Rapid and Accurate Detection of the SARS-CoV-2 Omicron Variant with a CRISPR-Cas12a Reaction in the RT-qPCR Pot

Gene sequencing in back of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the current approach for discriminating infections produced by different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants in the clinic. However, sequencing is often a time-consuming step, which hinders the deployment of a very fast response during a pandemic. Here, we propose to run a CRISPR-Cas12a reaction after completing the RT-qPCR and in the very same pot to detect with high specificity genetic marks characterizing variants of concern. A crRNA was appropriately designed to detect the S gene of the SARS-CoV-2 Omicron BA.1 variant. A significant response with >20-fold dynamic range was obtained for the Omicron BA.1 S gene, while the Delta S gene did not produce any detectable signal. The sensitivity of the method was analyzed with a series of diluted samples and different Cas12a nucleases. A correlation between the RT-qPCR CT values and the CRISPR-Cas12a reaction signals was observed. Variant discrimination with the CRISPR-Cas12a reaction was possible in some minutes with high accuracy from patient samples. In conclusion, CRISPR-Cas systems seem ready to be exploited in the clinic to boost personalized diagnoses and accelerate epidemiological surveillance in a cost-effective way.

Loop diuretic down-titration at discharge in patients hospitalized for acute heart failure

AIMS

The current literature provides limited guidance on the best diuretic strategy post-hospitalization for acute heart failure (AHF). It is postulated that the efficacy and safety of the outpatient diuretic regimen may be significantly influenced by the degree of fluid overload (FO) encountered during hospitalization. We hypothesize that in patients with more pronounced FO, reducing their regular oral diuretic dosage might be associated with an elevated risk of unfavourable clinical outcomes.

METHODS AND RESULTS

It was a retrospective observational study of 410 patients hospitalized for AHF in which the dose of furosemide at admission and discharge was collected. Patients were categorized across diuretic dose status into two groups: (i) the down-titration group and (ii) the stable/up-titration group. FO status was evaluated by a clinical congestion score and circulating biomarkers. The endpoint of interest was the composite of time to all-cause death and/or heart failure readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 86 (78-92) years, 256 (62%) were women, and 80% had heart failure with preserved ejection fraction. After multivariate adjustment, the down-titration furosemide equivalent dose remained not associated with the risk of the combined endpoint in the whole sample (hazard ratio 1.34, 95% confidence interval 0.86-2.06, P = 0.184). The risk of the combination of death and/or worsening heart failure associated with the diuretic strategy at discharge was significantly influenced by FO status, including clinical congestion scores and circulating proxies of FO like BNP and cancer antigen 125.

CONCLUSIONS

In patients hospitalized for AHF, furosemide down-titration does not imply an increased risk of mortality and/or heart failure readmission. However, FO status modifies the effect of down-titration on the outcome. In patients with severe congestion or residual congestion at discharge, down-titration was associated with an increased risk of mortality and/or heart failure readmission.

Repurposing the mammalian RNA-binding protein Musashi-1 as an allosteric translation repressor in bacteria

The RNA recognition motif (RRM) is the most common RNA-binding protein domain identified in nature. However, RRM-containing proteins are only prevalent in eukaryotic phyla, in which they play central regulatory roles. Here, we engineered an orthogonal post-transcriptional control system of gene expression in the bacterium Escherichia coli with the mammalian RNA-binding protein Musashi-1, which is a stem cell marker with neurodevelopmental role that contains two canonical RRMs. In the circuit, Musashi-1 is regulated transcriptionally and works as an allosteric translation repressor thanks to a specific interaction with the N-terminal coding region of a messenger RNA and its structural plasticity to respond to fatty acids. We fully characterized the genetic system at the population and single-cell levels showing a significant fold change in reporter expression, and the underlying molecular mechanism by assessing the in vitro binding kinetics and in vivo functionality of a series of RNA mutants. The dynamic response of the system was well recapitulated by a bottom-up mathematical model. Moreover, we applied the post-transcriptional mechanism engineered with Musashi-1 to specifically regulate a gene within an operon, implement combinatorial regulation, and reduce protein expression noise. This work illustrates how RRM-based regulation can be adapted to simple organisms, thereby adding a new regulatory layer in prokaryotes for translation control.

