Maria M. Shevchuk

Anatomical grades of nerve sparing: a risk-stratified approach to neural-hammock sparing during robot-assisted radical prostatectomy (RARP).

Whats known on the subject? and What does the study add?

Effect of a Risk-stratified Grade of Nerve-sparing Technique on Early Return of Continence After Robot-assisted Laparoscopic Radical Prostatectomy

BACKGROUND The impact of nerve sparing (NS) on urinary continence recovery after robot-assisted laparoscopic radical prostatectomy (RALP) has yet to be defined. OBJECTIVE To evaluate the effect of a risk-stratified grade of NS technique on early return of urinary continence. DESIGN, SETTING, AND PARTICIPANTS Data were collected from 1546 patients who underwent RALP by a single surgeon at a tertiary care center from December 2008 to October 2011. Patients were categorized preoperatively by a risk-stratified approach into risk grades 1-4, with risk grade 1 patients more likely to receive NS grade 1 or complete hammock preservation. This categorization was also conducted for risk grades 2-4, with grade 4 patients receiving a non-NS procedure. INTERVENTION Risk-stratified grading of NS RALP. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Univariate and multivariate analysis identified predictors of early return of urinary continence, defined as no pad use at ≤ 12 wk postoperatively. RESULTS AND LIMITATIONS Early return of continence was achieved by 791 of 1417 men (55.8%); of those, 199 of 277 (71.8%) were in NS grade 1, 440 of 805 (54.7%) were in NS grade 2, 132 of 289 (45.7%) were in NS grade 3, and 20 of 46 (43.5%) were in NS grade 4 (p<0.001). On multivariate analysis, better NS grade was a significant independent predictor of early return of urinary continence when NS grade 1 was the reference variable compared with NS grade 2 (p<0.001; odds ratio [OR]: 0.46), NS grade 3 (p<0.001; OR: 0.35), and NS grade 4 (p=0.001; OR: 0.29). Lower preoperative International Prostate Symptom Score (p=0.001; OR: 0.97) and higher preoperative Sexual Health Inventory for Men score (p=0.002; OR: 1.03) were indicative of early return of urinary continence. Positive surgical margin rates were 7.2% (20 of 277) of grade 1 cases, 7.6% (61 of 805) of grade 2 cases, 7.6% (22 of 289) of grade 3 cases, and 17.4% (8 of 46) of grade 4 cases (p=0.111). Extraprostatic extension occurred in 6.1% (17 of 277) of NS grade 1 cases, 17.5% (141 of 805) of NS grade 2 cases, 42.5% (123 of 289) of NS grade 3 cases, and 63% (29 of 46) of NS grade 4 cases (p<0.001). Some limitations of the study are that the study was not randomized, grading of NS was subjective, and possible selection bias existed. CONCLUSIONS Our study reports a correlation between risk-stratified grade of NS technique and early return of urinary continence as patients with a lower grade (higher degree) of NS achieved an early return of urinary continence without compromising oncologic safety.

Generation of a Mouse Model of Von Hippel-Lindau Kidney Disease Leading to Renal Cancers by Expression of a Constitutively Active Mutant of HIF1α

Renal cancers are highly aggressive and clinically challenging, but a transgenic mouse model to promote pathologic studies and therapeutic advances has yet to be established. Here, we report the generation of a transgenic mouse model of von Hippel-Lindau (VHL) renal cancer termed the TRACK model (transgenic model of cancer of the kidney). TRACK mice specifically express a mutated, constitutively active HIF1α in kidney proximal tubule (PT) cells. Kidney histologies displayed by TRACK mice are highly similar to histologies seen in patients with VHL disease, including areas of distorted tubular structure, cells with clear cytoplasm and increased glycogen and lipid deposition, multiple renal cysts, and early onset of clear cell renal cell carcinoma (ccRCC). Distorted tubules in TRACK mice exhibit higher levels of CA-IX, Glut1, and VEGF than tubules in nontransgenic control mice. Furthermore, these tubules exhibit increased numbers of endothelial cells, increased cell proliferation, and increased expression of the human ccRCC marker CD70(TNFSF7). Moreover, PT cells in kidney tubules from TRACK mice exhibit increased genomic instability, as monitored by elevated levels of γH2AX. Our findings establish that activated HIF1α in murine kidney PT cells is sufficient to promote cell proliferation, angiogenesis, genomic instability, and other phenotypic alterations characteristic of human VHL kidney disease, establishing the TRACK mouse as a valid preclinical model of human renal cell carcinoma.

Anatomical retro-apical technique of synchronous (posterior and anterior) urethral transection: a novel approach for ameliorating apical margin positivity during robotic radical prostatectomy.

Study Type – Therapy (case series)
Level of Evidence 4

Multiphoton microscopy for structure identification in human prostate and periprostatic tissue: implications in prostate cancer surgery

Study Type – Diagnostic (exploratory cohort)

Visual cues as a surrogate for tactile feedback during robotic-assisted laparoscopic prostatectomy: posterolateral margin rates in 1340 consecutive patients.

Study Type – Therapy (case series)
Level of Evidence 4

Activation of HIF2α in kidney proximal tubule cells causes abnormal glycogen deposition but not tumorigenesis.

