The study found that higher levels of the IGF‑1Ec protein are linked to more advanced prostate cancer, meaning that this form of IGF‑1 tends to increase as tumors get bigger and more aggressive.

Recent evidence suggests a role for the insulin-like growth factor-1Ec (IGF-IEc) transcript variant in cancer biology. The aim of the present study was to investigate whether IGF-IEc expression is associated with prostate cancer stage. Formalin-fixed and paraffin-embedded prostate cancer surgical specimens from 83 patients were assessed by immunohistochemistry for IGF-IEc expression. Normal prostate epithelium was negative or demonstrated mild IGF-IEc cytoplasmic expression whereas prostate cancer exhibited mild to strong cytoplasmic immunoexpression. The mean IGF-1Ec expression, was significantly lower (p=0.004) in localized (stage ≤ IIb) prostate cancer, compared to locally advanced tumors (stage ≥ III). Only one out of 83 (1.2%) prostate cancer samples was completely negative for IGF-IEc. A weak-positive correlation was also observed between IGF-IEc expression levels and Gleason score (r=0.247; p=0.024). The present data demonstrate that the expression of IGF-IEc is positively-associated with more advanced stage and higher Gleason score of prostate carcinomas.