High-resolution profiling of histone h3 lysine 36 trimethylation in metastatic renal cell carcinoma

Mutations in SETD2, a histone H3 lysine trimethyltransferase, have been identified in clear cell renal cell carcinoma (ccRCC); however it is unclear if loss of SETD2 function alters the genomic distribution of histone 3 lysine 36 trimethylation (H3K36me3) in ccRCC. Furthermore, published epigenomic profiles are not specific to H3K36me3 or metastatic tumors. To determine if progressive SETD2 and H3K36me3 dysregulation occurs in metastatic tumors, H3K36me3, SETD2 copy number (CN) or SETD2 mRNA abundance was assessed in two independent cohorts: metastatic ccRCC (n=71) and the Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma data set (n=413). Although SETD2 CN loss occurs with high frequency (>90%), H3K36me3 is not significantly impacted by monoallelic loss of SETD2. H3K36me3-positive nuclei were reduced an average of ~20% in primary ccRCC (90% positive nuclei in uninvolved vs 70% positive nuclei in ccRCC) and reduced by ~60% in metastases (90% positive in uninvolved kidney vs 30% positive in metastases) (P<0.001). To define a kidney-specific H3K36me3 profile, we generated genome-wide H3K36me3 profiles from four cytoreductive nephrectomies and SETD2 isogenic renal cell carcinoma (RCC) cell lines using chromatin immunoprecipitation coupled with high-throughput DNA sequencing and RNA sequencing. SETD2 loss of methyltransferase activity leads to regional alterations of H3K36me3 associated with aberrant RNA splicing in a SETD2 mutant RCC and SETD2 knockout cell line. These data suggest that during progression of ccRCC, a decline in H3K36me3 is observed in distant metastases, and regional H3K36me3 alterations influence alternative splicing in ccRCC.

Update on contemporary management of clinically localized renal cell carcinoma

Renal cell carcinoma (RCC) continues to increase in incidence with the largest increase manifesting in small, organ-confined tumors. This review outlines the epidemiology and current data pertaining to the management of clinically-localized RCC. In this manuscript, the current data outlining the benefit of nephron sparing to the overall survival of the patient is described. The data pertaining to minimally invasive nephron sparing is also explained in detail. From laparoscopic and robotic partial nephrectomy to watchful waiting and percutaneous ablation, the urologist is continually assaulted with new data for the management of clinically-localized RCC. The data can be confusing, and much of it is conflicting. The addition of new scoring systems or nomograms may aid in predicting which therapy would be most beneficial in certain patient groups. New scoring systems may also predict the difficulty of surgical resection and predict surgical complications. The limitations of the data pertaining to the management of clinically-localized RCC are also outlined.

Oncologic outcomes for node-positive patients undergoing robotic radical cystectomy

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Background: Previous studies have shown robot assisted radical cystectomy (RARC) to have equivalent perioperative outcomes to open radical cystectomy. There are few reports that have examined the oncologic results of RARC specifically with respect to node-positive patients. We report the outcomes of node-positive patients who have undergone RARC with medium-term (at least 1 year) follow-up.

Methods: A total of 275 patients underwent RARC at two institutions for invasive bladder cancer between 2005-present. We examined the 50 patients with node-positive disease that had a minimum of one year follow-up. Oncologic outcomes, recurrence free survival (RFS), and disease specific survival (DSS) were analyzed and compared to the open literature.

Results: Mean clinical follow up in this case series was 29 months (range 12–64 months). The mean number of lymph nodes removed was 18 (range 5–35), and mean number of positive LNs was 3.1 (range 1–12). Overall rate of LN positivity was 26%. Mean LN density was 18%. Seventeen (34%) patients had ≤ pT2 disease and 33 (66%) pT3/T4 disease. At this follow-up, 29 patients have recurred, 21 patients died of disease, giving a RFS and DSS of 42% and 58%, respectively. Mean (median) time to recurrence was 10.2 months (9 months). A total of 60% of patients received peri-operative chemotherapy in this cohort. These findings are consistent with prior reports of such oncologic outcomes in node-positive patients in open series.

Conclusions: The oncologic follow-up of patients undergoing RARC with LN positive disease appears to have acceptable outcomes during medium term (mean 29 months) follow-up. As our follow-up increases, we expect to continue to accurately define the long-term clinical suitability and oncologic success of this procedure in this high-risk population.

No significant financial relationships to disclose.

Robotic radical cystectomy: Medium-term oncologic follow-up

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Background: We report our experience with robot assisted radical cystectomy (RARC) with regard to medium-term (at least 2 year) oncologic outcomes.

Methods: A total of 275 patients have undergone RARC and urinary diversion at two institutions for invasive bladder cancer between 2005-present. We performed a retrospective analysis of the 139 patients who underwent RARC with a minimum of 2 years follow-up. Medium term oncologic outcomes including recurrence rates, time to recurrence, recurrence free survival (RFS), disease specific survival (DSS) were analyzed. Follow-up was measured from time of surgery to time of most recent clinical follow-up.

Results: This cohort of patients consisted of 108 men (78%) and 31 women (22%) at a mean age of 67.3 years (range 45-86 years). Sixty-one (44%) patients had ≤ pT2 disease, 38 (27%) pT3/T4 disease, and 40 (29%) N+ disease. The mean number of lymph nodes removed was 18 (range 3-41). The average clinical follow up in this case series was nearly 3 years with a mean of 35.9 months (range 24-64 months). At this follow-up, 39 patients have recurred, 27 patients died of disease, and 5 patients died of other causes giving an overall RFS, DSS, and OS rates of 80%, 71%, and 68%, respectively. The mean (median) time to recurrence was 12.3 months (10 months). These findings are consistent with prior reports of the oncologic outcomes for open radical cystectomy.

Conclusions: The oncologic follow-up of patients undergoing RARC appears to be favorable with acceptable outcomes in the medium-term (mean – 3 years). As our follow-up increases, we should expect to truly define the long-term clinical appropriateness and oncologic success of this procedure.

No significant financial relationships to disclose.

Effect of the simultaneous blockade of androgen and estrogen receptors on prostate cancer: Preliminary results

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Background: Androgens and estrogens have been shown to play an important role in normal prostate development and function as well as carcinogenesis and development of the castration resistant phenotype of disease. The aim of this study was to evaluate the effect of a simultaneous administration of an androgen receptor antagonist (bicalutamide) and a selective estrogen receptor modulator (raloxifene) on both androgen sensitive and androgen insensitive prostate cancer cell lines.

Methods: Experiments were performed on LNCaP, PC3 and DU145 cell lines. Western blot was utilized for the identification of androgen and estrogen receptors (a andb) in the cell lines. Drug concentrations required to achieve IC 50 were obtained using the MTT assay; such concentrations were identified for the drugs individually and when used in combination. The effect of the drugs on apoptosis was assessed using flow cytometry.

Results: Results of the IC 50 for the drugs alone and in combination by each cell line are shown in the table. An enhanced effect was observed when the drugs were used in combination in all the cell lines. It was evident that the combination of the drugs decreased the total drug required to achieve the IC50 decreases considerably. Apoptosis rates were also affected by the simultaneous administration of bicalutamide and raloxifene. The synergistic effect of the combination was reflected in the increase of the apoptosis rate in all cell lines.

Conclusions: The simultaneous administration of bicalutamide and raloxifene has a synergistic effect on cell death and apoptosis of DU145, PC3 and LNCaP cell lines. The pathway(s) responsible for this observation may be independent of the androgen receptor as both AR negative cell lines were still affected by the combination over the SERM alone.

[Table: see text]

No significant financial relationships to disclose.