Incidence of positive pelvic lymph nodes in patients with prostate cancer, a prostate-specific antigen (PSA) level of < or =10 ng/mL and biopsy Gleason score of < or =6, and their influence on PSA progression-free survival after radical prostatectomy

Whole-body magnetic resonance imaging for prostate cancer assessment: Current status and future directions

Over the past decade, updated definitions for the different stages of prostate cancer and risk for distant disease, along with the advent of new therapies, have remarkably changed the management of patients. The two expectations from imaging are accurate staging and appropriate assessment of disease response to therapies. Modern, next-generation imaging (NGI) modalities, including whole-body magnetic resonance imaging (WB-MRI) and nuclear medicine (most often prostate-specific membrane antigen [PSMA] positron emission tomography [PET]/computed tomography [CT]) bring added value to these imaging tasks. WB-MRI has proven its superiority over bone scintigraphy (BS) and CT for the detection of distant metastasis, also providing reliable evaluations of disease response to treatment. Comparison of the effectiveness of WB-MRI and molecular nuclear imaging techniques with regard to indications and the definition of their respective/complementary roles in clinical practice is ongoing. This paper illustrates the evolution of WB-MRI imaging protocols, defines the current state-of-the art, and highlights the latest developments and future challenges. The paper presents and discusses WB-MRI indications in the care pathway of men with prostate cancer in specific key situations: response assessment of metastatic disease, "all in one" cancer staging, and oligometastatic disease.

Combination possibility and deep learning model as clinical decision-aided approach for prostate cancer

This study aims to introduce as proof of concept a combination model for classification of prostate cancer using deep learning approaches. We utilized patients with prostate cancer who underwent surgical treatment representing the various conditions of disease progression. All possible combinations of significant variables from logistic regression and correlation analyses were determined from study data sets. The combination possibility and deep learning model was developed to predict these combinations that represented clinically meaningful patient's subgroups. The observed relative frequencies of different tumor stages and Gleason score Gls changes from biopsy to prostatectomy were available for each group. Deep learning models and seven machine learning approaches were compared for the classification performance of Gleason score changes and pT2 stage. Deep models achieved the highest F1 scores by pT2 tumors (0.849) and Gls change (0.574). Combination possibility and deep learning model is a useful decision-aided tool for prostate cancer and to group patients with prostate cancer into clinically meaningful groups.

Current controversies on the role of lymphadenectomy for prostate cancer

Lymph node dissection is part of the standard treatment protocol for various cancers, but its role in prostate cancer has been debatable for some time. Pelvic lymphadenectomy has been shown to better help stage prostate cancer patients, but has yet to be definitively proven to be of any benefit for survival. Various templates for lymph node dissections exist, and though some national guidelines have endorsed an extended pelvic node dissection, the choice of template is still controversial. Pelvic lymphadenectomy may lead to a slightly higher rate complications and operative time, and their use must be judiciously applied to patients with a high enough risk of lymph node involvement. We present a comprehensive review of the literature regarding the benefits and harms of lymph node dissection in prostate cancer.

Sentinel node evaluation in prostate cancer

Sentinel lymph node (SLN) based pelvic lymph node dissection (PLND) in prostate cancer (PCa) is appealing over the time, cost and morbidity classically attributed to conventional PLND during radical prostatectomy. The initial report of feasibility of the SLN concept in prostate cancer was nearly 20 years ago. However, PLND based on the SLN concept, either SLN biopsy of a single node or targeted SLN dissection of multiple nodes, is still considered investigational in PCa. To better appreciate the challenges, and potential solutions, associated with SLN-based PLND in PCa, this review will discuss the rationale behind PLND in PCa and evaluate current SLN efforts in the most commonly diagnosed malignancy in men in the US.

Blinded review of archival radical prostatectomy specimens supports that contemporary Gleason score 6 prostate cancer lacks metastatic potential

BACKGROUND

Retrospective identification of Gleason pattern 4 in metastatic Gleason score 3 + 3 = 6 (GS6) radical prostatectomy (RP) specimens has suggested true GS6 prostate cancer (CaP) lacks metastatic potential. However, pathologist awareness of study design and metastasis outcomes at the time of RP review might have introduced upgrading bias. We used pathologist-blinded methodology for unbiased characterization of metastasis rates for contemporarily defined pathologic GS6 (pGS6) CaP.

METHODS

An institutional RP database was queried to identify pGS6 patients with metastasis or concern for micrometastasis based on: 1) biochemical failure (BF) despite negative surgical margins or 2) incomplete biochemical response to salvage/adjuvant radiation. RP specimens were regraded independently by two genitourinary pathologists blinded to study aims or clinical outcomes. Additional blinding was performed by random inclusion of pGS6 control specimens from BF-free patients. Only upgrading identified independently by both pathologists was considered.

