Insulin-like growth factor 1, chromogranin A and prostate specific antigen serum levels in prostate cancer patients and controls.

OBJECTIVE: Insulin-like growth factor 1 (IGF-1) and chromogranin A (CGA) are currently discussed as supplemental serum markers for prostate cancer (PC) diagnosis. To address this issue we determined serum levels of IGF-1, CGA and PSA in men with newly diagnosed PC and controls.
METHODS: A consecutive series of 156 men (median age: 67 yrs) with newly diagnosed, untreated PC and 271 controls (69 yrs) were recruited. The diagnosis of PC was made by transrectal ultrasound guided biopsies only. In controls, the presence of PC was excluded by digito-rectal examination, serum prostate specific antigen (PSA) levels by using age-specific reference values and-if indicated-by transrectal ultrasound guided 12-core biopsies. Serum levels of IGF-1, CGA and PSA were compared between cases and controls and correlated to histopathological findings and age.
RESULTS: Serum PSA-levels were significantly higher in men with PC (49.6+/-13.9 ng/ml, mean+/-standard error of the mean; median: 7.0 ng/ml) than in controls (2.6+/-0.2 ng/ml; median: 1.3 ng/ml) (p<0.001). In contrast, serum levels of IGF-1 (PC: 166+/-6.1 ng/ml, median: 155 ng/ml; controls: 159+/-4.5 ng/ml, 153 ng/ml) and CGA (PC: 92+/-7.4 U/l, median: 67 U/l; controls: 117+/-12.0 U/l; median: 74 U/l) were identical in both groups (p>0.05). Serum levels of IGF-1 and CGA revealed no correlation to serum PSA, Gleason score and number of positive biopsy cores. In the PC-cohort all three serum markers did not correlate with age. In controls, PSA (p=0.018) and CGA (p<0.001) correlated positively and IGF-1 (p<0.001) negatively with age.
CONCLUSION: Our data suggest that quantification of IGF-1 and CGA-serum levels provides no useful information in the diagnosis of PC.