The role of lymphadenectomy in prostate cancer

Data-Driven Design of Triple-Targeted Protein Nanoprobes for Multiplexed Imaging of Cancer Lymphatic Metastasis

Targeted imaging of cancer lymphatic metastasis remains challenging due to its highly heterogeneous molecular and phenotypic diversity. Herein, triple-targeted protein nanoprobes capable of specifically binding to three targets for imaging cancer lymphatic metastasis, through a data-driven design approach combined with a synthetic biology-based assembly strategy, are introduced. Specifically, to address the diversity of metastatic lymph nodes (LNs), a combination of three targets, including C-X-C motif chemokine receptor 4 (CXCR4), transferrin receptor protein 1 (TfR1), and vascular endothelial growth factor receptor 3 (VEGFR3) is identified, leveraging machine leaning-based bioinformatics analysis and examination of LN tissues from patients with gastric cancer. Using this identified target combination, ferritin nanocage-based nanoprobes capable of specifically binding to all three targets are designed through the self-assembly of genetically engineered ferritin subunits using a synthetic biology approach. Using these nanoprobes, multiplexed imaging of heterogeneous metastatic LNs is successfully achieved in a polyclonal lymphatic metastasis animal model. In 19 freshly resected human gastric specimens, the signal from the triple-targeted nanoprobes significantly differentiates metastatic LNs from benign LNs. This study not only provides an effective nanoprobe for imaging highly heterogeneous lymphatic metastasis but also proposes a potential strategy for guiding the design of targeted nanomedicines for cancer lymphatic metastasis.

Correlation between extended pelvic lymph node dissection and urinary incontinence at early phase after robot‐assisted radical prostatectomy

OBJECTIVES

To investigate the impact of extended pelvic lymph node dissection (ePLND) on urinary incontinence (UI) at early post-surgery robot-assisted radical prostatectomy (RARP).

METHODS

Patients who underwent RARP without cavernous nerve sparing were included between 2014 and 2019. Patient data were obtained prospectively. The associations between ePLND and postoperative urinary continence were defined as a maximum of one daily pad use. International prostate symptom score (IPSS) was examined. Expression of synaptophysin and tyrosine hydroxylase (TH) in perilymph node adipose tissue (PLA) was evaluated by immunohistochemistry.

RESULTS

In total, 186 and 163 patients underwent RARP with and without ePLND. Urinary continence rate at 1 month postoperatively among patients with ePLND was lower than those without ePLND (24.1% vs. 35.1%, p < 0.05), however, not significantly different at 3, 6, and 12 months after RARP (57.4 vs. 62.6%, 73.1 vs. 74.2%, and 83.0 vs. 81.2%, respectively). Total and voiding plus postvoiding IPSS scores at 1 month were higher in patients with ePLND than in those without ePLND (14.5 ± 0.5 vs. 13.6 ± 0.6, 7.0 ± 0.3 vs. 6.2 ± 0.4, respectively, p < 0.05). In univariate and multivariate analyses, larger prostate volume and ePLND were factors associated with an increased UI rate. Among patients who underwent ePLND, synaptophysin and TH-positive nerve fibers were detected in PLA.

CONCLUSIONS

Detection of synaptophysin and TH-immunopositive nerves suggested denervation of sympathetic and peripheral nerves caused by ePLND might be associated with a higher UI rate and poor urinary symptoms at an early stage after RARP.

A narrative review of pelvic lymph node dissection in prostate cancer

Pelvic lymph node dissection (PLND) is an important component in the staging and prognostication of prostate cancer. We performed a narrative review to assess the literature surrounding PLND: (I) the current guideline recommendations and contemporary utilization, (II) the calculation of patient-specific risk to perform PLND using available nomograms, (III) to review the extent of dissection, and its associated outcomes and complications. Due to the improved lymph node yield, better staging, and theoretical improvement in the control of micro-metastatic disease, guidelines have supported the use of (extended-) PLND in patients deemed to be at intermediate or high risk of lymph node involvement (often at a threshold of 5% on modern risk nomograms). However, in practice, real-world utilization of PLND varies considerably due to multiple reasons. Conflicting evidence persists with no clear oncological benefit to PLND, and a small, but important, risk of morbidity. Complications are rare, but include lymphoceles; thromboembolic events; and more rarely, obturator nerve, vascular, and ureteric injury. Furthermore, changing disease incidence and stage migration in the context of earlier detection overall have led to a decreased risk of nodal disease. The trade-offs between the benefits, harms, and risk tolerance/threshold must be carefully considered between each patient and their clinician.