RESULTS

Among 451 pGS6 patients identified, none had synchronous lymph node metastases and 43/451 (10%) suffered BF. Two patients (0.4%) developed metachronous metastasis during a 110-month median follow-up for BF patients. Both metastatic cases had Gleason pattern 4 on blinded RP review, as did 88% of cases with concern for micrometastasis versus 38% of control cases (P = 0.02). All BF patients (29/29) undergoing postoperative radiation had a complete biochemical response or Gleason pattern 4 on blinded RP review.

CONCLUSIONS

Unbiased pathologist review of archival RP specimens supports absent metastatic potential for contemporarily defined GS6 CaP. Reduced postoperative monitoring is appropriate for pGS6, but may require pathology review to confirm absent Gleason pattern 4.

Predictive efficacy of the 2014 International Society of Urological Pathology Gleason grading system in initially diagnosed metastatic prostate cancer

We compared the predictive ability of the 2014 and 2005 Gleason grading systems in 568 patients initially diagnosed with metastatic prostate cancer (PCa). Outcomes included the duration of castration-resistant prostate cancer-free survival (CFS) and overall survival (OS). Univariate analyses and log-rank tests were used to identify prognosis indicators and assess univariable differences in CFS and OS in Gleason score (GS) groups. Cox proportional hazards and area under the curves of receiver operator characteristics methods were used to evaluate the predictive efficacy of the 2005 and 2014 ISUP grading systems. Univariate analyses showed that the 2005 and 2014 grading systems were prognosticators for CFS and OS; both systems could distinguish the clinical outcome of patients with GS 6, GS 7, and GS 8–10. Using the 2014 criteria, no statistical differences in patient survival were observed between GS 3 + 4 and GS 4 + 3 or GS 8 and GS 9–10. The predictive ability of the 2014 and 2005 grading systems was comparable for CFS and OS (P = 0.321). However, the 2014 grading system did not exhibit superior predictive efficacy in patients initially diagnosed with PCa and bone metastasis; trials using larger cohorts are required to confirm its predictive value. To the best of our knowledge, ours is the first study to compare the 2005 and 2014 grading systems in initially diagnosed PCa with bone metastasis. At present, we recommend that both systems should be used to predict the prognosis of patients with metastatic PCa.

Pelvic lymph node dissection in prostate cancer: indications, extent and tailored approaches

PURPOSE

The purpose of this study is to review the current literature concerning the indication of pelvic lymph node dissection (PLND), its extent and complications in prostate cancer (PCa) staging, the available tools, and the future perspectives to assess the risk of lymph node invasion (LNI).

METHODS

A literature review was performed using the Medline, Embase, and Web of Science databases. The search strategy included the terms pelvic lymph nodes, PLND, radical prostatectomy, prostate cancer, lymph node invasion, biochemical recurrence, staging, sentinel lymph node dissection, imaging, and molecular markers.

RESULTS

PLND currently represents the gold standard for nodal staging in PCa patients. Available imaging techniques are characterized by poor accuracy in the prediction of LNI before surgery. On the contrary, an extended PLND (ePLND) would result into proper staging in the majority of the cases. Several models based on preoperative disease characteristics are available to assess the risk of LNI. Although ePLND is not associated with a substantial risk of severe complications, up to 10% of the men undergoing this procedure experience lymphoceles. Concerns over potential morbidity of ePLND led many authors to investigate the role of sentinel lymph node dissection in order to prevent unnecessary ePLND. Finally, the incorporation of novel biomarkers in currently available tools would improve our ability to identify men who should receive an ePLND.

CONCLUSIONS

Nowadays, the most informative tools predicting LNI in PCa patients consist in preoperative clinical nomograms. Sentinel lymph node dissection still remains experimental and novel biomarkers are needed to identify patients at a higher risk of LNI.

The role of extended pelvic lymphadenectomy with radical prostatectomy for high-risk prostate cancer

INTRODUCTION

The role of pelvic lymph node dissection (PLND) during radical prostatectomy (RP) for prostate cancer (PCa) is controversial. Despite extensive research in both patterns of lymphatic drainage and the clinical effect of lymph node involvement, the exact role of PLND in PCa is yet to be defined.

METHODS

A systematic search of the MEDLINE database was performed, and all relevant articles were reviewed in depth.

RESULTS

We included 84 relevant articles in our review and subdivided the information into the following categories: preoperative patient evaluation, procedure/extent of dissection, complications, and robotic surgery era. Most authors agree that the greatest benefit is seen in patients with high-risk PCa undergoing RP. Multiple imaging modalities have been evaluated for assistance in patient selection, but the use of preoperative nomograms appears to be the most helpful selection tool. The role of limited PLND vs. extended PLND (e-PLND) is yet to be defined, though many authors agree that e-PLND is preferred in the setting of high-risk PCa. Although PLND is associated with a higher incidence of complications, especially lymphocele formation, it is unclear whether e-PLND leads to more complications than limited PLND. The introduction of minimally invasive surgery may have had a negative effect on implementation of PLND in the appropriate patients undergoing RP.

