BRCA1 deficiencies cause breast, ovarian, prostate and other cancers, and render tumours hypersensitive to poly(ADP-ribose) polymerase (PARP) inhibitors. To understand the resistance mechanisms, we ...conducted whole-genome CRISPR-Cas9 synthetic-viability/resistance screens in BRCA1-deficient breast cancer cells treated with PARP inhibitors. We identified two previously uncharacterized proteins, C20orf196 and FAM35A, whose inactivation confers strong PARP-inhibitor resistance. Mechanistically, we show that C20orf196 and FAM35A form a complex, 'Shieldin' (SHLD1/2), with FAM35A interacting with single-stranded DNA through its C-terminal oligonucleotide/oligosaccharide-binding fold region. We establish that Shieldin acts as the downstream effector of 53BP1/RIF1/MAD2L2 to promote DNA double-strand break (DSB) end-joining by restricting DSB resection and to counteract homologous recombination by antagonizing BRCA2/RAD51 loading in BRCA1-deficient cells. Notably, Shieldin inactivation further sensitizes BRCA1-deficient cells to cisplatin, suggesting how defining the SHLD1/2 status of BRCA1-deficient tumours might aid patient stratification and yield new treatment opportunities. Highlighting this potential, we document reduced SHLD1/2 expression in human breast cancers displaying intrinsic or acquired PARP-inhibitor resistance.
Objectives
Evidence of the accuracy of predictive tests in confirming the presence and grade of upper urinary tract urothelial carcinomas (UUTUC) is limited. We present the largest series evaluating ...the diagnostic value of pre- and intra-operative parameters in the detection of UUTUC.
Materials and methods
We retrospectively analysed records of patients who underwent diagnostic ureteroscopy between 2005 and 2014 for suspected UUTUC. Pre-operative workup included voided urine cytology and CT imaging. Intra-operative assessments involved ureteroscopy to directly visualise suspicious lesions, and where possible selective cytology and biopsy. Primary outcomes were the visualisation of UUTUC and histopathological confirmation of tumour.
Results
Hundred out of 160 (63 %) patients presenting with suspected upper tract malignancy had UUTUC. Voided and selective urine cytology and CT individually predicted UUTUC with a sensitivity/specificity of 63/67, 76/73, and 95/26 %, respectively. Forty out of 48 (83 %) patients who had abnormal CT and abnormal voided urine cytology had UUTUC, while 100 % of those with normal CT and normal voided cytology (investigated for ongoing symptoms) were normal. Comparing endoscopic biopsy to nephroureterectomy specimen grade, 19 (46 %), 18 (44 %), and 4 (10 %) were identical, upgraded, and downgraded, respectively.
Conclusion
Pre-operative investigations can predict UUTUCs. When these investigations were normal, the risk of UUTUC is negligible. In selective patients with abnormal investigations, ureteroscopy should be performed to confirm and predict the grade of UUTUC, in order to guide future management. Selective cytology is unlikely to significantly contribute to the diagnostic workup of UUTUC.
Abstract Background Robotic-assisted laparoscopic radical prostatectomy is a current standard treatment for localized prostate cancer, with treatment failure defined by biochemical recurrence (BCR). ...Open radical prostatectomy series have identified the presence of a positive surgical margin (PSM) as a predictor of long-term recurrence, a measure that is affected by the surgeon׳s skill. We evaluate the effect of PSM parameters on BCR rates from robotic-assisted laparoscopic radical prostatectomy, across 3 high-volume institutions. Methods De-identifiable clinicopathological and histopathological data were prospectively collected for 4,001 patients with at least 3 years of follow-up. Kaplan-Meier plots and 3 statistical models were used to evaluate the effect of margin parameters on BCR, via crude rates, traditional multivariable Cox regression, and a propensity-adjusted Cox regression model. Results Overall, 37% of men with a PSM developed BCR compared with 10% of men with negative margins (hazard ratio HR = 1.81, 95% CI: 1.47–2.22). Length ≥3 mm or a multifocal positive margin was associated with a higher risk of BCR compared with negative margin cases. On multivariable Cox regression analysis of the positive margin cohort, only apical margins significantly predicted BCR relative to basal margins (HR = 2.03, 95% CI: 1.01–4.09), whereas there was no significant difference in BCR rates for posterolateral margins relative to basal margins (HR = 1.62, 95% CI: 0.84–3.11). Propensity-adjusted modeling confirmed a greater effect of apical compared with posterolateral PSM. Conclusions A PSM length ≥3 mm is predictive of BCR, as is to a lesser extent multiple positive margins. In contrast to open prostatectomy series, posterolateral margins carry a smaller risk of BCR compared with apical margins.
