False-negative prostate needle biopsies: frequency, histopathologic features, and follow-up

Area of Science:

• Uropathology
• Prostate Cancer Screening
• Diagnostic Accuracy

Background:

• False-negative prostate biopsies, where initial benign findings conceal adenocarcinoma or atypical small acinar proliferations (ASAP), are not well understood.
• Evaluating these missed diagnoses is crucial for improving prostate cancer detection rates in screening programs.

Purpose of the Study:

• To assess the frequency, histopathologic features, and clinical implications of false-negative prostate biopsies within a prostate cancer screening context.
• To identify risk factors associated with missed prostate cancer diagnoses on initial biopsy.

Main Methods:

• Retrospective review of prostate biopsy sets from 196 participants in a screening trial initially reported as benign.
• Two urologic pathologists re-examined biopsy cores, identifying adenocarcinoma and ASAP.
• Clinicopathologic data from initial and subsequent diagnoses were analyzed.

Main Results:

• Adenocarcinoma was found in 16 patients (8.2%) and ASAP in 19 patients (9.7%) upon re-examination.
• All missed cancers were Gleason score 6 (3+3).
• Estimated false-negative rates were 2.4% overall, 1.1% for cancer, and 1.3% for ASAP, with no significant clinical differences between false-negative and true benign cases.

Conclusions:

• Low gland counts, intermingling, and lack of disorganization were key risk factors for false-negative diagnoses.
• Prostate cancer variants (foamy gland, pseudohyperplastic) pose diagnostic challenges.
• Enhanced microscopic examination and awareness of variants can reduce missed prostate cancer diagnoses.