Prediction of potentially insignificant prostate cancer in men undergoing radical prostatectomy for clinically organ‐confined disease

Abstract

Background : The objectives of the present study were to characterize, according to tumor significance, the clinicopathological features of patients with prostate cancer who underwent radical prostatectomy, and to determine useful parameters for predicting insignificant disease before surgery . Methods : In this series, we included 195 patients who underwent radical prostatectomy for clinically organ-confined prostate cancer at our institution between January 1999 and November 2003. Several clinicopathological factors were analyzed, focusing on whether the largest tumor volume in radical prostatectomy specimens was ≥ 0.5 cm 3 or < 0.5 cm 3 , which is the criterion defined to distinguish insignificant cancer from significant cancer . Results : Potentially insignificant cancer was detected in 28 of 195 patients (14.4%). There were significant differences between patients with insignificant disease and those with significant disease in serum prostate specific antigen (PSA) as well as all biopsy parameters, with the exception of biopsy Gleason score. Furthermore, final pathological examination demonstrated that these two patient groups showed significant differences in Gleason score and the incidence of extraprostatic disease extension. Pearson's correlation analysis showed that tumor volume in the prostatectomy specimens was significantly associated with serum PSA and all biopsy parameters; however, each of the correlations was comparatively weak. There was no single parameter that could viewed as a useful predictor of tumor significance. The best model for predicting insignificant tumor was the combined use of biopsy Gleason score < 7 and percent of positive biopsy core (PPBC) < 15%; however, the further addition of serum PSA < 10 ng/mL to these two parameters failed to enhance the predictive value of cancer significance . Conclusions : These findings indicate that clinicopathological findings suggesting favorable features are well observed in patients with potentially insignificant prostate cancer compared to those with significant prostate cancer, and the combination of a biopsy Gleason score < 7 and PPBC < 15% might be useful as a predictor of insignificant disease.

The Epstein Criteria Predict for Organ-Confined But Not Insignificant Disease and a High Likelihood of Cure at Radical Prostatectomy

“…We found that the performance of the Epstein criteria for predicting insignificant (as opposed to organ-confined) disease to be variable for both the classical and liberal definitions, primarily underestimating the presence of Gleason 7 disease and EPE, and was not sufficiently robust to be used clinically to predict for this end point. This latter finding is consistent with studies showing a substantial underestimation of potentially biologically significant disease as defined by higher Gleason grade and/or non-organ-confined disease despite meeting the Epstein or similar criteria on biopsy [7,[19][20][21]. In the Hopkins active surveillance cohort, which required fulfillment of the Epstein criteria for eligibility, 20% of men with delayed intervention (triggered by violation of the criteria during surveillance) had incurable disease as estimated by nomogram prediction at the time of RP [17].…”

‘Insignificant’ prostate cancer on biopsy: pathologic results from subsequent radical prostatectomy

“…Beginning with Epstein et al's 1 first description in 1994, there have been over a dozen studies of the subject. [2][3][4][5][6][7][8][9][10][11][12][13] The construct was originally intended to describe cancers that 'pose no threat to the patient and might be followed up without immediate treatment'. 1 Although much data have been analyzed, it has almost exclusively been in radical prostatectomy (RP) specimens.…”

Do Clinically Insignificant Tumors of the Prostate Exist?

“…Therefore, the clinical and pathological features associated with clinically important PC include a palpable tumor, diffuse involvement and moderately or poorly differentiated histology. In contrast, microfocal, well-differentiated PCs have a relatively good biological behavior [9] . Indeed, microscopic foci of highly differentiated tumors, have been demonstrated to have a constant (log-linear) growth rate that is very slow [10] .…”

“…Literature reviews indicate that such a disease progresses in only about 2-8% of patients and that virtually none of them succumb to the disease [11,12] . For these reasons, well-differentiated and focal microcarcinomas are probably clinically not important and insufficient to threaten survival [9] . Based on the current autopsy study, the majority of impalpable prostate carcinomas are low volume, well-differentiated tumors corresponding to clinically insignificant neoplasms, and similar characteristics could be attributed to most of the impalpable carcinomas detected after prostatectomy for BPH in clinical practice (stage T1A).…”