using prostate cancer tissue microarrays

Objectives Due to PSA screening and increased aware-ness, prostate cancer (PCa) is identiWed earlier resulting in smaller diagnostic samples on prostate needle biopsy. Because Gleason grading plays a critical role in treatment planning, we undertook a controlled study to evaluate inter-observer variability among German pathologists to grade small PCas using a series of tissue microarray (TMA) images. Methods We have previously demonstrated excellent agreement in Gleason grading using TMAs among expert genitourinary pathologists. In the current study, we identiWed 331 TMA images (95 % PCa and 5% benign) to be evaluated by an expert PCa pathologist and subsequently by practicing pathologists throughou