[Incidence of high grade prostatic intraepithelial neoplasm in transrectal biopsy of the prostate]. / Incidencia de la neoplasia intraepitelial prostática de alto grado en las biopsias transrectales de la próstata.

OBJECTIVE: To analyze the incidence of high grade prostatic intraepithelial neoplasia (PIN) in the transrectal prostate biopsies of patients from the Urology department. METHODS: From 1995 to 1999, 2018 patients aged 46-92 years (mean 68 +/- 10) had a transrectal biopsy. Thirty-six percent had a suspicious DRE and the mean serum PSA was 31.7 +/- 152.9 ng/ml. The anatomopathological diagnoses were: a) cancer, b) benign pathology, c) high grade PIN and d) glandular atypia. Statistical analysis using the chi square and Mann-Whitney tests was performed to compare the following variables: age, DRE, PSA, PSAf/PSAt ratio and the finding of a suspicious node on ultrasound. RESULTS: The incidence of high grade PIN in this series was 8% and the incidence of prostate cancer was 38.6%, PIN grade 3 was diagnosed in 94 patients and PIN grade 2 in 67, and was associated with glandular atypia in 13 patients. Patients with prostate cancer were older and showed statistically significant higher PSA, percentage of suspicious DRE, sonographically suspicious nodes, and a lower PSAf/PSAt ratio than the other diagnoses (p < 0.001). Comparison of patients with high grade PIN and those with benign pathology showed no differences for age, DRE, PSA levels and PSAf/PSAt ratio. However, a significantly lower incidence of sonographically suspicious nodes was found (p < 0.001). CONCLUSIONS: The incidence of high grade PIN was 8%. High grade PIN does not cause sufficient changes in the clinical variables analyzed to suspect this lesion before it is confirmed by the pathological findings.