Evaluation of prostate needle biopsies in a population-based screening study: the impact of borderline lesions.

Background: The finding of isolated high grade prostatic intraepithelial neoplasia (PIN) or borderline lesions (lesions suspicious for malignancy) in prostate needle biopsies warrants repeat biopsies. The reported frequency of these lesions in prostate needle biopsies varies considerably. The authors evaluated the frequency and clinical impact of high grade PIN and borderline lesions in sextant prostate needle biopsies obtained from screened participants in the European Randomized study of Screening for Prostate Cancer (ERSPC).
Methods: A total of 8763 participants in the Rotterdam section of the ERSPC ages 55-75 years were screened systematically for prostate carcinoma. Systematic sextant prostate needle biopsies were prompted by an abnormal digital rectal examination and/or abnormal transrectal ultrasonography findings at serum prostate specific antigen (PSA) levels > or = 1.0 ng/mL or a PSA level > or = 4.0 ng/mL. Repeat biopsies were obtained within 6 months after initial biopsy.
Results: Of 1824 biopsied men, 384 (21.1%) were found to have prostate carcinoma on initial biopsy. Twelve participants (0.7%) had isolated high grade PIN and 43 (2.4%) had borderline lesions. Repeat biopsies yielded no carcinoma in 7 participants with initial high grade PIN and 15 tumors (38.5%) in 39 participants with borderline lesions.
Conclusions: In prostate needle biopsies obtained from a screened population, indications for repeat biopsy such as high grade PIN and borderline lesions do not represent large diagnostic subsets. Borderline lesions comprise the most important indication for a repeat biopsy. The low frequency of equivocal biopsy diagnoses in the current study supports the clinical applicability of sextant needle biopsies in population-based screening for prostate carcinoma.