Comparative analysis of sampling methods for grossing radical prostatectomy specimens performed for nonpalpable (Stage T1c) prostatic adenocarcinoma

Scant data are available comparing sampling methods of radical prostatectomy specimens performed for clinical stage T1c (nonpalpable) cancer. Seventy-eight stage T1c radical prostatectomies that had 1 or more of the following adverse pathologic findings - Gleason score ≥ 7, positive margins, and extraprostatic extension - were compared using 10 different sampling techniques. Of the 78 entirely submitted cases, 52 had Gleason score ≥ 7, 14 had positive margins, and 54 had extraprostatic extension (mean 34 slides). Of the partial sampling methods, we favor the following two methods. The first is submitting every posterior section plus 1 midanterior section from right and left sides; if either of these anterior sections show sizeable tumor, all ipsilateral anterior slides are examined. This method detects 98% of tumors with Gleason score ≥ 7, 100% of positive margins, and 96% of cases with extraprostatic extension (mean 27 slides). The second method is to use the above method but restrict it to sections ipsilateral to the previous positive needle biopsy. This method detects 92% of tumors with Gleason score ≥ 7, 93% of positive margins, and 85% of cases with extraprostatic extension (mean 17 slides). Partial sampling can detect important prognostic parameters. By balancing the extra expense and time involved to process and examine additional sections with the risk of missing important prognostic parameters, pathologists can decide which sampling method to use.