Can Anterior Prostatic Fat Harbor Prostate Cancer Metastasis? A Prospective Cohort Study

OBJECTIVES

Traditionally anterior prostatic fat (APF) hasn't been included in pelvic lymph node (LN) dissection templates following radical prostatectomy. In this study we evaluate the incidence of lymphoid tissue in the APF and the incidence of LN metastasis in APF in patients who have undergone robotic-assisted laparoscopic radical prostatectomy (RALP).

METHODS

A prospective database of RALP has been maintained between January 2010 and September 2015. APF is routinely excised and sent separately for histopathological evaluation to identify lymphoid tissue and metastatic prostate cancer.

RESULTS

A total of 629 underwent RALP. Forty-six (7.3%) of the patients had lymphoid tissue on histopathological evaluation. Two patients had meta-static disease. Both patients with positive LNs were intermediate risk on pre-operative evolution (A-PSA 16.6 ng/ml, Gleason 3 + 4; B PSA 7.3 ng/ml, Gleason 4 + 3) and upgraded on final prostate pathological evaluation to high risk disease (A-Gleason 4 + 5, pT3b, B-Gleason 4 + 3, pT4).

CONCLUSION

There appears to be lymphatic drainage to the APF from the prostate. Hence APF should be included in pelvic LN dissection templates when lymphadenectomy is contemplated in patients undergoing radical prostatectomy.

The Benefits and Harms of Different Extents of Lymph Node Dissection During Radical Prostatectomy for Prostate Cancer: A Systematic Review

CONTEXT

There is controversy regarding the therapeutic role of pelvic lymph node dissection (PLND) in patients undergoing radical prostatectomy for prostate cancer (PCa).

OBJECTIVE

To systematically review the relevant literature assessing the relative benefits and harms of PLND for oncological and non-oncological outcomes in patients undergoing radical prostatectomy for PCa.

EVIDENCE ACQUISITION

MEDLINE, MEDLINE In-Process, Embase, and the Cochrane Central Register of Controlled Trials were searched up to December 2015. Comparative studies evaluating no PLND, limited, standard, and (super)-extended PLND that reported oncological and non-oncological outcomes were included. Risk-of-bias and confounding assessments were performed. A narrative synthesis was undertaken.

EVIDENCE SYNTHESIS

Overall, 66 studies recruiting a total of 275,269 patients were included (44 full-text articles and 22 conference abstracts). Oncological outcomes were addressed by 29 studies, one of which was a randomized clinical trial (RCT). Non-oncological outcomes were addressed by 43 studies, three of which were RCTs. There were high risks of bias and confounding in most studies. Conflicting results emerged when comparing biochemical and clinical recurrence, while no significant differences were observed among groups for survival. Conversely, the majority of studies showed that the more extensive the PLND, the greater the adverse outcomes in terms of operating time, blood loss, length of stay, and postoperative complications. No significant differences were observed in terms of urinary continence and erectile function recovery.

CONCLUSIONS

Although representing the most accurate staging procedure, PLND and its extension are associated with worse intraoperative and perioperative outcomes, whereas a direct therapeutic effect is still not evident from the current literature. The current poor quality of evidence indicates the need for robust and adequately powered clinical trials.

PATIENT SUMMARY

Based on a comprehensive review of the literature, this article summarizes the benefits and harms of removing lymph nodes during surgery to remove the prostate because of PCa. Although the quality of the data from the studies was poor, the review suggests that lymph node removal may not have any direct benefit on cancer outcomes and may instead result in more complications. Nevertheless, the procedure remains justified because it enables accurate assessment of cancer spread.

Is extended pelvic lymph node dissection for prostate cancer the only recommended option? A systematic over-view of the literature

OBJECTIVE

Pelvic lymph node dissection (PLND) is performed alongside radical prostatectomy as the most accurate method of staging prostate cancer. Yet the potential therapeutic benefits of lymphadenectomy are yet to be confirmed.

