Gopal N. Gupta

Multiparametric Magnetic Resonance Imaging and Ultrasound Fusion Biopsy Detect Prostate Cancer in Patients with Prior Negative Transrectal Ultrasound Biopsies

PURPOSE Patients with negative transrectal ultrasound biopsies and a persistent clinical suspicion are at risk for occult but significant prostate cancer. The ability of multiparametric magnetic resonance imaging/ultrasound fusion biopsy to detect these occult prostate lesions may make it an effective tool in this challenging scenario. MATERIALS AND METHODS Between March 2007 and November 2011 all men underwent prostate 3 T endorectal coil magnetic resonance imaging. All concerning lesions were targeted with magnetic resonance imaging/ultrasound fusion biopsy. In addition, all patients underwent standard 12-core transrectal ultrasound biopsy. Men with 1 or more negative systematic prostate biopsies were included in our cohort. RESULTS Of the 195 men with previous negative biopsies, 73 (37%) were found to have cancer using the magnetic resonance imaging/ultrasound fusion biopsy combined with 12-core transrectal ultrasound biopsy. High grade cancer (Gleason score 8+) was discovered in 21 men (11%), all of whom had disease detected with magnetic resonance imaging/ultrasound fusion biopsy. However, standard transrectal ultrasound biopsy missed 12 of these high grade cancers (55%). Pathological upgrading occurred in 28 men (38.9%) as a result of magnetic resonance imaging/ultrasound fusion targeting vs standard transrectal ultrasound biopsy. The diagnostic yield of combined magnetic resonance imaging/ultrasound fusion platform was unrelated to the number of previous negative biopsies and persisted despite increasing the number of previous biopsy sessions. On multivariate analysis only prostate specific antigen density and magnetic resonance imaging suspicion level remained significant predictors of cancer. CONCLUSIONS Multiparametric magnetic resonance imaging with a magnetic resonance imaging/ultrasound fusion biopsy platform is a novel diagnostic tool for detecting prostate cancer and may be ideally suited for patients with negative transrectal ultrasound biopsies in the face of a persistent clinical suspicion for cancer.

Low Suspicion Lesions on Multiparametric Magnetic Resonance Imaging Predict for the Absence of High Risk Prostate Cancer

Study Type – Diagnostic (case series) Level of Evidence 4 Whats known on the subject? and What does the study add? Over‐treatment of indolent prostate cancer lesions is a problem which can result in increased human and medical costs. Lesions with a low suspician level at mpMRI of the prostate have low risk of including high risk prostate cancer.

Characterization of Uptake and Internalization of Exosomes by Bladder Cancer Cells

Bladder tumors represent a special therapeutic challenge as they have a high recurrence rate requiring repeated interventions and may progress to invasive or metastatic disease. Exosomes carry proteins implicated in bladder cancer progression and have been implicated in bladder cancer cell survival. Here, we characterized exosome uptake and internalization by human bladder cancer cells using Amnis ImageStreamX, an image cytometer. Exosomes were isolated by ultracentrifugation from bladder cancer culture conditioned supernatant, labeled with PKH-26, and analyzed on the ImageStreamX with an internal standard added to determine concentration. Exosomes were cocultured with bladder cancer cells and analyzed for internalization. Using the IDEAS software, we determined exosome uptake based on the number of PKH-26+ spots and overall PKH-26 fluorescence intensity. Using unlabeled beads of a known concentration and size, we were able to determine concentrations of exosomes isolated from bladder cancer cells. We measured exosome uptake by recipient bladder cancer cells, and we demonstrated that uptake is dose and time dependent. Finally, we found that uptake is active and specific, which can be partially blocked by heparin treatment. The characterization of cellular uptake and internalization by bladder cancer cells may shed light on the role of exosomes on bladder cancer recurrence and progression.

Robot-assisted laparoscopic partial nephrectomy for tumors greater than 4 cm and high nephrometry score: feasibility, renal functional, and oncological outcomes with minimum 1 year follow-up.

