Validation of criteria used to predict extraprostatic cancer extension: a tool for use in selecting patients for nerve sparing radical prostatectomy

Selection of patients for nerve sparing surgery in robot‐assisted radical prostatectomy

Context

Robot‐assisted radical prostatectomy (RARP) has become the standard surgical procedure for localized prostate‐cancer (PCa). Nerve‐sparing surgery (NSS) during RARP has been associated with improved erectile function and continence rates after surgery. However, it remains unclear what are the most appropriate indications for NSS.

Objective

The objective of this study is to systematically review the available parameters for selection of patients for NSS. The weight of different clinical variables, multiparametric magnetic‐resonance‐imaging (mpMRI) findings, and the impact of multiparametric‐nomograms in the decision‐making process on (side‐specific) NSS were assessed.

Evidence acquisition

This systematic review searched relevant databases and included studies performed from January 2000 until December 2020 and recruited a total of 15 840 PCa patients. Studies were assessed that defined criteria for (side‐specific) NSS and associated them with oncological safety and/or functional outcomes. Risk of bias assessment was performed.

Evidence synthesis

Nineteen articles were eligible for full‐text review. NSS is primarily recommended in men with adequate erectile function, and with low‐risk of extracapsular extension (ECE) on the side‐of NSS. Separate clinical and radiological variables have low accuracy for predicting ECE, whereas nomograms optimize the risk‐stratification and decision‐making process to perform or to refrain from NSS when oncological safety (organ‐confined disease, PSM rates) and functional outcomes (erectile function and continence rates) were assessed.

Conclusions

Consensus exists that patients who are at high risk of ECE should refrain from NSS. Several multiparametric preoperative nomograms were developed to predict ECE with increased accuracy compared with single clinical, pathological, or radiological variables, but controversy exists on risk thresholds and decision rules on a conservative versus a less‐conservative surgical approach. An individual clinical judgment on the possibilities of NSS set against the risks of ECE is warranted.

Patient summary

NSS is aimed at sparing the nerves responsible for erection. NSS may lead to unfavorable tumor control if the risk of capsule penetration is high. Nomograms predicting extraprostatic tumor‐growth are probably most helpful.

Evaluation of Oncological Outcomes and Data Quality in Studies Assessing Nerve-sparing Versus Non-Nerve-sparing Radical Prostatectomy in Nonmetastatic Prostate Cancer: A Systematic Review

CONTEXT

Surgical techniques aimed at preserving the neurovascular bundles during radical prostatectomy (RP) have been proposed to improve functional outcomes. However, it remains unclear if nerve-sparing (NS) surgery adversely affects oncological metrics.

OBJECTIVE

To explore the oncological safety of NS versus non-NS (NNS) surgery and to identify factors affecting the oncological outcomes of NS surgery.

EVIDENCE ACQUISITION

Relevant databases were searched for English language articles published between January 1, 1990 and May 8, 2020. Comparative studies for patients with nonmetastatic prostate cancer (PCa) treated with primary RP were included. NS and NNS techniques were compared. The main outcomes were side-specific positive surgical margins (ssPSM) and biochemical recurrence (BCR). Risk of bias (RoB) and confounding assessments were performed.

EVIDENCE SYNTHESIS

Out of 1573 articles identified, 18 studies recruiting a total of 21 654 patients were included. The overall RoB and confounding were high across all domains. The most common selection criteria for NS RP identified were characteristic of low-risk disease, including low core-biopsy involvement. Seven studies evaluated the link with ssPSM and showed an increase in ssPSM after adjustment for side-specific confounders, with the relative risk for NS RP ranging from 1.50 to 1.53. Thirteen papers assessing BCR showed no difference in outcomes with at least 12 mo of follow-up. Lack of data prevented any subgroup analysis for potentially important variables. The definitions of NS were heterogeneous and poorly described in most studies.

CONCLUSIONS

Current data revealed an association between NS surgery and an increase in the risk of ssPSM. This did not translate into a negative impact on BCR, although follow-up was short and many men harbored low-risk PCa. There are significant knowledge gaps in terms of how various patient, disease, and surgical factors affect outcomes. Adequately powered and well-designed prospective trials and cohort studies accounting for these issues with long-term follow-up are recommended.

PATIENT SUMMARY

Neurovascular bundles (NVBs) are structures containing nerves and blood vessels. The NVBs close to the prostate are responsible for erections. We reviewed the literature to determine if a technique to preserve the NVBs during removal of the prostate causes worse cancer outcomes. We found that NVB preservation was poorly defined but, if applied, was associated with a higher risk of cancer at the margins of the tissue removed, even in patients with low-risk prostate cancer. The long-term importance of this finding for patients is unclear. More data are needed to provide recommendations.

