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

Schema and cancer detection rates for transperineal prostate biopsy templates: a review

Prostate cancer (PCa) is the most common noncutaneous malignancy in men and is the second leading cause of cancer mortality in men in the United States. Current practice requires histopathological confirmation of cancer achieved through biopsy for diagnosis. The transrectal approach for prostate biopsy has been the standard for several decades. However, the risks and limitations of transrectal biopsies have led to a recent resurgence of transperineal prostatic biopsies. Recent studies have demonstrated the transperineal approach for prostate biopsies to be effective, associated with minimal complications and superior in several aspects to traditional transrectal biopsies. While sextant and extended sextant templates are widely accepted templates for transrectal biopsy, there are a diverse set of transperineal biopsy templates available for use, without consensus on the optimal sampling strategy. We aim to critically appraise the salient features of established transperineal biopsy templates.

Cost-effectiveness of SelectMDx for prostate cancer in four European countries: a comparative modeling study

BACKGROUND

Low specificity of prostate-specific antigen results in a considerable number of unnecessary prostate biopsies in current practice. SelectMDx® predicts significant prostate cancer upon biopsy and is used to reduce the number of unnecessary initial prostate biopsies. Furthermore, potential overtreatment of insignificant prostate cancer can be reduced. Besides the diagnostic accuracy of the test, also the context in a specific country determines the potential health benefit and cost-effectiveness. Therefore, the health benefit and cost-effectiveness of SelectMDx were assessed in France, Germany, Italy, and Spain.

SUBJECT AND METHODS

A decision model was used to compare the current standard of care in which men undergo initial prostate biopsy in case of an elevated prostate-specific antigen, to a strategy in which SelectMDx was used to select men for biopsy. Model inputs most relevant to each of the four countries were obtained. With use of the model long-term quality-adjusted life years (QALYs) and healthcare costs were calculated for both strategies.

RESULTS

In all four countries, the SelectMDx resulted in QALY gain and cost savings compared with the current standard of care. In France, SelectMDx resulted in 0.022 QALYs gained and cost savings of €1217 per patient. For Germany, the model showed a QALY gain of 0.016 and a cost saving of €442. In Italy, the QALY gain and cost savings were 0.031 and €762. In Spain 0.020 QALYs were gained and €250 costs were saved.

CONCLUSIONS

The results of the model showed that with SelectMDx, QALYs could be gained while saving healthcare costs in the initial diagnosis of prostate cancer. The significant presence of overtreatment in the current standard of care in all four countries was the main factor that resulted in the beneficial outcomes with SelectMDx.

On the relationship between tumor structure and complexity of the spatial distribution of cancer cell nuclei: a fractal geometrical model of prostate carcinoma

BACKGROUND

A risk of the prostate cancer patient is defined by both the objective and subjective criteria, that is, PSA concentration, Gleason score, and pTNM-stage. The subjectivity of tumor grading influences the risk assessment owing to a large inter- and intra-observer variability. Pathologists propose a central prostate pathology review as a remedy for this problem; yet, the review cannot eliminate the subjectivity from the diagnostic algorithm. The spatial distribution of cancer cell nuclei changes during tumor progression. It implies changes in complexity measured by the capacity dimension D0, the information dimension D1, and the correlation dimension D2.

METHODS

The cornerstone of the approach is a model of prostate carcinomas composed of the circular fractals CF(4), CF(6 + 0), and CF(6 + 1). This model is both geometrical and analytical, that is, its structure is well-defined, the capacity fractal dimension D0 can be calculated for the infinite circular fractals, and the dimensions D0, D1, D2 can be computed for their finite counterparts representing distribution of cell nuclei. The model enabled both the calibration of the software and the validation of the measurements in 124 prostate carcinomas. The ROC analysis defined the cut-off D0 values for seven classes of complexity.

