Incidental prostate cancer prevalence at radical cystoprostatectomy—importance of the histopathological work-up

Abstract

The reported incidental prostate cancer prevalence rates at radical cystoprostatectomy cover a range from 4 to 60 %. We investigated the influence of the histopathological work-up on prostate cancer prevalence rates. We identified 114 patients who had undergone cystoprostatectomy for bladder cancer between 2000 and 2012. Complete histopathological assessment was defined as follows: (i) complete embedding of the prostate gland, (ii) sectioning of 15 or more prostate sections, and (iii) processing as whole mount slides. Prostate cancer prevalence rates derived from complete and incomplete histopathological assessments were compared. The overall prostate cancer prevalence rate was 59.6 %. A mean of 14.4 macroscopic tissue sections (thickness 3-5 mm) were sectioned. Sectioning ≥15 sections resulted in a prostate cancer detection rate of 75 %, compared to 42.6 % when sectioning <15 sections (p < 0.001). Complete embedding yielded a prostate cancer detection rate of 72.3 and of 23.1 % for partly embedded prostates (p < 0.0001). Prostate cancer was detected in 68.8 % of the whole mounted samples and in 38.2 % of the samples sectioned as standard slides (p < 0.01); according to the criteria described by Epstein and Ohori, 44.1 % of the detected prostate cancers were clinically significant. The quality of the histopathological work-up significantly influences prostate cancer detection rates and might at least partially explain the highly variable reported incidental prostate cancer prevalence rates at cystoprostatectomy (CP). The high proportion of significant prostate cancer found in our series calls for a careful surgical approach to the prostate during CP.

Influence of gross specimen sampling on the incidence of incidental prostatic carcinoma in cystoprostatectomy specimens of patients with bladder carcinoma

“…Twenty-seven percent of the partially sampled cases fulfilled one of those two criteria, while 40% did so in cases with complete embedding. In keeping with these results, it has been shown by two previous studies that the rate of clinically significant incidental prostate cancer is much higher in completely as opposed to partially processed prostates (18% vs. 9% and 44% vs. 4%, respectively) [20,23]. Patients with incidental prostatic carcinoma were slightly younger in our study, as compared to those without it.…”

“…Four percent to 57% of prostate specimens included in studies with partial processing harboured clinically significant cancer [23,24]. In our study, 21 out of 56 (37.5%) incidental prostate cancers had a Gleason score of 7 or more and/or a stage of pT3a or more and/or invasion of the surgical margin.…”

“…In a study by Fritsche et al, it was shown that 19% of partially processed prostates harbour cancer, while the rate was twice as high (40%) after complete processing [20]. In another study, by Wetterauer et al, the rates were 23% and 72% for partially and completely sampled prostates, respectively [23]. In our study, the incidence of prostate cancer in completely processed prostates was approximately 4.5 times higher (6.7% vs. 30.2%) than the incidence in partially sampled prostates.…”

“…To date, the reported rates of incidental prostate cancer in cystoprostatectomised patients have been in the range of 14-45% in studies with partial sampling and 3-72% in those with complete sampling [23,24,25,26]. Recent evidence shows that complete prostate processing results in a substantially higher rate of finding the carcinoma.…”

“…One consists of processing the entire prostate, while the other involves only representative sampling, with a variable number of samples and slice thickness among institutions. In the past few years, several reports have been published that indicate a higher diagnostic accuracy of completely processed prostates in cystoprostatectomy specimens of patients with bladder carcinoma [20,21,22,23].…”