Complete embedding and close step-sectioning of radical prostatectomy specimens both increase detection of extraprostatic extension, and correlate with increased disease-free survival by stage of prostate cancer patients

The objectives of this work were to evaluate the efficacy of controlled close step-sectioned and whole-mounted radical prostatectomy specimen processing in prediction of clinical outcome as compared to the traditional processing techniques. Two-hundred and forty nine radical prostatectomy (RP) specimens were whole-mounted and close step-sectioned at caliper-measured 2.2-2.3mm intervals. A group of 682 radical prostatectomy specimens were partially sampled as control. The RPs were performed during 1993-1999 with a mean follow-up of 29.3 months, pretreatment PSA of 0.1-40, and biopsy Gleason sums of 5-8. Disease-free survival based on biochemical or clinical recurrence and secondary intervention were computed using a Kaplan-Meier analysis. There were no significant differences in age at diagnosis, age at surgery, PSA at diagnosis, or biopsy Gleason between the two groups (P < 0.05). Compared with the non-close step-sectioned group, the close step-sectioned group showed higher detection rates of extra-prostatic extension (215 (34.1%) vs, 128 (55.4%), P < 0.01), and seminal vesicle invasion (50 (7.6%) vs 35 (14.7%), P < 0.01). The close step-sectioned group correlated with greater 3-y disease-free survival in organ-confined (P < 0.01) and specimen-confined (P < 0.01) cases, over the non-uniform group. The close step-sectioned group showed significantly higher disease-free survival for cases with seminal vesicle invasion (P = 0.046). No significant difference in disease-free survival was found for the positive margin group (P = 0.39) between the close step-sectioned and non-uniform groups. The close step-sectioned technique correlates with increased disease-free survival rates for organ and specimen confined cases, possibly due to higher detection rates of extra-prostatic extension and seminal vesicle invasion. Close step-sectioning provides better assurance of organ-confined disease, resulting in enhanced prediction of outcome by pathological (TNM) stage.