RESULTS

The Gleason classification matched in part with the classification based on the D0 values. The mean ROC sensitivity was 81.3% and the mean ROC specificity 75.2%. Prostate carcinomas were re-stratified into seven classes of complexity according to their D0 values. This increased both the mean ROC sensitivity and the mean ROC specificity to 100%. All homogeneous Gleason patterns were subordinated to the class C1, C4, or C7. D0 = 1.5820 was the cut-off D0 value between the complexity class C2 and C3 representing low-risk cancers and intermediate-risk cancers, respectively.

CONCLUSIONS

The global fractal dimensions eliminate the subjectivity in the diagnostic algorithm of prostate cancer. Those complexity measures enable the objective subordination of carcinomas to the well-defined complexity classes, and define subgroups of carcinomas with very low malignant potential (complexity class C1) or at a large risk of progression (complexity ass C7).

Multiple repeat prostate biopsies and the detection of clinically insignificant cancer in men with large prostates

OBJECTIVE

To determine the impact of repeating prostate biopsies on the risk of detecting clinically insignificant prostate cancer (PCa) in larger prostate glands.

METHODS

We performed a retrospective cohort study using patients enrolled in our institutional PCa registry from 1991 to 2008 to assess the association of prostate volume and clinically insignificant PCa in men undergoing multiple prostate biopsies. Patients were stratified by prostate volume into 2 cohorts (<50 cm(3) or ≥50 cm(3)). Additionally, patients were stratified by prostate biopsy on which PCa was identified (1 biopsy or ≥3 biopsies).

RESULTS

Within the subgroup of patients with prostate volume ≥50 cm(3) requiring ≥3 biopsies before cancer diagnosis, 72.6% (45/62) had pathologic Gleason scores ≤6 and 81.6% (49/60) had an estimated tumor volume of ≤10% at the time of radical prostatectomy. This was significantly different from patients with prostate volume <50 cm(3) diagnosed on their first biopsy, in which only 48.5% (656/1349) were found to have Gleason scores ≤6 and 54.2% (705/1300) had estimated tumor volume ≤10% (P <.01). There was no significant difference in the rate of Gleason score upgrading at time of prostatectomy between any of the subgroups.

CONCLUSION

PCas detected in men with prostatic enlargement requiring multiple biopsies are more likely to be low-grade, low-volume tumors at final pathology than men without prostate enlargement. Men with larger prostates who have already had prior negative biopsies should be counseled regarding the increased risk of detecting clinically insignificant PCa with additional biopsies.

Comparison of transperineal mapping biopsy results with whole-mount radical prostatectomy pathology in patients with localized prostate cancer

Objective. We sought to evaluate the accuracy of transperineal mapping biopsy (TMB) by comparing it to the pathology specimen of patients who underwent radical prostatectomy (RP) for localized prostate cancer. Methods. From March 2007 to September 2009, 78 men at a single center underwent TMB; 17 of 78 subsequently underwent RP. TMB cores were grouped into four quadrants and matched to data from RP whole-mount slides. Gleason score, tumor location and volume, cross-sectional area, and maximal diameter were measured; sensitivity and specificity were assessed. Results. For the 17 patients who underwent RP, TMB revealed 12 (71%) had biopsy Gleason grades ≥ 3 + 4 and 13 (76%) had bilateral disease. RP specimens showed 14 (82%) had Gleason scores ≥ 3 + 4 and 13 (76%) had bilateral disease. Sensitivity and specificity of TMB for prostate cancer detection were 86% (95% confidence interval [CI] 72%-94%) and 83% (95% CI 62%-95%), respectively. Four quadrants negative for cancer on TMB were positive on prostatectomy, and six positive on TMB were negative on prostatectomy. Conclusion. TMB is a highly invasive procedure that can accurately detect and localize prostate cancer. These findings help establish baseline performance characteristics for TMB and its utility for organ-sparing strategies.

The Study of Active Monitoring in Sweden (SAMS): a randomized study comparing two different follow-up schedules for active surveillance of low-risk prostate cancer

OBJECTIVE

Only a minority of patients with low-risk prostate cancer needs treatment, but the methods for optimal selection of patients for treatment are not established. This article describes the Study of Active Monitoring in Sweden (SAMS), which aims to improve those methods.