CONCLUSION

Despite a lack of prospective, randomized trials evaluating PLND in RP, there does appear to be a consistent benefit in patients with high-risk disease.

Clinical Outcome of Patients with Lymph Node-Positive Prostate Cancer following Radical Prostatectomy and Extended Sentinel Lymph Node Dissection

Objective: This study sought to evaluate the clinical outcome after extended sentinel lymph node dissection (eSLND) and radical retropubic prostatectomy (RRP) in patients with clinically localized prostate cancer (PCa). Subjects and Methods: From August 2002 until February 2011, a total of 819 patients with clinically localized PCa, confirmed by biopsy, were treated with RRP plus eSLND. Biochemical recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were assessed with Kaplan-Meier curves. Various histopathological parameters were analyzed by univariate and multivariate analysis. Results: The mean follow-up was 5.3 years. Lymph node (LN) metastases occurred in 140 patients. We removed an average of 10.9 LNs via eSLND from patients with pN1 PCa. Postoperatively, 121 pN1 patients temporarily received adjuvant androgen deprivation therapy. The mean survival periods for RFS, RFS after secondary treatment, CSS, and OS were 4.7, 7.0, 8.8, and 8.1 years, respectively. The cancer-specific death rate of the 140 pN1 patients was 13.6%. RFS, CSS, and OS were significantly correlated with pathological margin status, LN density, the total diameter of evident metastases, and membership in the subgroup ‘micrometastases only'. Conclusion: Despite the presence of LN metastases, patients with a low nodal tumor burden demonstrate a remarkable clinical outcome after undergoing eSLND and RRP, thus suggesting a potential curative therapeutic approach.

CtBP2 could promote prostate cancer cell proliferation through c-Myc signaling

C-terminal binding protein-2 (CtBP2) is a CtBP-family member which plays a significant role in tumor initiation, progression and response to therapy. However, little has been known about the potential oncobiological role of CtBP2 and its mechanism in human prostate cancer. In this study, we observed the overexpression of CtBP2 in prostate cancer and demonstrated that its expression was closely correlated with several malignant behaviors, e.g., increased serum PSA level, advanced tumor stage (T3), higher Gleason scores and poor outcome. Furthermore, downregulation of CtBP2 expression in prostate cancer PC3 cells could markedly inhibit their proliferation by inducing apoptosis in vitro. Additionally, CtBP2 inhibition could decrease the level of c-Myc and its direct transcriptional target, HSPC111. Taken together, our investigations demonstrated that low-expression of CtBP2 could highly inhibit proliferation of prostate cancer by c-Myc induced signaling, suggesting that targeting CtBP2 may yield a viable anti-tumor strategy by restraining tumor progression in prostate cancer.

A systematic review and meta-analysis of comparative studies on the efficacy of extended pelvic lymph node dissection in patients with clinically localized prostatic carcinoma

PURPOSE

Pelvic lymph node dissection (PLND) has been performed during radical prostatectomy in nearly all patients with clinically localized prostatic carcinoma (PCa), while the specific regions that needed to be removed demonstrated bifurcation among urologist. However, clinical studies comparing extended PLND (ePLND) with standard PLND (sPLND) and limited PLND (lPLND) reveal conflicting, or even opposing results.

METHODS

All controlled trials comparing ePLND with sPLND or lPLND were identified through comprehensive searches of the PubMed, Cochrane Library and Embase databases. A systematic review and meta-analysis of these studies were then performed.

RESULTS

Eighteen studies with a total of 8,914 patients were included. Regardless of being compared with sPLND or lPLND, ePLND significantly improved LN retrieval [ePLND vs. sPLND: weighted mean difference (WMD) 11.93, 95 % confidence interval (CI) 9.91-13.95, p < 0.00001; ePLND vs. lPLND: WMD 8.27, 95 % CI 3.53-13.01, p = 0.0006] and the detection of more LNs positive of metastasis [risk ratio (RR) 3.51, 95 % CI 2.14-5.75, p < 0.00001; RR 3.50, 95 % CI 2.20-5.55, p < 0.00001, respectively]. EPLND decreased the complication rate, but the differences were not statistically significant (RR 1.52, 95 % CI 0.87-2.65, p = 0.14; RR 1.52, 95 % CI 0.67-3.45, p = 0.32, respectively). Operating time, estimated blood loss, length of hospital stay and biochemical recurrence (BCR) were statistically insignificant between techniques.

CONCLUSIONS

ePLND shows benefits associated with increased LNs yield, LNs positivity, and safety, significantly with no risk of side effects. However, ePLND did not decrease BCR. Additional high-quality, well-designed randomized controlled trials and comparative studies with long-term follow-up results are required to define the optimal procedure for patients with clinically localized PCa.