Optimization of initial prostate biopsy in clinical practice: sampling, labeling and specimen processing

PURPOSE

An optimal prostate biopsy in clinical practice is based on a balance among adequate detection of clinically significant prostate cancers (sensitivity), assuredness regarding the accuracy of negative sampling (negative predictive value), limited detection of clinically insignificant cancers and good concordance with whole gland surgical pathology results to allow accurate risk stratification and disease localization for treatment selection. Inherent within this optimization is variation of the core number, location, labeling and processing for pathological evaluation. To date, there is no consensus in this regard. The purpose of this review is to 1) define the optimal number and location of biopsy cores during primary prostate biopsy among men with suspected prostate cancer, 2) define the optimal method of labeling prostate biopsy cores for pathological processing which will provide relevant and necessary clinical information for all potential clinical scenarios, and 3) determine the maximal number of prostate biopsy cores allowable within a specimen jar which would not preclude accurate histological evaluation of the tissue.

MATERIALS AND METHODS

A bibliographic search using PubMed® covering the period up to July 2012 yielded approximately 550 articles. Articles were reviewed and categorized based on which of the 3 objectives of this review was addressed. Data were extracted, analyzed and summarized. Recommendations are provided based on this literature review and our clinical experience.

RESULTS

The use of 10 to 12-core extended sampling protocols increases cancer detection rates compared to traditional sextant sampling methods and reduces the likelihood of repeat biopsy by increasing negative predictive value, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12, the increase in diagnostic yield becomes marginal. Only limited evidence supports the use of initial biopsy schemes involving more than 12 cores or saturation. Apical and laterally directed sampling of the peripheral zone increases cancer detection rate, reduces the need for repeat biopsies and predicts pathological features on prostatectomy while transition zone biopsies do not. There are little data to suggest that knowing the exact site of an individual positive biopsy core provides meaningful clinical information. However, determining laterality of cancer on biopsy may be helpful for predicting sites of extracapsular extension and therapeutic planning. Placement of multiple biopsy cores in a single container (greater than 2) appears to compromise pathological evaluation, which can reduce cancer detection rate and increase the likelihood of equivocal diagnoses.

CONCLUSIONS

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoids repeat biopsy, and provides information adequate for identifying men who need therapy and planning that therapy while minimizing the detection of occult, indolent prostate cancers. This literature review does not provide compelling evidence that individual site specific labeling of cores benefits clinical decision making regarding the management of prostate cancer. Based on the available literature, we recommend packaging no more than 2 cores in each jar to avoid reduction of the cancer detection rate through inadequate tissue sampling.

Robot-assisted extended pelvic lymph node dissection (PLND) at the time of radical prostatectomy (RP): a video-based illustration of technique, results, and unmet patient selection needs

OBJECTIVE

• To describe the differences in technique and results between standard vs extended template pelvic lymph node dissection (PLND) at the time of radical prostatectomy (RP) using a robot-assisted (RA) technique.

PATIENTS AND METHODS

• Using extended templates illustrated for the open surgical technique, a RA technique was developed to solve obstacles related to surgical exposure, identification of key landmarks, proper sequencing of operative steps, and prevention of complicationsshown in the accompanying video. • From May 2006 to October 2007, 261 patients underwent a standard PLND, and from November 2007 to November 2010, 670 underwent an extended PLND (E-PLND) by one surgeon.

RESULTS

• The lymph node (LN) yield increased from a median(interquartile range) of 8 (5-11) to 16 (11-21) with the extended technique (P < 0.001). • The ratio of positive LNs increased from 7% to 18%. Among E-PLND cases by risk group, positive LNs were found in 39%, 9%, and 3% of high-, intermediate-, and low-risk cases, and the later two groups strongly associated with upgrading and/or upstaging. • Extensive clipping appears necessary to avoid postoperative lymphoceles, and peritoneal fenestration for the extraperitoneal technique. • The median operative duration for E-PLND was 42 min, roughly double that of a standard PLND.

CONCLUSIONS

• E-PLND is feasible with a RA technique, and increases the LN yield and positive LN ratio;the latter especially in high-risk disease. • The procedure takes twice as long and requires several updates in technique shown in the video.

