto, não há evidência de que a dosagem do IGF-I melhore a especificidade na detecção do câncer de próstata, além daquela alcançada pelos níveis de antígeno prostático específico (PSA). Até hoje, não há consenso sobre a possível associação entre IGFBP-3 e risco de câncer de próstata. Apesar de não estar estabelecido, altos níveis de insulina parecem particularmente associados ao risco de tumores prostáticos agressivos. Esta revisão descreveu base fisiopatológica, evidências epidemiológi-cas e modelos animais que apoiam a associação da família das IGFs e insulina com câncer de próstata. Também foram descritas terapias potenciais que têm como alvo esses fatores de crescimento, os quais, no futuro, poderão ser usados para tratar pacientes com câncer de próstata.Arq Bras Endocrinol Metab. 2009;53(8):969-75

Introduction Non-androgenic growth factors are involved in the growth regulation of prostate cancer (PCa).Objective This is the first Brazilian study to correlate, in a population of patients operated for PCa, PSA, total testosterone, insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) with Gleason score and to compare with a control group with benign prostate hyperplasia (BPH).Materials and Methods This retrospective single-center study included 49 men with previously diagnosed PCa and 45 with previously diagnosed BPH. PSA, testosterone, IGF-I, IGFBP-3 were determined in both groups.Results PSA and IGFBP-3 levels were significantly higher in the PCa group as compared to the BPH group (p<0.001 and p=0.004, respectively). There was a significant difference when we compared the PSA before surgery (p<0.001) and at the inclusion in the study (p<0.001) and IGFBP3 (0.016) among patients with Gleason <7, ≥7 and BPH. In the PCa group, PSA, testosterone, IGF-I and IGFBP-3 levels were comparable between Gleason <7 and ≥7.Conclusions Our data suggest that in localized PCa, the quantification of PSA and, not of IGF-1, may provide independent significant information in the aggressiveness. IGFBP-3 could be a biochemical marker of disease control in PCa patients.