Multicentre outcomes of robot-assisted partial nephrectomy after major open abdominal surgery.

OBJECTIVE: To evaluate the outcomes of robot-assisted partial nephrectomy RAPN after major prior abdominal surgery (PAS) using a large multicentre database. PATIENTS AND METHODS: We identified 1 686 RAPN from five academic centres between 2006 and 2014. In all, 216 patients had previously undergone major PAS, defined as having an open upper midline/ipsilateral incision. Perioperative outcomes were compared with those 1 470 patients who had had no major PAS. The chi-squared test and Mann-Whitney U-test were used for categorical and continuous variables, respectively. RESULTS: There was no statistically significant difference in Charlson comorbidity index, tumour size, R.E.N.A.L. nephrometry score or preoperative estimated glomerular filtration rate (eGFR) between the groups. Age and body mass index were higher in patients with PAS. The PAS group had a higher estimated blood loss (EBL) but this did not lead to a higher transfusion rate. A retroperitoneal approach was used more often in patients with major PAS (11.2 vs 5.4%), although this group did not have a higher percentage of posterior tumours (38.8 vs 43.3%, P = 0.286). Operative time, warm ischaemia time, length of stay, positive surgical margin, percentage change in eGFR, and perioperative complications were not significantly different between the groups. CONCLUSIONS: RAPN in patients with major PAS is safe and feasible, with increased EBL but no increased rate of transfusion. Patients with major PAS had almost twice the likelihood of having a retroperitoneal approach.

HER3, p95HER2, and HER2 protein expression levels define multiple subtypes of HER2-positive metastatic breast cancer.

Trastuzumab is effective in the treatment of HER2/neu over-expressing breast cancer, but not all patients benefit from it. In vitro data suggest a role for HER3 in the initiation of signaling activity involving the AKT­mTOR pathway leading to trastuzumab insensitivity. We sought to investigate the potential of HER3 alone and in the context of p95HER2 (p95), a trastuzumab resistance marker, as biomarkers of trastuzumab escape. Using the VeraTag® assay platform, we developed a dual antibody proximity-based assay for the precise quantitation of HER3 total protein (H3T) from formalin-fixed paraffin-embedded (FFPE) breast tumors. We then measured H3T in 89 patients with metastatic breast cancer treated with trastuzumab-based therapy, and correlated the results with progression-free survival and overall survival using Kaplan­Meier and decision tree analyses that also included HER2 total (H2T) and p95 expression levels. Within the sub-population of patients that over-expressed HER2, high levels of HER3 and/or p95 protein expression were significantly associated with poor clinical outcomes on trastuzumab-based therapy. Based on quantitative H3T, p95, and H2T measurements, multiple subtypes of HER2-positive breast cancer were identified that differ in their outcome following trastuzumab therapy. These data suggest that HER3 and p95 are informative biomarkers of clinical outcomes on trastuzumab therapy, and that multiple subtypes of HER2-positive breast cancer may be defined by quantitative measurements of H3T, p95, and H2T.

Use of the Satinsky clamp for hilar clamping during robotic partial nephrectomy: indications, technique, and multi-center outcomes.

A Satinsky clamp may be a backup option for hilar clamping during robotic partial nephrectomy (RPN) if there are challenges with application of bulldog clamps, but there are potential safety concerns. We evaluate outcomes of RPN using Satinsky vs. bulldog clamps, and provide tips for safe use of the Satinsky as a backup option. Using a multi-center database, we identified 1073 patients who underwent RPN between 2006 and 2013, and had information available about method of hilar clamping (bulldog clamp vs. Satinsky clamp). Patient baseline characteristics, tumor features, and perioperative outcomes were compared between the Satinsky and bulldog clamp groups. A Satinsky clamp was used for hilar clamping in 94 (8.8 %) RPN cases, and bulldog clamps were used in 979 (91.2 %) cases. The use of a Satinsky clamp was associated with greater operative time (198 vs. 175 min, p < 0.001), estimated blood loss (EBL, 200 vs. 100 ml, p < 0.001), warm ischemia time (WIT, 20 vs. 19 min, p = 0.036), transfusion rate (12.8 vs. 4.8 %, p = 0.001), and hospital stay (3 vs. 2 days, p < 0.001). Tumor characteristics and number of renal vessels were similar between groups. There were six intraoperative complications in the Satinsky clamp group, but none were directly related to the Satinsky clamp. On multivariable analysis, the use of the Satinsky clamp was not associated with increase in intraoperative or Clavien ≥3 postoperative complications, positive surgical margin rate or percentage change in estimated glomerular filtration rate. A Satinsky clamp can be a backup option for hilar clamping during challenging RPN cases, but requires careful technique, and was rarely necessary.

