NeuroSAFE robot-assisted laparoscopic prostatectomy versus standard robot-assisted laparoscopic prostatectomy for men with localised prostate cancer (NeuroSAFE PROOF): protocol for a randomised controlled feasibility study

INTRODUCTION

Robot-assisted laparoscopic prostatectomy (RALP) offers potential cure for localised prostate cancer but is associated with considerable toxicity. Potency and urinary continence are improved when the neurovascular bundles (NVBs) are spared during a nerve spare (NS) RALP. There is reluctance, however, to perform NS RALP when there are concerns that the cancer extends beyond the capsule of the prostate into the NVB, as NS RALP in this instance increases the risk of a positive surgical margin (PSM). The NeuroSAFE technique involves intraoperative fresh-frozen section analysis of the posterolateral aspect of the prostate margin to assess whether cancer extends beyond the capsule. There is evidence from large observational studies that functional outcomes can be improved and PSM rates reduced when the NeuroSAFE technique is used during RALP. To date, however, there has been no randomised controlled trial (RCT) to substantiate this finding. The NeuroSAFE PROOF feasibility study is designed to assess whether it is feasible to randomise men to NeuroSAFE RALP versus a control arm of 'standard of practice' RALP.

METHODS

NeuroSAFE PROOF feasibility study will be a multicentre, single-blinded RCT with patients randomised 1:1 to either NeuroSAFE RALP (intervention) or standard RALP (control). Treatment allocation will occur after trial entry and consent. The primary outcome will be assessed as the successful accrual of 50 men at three sites over 15 months. Secondary outcomes will be used to aid subsequent power calculations for the definitive full-scale RCT and will include rates of NS; PSM; biochemical recurrence; adjuvant treatments; and patient-reported functional outcomes on potency, continence and quality of life.

ETHICS AND DISSEMINATION

NeuroSAFE PROOF has ethical approval (Regional Ethics Committee reference 17/LO/1978). NeuroSAFE PROOF is supported by National Institute for Healthcare Research Research for Patient Benefit funding (NIHR reference PB-PG-1216-20013). Findings will be made available through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03317990.

A case of benign vesica melanosis – four-year follow-up

Benign vesica melanosis (BVM) is a rare condition with only 15 reported cases in the literature (Table 1). There is limited understanding of its aetiology. Here we present a four-year follow-up of a case of BVM in a 53-year-old Caucasian male presenting with lower urinary tract symptoms.

Retroperitoneal anomalies in men with testicular germ cell tumours

OBJECTIVES

To assess whether vascular and other retroperitoneal anomalies are more frequent during retroperitoneal lymph node dissection (RPLND) for metastatic testicular tumours (when retroperitoneal masses persist after chemotherapy) than would be expected, based on the initial observations from one centre with a large experience of RPLND in the UK.

PATIENTS AND METHODS

A prospective series of 278 consecutive patients treated with RPLND for testicular tumours comprised the sample population. For each patient the presence or absence of four factors from the history was recorded. Each patient then underwent RPLND. During surgery, a template was constructed of the anatomy of the retroperitoneum and the information stored. Eight different retroperitoneal anatomical anomalies were identified in the sample population; the incidence of each was then compared with the largest available study of a normal population, and differences analysed statistically.

RESULTS

Of the 278 patients who had RPLND, 55 had 59 anomalies (21%), found by history and as retroperitoneal vascular and urological anomalies; cryptorchidism was present in 7.6%, 9.5 times the incidence in the control population (P < 0.01). A left-sided inferior vena cava was present in 3.6% of patients, 21 times the incidence in the control population (P < 0.001); a retro-aortic left renal vein in 3.2%, four times that in the control population (P < 0.05); and ipsilateral renal agenesis had an incidence of 1% in the test population, 11 times greater than in the control population (P < 0.01).

CONCLUSIONS

This prospective study of 278 RPLNDs provides evidence that some retroperitoneal anatomical anomalies are associated with testicular germ cell tumours. The link between maldescent and testicular tumours, rather than an isolated association, should be considered as part of a spectrum of retroperitoneal anomalies that occur in these men.

First Clinical Experience with New Transurethral Bipolar Prostate Electrosurgery Resection System: Controlled Tissue Ablation (Coblation Technology®)

BACKGROUND AND PURPOSE

Bipolar transurethral resection of the prostate (TURP) can allow transurethral debulking of the adenoma with a lower potential for complications from systemic absorption of hypotonic irrigant. We evaluated a new bipolar double-loop resection system with a dedicated controlled ablation (Coblation) generator in this context.

PATIENTS AND METHODS

In our series of 36 patients, 32 underwent transurethral bipolar loop resection, of whom 12 had prostates >50 cc (range for entire series 30-126 cc) on transrectal ultrasonography. Ten men had indwelling catheters because of urinary retention. The four other patients underwent transurethral resection of bladder tumors. After an initial learning curve of eight TURPs, some minor technical modifications were made, both to the bipolar-loop resection technique and to the hardware. The modified Vista Coblation system was subsequently evaluated by 18 other urologists in 17 other centers throughout the U.S.