Optimizing Cancer Control and Functional Outcomes following Robotic Prostatectomy

Background

Since robotic-assisted laparoscopic radical prostatectomy was introduced, different modifications in the technique have been described to improve cancer control and minimize the possibility of erectile dysfunction and incontinence.

Methods

We reviewed the recent English literature on specific topics including when to preserve the neurovascular bundle (NVB), and we describe techniques to diminish the rate of positive margins and to preserve continence and potency.

Results

Identifying predictor factors of local advanced disease helps in deciding when to preserve the NVB without compromising cancer control. Techniques to decrease the positive margins based on experience and modifications of the apical dissection are reviewed. Minimal disruption or reconstruction of the anatomic structures of the periprostatic tissues helps to maintain continence. Different degrees of NVB preservation can be performed based on the characteristics of the cancer. Cautery-free techniques and other modifications in the dissection to minimize the NVB injury are also discussed.

Conclusions

The understanding of the predictor factors of local advanced disease, together with modifications in the technique, helps to not only achieve cancer control but also improve quality of life after robotic-assisted laparoscopic radical prostatectomy.

Incremental value of magnetic resonance imaging in the advanced management of prostate cancer

Prostate cancer is a major public health burden throughout the world. The high incidence of prostate cancer, combined with earlier detection and downstaging at the time of diagnosis, and the slow natural progression and biological heterogeneity of the disease, has made its management a complex and controversial issue. There is growing demand for patient-specific therapies that can minimize treatment morbidity while maximizing treatment benefits. There are a number of clinical parameters and clinical nomograms to help with the choice of treatment. Magnetic resonance imaging (MRI) is a technique which makes safer, more individualized therapies possible due to high spatial resolution, superior contrast resolution, multiplanar capability, and a large field of view. Other MRI techniques such as MR spectroscopic imaging, dynamic contrast-enhanced MRI or perfusion MRI, and diffusion-weighted imaging complement MRI by reflecting tissue biochemistry, Brownian motion of water molecules, and capillary wall permeability, respectively. This editorial review highlights the incremental value of MRI in the advanced management of prostate cancer to non-invasively improve cancer staging, biologic potential, treatment planning, therapy response, local recurrence, and to guide target biopsy for clinical suspected cancer with previous negative biopsy. Finally, some future prospects for MRI in prostate cancer management are given.

Tissue-marking scheme for a cost-effective extended prostate biopsy protocol

OBJECTIVES

Extended biopsy schemes are now the standard of care for detection of prostate cancer. Submitting biopsy cores individually raises the cost of pathologic evaluation significantly while important prognostic information is lost when the samples are bundled into fewer containers. We devised a protocol for bundling biopsy cores to reduce the cost while maintaining our ability to identify important biopsy features.

MATERIALS AND METHODS

Four hundred fifty-two consecutive men underwent a prostate biopsy using our prospectively designed protocol. The lateral peripheral cores were marked with India ink and combined with cores from the corresponding sextant site into one container (maximum containers = 6). Prognostic information from each core was recorded. Cost analysis was based on the reimbursement rates for variable number of containers.

RESULTS

Tissue-labeling protocol did not increase the procedure time or introduce any tissue artifacts. Cancer was detected in 177 (39%) men with mean Gleason score of 7. A single core with cancer was noted in 28%, and cancer in < or =25% of the core was found in 41%. Thirteen of 64 (20%) men undergoing radical prostatectomy had extracapsular extension (ECE) and 10 (15%) had a positive surgical margin. The location of ECE on prostatectomy specimen correlated with a positive biopsy site in 9 (70%) patients. The cost of histopathologic evaluation is based on number of individually labeled specimen containers. By reducing the number of specimen containers from 12 to 6, the potential savings may be in hundreds of million per year.

CONCLUSIONS

This simple tissue-labeling protocol facilitates extended prostate biopsies in a cost-effective manner, while maintaining our ability to glean important prognostic information from each core.

Imaging in Oncology from The University of Texas M. D. Anderson Cancer Center: Diagnosis, Staging, and Surveillance of Prostate Cancer

OBJECTIVE

The purpose of this article is to discuss the epidemiology, risk factors, and presentation of prostate cancer. After reviewing the prostate anatomy, the article will show how imaging plays an important role in establishing the diagnosis, staging, and monitoring the therapeutic response in prostate cancer, with a focus on adenocarcinomas.

CONCLUSION

Imaging studies, in the appropriate laboratory and clinical context, contribute essential information that enhances the capacity to provide individualized risk stratification, a suitable treatment strategy, and monitoring for the patient with prostate cancer.