LAUSR

It is known that core‐type fucosylation is higher in prostate cancer cells than in other cancer cell types and is associated with high‐risk prostate cancer. Here, we developed an automated microcapillary electrophoresis‐based immunoassay system for measuring serum core‐type fucosylated prostate‐specific antigen (PSA) and evaluated whether the serum fucosylated PSA index (FPI) can detect high‐risk prostate cancer. Core‐type fucosylated‐free PSA was measured by our automated microcapillary electrophoresis‐based immunoassay system with Pholiota squarrosa lectin. The FPI was calculated from total PSA and the percentage of fucosylated‐free PSA. The optimum model to predict Gleason grade (GG) ≥2 was constructed by multivariate logistic regression analysis. Discrimination was assessed by determining the area under the receiver operator characteristic curve (AUC). The study included 252 men who underwent prostate needle biopsy due to elevated serum PSA levels (4‐20 ng/mL), including 138 with GG ≥2. A higher FPI was significantly associated with GG (P < .0001). Multivariate logistic regression analysis showed that age, prostate volume and FPI were significant predictors of GG ≥2. The AUC of FPI and the model were 0.729 (95% confidence interval [CI]: 0.668‐0.790) and 0.837 (95% CI: 0.788‐0.886), respectively, compared to 0.629 (95% CI: 0.561‐0.698) for PSA. Decision curve analysis showed the superior benefit of FPI and the model when compared to PSA. In a cohort with serum PSA levels <20 ng/mL, FPI could differentiate high‐risk prostate cancer from biopsy‐negative or low‐risk prostate cancer. Therefore, FPI could be a useful adjunct in prostate biopsy counseling for men with abnormal PSA levels.