Predictive factors for prostate cancer in biopsy of patients with prostate-specific antigen levels equal to or less than 4 ng/ml

Purpose: This study was conducted to identify the predictive factors for prostate cancer in patients with prostate-specific antigen (PSA) levels equal to or less than 4 ng/ml. Materials and Methods: A retrospective study of medical records was conducted on 292 patients with initial serum PSA ≤4 ng/ml among 2,305 patients who underwent prostate biopsy from January 2003 to December 2008. Prostate biopsy was performed on patients with PSA ≤4 ng/ml in the case of abnormal findings in the digital rectal examination (DRE) or transrectal ultrasonography (TRUS) or in those with a PSA level higher than the age-adjusted PSA levels. The patients were divided into the group diagnosed with prostate cancer and the non-prostate-cancer group. Subsequently, the variables of the two groups were compared. Results: The patients' mean age was significantly higher in the prostate cancer group (n=28) than in the non-prostate-cancer group (n=264; p=0.033). In addition, for the patients with a PSA range of 2.0-2.9 ng/ml, their age (p=0.049) and PSA density (PSAD; p=0.042) were significantly higher and the prostate volume (p=0.028) was significantly smaller in the prostate cancer group than in the non-prostate-cancer group. Conclusions: Of the patients with PSA ≤4 ng/ml, the age of the patients who showed abnormal findings in the DRE or TRUS or who had a PSA level higher than the age-adjusted PSA level was a significant predictive factor for prostate cancer. In particular, for the PSA range of 2.0-2.9 ng/ml, a thorough screening test for prostate cancer was required if the patients had conditions such as higher age, smaller prostate, and higher PSAD.