Christopher Silvers

Near infrared fluorescence imaging with robotic assisted laparoscopic partial nephrectomy: initial clinical experience for renal cortical tumors.

PURPOSE We evaluated the utility of near infrared fluorescence of intravenously injected indocyanine green in performing robotic assisted laparoscopic partial nephrectomy. In addition, we evaluated the initial performance of a novel near infrared fluorescence imaging system integrated into the da Vinci® Si Surgical System during robotic assisted laparoscopic nephrectomy. MATERIALS AND METHODS Fluorescence imaging for the da Vinci Si Surgical System was used for all cases. Indocyanine green was injected before near infrared imaging. Immediate imaging assessed the renal vasculature while delayed imaging differentiated renal cortical tumors from normal parenchyma. The intraoperative performance of near infrared fluorescence of intravenous indocyanine green was evaluated for tumor appearance relative to surrounding renal parenchyma as well as identification of the renal vasculature. RESULTS A total of 11 patients underwent robotic assisted laparoscopic nephrectomy with 2 converted to robotic assisted laparoscopic radical nephrectomy. Indocyanine green injections were repeated up to a total of 5 times depending on the goal of visualization. Of the 11 patients 10 demonstrated malignancy on final pathology. Of the malignant tumors 7 were hypofluorescent and 3 were isofluorescent compared to the surrounding renal parenchyma. Near infrared fluorescence imaging delineated the vascular anatomy in all cases. All surgical margins were negative on final pathology. CONCLUSIONS Intraoperative imaging of indocyanine green with near infrared fluorescence is a safe and effective method to accurately identify the renal vasculature and to differentiate renal tumors from surrounding normal parenchyma. The capacity for multimodal imaging within the surgical console further facilitates this imaging. Further study is needed to determine if this technique will help improve outcomes of robotic assisted laparoscopic nephrectomy.

Selective expression of CD44, a putative prostate cancer stem cell marker, in neuroendocrine tumor cells of human prostate cancer.

Hormonal therapy is effective for advanced prostate cancer (PC) but the disease often recurs and becomes hormone‐refractory. It is hypothesized that a subpopulation of cancer cells, that is, cancer stem cells (CSCs), survives hormonal therapy and leads to tumor recurrence. CD44 expression was shown to identify tumor cells with CSC features. PC contains secretory type epithelial cells and a minor population of neuroendocrine cells. Neuroendocrine cells do not express androgen receptor and are quiescent, features associated with CSCs. The purpose of the study was to determine the expression of CD44 in human PC and its relationship to neuroendocrine tumor cells.

Near Infrared Fluorescence Imaging After Intravenous Indocyanine Green: Initial Clinical Experience With Open Partial Nephrectomy for Renal Cortical Tumors

OBJECTIVE To evaluate the safety of near infrared fluorescence (NIRF) of intravenously injected indocyanine green (ICG) during open partial nephrectomy, and to demonstrate the feasibility of this technology to identify the renal vasculature and distinguish renal cortical tumors from normal parenchyma. METHODS Patients undergoing open partial nephrectomy provided written informed consent for inclusion in this institutional review board-approved study. Perirenal fat was removed to allow visualization of the renal parenchyma and lesions to be excised. The patients received intravenous injections of ICG, and NIRF imaging was performed using the SPY system. Intraoperative NIRF video images were evaluated for differentiation of tumor from normal parenchyma and for renal vasculature identification. RESULTS A total of 15 patients underwent 16 open partial nephrectomies. The mean cold ischemia time was 26.6 minutes (range 20-33). All 14 malignant lesions were afluorescent or hypofluorescent compared with the surrounding normal renal parenchyma. NIRF imaging of intravenously injected ICG clearly identified the renal hilar vessels and guided selective arterial clamping in 3 patients. No adverse reactions to ICG were noted, and all surgical margins were negative on final pathologic examination. CONCLUSION The intravenous use of ICG combined with NIRF is safe during open renal surgery. This technology allows the surgeon to distinguish renal cortical tumors from normal tissue and highlights the renal vasculature, with the potential to maximize oncologic control and nephron sparing during open partial nephrectomy. Additional study is needed to determine whether this imaging technique will help improve the outcomes during open partial nephrectomy.