Trajectory of Urine Albumin-Creatinine Ratio in Patients with Acute Heart Failure

INTRODUCTION

Albuminuria is prevalent in patients with chronic heart failure and is a risk factor for disease progression. However, its clinical meaning in acute heart failure remains elusive. This study analyzed the trajectory of urine albumin to creatinine ratio (UACR) between admission and discharge and its association with decongestion.

METHODS

In this prospective observational study, 63 patients were enrolled. UACR, B-type natriuretic peptide (BNP), and clinical congestion score (CCS) were obtained at admission and discharge. We used linear mixed regression analysis to compare changes in the natural logarithm of UACR (logUACR) and its association with changes in markers of decongestion. Estimates were reported as least squares mean with their respective 95% CIs.

RESULTS

The median age of the study population was 87 years, 68.5% were women, and 69.8% had a left ventricular ejection fraction >50%. LogUACR at discharge significantly decreased in the overall population compared to admission (Δ -0.47, 95% CI: -0.78 to -0.15, p value = 0.003). The magnitude of UACR drop at discharge was associated with changes in surrogate markers of decongestion. Patients who showed a greater reduction in BNP at discharge exhibited a greater reduction in UACR (p = 0.016). The same trend was also found with clinical decongestion, as assessed by changes in CCS, however, without achieving statistical significance (p = 0.171). UACR change at discharge was not associated with changes in serum creatinine (p value = 0.923).

CONCLUSION

In elderly patients with AHF and volume overload, the level of UACR significantly decreased upon discharge compared to admission. This reduction in UACR was closely linked to decreases in BNP.

Preeclampsia and risk of maternal pulmonary hypertension at high altitude in Bolivia

Women with a history of preeclampsia (PE) have a greater risk of pulmonary arterial hypertension (PAH). In turn, pregnancy at high altitude is a risk factor for PE. However, whether women who develop PE during highland pregnancy are at risk of PAH before and after birth has not been investigated. We tested the hypothesis that during highland pregnancy, women who develop PE are at greater risk of PAH compared to women undergoing healthy highland pregnancies. The study was on 140 women in La Paz, Bolivia (3640m). Women undergoing healthy highland pregnancy were controls (C, n = 70; 29 ± 3.3 years old, mean±SD). Women diagnosed with PE were the experimental group (PE, n = 70, 31 ± 2 years old). Conventional (B- and M-mode, PW Doppler) and modern (pulsed wave tissue Doppler imaging) ultrasound were applied for cardiovascular íííassessment. Spirometry determined maternal lung function. Assessments occurred at 35 ± 4 weeks of pregnancy and 6 ± 0.3 weeks after birth. Relative to highland controls, highland PE women had enlarged right ventricular (RV) and right atrial chamber sizes, greater pulmonary artery dimensions and increased estimated RV contractility, pulmonary artery pressure and pulmonary vascular resistance. Highland PE women had lower values for peripheral oxygen saturation, forced expiratory flow and the bronchial permeability index. Differences remained 6 weeks after birth. Therefore, women who develop PE at high altitude are at greater risk of PAH before and long after birth. Hence, women with a history of PE at high altitude have an increased cardiovascular risk that transcends the systemic circulation to include the pulmonary vascular bed.

Usefulness of urinary potassium to creatinine ratio to predict diuretic response in patients with acute heart failure and preserved ejection fraction

BACKGROUND

Patients with acute heart failure (AHF) require intensification in the diuretic strategy. However, the optimal diuretic strategy remains unclear. In this work, we aimed to evaluate the role of urinary potassium to creatinine ratio (K/Cr) to predict diuretic and natriuretic response to thiazide or mineralocorticoid receptor antagonists (MRAs) in a cohort of patients with AHF and preserved ejection fraction (AHF-pEF).

HYPOTHESIS

Patients with a high urinary K/Cr ratio will have a better diuretic and natriuretic response with spironolactone versus chlorthalidone.