Clinical experience with limited lymph node dissection for prostate cancer in Korea: single center comparison of 247 open and 354 robot-assisted laparoscopic radical prostatectomy series

PURPOSE

There are limited data on the role of limited pelvic lymph node dissection (PLND) in patients with prostate cancer in Korea. The objective of this study was to demonstrate our clinical experience with limited PLND and the difference in its yield between open retropubic radical prostatectomy (RRP) and robot-assisted laparoscopic radical prostatectomy (RALP) for prostate cancer patients in Korea.

MATERIALS AND METHODS

We retrospectively analyzed 601 consecutive patients undergoing radical prostatectomy and bilateral limited PLND by either RRP (n=247) or RALP (n=354) in Asan Medical Center. All patients were divided into three groups according to the D'Amico's risk stratification method. Clinicopathologic data, including the yield of lymph nodes, were thoroughly reviewed and compared among the three risk groups or between the RRP and RALP subjects.

RESULTS

The mean patient age was 64.9 years and the mean preoperative prostate-specific antigen was 9.8 ng/ml. The median number of removed lymph nodes per patient was 5 (range, 0 to 20). The numbers of patients of each risk group were 167, 199, and 238, and the numbers of patients with tumor-positive lymph nodes were 1 (0.6%), 4 (2.0%), and 17 (7.1%) in the low-, intermediate-, and high-risk groups, respectively. In the high-risk group, the lymph node-positive ratio was higher in RRP (14.9%) than in RALP subjects (2.4%).

CONCLUSIONS

We speculate that limited PLND may help in prostate cancer staging in intermediate- and high-risk prostate cancer groups. RRP is a more effective surgical modality for PLND than is RALP, especially in high-risk prostate cancer groups.

Do adenocarcinomas of the prostate with Gleason score (GS) ≤6 have the potential to metastasize to lymph nodes?

Although rare, there are cases within reported series of men with Gleason score (GS) ≤6 on radical prostatectomies that show pelvic lymph node (LN) metastases. However, there are no studies on whether pelvic LN metastases occur in tumors with GS ≤6 using the International Society of Urological Pathology (ISUP) updated GS system. We performed a search of the radical prostatectomy databases at 4 large academic centers for cases of GS ≤6. Only prostatectomies submitted and embedded in entirety with pelvic LN dissections were included. A combined total of 14,123 cases were identified, of which 22 cases had a positive LN. Histopathologic review of 19 cases (3 cases unavailable for review) showed higher grade than originally reported by the pathologists in all cases. Of the 17 pre-ISUP reviewed cases, 2 were upgraded to 4+3=7 with both cribriform and poorly formed glands. One case was upgraded to 4+3=7 with tertiary pattern 5 displaying cribriform glands, poorly formed glands, and cords of single cells. Eleven cases were upgraded to 3+4=7 with glomeruloid structures and small to large cribriform glands (1 of these also had features of ductal adenocarcinoma). Two cases had tertiary pattern 4 with small cribriform glands. One case had a prominent colloid component that would currently be graded as 4+5=9 because of large cribriform glands and solid sheets of cells within the mucin. Of the 2 post-ISUP cases, 1 demonstrated tertiary pattern 4, and the other showed GS 3+4=7 with irregular cribriform glands. Undergrading is the primary reason for LN positivity with GS ≤6, which has decreased significantly since the adoption of the ISUP grading system in 2005. Of over 14,000 totally embedded radical prostatectomies from multiple institutions, there was not a single case of a GS ≤6 tumor with LN metastases. In contrast to prevailing assumptions, GS ≤6 tumors do not appear to metastasize to LNs. Rather, Gleason pattern 4 or 5, as better defined by the current ISUP updated grading system, is required for metastatic disease.

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.

Role of lymphadenectomy for prostate cancer: indications and controversies

Pelvic lymph node dissection is the only reliable technique to detect low-volume lymph node involvement in prostate cancer. Extended lymph node dissections that include the internal iliac chain in addition to the external iliac and obturator packets have shown a significantly higher proportion of patients to have lymphatic involvement than previously recognized. The improved staging afforded by a more extended dissection raises several questions. Addressing these questions is the focus of this review.

The Role of C-Choline-PET/CT-Guided Secondary Lymphadenectomy in Patients with PSA Failure after Radical Prostatectomy: Lessons Learned from Eight Cases

Introduction. ¹¹C-choline-PET/CT is a promising technique for detection/restaging of patients with biochemical failure (BF) after curative therapy for prostate cancer (PCA). The aim of this paper was to evaluate the PSA response in patients with BF after radical prostatectomy (RP) who underwent secondary lymphadenectomy (LAD) due to ¹¹C-choline-PET/CT findings. Material and Methods. Eight patients with BF and positive lymph nodes in ¹¹C-choline-PET/CT after RP were retrospectively included in the study. Extended LAD until the common iliac arteries was performed in all patients. Results. Six of 8 patients had histologically proven lymph node metastases. Four patients showed an initial PSA reduction after LAD, and in 4 patients the PSA increased. Two of the latter had no histological lymph node metastases. Conclusions. Because 50% of our patients showed an initial PSA response, our data suggest that positive ¹¹C-choline-PET/CT after RP and BF could help to select patients that could benefit from secondary LAD.