Robot-Assisted and Laparoscopic Partial Nephrectomy with Near Infrared Fluorescence Imaging

BACKGROUND AND PURPOSE Recent literature has focused on the importance of maximal nephron preservation during partial nephrectomy to avoid complications associated with chronic renal insufficiency. Accurate differentiation of tumor from normal surrounding parenchyma is critical to ensure excessive normal renal tissue is not made ischemic or excised along with the tumor. The feasibility of a novel intraoperative imaging technique to differentiate tumor from surrounding parenchyma during laparoscopic and robot-assisted partial nephrectomy was evaluated. PATIENTS AND METHODS Patients who were scheduled to undergo laparoscopic or robot-assisted partial nephrectomy were recruited from April 2009 to July 2010. The Endoscopic SPY Imaging System was used as an adjunct to intraoperative imaging in all cases. Patients received intravenous injections of indocyanine green (ICG), which was visualized intraoperatively with the near infrared fluorescence (NIRF) imaging capability of the SPY scope. The degree of tumor fluorescence compared with surrounding renal parenchyma was qualitatively assessed before tumor resection, and partial nephrectomy was then performed with standard techniques while intermittently using NIRF imaging. RESULTS Nineteen patients underwent intravenous administration of ICG followed by NIRF during partial nephrectomy. Average tumor size was 3.0 cm (range 0.8-5.9 cm). Thirteen masses were malignant on final pathology results, and all of these were seen to be hypofluorescent compared with surrounding renal parenchyma during intraoperative imaging. The imaging behavior of benign tumors ranged from isofluorescent to hyperfluorescent compared with normal parenchyma. No complications were associated with ICG injection. CONCLUSION NIRF imaging after intravenous ICG administration may be a useful intraoperative imaging tool to differentiate malignant tumors from normal renal parenchyma during laparoscopic and robot-assisted partial nephrectomy. Advanced intraoperative imaging techniques such as this one may become increasingly helpful as more complicated tumors are resected with minimally invasive approaches.

Identifying additional lymph nodes in radical cystectomy lymphadenectomy specimens

Lymph node count has prognostic implications in bladder cancer patients who are treated with radical cystectomy. Lymph nodes that are too small to identify grossly can easily be missed, potentially leading to missed nodal metastases and inaccurate nodal counts, resulting in inaccurate prognoses. We investigated whether there is a benefit to submitting the entire lymph node packet for histological examination to identify additional lymph nodes. We prospectively assessed 61 pelvic lymphadenectomy specimens in 14 consecutive patients undergoing radical cystectomy. The specimens were placed in Carnoys solution overnight, then analyzed for lymph nodes. The residual tissue was entirely submitted to assess for additional lymph nodes. In 61 specimens, we identified 391 lymph nodes, ranging from 4–44 nodes per patient. We identified 238 (61%) lymph nodes with standard techniques and 153 (39%) lymph nodes in submitted residual tissue. The number of additional lymph nodes found in the residual tissue ranged from 0 to 26 (0–75%) per patient. These lymph nodes ranged in size from 0.05 to 1 cm. All additional lymph nodes were negative for metastatic disease. Submitting the entire specimen for histological examination allowed for identification of more lymph nodes in radical cystectomy pelvic lymphadenectomy specimens. However, as none of the additional lymph nodes contained metastatic disease, it is unclear if there is a clinical benefit in evaluating lymph nodes that are neither visible nor palpable in lymphadenectomy specimens.

Identification of extracellular vesicle-borne periostin as a feature of muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is an aggressive malignancy with high mortality, and heterogeneity in MIBC results in variable clinical outcomes, posing challenges for clinical management. Extracellular vesicles (EVs) derived from MIBC have been shown to promote cancer progression. EVs derived from bladder cell lines were subjected to proteomic analysis, and periostin was chosen for further characterization due to its stage-specific gene expression profile. Knockdown of periostin by RNA interference reduces invasiveness in vitro and produces a rounder morphology. Importantly, treating low grade BC cells with periostin-rich EVs promotes cell aggressiveness and activates ERK oncogenic signals, and periostin suppression reverses these effects. These data suggest that MIBC might transfer periostin in an EV-mediated paracrine manner to promote the disease. To determine the potential of periostin as a bladder cancer indicator, patient urinary EVs were examined and found to have markedly higher levels of periostin than controls. In addition, immunohistochemical staining of a bladder cancer tissue microarray revealed that the presence of periostin in MIBC cells is correlated with worse prognosis. In conclusion, periostin is a component of bladder cancer cells associated with poor clinical outcome, and EVs can transfer oncogenic molecules such as periostin to affect the tumor environment and promote cancer progression.