OBJECTIVES Minimally invasive robotic assistance is being increasingly utilized to treat larger complex renal masses. We report on the technical feasibility and renal functional and oncologic outcomes with minimum 1 year follow-up of robot-assisted laparoscopic partial nephrectomy (RALPN) for tumors greater than 4 cm. MATERIALS AND METHODS The urologic oncology database was queried to identify patients treated with RALPN for tumors greater than 4 cm and a minimum follow-up of 12 months. We identified 19 RALPN on 17 patients treated between June 2007 and July 2009. Two patients underwent staged bilateral RALPN. Demographic, operative, and pathologic data were collected. Renal function was assessed by serum creatinine levels, estimated glomerular filtration rate, and nuclear renal scans assessed at baseline, 3, and 12 months postoperatively. All tumors were assigned R.E.N.A.L. nephrometry scores (http://www.nephrometry.com). RESULTS The median nephrometry score for the largest tumor from each kidney was 9 (range 6-11) while the median size was 5 cm (range 4.1-15). Three of 19 cases (16%) required intraoperative conversion to open partial nephrectomy. No renal units were lost. There were no statistically significant differences between preoperative and postoperative creatinine and eGFR. A statistically significant decline of ipsilateral renal scan function (49% vs. 46.5%, P = 0.006) was observed at 3 months and at 12 mo postoperatively (49% vs. 45.5%, P = 0.014). None of the patients had evidence of recurrence or metastatic disease at a median follow-up of 22 months (range 12-36). CONCLUSIONS RALPN is feasible for renal tumors greater than 4 cm with moderate or high nephrometry scores. Although there was a modest decline in renal function of the operated unit, RALPN may afford the ability resect challenging tumors requiring complex renal reconstruction. The renal functional and oncologic outcomes are promising at a median follow-up of 22 months, but longer follow-up is required.

Osteopontin Mediates an MZF1-TGF-β1-Dependent Transformation of Mesenchymal Stem Cells into Cancer Associated Fibroblasts in Breast Cancer

Interactions between tumor cells and cancer-associated fibroblasts (CAFs) in the tumor microenvironment significantly influence cancer growth and metastasis. Transforming growth factor-β (TGF-β) is known to be a critical mediator of the CAF phenotype, and osteopontin (OPN) expression in tumors is associated with more aggressive phenotypes and poor patient outcomes. The potential link between these two pathways has not been previously addressed. Utilizing in vitro studies using human mesenchymal stem cells (MSCs) and MDA-MB231 (OPN+) and MCF7 (OPN−) human breast cancer cell lines, we demonstrate that OPN induces integrin-dependent MSC expression of TGF-β1 to mediate adoption of the CAF phenotype. This OPN–TGF-β1 pathway requires the transcription factor, myeloid zinc finger 1 (MZF1). In vivo studies with xenotransplant models in NOD-scid mice showed that OPN expression increases cancer growth and metastasis by mediating MSC-to-CAF transformation in a process that is MZF1 and TGF-β1 dependent. We conclude that tumor-derived OPN engenders MSC-to-CAF transformation in the microenvironment to promote tumor growth and metastasis via the OPN–MZF1–TGF-β1 pathway.

Targeted therapeutic strategies for the management of renal cell carcinoma.

Purpose of review This article reviews recent developments in the use of systemic targeted therapies for the treatment of advanced clear and nonclear cell renal cell carcinoma (RCC). The genetic/molecular basis of each form of RCC is discussed and current treatments and clinical trials are described. Recent findings The treatment of advanced RCC continues to be a major challenge for uro-oncologists. The rapid growth in therapeutic options has brought much needed improvements in overall and progression-free survival, although durable complete responses remain elusive. The recent identification of mutations in genes involved in chromatin remodeling will likely lead to the investigation of whether components of this critical process can also be valid therapeutic targets in clear cell RCC. Similarly, efforts to decipher the molecular mechanisms underlying nonclear cell variants of RCC are beginning to engender novel therapeutic strategies directed against these rarer forms of kidney cancer. Despite the availability of multiple treatment options, several challenges remain: selecting the best first-line or subsequent therapy for a given patient, the optimal sequencing of the various agents available, designing trials with appropriate comparison arms and endpoints, and identifying well tolerated and effective drug combinations. Summary Agents targeting the vascular endothelial growth factor and mammalian target of rapamycin pathways remain the mainstay in the management of metastatic RCC. Ongoing and future studies are expected to facilitate the development of therapeutic regimens that incorporate agents with improved tolerability and enhanced efficacy by continuing to capitalize on the strides made by basic and translational scientists in uncovering the mechanisms underlying the various forms of RCC.

Update on targeted therapies for clear cell renal cell carcinoma.

Purpose of review The article reviews the evolution of targeted therapies for clear cell renal cell carcinoma (RCC) and recent developments in the field. The vast majority of work in kidney cancer deals with clear cell RCC, which is the most common variant of this malignancy. The identification of loss of function of the von Hippel-Lindau protein as the basis for clear cell RCC, in addition to the well designed clinical trials that have ensued, provide an outstanding model for the development of mechanism-based targeted therapy in cancer. Recent findings The treatment of advanced and metastatic RCC continues to be a major challenge for uro-oncologists despite the approval of six targeted therapies over the past 5 years. This rapid growth in therapeutic options has brought much needed improvements in overall and progression-free survival, although durable complete responses are rare. However, the plurality of treatments also poses challenges in terms of selecting the best therapy for a given patient, designing trials with appropriate comparison arms and endpoints, identifying well tolerated and effective drug combinations or sequences, and determining the role of targeted therapies in the neoadjuvant and adjuvant settings. Summary Vascular endothelial growth factor and mammalian target of rapamycin-targeted therapies continue to play a critical role in the management of advanced and metastatic RCC. Ongoing research to identify novel agents continues to build upon the work done during the elucidation of the von Hippel-Lindau/clear cell RCC pathway. It is hoped that ongoing and planned studies will enable development of therapeutic regimens that will incorporate agents with improved toxicity and better efficacy as well as defining a role for a multidisciplinary approach to the management of advanced RCC.