Robotic partial nephrectomy for renal tumours in obese patients: Perioperative outcomes in a multi-institutional analysis.

INTRODUCTION: We sought to evaluate the association of obesity with surgical outcomes of robotic partial nephrectomy (RPN) using a large, multicentre database. METHODS: We identified 1836 patients who underwent RPN from five academic centres from 2006-2014. A total of 806 patients were obese (body mass index [BMI] ≥30 kg/m(2)). Patient characteristics and outcomes were compared between obese and non-obese patients. Multivariable analysis was used to assess the association of obesity on RPN outcomes. RESULTS: A total of 806 (44%) patients were obese with median BMI of 33.8kg/m(2). Compared to non-obese patients, obese patients had greater median tumour size (2.9 vs. 2.5cm, p<0.001), mean RENAL nephrometry score (7.3 vs. 7.1, p=0.04), median operating time (176 vs. 165 min, p=0.002), and median estimated blood loss (EBL, 150 vs. 100 ml, p=0.002), but no difference in complications. Obesity was not an independent predictor of operative time or EBL on regression analysis. Among obese patients, males had a greater EBL (150 vs. 100 ml, p<0.001), operative time (180 vs. 166 min, p<0.001) and warm ischemia time (WIT, 20 vs. 18, p=0.001), and male sex was an independent predictor of these outcomes on regression analysis. CONCLUSIONS: In this large, multicentre study on RPN, obesity was not associated with increased complications and was not an independent predictor of operating time or blood loss. However, in obese patients, male gender was an independent predictor of greater EBL, operative time, and WIT. Our results indicate that obesity alone should not preclude consideration for RPN.

Biodistribution and safety studies of hDel-1 plasmid-based gene therapy in mouse and rabbit models.

A plasmid encoding the human developmentally regulated endothelial locus-1 (hDel-1) protein formulated with poloxamer 188 is a potential gene therapy for peripheral arterial disease in man. As a prelude to clinical trials, the biodistribution and safety of this therapy were evaluated after intramuscular and intravenous administration in mice and rabbits. In mice, plasmid DNA persisted at the intramuscular injection site for at least 28 days, but was barely detectable in distal tissues by 24 h and essentially cleared by 28 days. By 24 h after intravenous administration, plasmid DNA was readily detected in blood, muscle, and lungs but sporadically and at low levels in other tissues. At 28 days, plasmid DNA was readily detectable only at the intravenous injection site (tail) after low- and high-dose administration, and sporadically in blood and muscle after high-dose administration. In rabbits, the highest intramuscular (4.2 mg kg(-1)) or intravenous (3.7 mg kg(-1)) dose caused no deaths; no treatment-related clinical signs; no changes in body weight, clinical pathology parameters, ophthalmology, ECG, or histopathology; and no detectable increase in antinuclear antibodies by 28 days. The results supported testing of hDel-1 plasmid-based gene therapy in phase I clinical trials.

A novel proximity assay for the detection of proteins and protein complexes: quantitation of HER1 and HER2 total protein expression and homodimerization in formalin-fixed, paraffin-embedded cell lines and breast cancer tissue.

The availability of drugs targeting the EGFR/HER/erbB signaling pathway has created a need for diagnostics that accurately predict treatment responses. We have developed and characterized a novel assay to provide sensitive and quantitative measures of HER proteins and homodimers in formalin-fixed, paraffin-embedded (FFPE) cell lines and breast tumor tissues, to test these variables. In the VeraTag assay, HER proteins and homodimers are detected through the release of fluorescent tags conjugated to specific HER antibodies, requiring proximity to a second HER antibody. HER2 protein quantification was normalized to tumor area, and compared to receptor numbers in 12 human tumor cell lines determined by fluorescence-activated cell sorting (FACS), and with HER immunohistochemistry (IHC) test categories and histoscores in cell lines and 170 breast tumors. HER1 and HER2 expression levels determined by the VeraTag assay are proportional to receptor number over more than a 2 log10 range, and HER homodimer levels are consistent with crosslinking and immunoprecipitation results. VeraTag HER2 measurements of breast tumor tissue and cell lines correlate with standard IHC test categories (P<0.001). VeraTag HER2 levels also agree with IHC histoscores at lower HER2 protein levels, but are continuous and overlapping between IHC test categories, extending the dynamic range 5-fold to 10-fold at higher HER2 levels. The VeraTag assay specifically and reproducibly measures HER1 and HER2 protein and homodimers in FFPE tissues. The continuous measure of HER2 protein levels over a broad dynamic range, and the novel HER2 homodimer measure, are presently being assessed as predictive markers for responses to targeted HER2 therapy.