Stephen Wyler

GreenLight Laser Vaporization of the Prostate: Single-Center Experience and Long-Term Results After 500 Procedures

BACKGROUND Long-term data of photoselective vaporization of the prostate (PVP) for treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) is scanty. OBJECTIVE Evaluate the long-term efficacy and the complication rate in 80-watt (W) PVP. DESIGN, SETTING, AND PARTICIPANTS 500 consecutive patients with LUTS secondary to BPH underwent PVP between September 2002 and April 2007. The mean follow-up was 30.6+/-16.6 (5.2-60.6) mo. INTERVENTION All patients underwent 80-W PVP performed by seven surgeons. MEASUREMENTS We evaluated perioperative parameters, including operation time, delivered energy, changes of hemoglobin and serum sodium, catheterization, and hospitalization time as well as intraoperative and postoperative complications. Patients presenting for follow-up had data assessed on the International Prostate Symptom Score and quality-of-life questionnaire (IPPS-QoL), maximal flow rate (Q(max)), and post-voiding residual volume (Vres). RESULTS AND LIMITATIONS Mean patient age was 71.4+/-9.6 (46-96) yr, with a mean preoperative prostate volume of 56.1+/-25.3 (10-180) ml. Mean operation time was 66.4+/-26.8 (10-160) min, and mean energy delivery was 206+/-94 (2.4-619.0) kJ. Despite ongoing oral anticoagulation in 45% of the patients (n=225), no severe intraoperative complications were observed. Mean catheterization and postoperative hospitalization time was 1.8+/-1.2 (0-10) and 3.7+/-2.9 (0-35) d, respectively. The mean IPSS after 3 yr was 8.0+/-6.2, the QoL score was 1.3+/-1.3, the Q(max) was 18.4+/-8.0 ml/s, and the Vres was 28+/-42 ml. The retreatment rate was 6.8%. Urethral and bladder neck strictures were observed in 4.4% and 3.6% of the patients, respectively. Localized prostate cancer was diagnosed during follow-up in six patients. CONCLUSION PVP is a safe and effective procedure for treatment of LUTS secondary to BPH. Patients on ongoing oral anticoagulation can be safely operated on. PVP leads to an immediate and sustained improvement of subjective and objective voiding parameters. The late complication rate is comparable to that of transurethral electroresection of the prostate.

Cancer genetics-guided discovery of serum biomarker signatures for diagnosis and prognosis of prostate cancer

A key barrier to the realization of personalized medicine for cancer is the identification of biomarkers. Here we describe a two-stage strategy for the discovery of serum biomarker signatures corresponding to specific cancer-causing mutations and its application to prostate cancer (PCa) in the context of the commonly occurring phosphatase and tensin homolog (PTEN) tumor-suppressor gene inactivation. In the first stage of our approach, we identified 775 N-linked glycoproteins from sera and prostate tissue of wild-type and Pten-null mice. Using label-free quantitative proteomics, we showed that Pten inactivation leads to measurable perturbations in the murine prostate and serum glycoproteome. Following bioinformatic prioritization, in a second stage we applied targeted proteomics to detect and quantify 39 human ortholog candidate biomarkers in the sera of PCa patients and control individuals. The resulting proteomic profiles were analyzed by machine learning to build predictive regression models for tissue PTEN status and diagnosis and grading of PCa. Our approach suggests a general path to rational cancer biomarker discovery and initial validation guided by cancer genetics and based on the integration of experimental mouse models, proteomics-based technologies, and computational modeling.

Comparison of potassium-titanyl-phosphate laser vaporization of the prostate and transurethral resection of the prostate: update of a prospective non-randomized two-centre study.

To evaluate the intermediate‐term clinical efficacy and the rate of complications in 80 W photoselective vaporization of the prostate (PVP) with the potassium‐titanyl‐phosphate laser (GreenlightTM, (AMS, Minnetonka, MN, USA) compared with transurethral resection of the prostate (TURP) in a prospective non‐randomised two‐centre study.

Quality of life and perioperative outcomes after retroperitoneoscopic radical nephrectomy (RN), open RN and nephron-sparing surgery in patients with renal cell carcinoma

To prospectively evaluate health‐related quality of life (HRQoL) and perioperative outcomes in patients with T1 and T2 renal cell carcinoma (RCC) after retroperitoneoscopic radical nephrectomy (RRN), open RN (ORN) or open nephron‐sparing surgery (NSS).

High expression of indoleamine 2,3-dioxygenase gene in prostate cancer

Arginase 2, inducible- and endothelial-nitric-oxide synthase (iNOS and eNOS), indoleamine 2,3-dioxygenase (IDO) and TGF-beta, might impair immune functions in prostate cancer (PCA) patients. However, their expression was not comparatively analysed in PCA and benign prostatic hyperplasia (BPH). We evaluated the expression of these genes in PCA and BPH tissues. Seventy-six patients (42 BPH, 34 PCA) were enrolled. Arginase 2, eNOS and iNOS gene expression was similar in BPH and PCA tissues. TGF-beta1 gene expression was higher in BPH than in PCA tissues (p=0.035). IDO gene expression was more frequently detectable (p=0.00007) and quantitatively higher (p=0.00001) in PCA tissues than in BPH. IDO protein, expressed in endothelial cells from both BPH and PCA, was detectable in tumour cells in PCA showing evidence of high specific gene expression. In these patients, IDO gene expression correlated with kynurenine/tryptophan ratio in sera. Thus high expression of IDO gene is specifically detectable in PCA.