MATERIAL AND METHODS

A PubMed database search was performed to identify all papers comparing techniques for PLND or none. The primary outcome measure was long term oncological outcomes. Studies looking at men with clinically localized prostate cancer at the time of radical prostatectomy who received no adjuvant treatment were included. Previous reviews and single case reports were excluded. The subsequent available papers were then systematically reviewed.

RESULTS

Limited PLND provides no benefit in low risk prostate cancer and is unlikely to provide a therapeutic benefit in higher risk groups either when compared with no PLND. Extended PLND may provide some therapeutic benefit, particularly in patients with occult metastases; however, the evidence base for this is not particularly strong and may be down to statistical phenomena.

CONCLUSION

When performed in prostate cancer patients, PLND should be extended, as it is a more accurate staging tool and may provide therapeutic benefit to some patients. However, to properly assess this, randomised controlled studies need to be performed in this area.

Extended pelvic lymphadenectomy in patients with clinically localised prostate cancer: A prospective observational study

OBJECTIVE

To determine the frequency of lymph node involvement in patients with clinically localised prostate adenocarcinoma who had radical prostatectomy and extended pelvic lymphadenectomy.

MATERIAL AND METHODS

A prospective observational study was conducted on 137 patients with clinically localised prostate cancer of low, intermediate or high risk according to the D'Amico classification. All participants underwent radical prostatectomy plus extended pelvic lymphadenectomy in 3 reference centres in Bogota, Colombia, between 2013 and 2014. The following variables were assessed: age, prostate specific antigen levels, Gleason score of the biopsy, probability of lymph node involvement calculated with Partin tables and the histopathology result of the surgical specimen, with the definitive Gleason pattern and the total number of resected and involved lymph nodes per tumour, according to the territory of the dissection.

RESULTS

A total of 2,876 lymph nodes were extracted (an average of 20.99 lymph nodes per patient). There was lymph node involvement in 14 (10.22%) patients. The high-risk and intermediate-risk group presented lymph node metastases in 28.57% and 5.25%, respectively. There was no lymph node involvement in the low-risk group. Of the patients at risk of lymph node involvement (≥2% according to the Partin tables), 19.40% had lymph node metastases.

CONCLUSION

Lymph node involvement in our population is similar to that reported in the worldwide literature. Extended pelvic lymphadenectomy increased the probability of detecting lymph node metastases in our community.

Consensus Guidelines and Contouring Atlas for Pelvic Node Delineation in Prostate and Pelvic Node Intensity Modulated Radiation Therapy

PURPOSE

The purpose of this study was to establish reproducible guidelines for delineating the clinical target volume (CTV) of the pelvic lymph nodes (LN) by combining the freehand Royal Marsden Hospital (RMH) and Radiation Therapy Oncology Group (RTOG) vascular expansion techniques.

METHODS AND MATERIALS

Seven patients with prostate cancer underwent standard planning computed tomography scanning. Four different CTVs (RMH, RTOG, modified RTOG, and Prostate and pelvIs Versus prOsTate Alone treatment for Locally advanced prostate cancer [PIVOTAL] trial) were created for each patient, and 6 different bowel expansion margins (BEM) were created to assess bowel avoidance by the CTV. The resulting CTVs were compared visually and by using Jaccard conformity indices. The volume of overlap between bowel and planning target volume (PTV) was measured to aid selection of an appropriate BEM to enable maximal LN yet minimal normal tissue coverage.

RESULTS

In total, 84 nodal contours were evaluated. LN coverage was similar in all groups, with all of the vascular-expansion techniques (RTOG, modified RTOG, and PIVOTAL), resulting in larger CTVs than that of the RMH technique (mean volumes: 287.3 cm(3), 326.7 cm(3), 310.3 cm(3), and 256.7 cm(3), respectively). Mean volumes of bowel within the modified RTOG PTV were 19.5 cm(3) (with 0 mm BEM), 17.4 cm(3) (1-mm BEM), 10.8 cm(3) (2-mm BEM), 6.9 cm(3) (3-mm BEM), 5.0 cm(3) (4-mm BEM), and 1.4 cm(3) (5-mm BEM) in comparison with an overlap of 9.2 cm(3) seen using the RMH technique. Evaluation of conformity between LN-CTVs from each technique revealed similar volumes and coverage.