MATERIAL AND METHODS

SAMS is a prospective, multicentre study of active surveillance for low-risk prostate cancer. It consists of a randomized part comparing standard rebiopsy and follow-up with an extensive initial rebiopsy coupled with less intensive follow-up and no further scheduled biopsies (SAMS-FU), as well as an observational part (SAMS-ObsQoL). Quality of life is assessed with questionnaires and compared with patients receiving primary curative treatment. SAMS-FU is planned to randomize 500 patients and SAMS-ObsQoL to include at least 500 patients during 5 years. The primary endpoint is conversion to active treatment. The secondary endpoints include symptoms, distant metastases and mortality. All patients will be followed for 10-15 years.

RESULTS

Inclusion started in October 2011. In March 2013, 148 patients were included at 13 Swedish urological centres.

CONCLUSIONS

It is hoped that the results of SAMS will contribute to fewer patients with indolent, low-risk prostate cancer receiving unnecessary treatment and more patients on active surveillance who need treatment receiving it when the disease is still curable. The less intensive investigational follow-up in the SAMS-FU trial would reduce the healthcare resources allocated to this large group of patients if it replaced the present standard schedule.

Aberrant PSA glycosylation--a sweet predictor of prostate cancer

Prostate cancer--the most commonly diagnosed cancer in men worldwide--can have a substantial effect on quality of life, regardless of the route the cancer takes. The serum PSA assay is the current gold standard option for diagnosing prostate cancer. However, a growing body of evidence suggests that PSA screening for prostate cancer results in extensive overdiagnosis and overtreatment. It is increasingly evident that the potential harm from overdiagnosis (in terms of unnecessary biopsies) must be weighed against the benefit derived from the early detection and treatment of potentially fatal prostate cancers. Rapid screening methods have been used to analyse glycosylation patterns on glycoproteins in large cohorts of patients, enabling the identification of a new generation of disease biomarkers. Changes to the expression status of certain glycan structures are now widely thought to be common features of tumour progression. In light of this development, much research has focused on the potential role of altered PSA glycosylation patterns in discriminating between significant and insignificant prostate cancers, with the aim of developing a more reliable diagnostic tool than the current serum PSA test.

Risk of Gleason grade inaccuracies in prostate cancer patients eligible for active surveillance

OBJECTIVE

To evaluate increases in Gleason grade because of sample bias after immediate rebiopsy or prostatectomy for patients considered active surveillance candidates by institutional protocol.

METHODS

A contemporary medical literature search was performed using PubMed. Series were included if the patients had no more than Gleason 6 prostate cancer score on initial biopsy and underwent a prostatectomy or rebiopsy within 6 months. Patient sets using neoadjuvant hormonal therapy or focal prostate treatment were excluded.

RESULTS

In patients who would have fallen into the D'Amico low-risk prostate cancer group, 42% were found to have an increase in the Gleason score: 32% resulting in grade ≥ 7 disease and 3% grade ≥ 8. For series that limited patients to the Epstein criteria, Gleason upgrades were 34%, 29%, and 2%, respectively. Of the 139 patients whose second tissue specimens were from a rebiopsy, 17% were found to have grade ≥ 7 disease, whereas only 1 patient had grade ≥ 8. There were no consistent multivariate analysis variables among the series to predict for an increase in Gleason score.

CONCLUSION

More than one third of the patients were found to have been undergraded based on their initial prostate biopsy. Therefore, 1 biopsy alone may not be sufficient to offer active surveillance as an option. Further exploration is necessary to better ensure low-risk disease before active surveillance.