METHODS

This is a study of 44 patients with AHF-pEF with suboptimal loop diuretic response. The primary endpoint was the baseline K/Cr associated with natriuretic and diuretic effect of chlorthalidone versus spironolactone at 24 and 72 h. Mixed linear regression models were used to analyze the endpoints. Estimates were reported as least squares mean with their respective 95% confidence interval (CIs).

RESULTS

The median age of the study population was 85 years (82.5-88.5), and 30 (68.2%) were women. The inferential multivariate analysis suggested a greater natriuretic and diuretic effect of chlorthalidone across K/Cr levels. In the upper category, chlorthalidone translated into a statistically increase in natriuresis at 24 and 72 h. Chlorthalidone versus spironolactone showed ∆uNa of 25.7 mmol/L at 24 h (95% CI = -3.7 to 55.4, p = .098) and ∆uNa of 24.8 mmol/L at 72 h (95% CI = -4 to 53.6, p = .0106). The omnibus p value is .027. Multivariate analyses revealed a significant increase in 72 h cumulative diuresis irrespective of K/Cr status in those on chlorthalidone.

CONCLUSIONS

In patients with AHF-pEF and suboptimal diuretic response, diuresis and natriuresis are higher with the administration of chlorthalidone over spironolactone. These data don't support the hypothesis that the K/Cr ratio can help guide the choice of thiazide diuretic versus MRA in AHF-pEF patients on loop diuretic.

A variant-dependent molecular clock with anomalous diffusion models SARS-CoV-2 evolution in humans

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans has been monitored at an unprecedented level due to the public health crisis, yet the stochastic dynamics underlying such a process is dubious. Here, considering the number of acquired mutations as the displacement of the viral particle from the origin, we performed biostatistical analyses from numerous whole genome sequences on the basis of a time-dependent probabilistic mathematical model. We showed that a model with a constant variant-dependent evolution rate and nonlinear mutational variance with time (i.e., anomalous diffusion) explained the SARS-CoV-2 evolutionary motion in humans during the first 120 wk of the pandemic in the United Kingdom. In particular, we found subdiffusion patterns for the Primal, Alpha, and Omicron variants but a weak superdiffusion pattern for the Delta variant. Our findings indicate that non-Brownian evolutionary motions occur in nature, thereby providing insight for viral phylodynamics.

Multiplexable and Biocomputational Virus Detection by CRISPR-Cas9-Mediated Strand Displacement

Recurrent disease outbreaks caused by different viruses, including the novel respiratory virus SARS-CoV-2, are challenging our society at a global scale; so versatile virus detection methods would enable a calculated and faster response. Here, we present a novel nucleic acid detection strategy based on CRISPR-Cas9, whose mode of action relies on strand displacement rather than on collateral catalysis, using the Streptococcus pyogenes Cas9 nuclease. Given a preamplification process, a suitable molecular beacon interacts with the ternary CRISPR complex upon targeting to produce a fluorescent signal. We show that SARS-CoV-2 DNA amplicons generated from patient samples can be detected with CRISPR-Cas9. We also show that CRISPR-Cas9 allows the simultaneous detection of different DNA amplicons with the same nuclease, either to detect different SARS-CoV-2 regions or different respiratory viruses. Furthermore, we demonstrate that engineered DNA logic circuits can process different SARS-CoV-2 signals detected by the CRISPR complexes. Collectively, this CRISPR-Cas9 R-loop usage for the molecular beacon opening (COLUMBO) platform allows a multiplexed detection in a single tube, complements the existing CRISPR-based methods, and displays diagnostic and biocomputing potential.

Prognostic significance of plasma chloride in elderly patients hospitalized for acute heart failure

AIMS

Previous studies demonstrated the relationship between hypochloraemia and poor prognosis in patients hospitalized for acute heart failure (AHF). However, the usefulness of chloride in clinical practice remains uncertain, notably in very old patients with predominantly heart failure (HF) with preserved ejection fraction (HFpEF). We aimed to evaluate the prognostic impact of chloride in a cohort of very aged patients with AHF and the possible existence of different phenotypes of hypochloraemia with distinct clinical significance.

