The neurovascular structure-adjacent frozen-section examination (NeuroSAFE) approach to nerve sparing in robot-assisted laparoscopic radical prostatectomy in a British setting - a prospective observational comparative study.

OBJECTIVES: To evaluate the neurovascular structure-adjacent frozen-section examination (NeuroSAFE) technique in a British setting in men undergoing robot-assisted laparoscopic radical prostatectomy (RALP) . PATIENTS AND METHODS: We retrospectively analysed our prospectively maintained database of patients who underwent RALP between November 2008 and February 2017. We examined preoperative pathological and functional parameters, intraoperative nerve sparing (NS), postoperative histology, as well as functional and oncological follow-up. We compared those who had a NeuroSAFE approach and those who had NS without NeuroSAFE. We also compared all the RALPs before and after the introduction of NeuroSAFE. Statistical analysis was done using the two-tailed t-test and chi-squared analysis. RESULTS: This single surgeon series included 417 RALPs, including 120 NeuroSAFEs. The NeuroSAFE cohort had a greater proportion of D'Amico high-risk disease (30.8% vs 9.6%, P < 0.001), higher Gleason scores and higher pT stage compared to the non-NeuroSAFE NS cohort. After the introduction of NeuroSAFE, more preoperatively potent men underwent bilateral NS with pT2 disease (84.6% vs 66.3%, P = 0.002) and more overall NS were performed in patients with pT3 disease (65.1% vs 36.7%, P = 0.012). Overall positive surgical margin (PSM) rates were lower in the NeuroSAFE cohort compared to those who had NS without NeuroSAFE (9.2% vs 17.8%, P = 0.04). The 12-month potency rates were also higher in the NeuroSAFE cohort for both bilateral (77.3% vs 50.9%, P = 0.009) and unilateral (70.6% vs 40%, P = 0.04) NS. Pad-free continence was also higher in the NeuroSAFE group (85.7% vs 70.9%, P = 0.019), but there was no significant difference between those who were wearing ≤1 safety pad. Although we only had short-term oncological follow-up, it did not significantly differ between the two groups. CONCLUSION: Adoption of NeuroSAFE allowed us to offer NS in higher risk patients, whilst reducing PSM rates and at the same time improving potency at 12 months.

Identification of a recurrent t(4;6) chromosomal translocation in prostate cancer.

PURPOSE: We developed and describe a practical method by which primary prostate cancer specimens can be screened for recurrent chromosomal translocations, which is a potential source of fusion genes, as well as a process by which identified translocations can be mapped to define the genes involved. MATERIALS AND METHODS: A series of 7 prostate cancer cell lines and 25 transiently established primary cell cultures, which were sourced from tissue harvested at 16 radical prostatectomies and 9 channel transurethral prostate resections, were screened for chromosomal translocations using multiplex-fluorescence in situ hybridization technology. A series of fluorescence in situ hybridization based breakpoint mapping experiments were performed to identify candidate genes involved in regions associated with recurrent translocation. RESULTS: Our analysis identified the repetition of 2 translocations in prostate cancer lines, that is t(1;15) and t(4;6), at a frequency of 28% and 57%, respectively. More significantly 4 of the 25 subsequently established primary cultures (16%) also revealed a t(4;6) translocation. Using the LNCaP cell line the breakpoints involved were mapped to the t(4;6)(q22;q15) region and a number of candidate genes were identified. CONCLUSIONS: We found that the t(4;6) translocation is also a repeat event in primary cell cultures from malignant prostate cancer. Breakpoint mapping showed that the gene UNC5C loses its promoter and first exon as a direct result of the translocation in the 4q22 region. As such, we identified it as a possible contributor to a putative fusion gene in prostate cancer.

A combination of molecular cytogenetic analyses reveals complex genetic alterations in conventional renal cell carcinoma.

Here we report the complex pattern of genomic imbalances and rearrangements in a panel of 19 renal cell carcinoma cell lines detected with molecular cytogenetic analysis. Consistent heterogeneity in chromosome number was found, and most cell lines showed a near-triploid chromosome complement. Several cell lines showed deletions of the TP53 (alias p53), CDKN2A (alias p16), and VHL genes. Multiplex fluorescence in situ hybridization (M-FISH) analysis revealed chromosome 3 translocated to several other partners chromosomes, as well as breakage events commonly affecting chromosomes 1, 5, 8, 10, and 17. The most common abnormality detected with comparative genomic hybridization (CGH) was deletions of chromosome 3p, with loss of the RASSF1, FHIT, and p44S10 loci frequently involved. CGH gain of 5q showed overrepresentation of the EGR1 and CSF1R genes. Recurrent alterations to chromosome 7 included rearrangement of 7q11 and gains of the EGFR, TIF1, and RFC2 genes. Several lines exhibited rearrangement of 12q11 approximately q14 and overrepresentation of CDK4 and SAS loci. M-FISH revealed several other recurrent translocations, and CGH findings included loss of 9p, 14q, and 18q and gain of 8q, 12, and 20. Further genomic microarray changes included loss of MTAP, IGH@, HTR1B, and SMAD4 (previously MADH4) and gains of MYC and TOP1. An excellent correlation was observed between the genomic array and FISH data, demonstrating that this technique is effective and accurate. The aberrations detected here may reflect important pathways in renal cancer pathogenesis.

Novel chromosome findings in bladder cancer cell lines detected with multiplex fluorescence in situ hybridization.

Bladder cancer is a common neoplasm worldwide, consisting mainly of transitional cell carcinomas, while squamous, adenocarcinoma, and sarcomatoid bladder cancers account for the remaining cases. In the present study, multiplex fluorescence in situ hybridization (M-FISH) has been used to characterize chromosome rearrangements in eight transitional and one squamous cell carcinoma cell line, RT112, of UMUC-3, 5637, CAT(wil), FGEN, EJ28, J82, 253J, and SCaBER. Alterations of chromosome 9 are the most frequent cytogenetic and molecular findings in transitional cell carcinomas of all grades and stages, while changes of chromosomes 3, 4, 8, 9, 11, 14, and 17 are also frequently observed. In the present study, alterations previously described, including del(8)(p10), del(9)(p10), del(17)(p10), and overrepresentation of chromosome 20, as well as several novel findings, were observed. These novel findings were a del(15)(q15) and isochromosome 14q, both occurring in three of nine cell lines examined. These abnormalities may reflect changes in bladder tumor biology. M-FISH represents an effective preliminary screening tool for the characterization of complex tumor karyotypes.