Guideline for optimization of surgical and pathological quality performance for radical prostatectomy in prostate cancer management: evidentiary base

BACKGROUND

The objective is to provide surgical and pathological guidelines for radical prostatectomy (RP) with or without concurrent pelvic lymph node dissection (PLND) to achieve optimal benefit for patients, with minimal risk of harm.

METHODS

For surgical questions, a literature search of MEDLINE, EMBASE and the Cochrane database was performed. A literature search for the pathological questions was not conducted since the protocol for invasive carcinomas of the prostate gland developed by the College of American Pathologists (CAP) was endorsed. Urologists and pathologists were consulted for their assessment of the surgical and pathological recommendations.

RESULTS

Limited high-quality evidence from 95 primary studies was available and, therefore, the expert panel developed recommendations on the basis of a consensus of the expert opinion of the working group and through a consultation with urologists and pathologists. In addition to the CAP protocol, some technical recommendations related to the handling and processing of the specimen were made.

CONCLUSION

Radical prostatectomy is recommended for the surgical treatment of prostate cancer, depending on a patient's preoperative risk profile. The panel unanimously determined that the goals for RP are to attain a positive margin rate of <25% for pT2 disease, a mortality rate of <1%, rates of rectal injury of <1% and blood transfusion rates of <10% in non-anemic patients. Standard PLND should be mandatory in high-risk patients, should be recommended for intermediate-risk patients and should be optional for low-risk patients. The quality and effectiveness of this treatment and of subsequent patient care depend on good management, effective communication and reporting between surgeons and pathologists working together as part of a multidisciplinary team. The complete guideline document is posted on the Cancer Care Ontario website (www.cancercare.on.ca); search in their Toolbox, Quality Guidelines & Standards, Clinical Program category under "surgery."

Pelvic nodal radiotherapy in patients with unfavorable intermediate and high-risk prostate cancer: evidence, rationale, and future directions

Over the past 15 years, there have been three major advances in the use of external beam radiotherapy in the management of men with clinically localized prostate made. They include: (1) image guided (IG) three-dimensional conformal/intensity modulated radiotherapy; (2) radiation dose escalation; and (3) androgen deprivation therapy. To date only the last of these three advances have been shown to improve overall survival. The presence of occult pelvic nodal involvement could explain the failure of increased conformality and dose escalation to prolong survival, because the men who appear to be at the greatest risk of death from clinically localized prostate cancer are those who are likely to have lymph node metastases. This review discusses the evidence for prophylactic pelvic nodal radiotherapy, including the key trials and controversies surrounding this issue.

Sentinel node mapping in the prostate cancer

Aim: Sentinel node (SN) biopsy is becoming a standard procedure in the management of several malignancies. Several groups have evaluated the feasibility and value of this procedure in prostate cancer patients. In the current meta-analysis, we comprehensively and quantitatively summarized the results of these studies. Methods: Several databases including Medline, SCOPUS, Google Scholar, Ovid, Springer, and Science direct were systematically searched for the relevant studies regarding SL biopsy in the prostate cancer (“prostate” AND “sentinel” as search keywords). The outcomes of interest were sensitivity and detection rate of the procedure. Results: For detection rate and sensitivity 21 and 16 studies met the criteria of inclusion respectively. Pooled detection rate was 93.8% (95% CI 89–96.6%). Cochrane Q value was 216.077 (I2 = 89.81% and p < 0.001). Pooled sensitivity was 94% (95% CI 91–96%). Cochrane Q value was 14.12 (I2 = 0.0 and p = 0.516). Conclusion: SL biopsy can prevent unnecessary pelvic lymph node dissection in prostate cancer patients. This procedure is feasible with low false negative rate and high detection rate.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.

Predicting biochemical recurrence-free survival for patients with positive pelvic lymph nodes at radical prostatectomy

PURPOSE

We evaluated predictors of freedom from biochemical recurrence in patients with pelvic lymph node metastasis at radical prostatectomy.

MATERIALS AND METHODS

Of 207 patients with lymph node metastasis treated with radical prostatectomy and bilateral pelvic lymph node dissection 45 received adjuvant androgen deprivation therapy and 162 did not. Cox proportional hazards regression models were used to investigate predictors of biochemical recurrence after radical prostatectomy. Recurrence probability was estimated using the Kaplan-Meier method.