METHODS AND RESULTS

It was an observational study of 429 patients hospitalized for AHF in which chloraemia was measured. Two different phenotypes of hypochloraemia were identified by their relationship with estimated plasma volume status (ePVS) as a proxy of intravascular congestion. The endpoint of interest was time to all-cause mortality and the composite of death and/or HF readmission. A multivariable Cox proportional hazard regression model was constructed to analyse the endpoints. The median age was 85 (78-92) years, 266 (62%) were women, and 80% had HFpEF. After multivariable analysis, chloraemia, but not natraemia, was associated with the risk of death and HF readmission in a U-shaped pattern. The phenotype characterized by hypochloraemia and low ePVS (depletional) was associated with an increased risk of mortality when compared with patients with normochloraemia [hazard ratio (HR) 1.86, P = 0.008]. In contrast, hypochloraemia with high ePVS (dilutional) had no prognostic significance (HR 0.94, P = 0.855).

CONCLUSIONS

In very old patients hospitalized with AHF, plasma chloride was associated with the risk of death and HF readmission in a U-shaped pattern and could potentially be used for congestion phenotyping.

P-104 A STEP-UP APPROACH FROM IPOM + IN MINIMALLY INVASIVE ABDOMINAL WALL SURGERY

Aim

To compare the early outcomes of two different techniques for ventral hernia repair in our abdominal wall surgery unit.

Materials and Methods

A prospective non-randomized review was perfomed including patients who underwent laparoscopic hernia repair from January 2018 to April 2022. All patients were followed-up for 1 month and the hernia orifice was closed in all cases. Patients and hernias characteristics, operative data and early complications were reviewed. Postoperative pain was defined as ≥4 value in Visual Analogue Scale.

We compared 2 laparoscopic techniques: intraperitoneal mesh fixed with a double crown of resorbable tackers (IPOM+) and self gripping sublay positioned mesh (preperitoneal –PREP- or retromuscular –RIVES- position).

Outcomes

During the study period, 44 patients were assigned into 2 groups: 31 (70%) in IPOM+ group and 13 (30%) in Rives/Preperitoneal group. No differences were found in risk factors, population and hernia data between both groups. 6 patients (19%) from IPOM+ group presented postoperative pain and only 1 patient (7,7%) in Rives/Prep group (p: 0,30). There was no differences in other complications, length of stay or operative time.

Conlusion

Early outcomes of sublay techniques (Rives or preperitoneal) do not report more complications during perioperative time, but they could help reducing immediately postoperatorive pain.

Diagnostics of Infections Produced by the Plant Viruses TMV, TEV, and PVX with CRISPR-Cas12 and CRISPR-Cas13

Viral infections in plants threaten food security. Thus, simple and effective methods for virus detection are required to adopt early measures that can prevent virus spread. However, current methods based on the amplification of the viral genome by polymerase chain reaction (PCR) require laboratory conditions. Here, we exploited the CRISPR-Cas12a and CRISPR-Cas13a/d systems to detect three RNA viruses, namely, Tobacco mosaic virus, Tobacco etch virus, and Potato virus X, in Nicotiana benthamiana plants. We applied the CRISPR-Cas12a system to detect viral DNA amplicons generated by PCR or isothermal amplification, and we also performed a multiplexed detection in plants with mixed infections. In addition, we adapted the detection system to bypass the costly RNA purification step and to get a visible readout with lateral flow strips. Finally, we applied the CRISPR-Cas13a/d system to directly detect viral RNA, thereby avoiding the necessity of a preamplification step and obtaining a readout that scales with the viral load. These approaches allow for the performance of viral diagnostics within half an hour of leaf harvest and are hence potentially relevant for field-deployable applications.

Comparison of chlorthalidone and spironolactone as additional diuretic therapy in patients with acute heart failure and preserved ejection fraction

AIMS

Patients with acute heart failure (AHF) require intensification in the diuretic strategy. However, the optimal diuretic strategy remains unclear. In this work, we aimed to evaluate the effect of chlorthalidone compared with spironolactone on diuretic efficacy and safety profile in a cohort of patients with AHF and preserved ejection fraction (AHF-pEF).