Renal cell carcinoma (RCC) is the most common primary cancer arising from the kidney in adults, with clear cell renal cell carcinoma (ccRCC) representing approximately 75% of all RCCs. Increased expression of the hypoxia-induced factors-1α (HIF1α) and HIF2α has been suggested as a pivotal step in ccRCC carcinogenesis, but this has not been thoroughly tested. Here, we report that expression of a constitutively activated form of HIF2α (P405A, P530A, and N851A, named as HIF2αM3) in the proximal tubules of mice is not sufficient to promote ccRCC by itself, nor does it enhance HIF1αM3 oncogenesis when coexpressed with constitutively active HIF1αM3. Neoplastic transformation in kidneys was not detected at up to 33 months of age, nor was increased expression of Ki67 (MKI67), γH2AX (H2AFX), or CD70 observed. Furthermore, the genome-wide transcriptome of the transgenic kidneys does not resemble human ccRCC. We conclude that a constitutively active HIF2α is not sufficient to cause neoplastic transformation of proximal tubules, arguing against the idea that HIF2α activation is critical for ccRCC tumorigenesis.

Full-field optical coherence tomography for the analysis of fresh unstained human lobectomy specimens

Background: Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that generates high-resolution three-dimensional tomographic images from unprocessed and unstained tissues. Lack of tissue processing and associated artifacts, along with the ability to generate large-field images quickly, warrants its exploration as an alternative diagnostic tool. Materials and Methods: One section each from the tumor and from adjacent non-neoplastic tissue was collected from 13 human lobectomy specimens. They were imaged fresh with FFOCT and then submitted for routine histopathology. Two blinded pathologists independently rendered diagnoses based on FFOCT images. Results: Normal lung architecture (alveoli, bronchi, pleura and blood vessels) was readily identified with FFOCT. Using FFOCT images alone, the study pathologists were able to correctly identify all tumor specimens and in many cases, the histological subtype of tumor (e.g., adenocarcinomas with various patterns). However, benign diagnosis was provided with high confidence in roughly half the tumor-free specimens (others were diagnosed as equivocal or false positive). Further analysis of these images revealed two major confounding features: (a) Extensive lung collapse and (b) presence of smoker′s macrophages. On a closer inspection, however, the smoker′s macrophages could often be identified as distinct from tumor cells based on their relative location in the alveoli, size and presence of anthracosis. We posit that greater pathologist experience, complemented with morphometric analysis and color-coding of image components, may help minimize the contribution of these confounders in the future. Conclusion: Our study provides evidence for the potential utility of FFOCT in identifying and differentiating lung tumors from non-neoplastic lung tissue. We foresee its potential as an adjunct to intra-surgical frozen section analysis for margin assessment, especially in limited lung resections.

Pilot Study of the Correlation of Multiphoton Tomography of Ex Vivo Human Testis with Histology

PURPOSE Although microdissection testicular sperm extraction has become first line therapy for sperm retrieval in men with nonobstructive azoospermia, there are challenges to the procedure, including difficulty differentiating between seminiferous tubules with normal and abnormal spermatogenesis. Multiphoton microscopy illuminates tissue with a near infrared laser to elicit autofluorescence, which enables real-time imaging of unprocessed tissue without labels. We hypothesized that we could accurately characterize seminiferous tubular histology in humans using multiphoton microscopy. MATERIALS AND METHODS Seven men with normal or abnormal spermatogenesis underwent testicular biopsies, which were imaged by multiphoton microscopy. We assessed these images in blinded fashion. The diagnosis rendered with multiphoton microscopy was then correlated with that of hematoxylin and eosin stained tissue. We evaluated the ability of multiphoton microscopy to differentiate normal from abnormal seminiferous tubules by examining autofluorescence characteristics and diameters, as imaged by multiphoton microscopy. Assessment was repeated with stained slides and results were compared. RESULTS The overall concordance rate between multiphoton microscopy and stained slides was 86%. The seminiferous tubules of patients with nonobstructive azoospermia were smaller than those of controls when measured by multiphoton microscopy and staining (p <0.05). The proportion of normal tubules and the diameters obtained with multiphoton microscopy were not different from those obtained with hematoxylin and eosin (p >0.05). CONCLUSION Multiphoton microscopy can be used to differentiate normal from abnormal spermatogenesis. Its characterization of seminiferous tubular architecture is similar to that provided by hematoxylin and eosin staining. Further investigation of the clinical applications of multiphoton microscopy may improve surgical sperm retrieval outcomes for patients with nonobstructive azoospermia.

Next-generation prostate cancer biobanking: toward a processing protocol amenable for the International Cancer Genome Consortium.

Next-generation DNA and RNA sequencing requires intact nucleic acids from high-quality human tissue samples to better elucidate the molecular basis of cancer. We have developed a prostate biobanking protocol to acquire suitable samples for sequencing without compromising the accuracy of clinical diagnosis. To assess the clinical implications of implementing this protocol, we evaluated 105 consecutive radical prostatectomy specimens from November 2008 to February 2009. Alternating levels of prostate samples were submitted to Surgical Pathology as formalin-fixed, paraffin-embedded blocks and to the institutional biobank as frozen blocks. Differences in reported pathologic characteristics between clinical and procured specimens were compared. Clinical staging and grading were not affected by the biobank protocol. Tumor foci on frozen hematoxylin and eosin slides were identified and high-density tumor foci were scored and processed for DNA and RNA extractions for sequencing. Both DNA and RNA were extracted from 22 cases of 44 with high-density tumor foci. Eighty-two percent (18/22) of the samples passed rigorous quality control steps for DNA and RNA sequencing. To date, DNA extracted from 7 cases has undergone whole-genome sequencing, and RNA from 18 cases has been RNA sequenced. This protocol provides prostate tissue for high-throughput biomedical research and confirms the feasibility of actively integrating prostate cancer into The Cancer Genome Atlas Program, a member of the International Cancer Genome Consortium.