RESULTS

A median of 13 lymph nodes were removed. Of the patients 122 had 1, 44 had 2 and 41 had 3 or greater positive lymph nodes. Of patients without androgen deprivation therapy 103 had 1, 35 had 2 and 24 had 3 or greater positive lymph nodes while 69 experienced biochemical recurrence. Median time to recurrence in patients with 1, 2 and 3 or greater lymph nodes was 59, 13 and 3 months, respectively. Only specimen Gleason score and the number of positive lymph nodes were independent predictors of biochemical recurrence. Recurrence-free probability 2 years after prostatectomy in men without androgen deprivation with 1 positive lymph node and a prostatectomy Gleason score of 7 or less was 79% vs 29% in those with Gleason score 8 or greater and 2 or more positive lymph nodes.

CONCLUSIONS

Prognosis in patients with lymph node metastasis depends on the number of positive lymph nodes and primary tumor Gleason grade. Of all patients with lymph node metastasis 80% had 1 or 2 positive nodes. A large subset of those patients had a favorable prognosis. Full bilateral pelvic lymph node dissection should be done in patients with intermediate and high risk cancer to identify those likely to benefit from metastatic node removal.

Anti-metastatic effects of liposomal gemcitabine in a human orthotopic LNCaP prostate cancer xenograft model

Fatal outcomes of prostate carcinoma (PCa) mostly result from metastatic spread rather than from primary tumor burden. Here, we monitored growth and metastatic spread of an orthotopic luciferase/GFP-expressing LNCaP PCa xenograft model in SCID mice by in vivo imaging and in vitro luciferase assay of tissues homogenates. Although the metastatic spread generally shows a significant correlation to primary tumor volumes, the susceptibility of various tissues to metastatic invasion was different in the number of affected animals as well as in absolute metastatic burden in the individual tissues. Using this xenograft model we showed that treatment with liposomal gemcitabine (GemLip) inhibited growth of the primary tumors (83.9 +/- 6.4%; P = 0.009) as well as metastatic burden in lymph nodes (95.6 +/- 24.0%; P = 0.047), lung (86.5 +/- 10.5%; P = 0.015), kidney (88.4 +/- 9.2%; P = 0.045) and stomach (79.5 +/- 6.6%; P = 0.036) already at very low efficient concentrations (8 mg/kg) as compared to conventional gemcitabine (360 mg/kg). Our data show that this orthotopic LNCaP xenograft PCa model seems to reflect the clinical situation characterized by the fact that at time of diagnosis, prostate neoplasms are biologically heterogeneous and thus, it is a useful model to investigate new anti-metastatic therapies.

Cytology of metastatic prostate cancer following orchiectomy and antiandrogen therapy: a diagnostic challenge

Androgen deprivation therapy induces apoptosis and decreases both cell proliferation and angiogenesis in prostate adenocarcinoma. The molecular alterations following androgen ablation translate into unique cytologic features in both primary and metastatic prostate adenocarcinoma. We describe the cytologic appearance of metastatic prostate carcinoma following both surgical castration and androgen deprivation therapy.

Laparoscopic Extended Pelvic Lymph Node Dissection for Prostate Cancer: Description of the Surgical Technique and Initial Results

OBJECTIVE

In patients with prostate cancer, extended pelvic lymph node dissection (ePLND) yields a higher number of lymph node metastases (LNM) than standard pelvic lymph node dissection (PLND) of the obturator fossa only. We describe our laparoscopic technique of extended lymph node dissection and provide the number and locations of positive lymph nodes from our experience.

METHODS

In a total of 35 selected patients with clinically localized prostate cancer, laparoscopic ePLND was performed prior to laparoscopic radical prostatectomy. The template included the genitofemoral nerve up to the bifurcation of the common iliac artery and down to the epigastric artery. In the "split and roll" technique the internal and external iliac arteries including the bifurcation and the external iliac vein were completely mobilized. After freeing the obturator nerve, the entire lymph node package was released from the pelvic side wall.

RESULTS

Mean operative time was 90min/patient. The complications were two temporary and reversible neurapraxias (ischiatic nerve and obturator nerve), one deep vein thrombosis, and two lymphoceles. One lymphocele healed conservatively; the second was marsupialized laparoscopically. Eleven (31.4%) patients had lymph node metastases; their mean prostate-specific antigen (PSA) level was 20.3+/-7.0 ng/ml (range: 5.2-39.7 ng/ml) and their median Gleason sum in biopsy was 7 (range: 6-8). Mean size of the LNM was 3.1+/-1.0 mm (range: 0.2-8). In 5 of the 11 patients with LNM these were detected exclusively outside the obturator fossa. LNM were in the obturator fossa only in two (one bilateral), around the external iliac artery only in two, around the internal iliac artery only in two, and around the external iliac artery and internal iliac only in one patient.