METHODS AND RESULTS

It was a prospective observational study in a single centre in Spain, included 44 consecutive patients admitted between June 2020 and March 2021, with AHF-pEF in which an additional diuretic was prescribed. The primary endpoint was changes in urinary sodium at 24 and 72 h, and the secondary were urine output, and other security endpoints. Mixed linear regression models were used to analyse the endpoints. Estimates were reported as least squares mean with their respective 95% confidence intervals. The median age of the study population was 85 years (82.5-88.5), and 30 (68.2%) were women. After multivariate analysis, the linear mixed regression analysis confirmed a greater natriuretic response of chlorthalidone over spironolactone, especially at 24 h (P = 0.009). Multivariate analysis also showed a greater cumulative diuretic response in those treated with chlorthalidone (P = 0.001). We did not find significant differences in glomerular filtration rate, serum sodium, and serum potassium at 72 h, neither significant differences were found in 24 and 72 h in systolic blood pressure.

CONCLUSION

In patients with AHF and left ventricular ejection fraction ≥50% receiving intravenous loop diuretics, chlorthalidone administration was associated with a greater short-term natriuresis.

Nano-Based Approved Pharmaceuticals for Cancer Treatment: Present and Future Challenges

Cancer is one of the main causes of death worldwide. To date, and despite the advances in conventional treatment options, therapy in cancer is still far from optimal due to the non-specific systemic biodistribution of antitumor agents. The inadequate drug concentrations at the tumor site led to an increased incidence of multiple drug resistance and the appearance of many severe undesirable side effects. Nanotechnology, through the development of nanoscale-based pharmaceuticals, has emerged to provide new and innovative drugs to overcome these limitations. In this review, we provide an overview of the approved nanomedicine for cancer treatment and the rationale behind their designs and applications. We also highlight the new approaches that are currently under investigation and the perspectives and challenges for nanopharmaceuticals, focusing on the tumor microenvironment and tumor disseminate cells as the most attractive and effective strategies for cancer treatments.

CRISPR-Cas12a-Based Detection of SARS-CoV-2 Harboring the E484K Mutation

The novel respiratory virus SARS-CoV-2 is rapidly evolving across the world with the potential of increasing its transmission and the induced disease. Here, we applied the CRISPR-Cas12a system to detect, without the need of sequencing, SARS-CoV-2 genomes harboring the E484K mutation, first identified in the Beta variant and catalogued as an escape mutation. The E484K mutation creates a canonical protospacer adjacent motif for Cas12a recognition in the resulting DNA amplicon, which was exploited to obtain a differential readout. We analyzed a series of fecal samples from hospitalized patients in Valencia (Spain), finding one infection with SARS-CoV-2 harboring the E484K mutation, which was then confirmed by sequencing. Overall, these results suggest that CRISPR diagnostics can be a useful tool in epidemiology to monitor the spread of escape mutations.

New Bicistronic TALENs Greatly Improve Genome Editing

Genome editing has become one of the most powerful tools in present-day stem cell and regenerative medicine research, but despite its rapid acceptance and widespread use, some elements of the technology still need improvement. In this unit, we present data regarding the use of a new, more efficient type of transcription activator-like effector nuclease (TALEN) for gene editing. Our group has generated bicistronic genes in which classical TALEN coding sequences are linked by 2A elements to different reporter molecules, such as fluorochromes (TALEN-F) or membrane receptors (TALEN-M). This structure results in two proteins transcribed from the same transcript, of which the second (the reporter) can be used as the target for selection by fluorescence-assisted cell sorting (FACS) or magnetic-activated cell sorting (MACS). The application of these new TALEN genes allows a rapid enrichment of cells in which both members of the TALEN pair are active, thus eliminating the need for lengthy selection in culture and laborious characterization of a large number of clones. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Generation of new TALENs Basic Protocol 2: Genome editing using TALEN-F Alternate Protocol 1: Generation of TALEN-M Support Protocol 1: mRNA in vitro transcription (IVT) of TALEN-T2A-reporter expression vector Alternate Protocol 2: Editing of primary T cells using TALEN-M Basic Protocol 3: Verifying gene editing Support Protocol 2: Rapid expansion protocol for edited T-cells.