CONCLUSIONS

Vascular expansion techniques result in larger LN-CTVs than the freehand RMH technique. Because the RMH technique is supported by phase 1 and 2 trial safety data, we proposed modifications to the RTOG technique, including the addition of a 3-mm BEM, which resulted in LN-CTV coverage similar to that of the RMH technique, with reduction in bowel and planning target volume overlap. On the basis of these findings, recommended guidelines including a detailed pelvic LN contouring atlas have been produced and implemented in the PIVOTAL trial.

Epidural analgesia during open radical prostatectomy does not improve long-term cancer-related outcome: a retrospective study in patients with advanced prostate cancer

Background

A beneficial effect of regional anesthesia on cancer related outcome in various solid tumors has been proposed. The data on prostate cancer is conflicting and reports on long-term cancer specific survival are lacking.

Methods

In a retrospective, single-center study, outcomes of 148 consecutive patients with locally advanced prostate cancer pT3/4 who underwent retropubic radical prostatectomy (RRP) with general anesthesia combined with intra- and postoperative epidural analgesia (n=67) or with postoperative ketorolac-morphine analgesia (n=81) were reviewed. The median observation time was 14.00 years (range 10.87-17.75 yrs). Biochemical recurrence (BCR)-free, local and distant recurrence-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier technique. Multivariate Cox proportional-hazards regression models were used to analyze clinicopathologic variables associated with disease progression and death.

Results

The survival estimates for BCR-free, local and distant recurrence-free, cancer-specific survival and overall survival did not differ between the two groups (P=0.64, P=0.75, P=0.18, P=0.32 and P=0.07). For both groups, higher preoperative PSA (hazard ratio (HR) 1.02, 95% confidence interval (CI) 1.01-1.02, P<0.0001), increased specimen Gleason score (HR 1.24, 95% CI 1.06-1.46, P=0.007) and positive nodal status (HR 1.66, 95% CI 1.03-2.67, P=0.04) were associated with higher risk of BCR. Increased specimen Gleason score predicted death from prostate cancer (HR 2.46, 95% CI 1.65-3.68, P<0.0001).

Conclusions

General anaesthesia combined with epidural analgesia did not reduce the risk of cancer progression or improve survival after RRP for prostate cancer in this group of patients at high risk for disease progression with a median observation time of 14.00 yrs.

Prostate specific antigen best practice statement: 2009 update

PURPOSE

We provide current information on the use of PSA testing for the evaluation of men at risk for prostate cancer, and the risks and benefits of early detection.

MATERIALS AND METHODS

The report is a summary of the American Urological Association PSA Best Practice Policy 2009. The summary statement is based on a review of the current professional literature, clinical experience and the expert opinions of a multispecialty panel. It is intended to serve as a resource for physicians, other health care professionals, and patients. It does not establish a fixed set of guidelines, define the legal standard of care or pre-empt physician judgment in individual cases.

RESULTS

There are two notable differences in the current policy. First, the age for obtaining a baseline PSA has been lowered to 40 years. Secondly, the current policy no longer recommends a single, threshold value of PSA, which should prompt prostate biopsy. Rather, the decision to proceed to prostate biopsy should be based primarily on PSA and DRE results, but should take into account multiple factors including free and total PSA, patient age, PSA velocity, PSA density, family history, ethnicity, prior biopsy history and comorbidities.

CONCLUSIONS

Although recently published trials show different results regarding the impact of prostate cancer screening on mortality, both suggest that prostate cancer screening leads to overdetection and overtreatment of some patients. Therefore, men should be informed of the risks and benefits of prostate cancer screening before biopsy and the option of active surveillance in lieu of immediate treatment for certain men diagnosed with prostate cancer.

Prostate specific antigen best practice statement: 2009 update

PURPOSE

We provide current information on the use of PSA testing for the evaluation of men at risk for prostate cancer, and the risks and benefits of early detection.

MATERIALS AND METHODS

The report is a summary of the American Urological Association PSA Best Practice Policy 2009. The summary statement is based on a review of the current professional literature, clinical experience and the expert opinions of a multispecialty panel. It is intended to serve as a resource for physicians, other health care professionals, and patients. It does not establish a fixed set of guidelines, define the legal standard of care or pre-empt physician judgment in individual cases.

