INSULIN-LIKE-GROWTH-FACTOR-1 IN RELATION TO PROSTATE-CANCER AND BENIGN PROSTATIC HYPERPLASIA

Blood samples were collected from 52 incident cases of histologically confirmed prostate cancer, an equal number of cases of benign prostati c hyperplasia (BPH) and an equal number of apparently healthy control subjects. The three groups were matched for age and town of residence in the greater Athens area. Steroid hormones, sex hormone-binding glob ulin, and insulin-like growth factor 1 (IGF-1) were measured in duplic ate by radioimmunoassay in a specialized US centre. Statistical analys es were performed using multiple logistical regression. The results fo r IGF-1 in relation to prostate cancer and BPH were adjusted for demog raphic and anthropometric factors, as well as for the other measured h ormones. There was no relation between IGF-1 and BPH, but increased va lues of this hormone were associated with increased risk of prostate c ancer; an increment of 60 ng ml(-1) corresponded to an odds ratio of 1 .91 with a 95% confidence interval of 1.00-3.73. There was also some e vidence for an interaction between high levels of testosterone and IGF -1 in relation to prostate cancer. This finding suggests that, in addi tion to testosterone, IGF-1 may increase the risk of prostate cancer i n humans.