Pathways for horizontal gene transfer in bacteria revealed by a global map of their plasmids

Plasmids can mediate horizontal gene transfer of antibiotic resistance, virulence genes, and other adaptive factors across bacterial populations. Here, we analyze genomic composition and pairwise sequence identity for over 10,000 reference plasmids to obtain a global map of the prokaryotic plasmidome. Plasmids in this map organize into discrete clusters, which we call plasmid taxonomic units (PTUs), with high average nucleotide identity between its members. We identify 83 PTUs in the order Enterobacterales, 28 of them corresponding to previously described archetypes. Furthermore, we develop an automated algorithm for PTU identification, and validate its performance using stochastic blockmodeling. The algorithm reveals a total of 276 PTUs in the bacterial domain. Each PTU exhibits a characteristic host distribution, organized into a six-grade scale (I–VI), ranging from plasmids restricted to a single host species (grade I) to plasmids able to colonize species from different phyla (grade VI). More than 60% of the plasmids in the global map are in groups with host ranges beyond the species barrier.

Plasmids can mediate gene transfer across bacterial populations. Here, the authors describe a global map of the prokaryotic plasmidome, where plasmids organize into discrete ‘plasmid taxonomic units’ based on their genomic composition and pairwise sequence identity.

Abstract P3-08-18: Clinicopathological characteristics associated with intermediate and high-risk ODx RS

Background: The gene expression profiling assay OncotypeDx (ODx) prognosticates the risk of estrogen receptor positive (ER+) breast cancer (BC) recurrence and assesses the likely benefit from adjuvant chemotherapy in addition to endocrine therapy. There have been several attempts to develop algorithms that provide similar outcome prediction to the ODx assay with the use of routine clinicopathological characteristics. These models appear to predict high-risk ODx RS but are unable to reliably rule out the presence of patients with intermediate-risk disease. Our objective was to identify the clinicopathological factors associated with intermediate and high-risk categories.

Methods: We retrospectively reviewed the electronic medical records of patients with early-stage ER+ BC for whom ODx recurrence score (RS) was available. Patients were diagnosed and treated at 3 specialized cancer centers between 2010 and 2017. Two multinomial logistic regression models (crude and adjusted) were constructed to assess the association between clinicopathological characteristics and ODx RS as a categorical variable. The adjusted model included the following variables: ODx RS, age, tumor size, node status, grade, lymphovascular invasion and hormonal receptors. The reported association measure was the relative prevalence ratio (RPR) with its respective 95%CI.

Results: A total of 551 patients were included. Patients had a mean age of 56.2 ± 11.9 (SD) (range: 26-89). 9.6% (n=53) of patients were≤40 years old.The size of the tumors ranged from 0.1 cm to 7.2 cm (median = 1.5 cm; IQR 1.0-2.2cm). A minority of patients had lymph node involvement (5.8%, n=32). By subtype, carcinomas were mostly ductal (83.5%, n=460), followed by lobular (10.0%, n=55) and mucinous (3.5%, n=19). The majority of tumor exhibited an intermediate histological grade (71.6%, n=386). Ki 67 was available in 58.8% patients (n= 324), with a median Ki67 of 20 (IQR 10-30). In the adjusted multinomial logistic regression model, factors associated with ODx intermediate-risk category were grade 3 (RPR=4.78; 95%CI: 2.01-11.39) and having either ER or PR <50 (RPR=2.80; 95%CI: 1.83-4.27). Factors associated with ODx high-risk category were grade 3 (RPR=15.89; 95%CI: 3.23-78.19), having either ER or PR <50 (RPR=4.58; 95%CI: 2.37-8.87), age≤40 (RPR=2.96; 95%CI: 1.20-7.29) and T2-3 (RPR=2.20; 95%CI: 1.13-4.32).

Conclusion: Grade 3, ER o PR <50, age ≤40 years and T2-3 are clinicopathological characteristics strongly associated with high-risk ODx RS. The associations with intermediate-risk ODx RS are weaker. The way these factors could be integrated into a clinicopathologic risk prediction model to identify high-risk patients needs further analysis.