RESULTS

The median resected dry weight was 22 g, and the median operating-room time was 48 minutes, giving a median resection rate of approximately 1 g every 2 minutes. Two of the eight men in our learning curve required treatment for delayed bleeding problems (clot obstruction of catheter), and one of these received a blood transfusion. Transfusion was not required subsequently regardless of prostate size, even in men with larger glands. One of the patients treated for bladder tumor had a minor perforation of the posterior bladder wall, which healed with conservative management. In the multicenter experience in the U.S., there were 59 evaluable patients. The median resected weight was 23 g, and the median resection time was 55 minutes. Two men required conversion to monopolar roller coagulation for intraoperative bleeding. Most patients (80%) were discharged from hospital within 24 hours. No adverse neuromuscular stimulation occurred.

CONCLUSION

This first single-center and international multicenter experience with Coblation technology for bipolar double-loop saline TURP confirms the feasibility and safety of this procedure. Subjective evaluation showed the four most important perceived benefits of bipolar over monopolar TURP to be smoother cutting action, elimination of TUR syndrome, less tissue burning (and no smell), and reduced bleeding. The results of randomized studies with this technology are awaited, while its role in bladder tumor resection remains unclear.

Biopsy of the red patch at cystoscopy: is it worthwhile?

OBJECTIVE

At cystoscopy red patches of urothelium are commonly seen within the bladder and frequently biopsied in order to exclude carcinoma in situ (CIS), which classically presents as a red, velvety patch. This appearance however is not specific and it is possible that many lesions are biopsied without significant benefit to the patient. The objective of this study was to determine whether routine biopsy of red patches seen in the bladder at cystoscopy is warranted.

PATIENTS AND METHODS

193 biopsies were taken from red patches seen at flexible and rigid cystoscopy during a 4-year period from December 1997 to January 2002 and examined by histopathology. Patients included in the study were those on cystoscopic follow-up for transitional cell carcinoma (TCC) of the bladder and those undergoing investigation for haematuria or lower urinary tract symptoms.

RESULTS

In 193 (17.7% of total biopsies) red patch biopsies, malignancy was found in 23 (11.9%) and 18 of 23 (78.3%) were CIS. No malignancies were detected in red patches from patients under the age of 60 years.

CONCLUSION

Red patch biopsy yields a positive finding of malignancy in 12% and was concluded to be a valuable exercise, particularly in those over the age of 60 years and on follow-up for TCC.

Expression of the developmental and oncogenic PAX2 gene in human prostate cancer

PURPOSE

In the human prostate cancer cell lines LNCaP, DU145 and PC3, 27 primary prostate cancers, 10 benign prostatic hyperplasia specimens and 5 normal prostates we investigated the expression pattern of PAX2, a member of the PAX family of developmental control genes. PAX2 is expressed at high levels in developing undifferentiated cells of the urogenital system and is repressed upon terminal differentiation with no expression in normal adult cells. It is also been shown to be a proto-oncogene in mice and is expressed in human renal cell carcinoma.

MATERIALS AND METHODS

PAX2 expression was assessed at the RNA level by reverse transcriptase-polymerase chain reaction and Southern blot analysis using specific sets of nucleotides. The expression pattern of PAX2 was reconfirmed at the protein level by immunofluorescence in the cell lines, and by Western blot analysis in primary human prostate cancers and benign prostatic tissue.

RESULTS

Using reverse transcription-polymerase chain reaction combined with Southern hybridization PAX2 expression was detected in 52% of primary cancers and all 3 cell lines. PAX2 expression in these samples was confirmed at a protein level using immunoblotting and immunofluorescence. PAX2 messenger RNA was not detected in any benign or normal prostatic samples. Immunoblotting of protein from benign prostatic hyperplasia samples confirmed the lack of expression of PAX2 protein.

CONCLUSIONS

The expression of PAX2 in prostate cancer compared to nonmalignant prostates is statistically significant (Fisher's exact test p = 0.0004). These results suggest a possible role for PAX2 in prostate cancer. Although previous studies have suggested a role for PAX2 for supporting proliferation in undifferentiated cells, no correlation of PAX2 expression with Gleason score was found in prostate cancer.

The expression of PAX5 in human transitional cell carcinoma of the bladder: relationship with de-differentiation

OBJECTIVE

To investigate the expression of PAX genes, a family of developmental control genes (which encode nine nuclear transcription factors essential for embryogenesis and are proto-oncogenes in mice) in human transitional cell carcinoma (TCC) of the bladder.

MATERIALS AND METHODS

PAX gene expression was assessed in three established bladder cancer cell lines and 29 primary tumours using the reverse transcriptase-polymerase chain reaction and Southern analysis.

RESULTS

All three established TCC cell lines and 79% of primary TCCs expressed PAX5 mRNA. There was a significantly higher proportion of PAX5 expression in malignant than in benign urothelium (P=0.02, Fisher's exact test); nine of 12 pTa tumours (mucosa-confined), seven of eight pT1 (invading lamina propria) and eight of nine pT2 (invading muscle) expressed PAX5. A higher proportion of tumours with increasing de-differentiation expressed PAX5, which correlates well with the expression pattern of PAX5 in development. In well-differentiated tumours (grade 1), half expressed PAX5, compared with 84% of moderately to poorly differentiated tumours (grades 2/3). The odds ratio for PAX5 expression in malignancy suggests that it increases the risk of malignancy four-fold.

CONCLUSION

These data support a role for the PAX family in oncogenesis, by identifying another human neoplasm in which they are inappropriately expressed. PAX5 expression in undifferentiated TCC cells may contribute to pathogenesis by supporting cellular proliferation in the de-differentiated state. Furthermore, the high incidence of PAX5 expression suggests its potential use as a diagnostic tool and therapeutic target in TCC.