Effects of a high dose, aglycone-rich soy extract on prostate-specific antigen and serum isoflavone concentrations in men with localized prostate cancer

The efficacy and safety of consuming high-dose isoflavone supplements for prostate cancer is not clear. A double-blind, placebo controlled, randomized trial was conducted in 53 men with prostate cancer enrolled in an active surveillance program. The treatment group consumed a supplement containing 450 mg genistein, 300 mg daidzein, and other isoflavones daily for 6 mo. Prostate-specific antigen (PSA) was measured in both groups at baseline, 3 mo, and 6 mo, and serum concentrations of genistein, daidzein, and equol were assessed at baseline and 6 mo in the treatment group. Following the completion of the 6-mo double-blind study, men were enrolled in a 6-mo open label trial with the same isoflavone-rich supplement, and PSA was measured at 3 and 6 mo. PSA concentrations did not change in either group after 6 mo or after 12 mo when the open-label study was included. The 6 mo serum concentrations of genistein and daidzein (39.85 and 45.59 μmol/l, respectively) were significantly greater than baseline values and substantially higher than levels previously reported in other studies. Equol levels did not change. Although high amounts of aglycone isoflavones may result in significantly elevated serum concentrations of genistein and daidzein, these dietary supplements alone did not lower PSA levels in men with low-volume prostate cancer.

The Role of Tumor Volume on Outcome in Prostate Cancer after Prostatectomy

Objective:

Significant study has been made of the role of tumor volume contributing to outcome in prostate cancer: almost two dozen studies have been published on the subject, without clear results either for or against a relationship.

Methods:

An extensive MEDLINE and PUBMED search yielded fourteen articles involving >10,600 patients describing analyses of institutional prostate cancer experiences including tumor volume after radical prostatectomy (RP). Studies were included if multivariate analysis (MVA) was performed including a variable related to tumor volume. All studies had a common outcome of biochemical disease-free (bNED) survival.

Results:

The more rigorous the MVA performed, the more likely tumor volume was to be independently predictive. When the analysis included only tumor volume and Gleason score, studies agreed on outcome half the time. As more variables were added to the analysis, the degree of concordance increased. The two studies with most complete MVAs concur in a volume effect on outcome in over 1470 patients.

Conclusion:

While no meta-analysis on the subject is possible without knowing particulars of each reported case, tumor volume as a predictive variable is likely to be less important than more frequently analyzed factors such as Gleason score and PSA. However, the studies that most completely address the complex and competing variables impacting bNED survival in prostate cancer are those that describe a relationship of tumor volume on outcome.

Sampling the spatial patterns of cancer: optimized biopsy procedures for estimating prostate cancer volume and Gleason Score

Prostate biopsy is the current gold-standard procedure for prostate cancer diagnosis. Existing prostate biopsy procedures have been mostly focusing on detecting cancer presence. However, they often ignore the potential use of biopsy to estimate cancer volume (CV) and Gleason Score (GS, a cancer grade descriptor), the two surrogate markers for cancer aggressiveness and the two crucial factors for treatment planning. To fill up this vacancy, this paper assumes and demonstrates that, by optimally sampling the spatial patterns of cancer, biopsy procedures can be specifically designed for estimating CV and GS. Our approach combines image analysis and machine learning tools in an atlas-based population study that consists of three steps. First, the spatial distributions of cancer in a patient population are learned, by constructing statistical atlases from histological images of prostate specimens with known cancer ground truths. Then, the optimal biopsy locations are determined in a feature selection formulation, so that biopsy outcomes (either cancer presence or absence) at those locations could be used to differentiate, at the best rate, between the existing specimens having different (high vs. low) CV/GS values. Finally, the optimized biopsy locations are utilized to estimate whether a new-coming prostate cancer patient has high or low CV/GS values, based on a binary classification formulation. The estimation accuracy and the generalization ability are evaluated by the classification rates and the associated receiver-operating-characteristic (ROC) curves in cross validations. The optimized biopsy procedures are also designed to be robust to the almost inevitable needle displacement errors in clinical practice, and are found to be robust to variations in the optimization parameters as well as the training populations.

Nerve-sparing focal cryoablation of prostate cancer

PURPOSE OF REVIEW

We evaluate the rationale, candidate selection, and results of the first clinical studies of focal cryoablation for select patients with low volume and low-to-low - moderate risk features of prostate cancer as a possible alternative to whole gland treatment.

