Is There a Relationship Between Biochemical Recurrence and Insulin-like Growth Factor-1 in Patients with Surgical Border Negative Radical Prostatectomy?
Objective: Levels of insulin-like growth factor 1 (IGF-1) have been associated with prostate carcinoma. We have investigated whether IGF-1 level has an early predictive value for the biochemical relapse in the prostate carcinoma patients with a negative surgical margin who underwent curative surgery. Materials and Methods: We retrospectively analyzed 82 patients who were followed-up regularly and did not receive neoadjuvant or adjuvant chemotherapy. We classified patients as having Gleason scores ≥7 and <7, PSA values ≥10 ng/ml and <10, biochemical relapse positive or negative, T stages ≥T2 and <T2, tumor burden in less or more than 50% pathologic specimens, respectively. PSA cut-off value accepted was as 0.2 ng/ml. According to average values in the literature, time to PSA relapses was considered early if it was less than 18 months and late if more than 18 months. We measured PSA and IGF-1 levels at each routine control visit. Results: During 60-month follow-up, 66 (80.4%) patients had no relapse, while in 8 (9.8%) patients had early, and other 8 (9.8%) patients had a late biochemical relapse. There was no statistically significant difference between these 3 groups of patients according to their age, tPSA levels, and BMI parameters. We compared IGF-1 levels with tumor burden, tPSA levels, tumor grade, and Gleason scores without any significant difference between these parameters. When we accepted IGF-1 cut-off values as 60 ng/ml, we observed higher Gleason scores (≥ 7 and more) in these patients. There was a weak relationship between IGF-1 levels of non-relapse and early relapse patients (p:0.078). However, when we evaluated IGF-1 levels among patients with relapse, the early relapse group had significantly higher IGF-1 levels (p: 0.006). When the cut-off value of IGF-1 was accepted as 60 ng/ml, which was found to be significant for Gleason score, the early relapse group had significantly higher IGF-1 levels compared to the non-relapse group (p:0.023). Conclusions: According to our study, the IGF-1 level has a predictive value for showing biochemical recurrence after surgery. Nevertheless, considering the number of patients, we need randomized controlled trials with a large number of patients.