Citation Format: Ruiz R, Morante Z, Namuche F, Urrunaga D, Leon M, Ziegler G, Aguilar A, Chavez Mac Gregor M, Gomez H. Clinicopathological characteristics associated with intermediate and high-risk ODx RS [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-18.

Abstract P3-08-16: Age's importance in early breast cancer: Oncotype Dx results in patients ≤40 years

Background

The 21-gene recurrence score (RS) predicts the benefit of adjuvant chemotherapy (CT) in ER-positive HER2-negative breast cancer (BC) and has been validated in population where women under 40 are underrepresented.Young BC pts are more likely to receive adjuvant chemotherapy (CT) in addition to endocrine therapy (ET). Our objective was to assess the RS results in young (≤40 yo) vs older (>40 yo) pts and evaluate the impact of age on clinical decision-making according to RS categories.

Methods

We retrospectively reviewed electronic medical files of all patients with early stage hormone receptor BC for whom RS was available between 2007 and 2017 in 3 specialized cancer centers. We used the Mann-Whitney and Chi-squared tests to assess differences between age group. Similarly, we evaluated the association between age groups and treatment, within each ODx category. To determine if age was associated with CT use in the low risk category, a logistic regression model was constructed.

Results

A total of 551 pts were included, 53 (9.6%) ≤40 yo and 498 (90.4%) >40 yo. No statistical differences were found between the younger and older groups in T (p=0.874), N (p=0.794), stage (p=0.188), or grade (p=0.791). Young patients underwent radical surgery more frequently than their older counterparts (41.5 vs 25.7%, p=0.014). Statistically significant differences were also observed in ER mean, which was lower in the younger group (80 vs 90%, p<0.001). The median RS result was significantly higher in the younger group (19 vs 16, p=0.009). Also, high-risk recurrence score category was significantly more frequent in the younger group (22.6 vs 9.2%, p=0.009). In the intermediate-risk category there were no differences in the proportion of patients who received CT according to age groups (p=0.484). In the low-risk category, 28.0% of patients ≤40 years vs 11.3% of patients >40 years received CT (p=0.037).

Conclusions

Our results indicate that RS tends to be higher in patients with BC ≤ 40 yo and that the frequency of high-risk RS is significantly higher in the younger group, suggesting biological differences between groups. 28% of young patients with low-risk RS from our cohort are overtreated. Based on these results, it should be considered to develop a test adjusted to the age of the patients.

Citation Format: Ruiz R, Namuche F, Morante Z, Aguilar A, Urrunaga D, Ziegler G, Chavez Mac Gregor M, Leon M, Gomez H. Age's importance in early breast cancer: Oncotype Dx results in patients ≤40 years [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-16.

Abstract P3-08-22: Oncotype Dx recurrence score risk groups according to Ki67, a predictor to be considered

Background

The gene expression profiling assay OncotypeDx (ODx) prognosticates the risk of estrogen receptor positive (ER+) breast cancer (BC) recurrence and assesses the likely benefit from adjuvant chemotherapy in addition to endocrine therapy. There have been several attempts to develop algorithms that provide similar outcome prediction to the ODx assay with the use of routine clinicopathological characteristics. Ki67 is frequently incorporated into these assessments, although there is no standard cut-off for its use.

Methods

We retrospectively reviewed the electronic medical records of 330 patients with early stage ER+ BC for whom ODx recurrence score (RS) was available. Patients were diagnosed and treated at two specialized cancer centers between 2014 and 2017.

Our objective was to determine the ki67's median differences between ODx risk groups.

We used Spearman rho for the correlation between Ki67 and ODx score and used Kruskal-Wallis test for compare medians, pairwaise comparison for the intergroup relations.

Results

Mean age at diagnosis was 57.42 years (range 28-89). Mean tumor diameter was 15.67 mm. 78.9% were intermediate histologic grade and 9.7% patients had lymph node involvement. Median expression of ER and PR were 90% (5-100) and 70% (0-100), respectively. We assessed the correlation between Ki67 and ODx score, with a pearson r:0.31, p<0.001. The data showed a directly proportional trend between Ki67 and ODx score.