RESULTS

There are two notable differences in the current policy. First, the age for obtaining a baseline PSA has been lowered to 40 years. Secondly, the current policy no longer recommends a single, threshold value of PSA, which should prompt prostate biopsy. Rather, the decision to proceed to prostate biopsy should be based primarily on PSA and DRE results, but should take into account multiple factors including free and total PSA, patient age, PSA velocity, PSA density, family history, ethnicity, prior biopsy history and comorbidities.

CONCLUSIONS

Although recently published trials show different results regarding the impact of prostate cancer screening on mortality, both suggest that prostate cancer screening leads to overdetection and overtreatment of some patients. Therefore, men should be informed of the risks and benefits of prostate cancer screening before biopsy and the option of active surveillance in lieu of immediate treatment for certain men diagnosed with prostate cancer.

Non-invasive molecular imaging of prostate cancer lymph node metastasis

Imaging in medicine has been classically based on the anatomical description of organs. In the past 15 years, new imaging techniques based on gene expression that characterize a pathological process have been developed. Molecular imaging is the use of such molecules to image cell-specific characteristics. Here, we review recent advances in molecular imaging, taking as our prime example lymph node (LN) metastasis in prostate cancer. We describe the new techniques and compare their accuracy in detecting LN metastasis in prostate cancer. We also present new molecular strategies for improving tumor detection using adenoviruses, molecular promoters and amplification systems. Finally, we present the concept of 'in vivo pathology', which envisages using molecular imaging to accurately localize metastatic lesions based on the molecular signature of the disease.

A review of high-risk prostate cancer and the role of neo-adjuvant and adjuvant therapies

High-risk, localized prostate cancer represents a complex and diverse disease with many available treatment modalities. Patients are often deemed high risk because they are at increased risk for biochemical failure after primary intervention. However, these "high-risk" men may not be at significant risk of dying from their cancer. In this review, an attempt will be made to better define high-risk patients and help identify men at increased risk for mortality, not simply biochemical failure, after a diagnosis of localized prostate cancer. A review of available monotherapies as well as previously successful multimodality treatments will also be presented. Finally, this review will provide a glimpse into the future direction of high-risk prostate cancer multimodal therapy by providing a synopsis several current randomized clinical trials using effective systemic adjuvant therapies following local treatment.

Laparoscopic pelvic lymph-node dissection in prostate cancer before external beam radiotherapy: Risk factors of nodal involvement and relapse following intended curative treatment

OBJECTIVE

To report experience with laparoscopic pelvic lymph-node dissection (LPLND) in patients with prostate cancer before radiotherapy. Selection of risk factors for nodal involvement (N1) and recurrence following radiotherapy was made.

MATERIAL AND METHODS

From November 1999 to June 2007, 177 patients with prostate cancer underwent LPLND at this department. The lymphadenectomy was limited to the obturator fossa bilaterally. Patients without nodal involvement were offered external beam radiotherapy with adjuvant hormone treatment.

RESULTS

Complications occurred in 17 patients (9%). The majority of these were minor and were managed by conservative methods. Twenty-six patients (15%) were diagnosed with N1. High Gleason score and a high percentage of positive needle core biopsies were both risk factors of N1 as well as recurrent disease following radiotherapy (p<0.01 and 0.01, respectively). Clinically, T3 disease was associated with a risk of recurrence but not N1. High prostate-specific antigen (PSA) nadir was also a significant predictor of recurrence. Neither pretreatment PSA nor prostate volume was associated with N1 or recurrence.

CONCLUSIONS

LPLND is a safe, well-established staging modality in clinically localized prostate cancer before radiotherapy. Risk factors upon diagnosis may be useful in the estimation of N1 and risk of recurrence.

MRI with a lymph-node-specific contrast agent as an alternative to CT scan and lymph-node dissection in patients with prostate cancer: a prospective multicohort study

BACKGROUND

In patients with prostate cancer who are deemed to be at intermediate or high risk of having nodal metastases, invasive diagnostic pelvic lymph-node dissection (PLND) is the gold standard for the detection of nodal disease. However, a new lymph-node-specific MR-contrast agent ferumoxtran-10 can detect metastases in normal-sized nodes (ie, <8 mm in size) by use of MR lymphoangiography (MRL). In this prospective, multicentre cohort study, we aimed to compare the diagnostic accuracy of MRL with up-to-date multidetector CT (MDCT), and test the hypothesis that a negative MRL finding obviates the need for a PLND.