Purpose
To describe and compare differences in peri-operative outcomes of robot-assisted (RA-RPLND) and open (O-RPLND) retroperitoneal lymph node dissection performed by a single surgeon where ...chemotherapy is the standard initial treatment for Stage 2 or greater non-seminomatous germ cell tumour.
Methods
Review of a prospective database of all RA-RPLNDs (28 patients) and O-RPLNDs (72 patients) performed by a single surgeon from 2014 to 2020. Peri-operative outcomes were compared for patients having RA-RPLND to all O-RPLNDs and a matched cohort of patients having O-RPLND (20 patients). Further comparison was performed between all patients in the RA-RPLND group (21 patients) and matched O-RPLND group (18 patients) who had previous chemotherapy. RA-RPLND was performed for patients suitable for a unilateral template dissection. O-RPLND was performed prior to the introduction of RA-RPLND and for patients not suitable for RA-RPLND after its introduction.
Results
RA-RPLND showed improved peri-operative outcomes compared to the matched cohort of O-RPLND—median blood loss (50 versus 400 ml,
p
< 0.00001), operative duration (150 versus 195 min,
p
= 0.023) length-of-stay (1 versus 5 days,
p
< 0.00001) and anejaculation (0 versus 4,
p
= 0.0249). There was no statistical difference in complication rates. RA-RPLND had lower median lymph node yields although not significant (9 versus 13,
p
= 0.070). These improved peri-operative outcomes were also seen in the post-chemotherapy RA-RPLND versus O-RPLND analysis. There were no tumour recurrences seen in either group with median follow-up of 36 months and 60 months, respectively.
Conclusions
Post-chemotherapy RA-RPLND may have decreased blood loss, operative duration, hospital length-of-stay and anejaculation rates in selected cases and should, therefore, be considered in selected patients. Differences in oncological outcomes require longer term follow-up.
Purpose
Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are an increasing concern regarding antibiotic resistance and their potential to cause serious infections which are ...difficult to treat. The purpose of this surveillance programme was to assess the incidence of ESBL in adults amongst urinary isolates, identify risk factors, and detail the antibiotic susceptibility profile in order to guide empirical treatment.
Methods
From 2006 to 2014, we reviewed 21,414 positive urine cultures for
E. coli
and
Klebsiella
sp. from a University hospital in the UK and found 1420 ESBL-positive specimens. Susceptibility testing was performed by British Society of Antimicrobial Chemotherapy disc diffusion testing. ESBL screening was performed on samples resistant to cefpodoxime and confirmed by double disc diffusion (Oxoid Ltd, Basingstoke, UK). Patient gender, age, inpatient status, and catheterisation were assessed as risk factors.
Results
ESBL production amongst
E. coli
urine cultures increased 44 %, from 4.6 to 6.6 % of all
E. coli
isolates. ESBL-positive organisms were associated with increases in drug resistance, particularly amongst fluoroquinolones, trimethoprim, and cephalexin. Multidrug resistance was a feature with 75 % of ESBL+
Klebsiella
sp.-resistant ≥6 antibiotic classes. ESBL producers remained largely susceptible to carbapenems. Male gender, urinary catheterisation, inpatient status, and increasing age were identified as risk factors for ESBL infection or colonisation.
Conclusion
We demonstrate that the incidence of ESBL-producing
E. coli
in urine cultures is increasing and that such isolates are multidrug resistant. Carbapenems and nitrofurantoin for
E. coli
infections remain effective, which may guide empirical antibiotic therapy.