RECENT FINDINGS

For a select cohort of patients with low-to-low - moderate risk unifocal or unilateral prostate cancer, a number of ablative treatment options for focal therapy are available with cryotherapy having the most clinical experience. However, retrospective pathological data from large prostatectomy series do not clearly reveal valid and reproducible criteria to select appropriate candidates for focal cryoablation due to the complexity of tumorigenesis in early stage disease.

SUMMARY

The concept of focal therapy is evolving with the understanding of the biologic variability (clinically aggressive, significant, or insignificant) of prostate cancers that may require different treatment approaches. Minimally-invasive, parenchyma-preserving cryoablation can be considered as a potential feasible option in the treatment armamentarium of early stage, localized prostate cancer in appropriately selected candidates.

[Insignificant prostate cancer. Analysis our series]

The objective of this study is to analyse the specimen of radical prostatectomy of patients who had, prior to the surgery insignificant prostate cancer biopsies. The end point is demonstrate the possibility of an active surveillance as a therapeutic option for prostate cancer in selected is the possibility of an active surveillance as therapeutic for the prostate cancer, in selected individuals if we are able to find diagnostic algorisms to predict the real insignificant tumours. The selected group of patients for the study has a PSA less or equal 10, one positive core of prostatic transrectal ultrasound biopsy with a Gleason score less than 7. This group of patients is considerate as having a potential insignificant tumour. We will consider prostatectomy's specimens and the Gleason sore is less than 7 and the tumoral volume is les or equal to 5%. Of 394 patients with prostate cancer and homogeneous criterias for our study, we have selected 53 patients according to the criteria of insignificant tumour in the biopsy. Our results showed that only 22 of 53 (41.5%) patients were identified as having an insignificant prostate cancer in the RP specimens. Moreover 92.2% of this tumours were organ-confined. In conclusion we are able to say that tumours of low-risk and low tumoral volume in the biopsy, do not correlate always to insignificant tumours in PR specimens, but we have observed that the majority are organ-confined tumours. Finally, the diagnostic's algorisms dies not to predict tumours that may safely treated with active monitoring.

Preoperative prediction of unifocal, unilateral, margin-negative, and small volume prostate cancer

OBJECTIVES

Contemporary prostate carcinoma is frequently of small volume and early stage. Subtotal gland ablation by minimally invasive therapies such as cryotherapy demands preoperative prediction of unifocal, unilateral, margin-negative, and small volume (less than 0.5 mL) cancer.

METHODS

We examined matched biopsy and prostatectomy and clinical data from 393 patients at two institutions who underwent surgery in 2000 through 2003. Radical prostatectomy specimens were uniformly sectioned at 5-mm intervals and completely embedded. Numerous clinical and biopsy variables were correlated by regression analysis with unifocal, unilateral, margin-negative, and 0.5 mL or less volume cancer in the prostatectomy specimen. Odds ratios (OR) were determined.

RESULTS

At prostatectomy, 92 (23%) had unifocal cancer, 90 (23%) had unilateral cancer, 348 (89%) had organ-confined cancer, and 106 (31%) had small volume cancer. Unilateral cancer occurred in 71% to 76% of cases of unilateral cancer in the biopsy (OR, 4.30; if 9 or more cores were sampled, OR rose to 6.83), and was predicted by unifocality in the biopsy (OR, 2.63). Unifocal cancer was predicted by unilateral (OR, 2.66) but not unifocal, cancer present in the biopsy. Negative surgical margins were predicted by unilateral (OR, 2.53; positive predictive value, 82%) cancer in the biopsy and by serum prostate specific antigen (OR, 5.33). Small volume cancer was predicted by unilateral (OR, 5.50) and unifocal (OR, 7.98) cancer in the biopsy; Gleason score greater than 7 predicted a non-small volume cancer (OR, 7.52).

CONCLUSIONS

Unilateral or unifocal cancer on biopsy are among the strongest predictors of unilateral, unifocal, and small volume prostate cancer in contemporary practice.