The significance of the extent of tissue embedding for the detection of incidental prostate carcinoma on transurethral prostate resection material: the more, the better?

Virchows Arch. 2022 Sep;481(3):387-396. doi: 10.1007/s00428-022-03331-6. Epub 2022 Jun 17.

Abstract

The aim of this study is to investigate the incidental prostate cancer (iPCa) detection rates of different embedding methods in a large, contemporary cohort of patients with bladder outlet obstruction (BOO) treated with transurethral surgery. We relied on an institutional tertiary-care database to identify BOO patients who underwent either transurethral loop resection or laser (Holmium:yttrium-aluminium garnet) enucleation of the prostate (HoLEP) between 01/2012 and 12/2019. Embedding methods differed with regard to the extent of the additional prostate tissue submitted following the first ten cassettes of primary embedding (cohort A: one [additional] cassette/10 g residual tissue vs. cohort B: complete embedding of the residual tissue). Detection rates of iPCa among the different embedding methods were compared. Subsequently, subgroup analyses by embedding protocol were repeated in HoLEP-treated patients only. In the overall cohort, the iPCa detection rate was 11% (46/420). In cohort A (n = 299), tissue embedding resulted in a median of 8 cassettes/patient (range 1-38) vs. a median of 15 (range 2-74) in cohort B (n = 121) (p < .001). The iPCa detection rate was 8% (23/299) and 19% (23/121) in cohort A vs. cohort B, respectively (p < .001). Virtual reduction of the number of tissue cassettes to ten cassettes resulted in a iPCa detection rate of 96% in both cohorts, missing one stage T1a/ISUP grade 1 carcinoma. Increasing the number of cassettes by two and eight cassettes, respectively, resulted in a detection rate of 100% in both cohorts without revealing high-grade carcinomas. Subgroup analyses in HoLEP patients confirmed these findings, demonstrated by a 100 vs. 96% iPCa detection rate following examination of the first ten cassettes, missing one case of T1a/ISUP 1. Examination of 8 additional cassettes resulted in a 100% detection rate. The extent of embedding of material obtained from transurethral prostate resection correlates with the iPCa detection rate. However, the submission of 10 cassettes appears to be a reasonable threshold to reduce resource utilization while maintaining secure cancer detection.

Keywords: HoLEP; Holmium laser enucleation; Incidental prostate cancer; Prostate cancer; TUR-P; Transurethral resection of the prostate.

MeSH terms

  • Aluminum
  • Carcinoma* / pathology
  • Holmium
  • Humans
  • Laser Therapy* / methods
  • Male
  • Prostate / pathology
  • Prostatic Hyperplasia* / diagnosis
  • Prostatic Hyperplasia* / pathology
  • Prostatic Hyperplasia* / surgery
  • Prostatic Neoplasms* / diagnosis
  • Prostatic Neoplasms* / pathology
  • Prostatic Neoplasms* / surgery
  • Tissue Embedding
  • Transurethral Resection of Prostate* / methods
  • Treatment Outcome
  • Urinary Bladder Neck Obstruction* / pathology
  • Urinary Bladder Neck Obstruction* / surgery
  • Yttrium

Substances

  • Yttrium
  • Aluminum
  • Holmium