A novel in vitro assay of tumor-initiating cells in xenograft prostate tumors.

The field of prostate cancer has been stymied by the difficulty of cultivating patient‐derived samples in the laboratory. In order to help circumvent this challenge, we sought to develop an in vitro assay of human prostate cancer initiation employing a prostate‐associated mesenchymal feeder layer.

Characterization of urinary extracellular vesicle proteins in muscle-invasive bladder cancer

The mechanisms of bladder cancer progression are unknown, and new treatments and biomarkers are needed. Patient urinary extracellular vesicles (EVs) derive in part from bladder cancer cells and contain a specific protein cargo which may provide information about the disease. We conducted a proteomics study comparing EVs from the muscle-invasive bladder cancer (MIBC) cell line TCCSUP to EVs from normal urothelial line SVHUC. GO term analysis showed that TCCSUP EVs are enriched in proteins associated with the cell membrane, extracellular matrix, and inflammation and angiogenesis signaling pathways. Proteins characteristic of cancer EVs were further screened at the mRNA level in bladder cancer cell lines. In Western blots, three of six proteins examined showed greater than fifteenfold enrichment in patient urinary EVs compared to healthy volunteers (n = 6). Finally, we performed immunohistochemical staining of bladder tissue microarrays for three proteins of interest. One of them, transaldolase (TALDO1), is a nearly ubiquitous enzyme and normally thought to reside in the cytoplasm. To our surprise, nuclei were stained for transaldolase in 94% of MIBC tissue samples (n = 51). While cytoplasmic transaldolase was found in 89–90% of both normal urothelium (n = 79) and non-muscle-invasive samples (n = 71), the rate falls to 39% in MIBC samples (P < 0.001), and negative cytoplasmic staining was correlated with worse cancer-specific survival in MIBC patients (P = 0.008). The differential EV proteomics strategy reported here successfully identified a number of proteins associated with bladder cancer and points the way to future investigation.

MP65-02 CANCER EXTRACELLULAR VESICLES PROMOTE BLADDER TUMORIGENESIS BY INDUCING CHRONIC ENDOPLASMIC RETICULUM STRESS AND INFLAMMATION: A NOVEL MECHANISM FOR FIELD CANCERIZATION

of BC patients. In addition, BCG induced expression of key immunomodulatory molecules in BC cells and within the EVs. This up-regulated expression of immuno-molecules in response to BCG supports the hypothesis that EVs have a role in activating the immune system during BCG immunotherapy. The immunologically active EVs detected in patients’ urine can be further explored as predictive biomarkers.

MP65-01 EXTRACELLULAR VESICLES AS A POSSIBLE MECHANISM FOR BACILLUS CALMETTE-GUÉRIN IMMUNOTHERAPY

INTRODUCTION AND OBJECTIVES: Persistently elevated prostate-specific antigen (PSA) after radical prostatectomy (RP) is associated with recurrent disease and poor prognosis. Predictors that may be associated with persistent PSA need to be evaluated in order to better counsel patients and gauge postoperative outcomes. We sought to assess independent clinical and pathologic predictors of persistently elevated PSA after RP in a contemporary cohort. METHODS: We identified a cohort of patients with non-metastatic prostate cancer who underwent RP from 2006-2016 at the Cleveland Clinic Foundation. Independent predictors of persistently elevated PSA were identified using chi-square and multivariate logistic regression analyses, accounting for patient demographic and clinicopathologic factors. Persistently elevated PSA was defined as 0.1 six weeks after RP. RESULTS: Of a total 2,710 patients undergoing RP, 158 patients had persistently elevated PSA after surgery (5.8%). On multivariate analysis, clinicopathologic factors associated with persistently elevated PSA included initial PSA >20 ng/mL (OR 2.8; p<0.01), extraprostatic extension (OR 3.3; p<0.01), seminal vesicle invasion (OR 1.6; p1⁄40.048), positive surgical margin (OR 2.0; p<0.01), lymph node involvement (OR 2.5; p<0.01), and pathologic Gleason score 8 (OR 4.5; p<0.01). CONCLUSIONS: With persistently elevated PSA after RP recognized as a marker of continued disease progression, clinicopathologic factors that predicted persistently elevated PSA were characterized in a contemporary cohort. These results highlight factors that can assist with determination of necessity for adjuvant therapy and help with better patient counseling prior to and following prostatectomy.