Prostate cancer screening using prostate-specific antigen (PSA) has been shown to reduce mortality but with substantial overdiagnosis, leading to unnecessary biopsies. The identification of a highly ...specific biomarker using liquid biopsies, represents an unmet need in the diagnostic pathway for prostate cancer. In this study, we employed a method that enriches for methylated cell-free DNA fragments coupled with a machine learning algorithm which enabled the detection of metastatic and localized cancers with AUCs of 0.96 and 0.74, respectively. The model also detected 51.8% (14/27) of localized and 88.7% (79/89) of patients with metastatic cancer in an external dataset. Furthermore, we show that the differentially methylated regions reflect epigenetic and transcriptomic changes at the tissue level. Notably, these regions are significantly enriched for biologically relevant pathways associated with the regulation of cellular proliferation and TGF-beta signaling. This demonstrates the potential of circulating tumor DNA methylation for prostate cancer detection and prognostication.
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•Enrichment of methylated cell-free DNA identifies prostate cancer biomarkers•A machine learning model detects prostate cancer using the identified biomarkers•The biomarkers are enriched for genes in cancer-related signaling pathways
Cancer; Machine learning
Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and ...determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment.
From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom.
Of these cultures, 542 (9.8%) were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin-resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance.
The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin-resistant Enterococcus sp.
There has been confusion about the subunit stoichiometry of the degenerin family of ion channels. Recently, a crystal structure of acid-sensing ion channel (ASIC) 1a revealed that it assembles as a ...trimer. Here, we used atomic force microscopy (AFM) to image unprocessed ASIC1a bound to mica. We detected a mixture of subunit monomers, dimers and trimers. In some cases, triple-subunit clusters were clearly visible, confirming the trimeric structure of the channel, and indicating that the trimer sometimes disaggregated after adhesion to the mica surface. This AFM-based technique will now enable us to determine the subunit arrangement within heteromeric ASICs.
Study Type – Therapy (case series)
Level of Evidence 4
What's known on the subject? and What does the study add?
Open partial nephrectomy has been defined as the standard of care for the treatment of ...small renal masses. Robotic platforms may offer the solution to bridge the gap between open and laparoscopic approaches, providing similar oncological and functional results via a shorter learning curve.
This study reviews the current literature, and reports developments in robotic‐assisted partial nephrectomy (RPN). It highlights the important results from various studies which investigate the oncological and functional efficacy of RPN, and establishes its current status as at least equivalent to the laparoscopic approach. Trends are emerging that highlight the advantage of the robotic interface in facilitating this approach, and we postulate that this may become more apparent in future studies.
OBJECTIVE
•
To establish its current status, this study reviews the literature, and reports developments in robotic‐assisted partial nephrectomy (RPN), highlighting results from various studies that investigate the oncological and functional efficacy of RPN. Partial nephrectomy has become the standard therapy for the management of small renal masses. In an effort to overcome the perioperative morbidity associated with an open approach, and the extended warm ischaemia times associated with a laparoscopic approach, robotic platforms have been introduced.
PATIENTS AND METHODS
•
A search of Medline, EMBASE and Cochrane library databases was completed in July 2010 and used to identify pertinent original articles, editorials, comments and reviews, using the search term ‘partial nephrectomy’. Links to related references were surveyed, and all articles finally included were based on relevance and importance of content, as determined by the authors.
RESULTS
•
The robotic platform may offer the solution to bridge the gap between open and laparoscopic approaches, achieving warm ischaemia times that consistently average 20 minutes, and providing similar oncological and functional results via a shorter learning curve. It offers cosmesis and convalescence equivalent to that from laparoscopic partial nephrectomy, but with potentially fewer postoperative complications.
CONCLUSION
•
In terms of oncological and functional outcomes, the early experiences of RPN in selected series of patients appear at least equivalent to open and laparoscopic partial nephrectomy series. Randomized comparisons between the approaches are lacking, as are longer‐term follow‐up data for the robotic technique and formal cost analysis; these will be necessary before RPN can replace open partial nephrectomy as the new standard for the management of small renal masses. Trends continue to emerge that highlight the advantage of using the robotic platform to achieve a minimally invasive approach for partial nephrectomy, and with time and increasing expertise, this may become further apparent.
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