Differences in biopsy features between prostate cancers located in the transition and peripheral zone

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Accurate pre-operative localization of prostate cancer is crucial for effective treatment planning.
• Distinguishing between transition zone (TZ) and peripheral zone (PZ) prostate cancers is important due to differing anatomical patterns and potential treatment implications.

Purpose of the Study:

• To determine the zonal location of prostate cancers before surgery using ultrasonography-guided systematic sextant biopsies.
• To analyze differences in biopsy mapping between TZ and PZ prostate cancers.
• To compare the correlation of Gleason scores between needle biopsies and radical prostatectomy (RP) specimens for TZ and PZ cancers.

Main Methods:

• 186 patients with TZ (46) and PZ (140) prostate cancers underwent ultrasonography-guided systematic sextant biopsy and RP.
• Clinical, pathological, and anatomical biopsy locations were analyzed.
• T-tests and chi-square tests were used for comparisons.
• Cohen kappa testing evaluated agreement between needle biopsy and RP Gleason scores.

Main Results:

• TZ cancers exhibited significantly lower positive biopsy rates in the prostate's middle and base compared to PZ cancers.
• Positive biopsies exclusively from the apex were more common in TZ cancers (19.6%) than PZ cancers (5%).
• Exact agreement between needle biopsy and RP Gleason scores was notably lower for TZ cancers (15.2%) versus PZ cancers (55%).

Conclusions:

• Prostate cancers in the transition zone demonstrate a different anatomical distribution of positive biopsies compared to peripheral zone cancers.
• Positive biopsies solely from the apex suggest a higher likelihood of transition zone prostate cancer.
• The correlation between needle biopsy and radical prostatectomy Gleason scores is significantly weaker for transition zone prostate cancers.