Urothelial cells undergo epithelial-to-mesenchymal transition after exposure to muscle invasive bladder cancer exosomes

Bladder cancer, the fourth most common noncutaneous malignancy in the United States, is characterized by high recurrence rate, with a subset of these cancers progressing to a deadly muscle invasive form of disease. Exosomes are small secreted vesicles that contain proteins, mRNA and miRNA, thus potentially modulating signaling pathways in recipient cells. Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell–cell adhesion and gain migratory and invasive properties to become mesenchymal stem cells. EMT has been implicated in the initiation of metastasis for cancer progression. We investigated the ability of bladder cancer-shed exosomes to induce EMT in urothelial cells. Exosomes were isolated by ultracentrifugation from T24 or UMUC3 invasive bladder cancer cell conditioned media or from patient urine or bladder barbotage samples. Exosomes were then added to the urothelial cells and EMT was assessed. Urothelial cells treated with bladder cancer exosomes showed an increased expression in several mesenchymal markers, including α-smooth muscle actin, S100A4 and snail, as compared with phosphate-buffered saline (PBS)-treated cells. Moreover, treatment of urothelial cells with bladder cancer exosomes resulted in decreased expression of epithelial markers E-cadherin and β-catenin, as compared with the control, PBS-treated cells. Bladder cancer exosomes also increased the migration and invasion of urothelial cells, and this was blocked by heparin pretreatment. We further showed that exosomes isolated from patient urine and bladder barbotage samples were able to induce the expression of several mesenchymal markers in recipient urothelial cells. In conclusion, the research presented here represents both a new insight into the role of exosomes in transition of bladder cancer into invasive disease, as well as an introduction to a new platform for exosome research in urothelial cells.

Robot Assisted Laparoscopic Partial Adrenalectomy: Initial Experience

OBJECTIVES To evaluate the feasibility of performing robot-assisted laparoscopic partial adrenalectomy (RALPA) in patients seen at the National Cancer Institute and report the results of our initial experience. METHODS We reviewed the records of patients with adrenal masses who underwent attempted RALPA from July of 2008 until January of 2010. Demographic, perioperative, and pathologic data were collected. The functional and early oncological outcomes were examined by the need for steroid replacement and development of recurrent disease, respectively. RESULTS Ten patients underwent a total of 13 attempted RALPAs for removal of 19 adrenal tumors. There was one open conversion with successful completion of partial adrenalectomy. Of the patients, 80% had a known hereditary syndrome predisposing them to adrenal tumors. One patient had bilateral multifocal adrenal masses with unknown germ line genetic alteration and 1 patient had a sporadic adrenal mass. Of the 19 tumors removed, 17 were pheochromocytoma and 2 were adrenal-cortical hyperplasia. Two patients underwent partial adrenalectomy on a solitary adrenal gland, with one subsequently requiring steroid replacement postoperatively. On postoperative imaging, all but one operated adrenal gland demonstrated contrast enhancement. No patient developed local recurrence at a median follow-up of 16.2 months (range, 2-29). CONCLUSIONS RALPA appears safe and feasible in our early experience. Only 1 patient in our series required steroid replacement. Local recurrence rates are low but will require longer follow-up.

Evolving therapeutic targets in renal cell carcinoma.

Purpose of review Recent developments in the treatment of advanced renal cell carcinoma (RCC) will be discussed, with emphasis on data published over the past year. The genetics and molecular biology of the various histologic subtypes of kidney cancer will be reviewed, as these subtle yet important genomic and metabolic alterations provide the opportunity for rational drug development and personalized treatment regimens. Recent findings Additional targeted agents continue to be added to the uro-oncologists armamentarium in the fight against metastatic kidney cancer. Targeting the vascular endothelial growth factor and its receptor, or the mammalian target of rapamycin complex, remains the foundation of systemic treatment. In clear cell RCC, increased emphasis is being placed on target selectivity and affinity in a bid to diminish off-target toxicity without compromising efficacy. Combination strategies targeting multiple pathways simultaneously continue to be explored. Histology-specific protocols testing later generation and novel agents in nonclear cell RCC should be made a priority, as there is still not a single drug approved specifically for a nonclear cell indication. Summary The number of approved treatments for advanced RCC continues to grow, but additional work is needed to further delineate the optimal drug, combination of agents, or sequence best suited to each subtype of RCC.