CONCLUSIONS

Laparoscopic ePLND can be combined with laparoscopic radical prostatectomy. Standardization of the technique facilitates surgery to a great extent. e-PLND detects LNM in a significant number of patients. The majority of LNM are outside the obturator fossa. The transperitoneal approach allows a wide exposure and is the most important factor to enable successful ePLND.

Evaluation of [(18)F]-choline PET/CT for staging and restaging of prostate cancer

PURPOSE

To evaluate the accuracy of [(18)F]-choline (FCH) positron emission tomography/computed tomography (PET/CT) for staging and restaging of prostate cancer.

METHODS

FCH PET/CT was performed in 111 patients with prostate cancer using 200 MBq FCH: 43 patients [mean age 63 years; mean prostrate specific antigen (PSA) 11.58 microg/l] were examined for initial staging, and 68 patients (mean age 66.4 years) were examined for restaging (mean PSA 10.81 microg/l). FCH PET/CT results were correlated to histopathology, bone scan, morphology as revealed by magnetic resonance imaging (MRI) and CT, PET/CT follow-up and PSA follow-up after therapy.

RESULTS

FCH PET/CT scans at initial staging correctly showed no metastases in 36/38 patients undergoing radical surgery, as confirmed by PSA levels <0.1 microg/l 6 months postoperatively. Lymphadenectomy was performed in 24 of these patients, revealing four false FCH-negative lymph nodes (LN). In one patient, only lymphadenectomy was performed since a FCH-positive LN was confirmed by histology. Four patients showed FCH-positive bone metastases, as proven by bone scan. FCH PET/CT scans at restaging correctly revealed local recurrence in 36 patients. No pathological FCH uptake was observed in 11 patients with biochemical recurrence. Twenty-three patients showed FCH-positive LN. Twenty LN were surgically removed in seven patients. Histopathology verified metastases in all LN, but revealed two additional metastastic, FCH-negative LN. Seventeen patients showed FCH-positive bone metastases, as proven by bone scan or MRI. Sensitivity to detect recurrent disease was 86%.

CONCLUSION

The results obtained using FCH PET/CT scans for initial N-staging were discouraging, especially in terms of its inability to detect small metastases. Recurrent disease can be localized reliably in patients with PSA levels of >2 microg/l.

Radioguided sentinel lymph node dissection in patients with localised prostate carcinoma: influence of the dose of radiolabelled colloid to avoid failure of the procedure

INTRODUCTION

The purpose of this study was to determine the role of the injected dose of tracer in the non-detection of pelvic sentinel lymph nodes (SLN) in patients with prostate carcinoma.

METHODS

Data were evaluated from 100 patients (age range 43-77, mean 63 years). The first 72 patients (group 1) received 2 x 0.3 ml of 30 MBq-nanocolloid-99 mTc and the remaining 28 patients (group 2) received 2 x 0.3 ml of 100 MBq. Surgery consisted of the detection and dissection of lymph nodes identified as sentinel nodes, followed by an extended lymphadenectomy.

RESULTS

SLNs were located in the interiliac group in 54.2% of patients, in the obturator fossa in 30.7%, in the external iliac group in 10.9% and in the common iliac group in 4.2% of cases. Lymph node involvement was observed in 12% of patients. But there was a 30.6% (22/72) failure rate of the SLN procedure in group 1 and 7.1% (2/28) in group 2. An increased risk of unsuccessful SLN procedure was statistically associated with the low dose of MBq-nanocolloids (p < 0.017). Statistical correlation is also found after the exclusion of the first 30 patients from the study (learning phase of the team) (p < 0.034). None of the other parameters showed a statistical association (age, p < 0.9; Gleason score, p < 0.3; grade pT, p < 0.7). A higher grade or a greater extension of cancer inside the prostate are not responsible for the failure of the SLN procedure.

CONCLUSION

It seems necessary to inject at least 200 MBq inside the prostate to avoid a failed SLN procedure.

Evidence-based radiation oncology: Definitive, adjuvant and salvage radiotherapy for non-metastatic prostate cancer