METHODS

We included consecutive patients with prostate cancer who had an intermediate or high risk (risk of >5% according to routinely used nomograms) of having lymph-node metastases. All patients were assessed by MDCT and MRL, and underwent PLND or fine-needle aspiration biopsy. Imaging results were correlated with histopathology. The primary outcomes were sensitivity, specificity, accuracy, NPV, and PPV of MRL and MDCT. This study is registered with ClinicalTrials.gov, number NCT00185029.

FINDINGS

The study was done in 11 hospitals in the Netherlands between April 8, 2003, and April 19, 2005. 375 consecutive patients were included. 61 of 375 (16%) patients had lymph-node metastases. Sensitivity was 34% (21 of 61; 95% CI 23-48) for MDCT and 82% (50 of 61; 70-90) for MRL (McNemar's test p<0.05). Specificity was 97% (303 of 314; 94-98) for MDCT and 93% (291 of 314; 89-95) for MRL. Positive predictive value (PPV) was 66% (21 of 32; 47-81) for MDCT and 69% (50 of 73; 56-79) for MRL. Negative predictive value (NPV) was 88% (303 of 343; 84-91) for MDCT and 96% (291 of 302; 93-98) for MRL (McNemar's test p<0.05). Of the 61 patients with lymph-node metastases, 50 were detected by MRL, of which 40 (80%) had metastases in normal-sized lymph nodes. The high sensitivity and NPV of MRL imply that in patients with a negative MRL, the chance of positive lymph nodes is less than 11/302 (4%).

INTERPRETATION

MRL had significantly higher sensitivity and NPV than MDCT for patients with prostate cancer who had intermediate or high risk of having lymph-node metastases. In such patients, after a negative MRL, the post-test probability of having lymph-node metastases is low enough to omit a PLND.

Detection Rate and Operating Time Required for γ Probe-Guided Sentinel Lymph Node Resection after Injection of Technetium-99m Nanocolloid into the Prostate with and without Preoperative Imaging

OBJECTIVE

To investigate the usefulness of presurgical image fusion of three-dimensional single photon emission computed tomography (SPECT) with computed tomography/magnetic resonance imaging (CT/MRI) for detecting primary prostatic lymphatic landing sites (sentinel lymph nodes [SLNs]) using an intraoperative gamma probe in patients undergoing radical prostatectomy for organ-confined prostate cancer after intraprostatic (99m)Tc-nanocolloid injection.

METHODS

In 15 patients the surgeon was unaware of the preoperative SPECT/CT/MRI fusion imaging results. In 21 patients the surgeon was supported by the preoperative SPECT/CT/MRI images. Selective SLN resection was followed by an extended backup pelvic lymph node dissection (PLND) and radical prostatectomy.

RESULTS

In the group of 15 patients (gamma probe-guided SLN search only) presurgical SPECT/CT/MRI identified 137 SLNs (median of 10/patient; range: 2-19) and a total of 135 SLNs (median of 8/patient; range: 2-20) were detected intraoperatively (detection rate 98.5%). In the group of 21 patients with the surgeon knowing the preoperative SPECT/CT/MRI findings, 189 (median of 9/patient; range: 3-20) of the 190 imaged SLNs (median of 8/patient, range: 2-19) were found intraoperatively (detection rate 99.5%). Median operating time for sentinel lymphadenectomy using gamma probe only was 100 min (range: 40-130) versus 70 min (range: 20-140) for the SPECT/CT/MRI-supported resection (p=0.025). A median of 9 SLNs per patient (range: 2-19) was confirmed histologically.

CONCLUSIONS

Preoperative SPECT/CT/MRI is highly reliable to detect nonmetastatic sentinel nodes of the prostate. The operating time for SPECT/CT/MRI-supported SLN resection is significantly reduced compared to SLN resection guided by gamma probe alone. Both procedures take significantly longer than routine extended PLND.