Klf4 transcription factor is expressed in the cytoplasm of prostate cancer cells.

BACKGROUND Cancer initiation and progression might be driven by small populations of cells endowed with stem cell-like properties. Here we comparatively addressed the expression of genes encoding putative stemness regulators including c-Myc, Klf4, Nanog, Oct4A and Sox2 genes in benign prostatic hyperplasia (BPH) and prostate cancer (PCA). METHODS Fifty-eight PCA and thirty-nine BPH tissues samples were used for gene expression analysis, as evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of specific Klf4 isoforms was tested by conventional PCR. Klf4 specific antibodies were used for protein detection in a tissue microarray including 404 prostate samples. RESULTS Nanog, Oct4A and Sox2 genes were comparably expressed in BPH and PCA samples, whereas c-Myc and Klf4 genes were expressed to significantly higher extents in PCA than in BPH specimens. Immunohistochemical studies revealed that Klf4 protein is detectable in a large majority of epithelial prostatic cells, irrespective of malignant transformation. However, in PCA, a predominantly cytoplasmic location was observed, consistent with the expression of a differentially spliced Klf4α isoform. CONCLUSION Klf4 is highly expressed at gene and protein level in BPH and PCA tissues but a cytoplasmic location of the specific gene product is predominantly detectable in malignant cells. Klf4 location might be of critical relevance to steer its functions during oncogenesis.

Laser prostatectomy of lower urinary tract symptoms due to benign prostate enlargement: a critical review of evidence

Purpose of review Different transurethral prostatic laser systems are available. In 2011, new Oxford evidence levels (LoEs) were published with significant changes compared with the former version. They are easier to use and incorporate more clinical aspects. Randomized trials of laser systems used before 2002, except Holmium laser, were not included in this critical evidence analysis, as these techniques are not in clinical use any more. Recent findings Twenty-five [18 Holmium enucleation of the prostate (HoLEP) and seven photoselective vaporization of the prostate (PVP)] randomized trials covering transurethral electroresection of the prostate or HoLEP, PVP or Thulium laser enucleation were identified. According to evidence levels, there is a large gap in terms of long-term follow-up. The majority of randomised controlled trials are of low quality. Typically with HoLEP, many articles were published covering the same patient population (LoE II). Only one randomised controlled trial was published with Tm:YAG prostatectomy (LoE II) and none with diode lasers (980–1340 nm, LoE IV-V). Large cohort studies (LoE III-IV) provide additional evidence for PVP and HoLEP, typically for subgroups. Summary In 2011, higher evidence on HoLEP and PVP has been published. Evidence levels for HoLEP and PVP are comparable with meta-analysis (LoE II). However, evidence that laser prostatectomy is better than transurethral electroresection of the prostate in terms of efficacy is lacking (LoE II). All lasers are safer in terms of perioperative bleeding (LoE II).

Rapid detection of urinary tract pathogens using microcalorimetry: principle, technique and first results

Study Type – Diagnostic (exploratory cohort)

The effect of increased maximum power output on perioperative and early postoperative outcome in photoselective vaporization of the prostate

Preclinical studies suggest an increased vaporization rate and speed of the 532 nm 180‐W XPS GreenLight laser (180‐W) compared with the 120‐W HPS GreenLight laser (120‐W) and the 80‐W PV GreenLight laser (80‐W). To test the clinical relevance of this observation we analyzed intraoperative data and early postoperative results after photoselective vaporization of the prostate (PVP) with the 180‐W, 120‐W, and 80‐W laser.

Health-Related Quality of Life after Radical Prostatectomy and Low-Dose-Rate Brachytherapy for Localized Prostate Cancer

Objective: To evaluate quality of life (QOL) after radical retropubic prostatectomy (RP) and low-dose-rate brachytherapy (BT). Methods: Between 2001 and 2004, RP or BT was performed in 212 patients. QOL data were evaluated with the European Organization for Research and Treatment of Cancer QLQ-C30 version 3.0, the International Prostate Symptom Score (IPSS) and the International Index of Erectile Function-5 questionnaires. QOL data were compared. Results: RP and BT were performed in 142 and 70 patients, respectively. The mean follow-up was 24 months (5–53). The mean overall global health score for patients after RP was 78 (0–100) and after BT it was 83 (33–100), and it showed a trend in favour of BT. The follow-up lasted at most 53 months, and the period was divided into yearly categories. Patients who underwent BT showed worse global health in the first year after operation, but thereafter they showed better health. Patients who received BT showed a trend towards having lower functional-scale and symptom-scale scores in the first year after operation, and then higher scores for any subsequent year of follow-up. Only diarrhoea was temporarily worse in the second year after BT compared to RP. The mean total IPSS and QOL score for BT and RP patients during follow-up showed no significant difference. Conclusion: Patients treated with BT or RP have similar QOL scores. QOL after BT is worse in the first year after treatment, but thereafter it is better than QOL after RP.