The standard treatment options based on the risk category (stage, Gleason score, PSA) for localized prostate cancer include surgery, radiotherapy and watchful waiting. The literature does not provide clear-cut evidence for the superiority of surgery over radiotherapy, whereas both approaches differ in their side effects. The definitive external beam irradiation is frequently employed in stage T1b-T1c, T2 and T3 tumors. There is a pretty strong evidence that intermediate- and high-risk patients benefit from dose escalation. The latter requires reduction of the irradiated normal tissue (using 3-dimensional conformal approach, intensity modulated radiotherapy, image-guided radiotherapy, etc.). Recent data suggest that prostate cancer may benefit from hypofractionation due to relatively low alpha/beta ratio; these findings warrant confirmation though. The role of whole pelvis irradiation is still controversial. Numerous randomized trials demonstrated a clinical benefit in terms of biochemical control, local and distant control, and overall survival from the addition of androgen suppression to external beam radiotherapy in intermediate- and high-risk patients. These studies typically included locally advanced (T3-T4) and poor-prognosis (Gleason score >7 and/or PSA >20 ng/mL) tumors and employed neoadjuvant/concomitant/adjuvant androgen suppression rather than only adjuvant setting. The ongoing trials will hopefully further define the role of endocrine treatment in more favorable risk patients and in the setting of the dose escalated radiotherapy. Brachytherapy (BRT) with permanent implants may be offered to low-risk patients (cT1-T2a, Gleason score <7, or 3+4, PSA <or=10 ng/mL), with prostate volume of <or=50 ml, no previous transurethral prostate resection and a good urinary function. Some recent data suggest a benefit from combining external beam irradiation and BRT for intermediate-risk patients. EBRT after radical prostatectomy improves disease-free survival and biochemical and local control rates in patients with positive surgical margins or pT3 tumors. Salvage radiotherapy may be considered at the time of biochemical failure in previously non-irradiated patients.

Anatomical Extent of Pelvic Lymphadenectomy in Patients Undergoing Radical Prostatectomy

OBJECTIVES

The rationale for locoregional staging lymphadenectomy in prostate cancer (pCA) lies in the accurate diagnosis of occult micrometastases to stratify patients who might benefit from adjuvant therapeutic measures. In pCA, the issues of the necessity and the therapeutic advantage of pelvic lymphadenectomy (PLND]) in patients with low-, intermediate-, and high-risk disease are still discussed controversially. The aim of this review manuscript is to critically evaluate the current status on PLND in pCA.

METHODS

A review of the literature was performed concerning radical prostatectomy and PLND with respect to anatomical extent, oncological outcome, and associated complications.

RESULTS

The anatomical lymphatic drainage of the prostate includes the obturator fossa, and the external and internal iliac arteries; therefore, at least these areas should be included in PLND. According to the current clinical studies, extended PLND (ePLND) significantly increases the yield of both total lymph nodes and lymph node metastases independent of the risk classification of pCA. Lymph node metastases will be detected in about 5-6%, 20-25%, and 30-40% of low-, intermediate-, and high-risk pCA, respectively. Exclusively 25% of all positive lymph nodes are located in the area around the internal iliac artery. With regard to progression-free and cancer-specific survival, retrospective analysis of the SEER data and additional case-control studies indicate a direct positive relationship between the number of removed lymph nodes and long-term oncological outcome in patients with limited lymph node involvement or negative lymph nodes. In these patients, cancer-specific survival is improved by about 15-20%. On the basis of results of large case-control studies, complication rates of ePLND are not significantly increased.

CONCLUSIONS

On the basis of current data, the following conclusions can be drawn: (1) If performed, PLND has to be done in the extended, anatomically adequate variant. (2) The frequency of lymph node metastases in low-risk pCA is low, and the issue of PLND has to be discussed with the patient. (3) If radical prostatectomy is performed in intermediate- and high-risk pCA, an ePLND should be option of choice. For the future, ongoing prospective trials have to demonstrate a benefit in terms of biochemical-free and cancer-specific survival.

[Incidence of pelvic lymph node metastasis in radical prostatectomy]

BACKGROUND/AIM

Radical prostatectomy (RP) provides the best cancer control in patients with clinically prostate gland confined cancer. Multiple models and nomograms combining preoperative prostate-specific antigen (PSA) serum level, clinical stage and Gleason score have been developed to predict the probability of metastatic disease. In prostate cancer (PC) the presence of metastases to the pelvic lymph nodes (PLNs) is recognized widely as an unfavorable prognostic factor. Currently, PLNs dissection is not done in a low-risk group of prostate cancer patients. The aim of this study was to analyze PLN metastases in PC patients, in clinically localized stages of PC.

METHODS

Radical prostatectomy specimens with pelvic lymphadenectomy specimens from 82 PC patients were reviewed. In this group of patients, serum preoperative PSA values ranged from 2 to 23 ng/ml.

RESULTS

We diagnosed 11/82 (13.4%) patients with PLN metastases. There were 8 (72%) patients with pT3c pathological stage, and 3 (28%) patients with pT4a stage. PSA below 4 ng/ml was detected in 2/5 (40%) patients with PLN metastases. There was no statistically significant difference between preoperative PSA values and postoperative T stage, and PLN metastases. A statistically significant correlation between PLN metastases and the stage was found in the patients with pT4 and the patients with pT3c PC stages (p < 0.05).

CONCLUSION

Recent RP series indicate PLN metastases to be less than 10%. We demonstrated higher detection of PLN metastases (13.4%) in our RP series. Our results suggest that PLNs dissection should be performed even in patients with low-risk PC.