Clinical significance of prostatic intraepithelial neoplasia

Lee, Hyun; Terreros, Daniel; Bahk, Jong Yoon

Abstract

To evaluate the clinical significance of the prostatic intraepithelial neoplasia (PIN) in prostatic tumors, we reviewed the clinical data of digital rectal examination (DRE), transrectal ultrasonography (TRUS) prostate specific antigen (PSA) and PIN from the patients of 50 benign prostatic hyperplasia (BPH) and 100 prostate cancers who were pathologically confirmed. The prostate nodules were palpated at DRE in 53% of prostate cancers. The 59% of the prostate cancer patients showed hypoechoic areas on TRUS and they were diagnosed with ultrasound guided directed prostate biopsy. Remaining 41% of the cancers were diagnosed at the directed or random biopsy or the hyperechoic or isoechoic area. Hypoechoic areas were detected from the 12 BPH patients and the PIN were detected at 7 of them at directed biopsies. The level of serum prostate specific antigen (PSA) less than 4ng/ml were 82% of BPH and 57% of prostate cancer. The major PIN grade in BPH patients were 62% for grade 1, 22% for grade 2 and 16% for grade 3 and in the prostate cancer, 9% for grade 1, 27% for grade 2 and 64% for grade 3. The distribution of PIN were even throughout the prostate in BPH but 17% of the prostate cancer showed PINs exclusively at peripheral zone. The remaining cancer patients were multifocal and 52% of total prostate cancers showed more than two thirds of the total PINs were located at peripheral zone. Among the 8 BPH patients who had the PIN grade 3, 3 were diagnosed as the prostate cancer at follow up. We assume that the nodules palpated at DRE and the hypoechoic areas TRUS are highly specific for the prostate cancer but the serum PSA values of 4ng/ml as the upper normal limit is not significantly reliable for the study for high risk group and early detection of prostate cancer. The combined application of DRE, TRUS, PSA and biopsy, including directed and random, would improve the results of prostate cancer diagnosis than single application. And the BPH patients with grade 3 PIN should be regarded as the high risk group for prostate cancer development and should be followed regularly.