The role of IGF-1 and the distribution of body fat in decreasing the number of prostate rebiopsies

• Published in: Actas urologicas españolas Vol. 41; no. 2; p. 82
• Main Authors: Morán, E, Martínez, M, Budía, A, Broseta, E, Cámara, R, Boronat, F
• Format: Journal Article
• Language: English; Spanish
• Published: Spain 01-03-2017
• Subjects: Adipose Tissue; Aged; Biopsy - statistics & numerical data; Electric Impedance; Humans; Insulin-Like Growth Factor I - analysis; Male; Middle Aged; Prospective Studies; Prostate - pathology; Prostatic Neoplasms - blood; Prostatic Neoplasms - pathology; Cáncer de próstata; Obesidad; Obesity; Rebiopsia; Insuline growth factor-1; Prostate cancer; Rebiopsy
• ISSN: 1699-7980
• DOI: 10.1016/j.acuro.2016.06.006

To assess the usefulness of IGF-1 and internal organ fat measured by bioelectrical impedance audiometry to avoid rebiopsies in patients with persistently high prostate-specific antigen (PSA) levels.
A prospective study was conducted with 92 patients who underwent prostate rebiopsy due to high PSA levels with negative results in the rectal examination and a lack of preneoplastic lesions. The patients previously had their IGF-1 levels measured and had undergone an impedance audiometry test using the abdominal Fat Analyser AB-140 TANITA system. We calculated the receiver operating characteristic (ROC) curves for the PSA levels, %PSA, internal organ fat and IGF-1 and PSA density.
Twenty-five patients were diagnosed with prostate cancer. These patients had significantly higher PSA, PSAd and IGF-1 values and a tendency towards higher internal organ fat levels and lower %PSA readings (p=.001, p=.003, p=.001, p=.24 and P=0.28, respectively). The ROC curve showed an area under the curve for IGF-1 and PSA of .82 and .81, respectively. Using the cutoff points for 95% sensitivity and using the 3 criteria as an indication of rebiopsy, 74% of the biopsies would have been spared, leaving undiagnosed only 1 patient with clinically significant cancer -Gleason score>7 (4+3)-. The positive and negative predictive values for the set of variables were higher than for each one separately (PPV: 66/NPV: 63). The cost of both determinations was 82 euros.
Our results suggest that measuring IGF-1 could significantly decrease the number of unnecessary rebiopsies in an inexpensive and safe manner.