Median Ki67 was 20 (1-100). According to ODX RS, 61.5% of tumors were low risk, 30.3% were intermediate risk and, 8.2% were high risk. Median Ki67 within each category group is as follows: low: 15 (IQR:15), intermediate: 20 (IQR:18) and high: 40 (IQR:35), with a statistically significant difference between medians (p<0.001). In the Pairwise comparison intergroup the data showed: Low-Intermediate (p<0.05), Low-High (p<0.001), Intermediate-High (p<0.001).

Conclusions

The data showed directly proportional trend between Ki67 and ODx score. In our population there is a statistically significant difference between Ki67 medians according to ODx risk groups.

Citation Format: Namuche F, Ruiz R, Morante Z, Aguilar A, Gomez H. Oncotype Dx recurrence score risk groups according to Ki67, a predictor to be considered [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-22.

Abstract P3-08-17: Evaluation of Oncotype DX testing and subsequent treatment choices in the Latin American setting

Background: The gene expression profiling assay OncotypeDx (ODx) prognosticates the risk of estrogen receptor positive (ER+) breast cancer (BC) recurrence and assesses the likely benefit from adjuvant chemotherapy in addition to endocrine therapy. Numerous clinical utility studies have shown that acknowledging the RS impacts on clinical decision making, leading to a decrease in chemotherapy (CT) use. However, the cost of the assay limits it widespread use, especially in low and middle-income countries. Our objective was to determine the patterns of use of ODx, its results and the subsequent treatment choices in a large Latin American cohort.

Methods: We retrospectively reviewed the electronic medical records of patients with early-stage ER+ BC for whom ODx recurrence score (RS) was available. Patients were diagnosed and treated at 3 specialized Peruvian cancer centers between 2007 and 2017. Descriptive results for numeric variables were presented as means with standard deviation (SD) or medians with interquartile range (IQR), depending on their distributions; otherwise, we expressed the qualitative variables as numbers with percentages. We evaluated the association between ODx RS category and treatment using the Chi-squared test.

Results: A total of 551 patients were included. Patients had a mean age of 56.2 ± 11.9 (SD) (range: 26-89). 9.6% (n=53) of patients were ≤40 years old. The size of the tumors ranged from 0.1 cm to 7.2 cm (median = 1.5 cm; IQR 1.0-2.2cm). 36 (6.5%) patients had tumors ≤ 0.5cm and 7 (1%) had tumors > 5cm. A minority of patients had lymph node involvement (5.8%, n=32). ODx was ordered in 55 cases (10%) of lobular carcinoma and in 23 cases (4%) of favorable histology tumors (19 mucinous, 4 tubular). Most tumors exhibited an intermediate histological grade (71.6%, n=386). Ki67 was available in 58.8% patients (n= 324), with a median Ki67 of 20 (IQR 10-30). Using commercial cutoffs RS was distributed as follows: low (0–17) = 316 (57.4%), intermediate (18–30) = 177 (32.1%), and high (≥31) = 58 (10.5%). In general, 57.5% (n=317) of patients received endocrine therapy (ET) as their only systemic treatment and 42.5% (n=234), also received CT (ET + CT). In the low-risk category, 87.3% (n=276) of patients received ET and 12.7% (n=40), ET + CT. Within the intermediate-risk category, most patients received ET + CT (77.4%, n=137). Only one patient in the high-risk category did not receive CT. There was a significant association between the RS group and treatment choice (p<0.001).

Impact of ODx RS results on treatment recommendations Oncotype risk categories  LowIntermediateHighp valueTreatmentn%n%n%<0.001Endocrine therapy27687.34022.611.7 Chemotherapy + Endocrine therapy4012.713777.45798.3 

Conclusion: ODx significantly influenced treatment decisions in our cohort, however an overutilization of CT was found in low-risk patients. Further data analysis is needed to explain the higher than expected use of CT. Also, there is room for improvement in the selection of cases that undergo ODx testing.

Citation Format: Ruiz R, Morante Z, Namuche F, Urrunaga D, Aguilar A, Schwarz J, Leon M, Ziegler G, Chavez Mac Gregor M, Gomez H. Evaluation of Oncotype DX testing and subsequent treatment choices in the Latin American setting [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-17.

Abstract P1-06-12: Optimizing the use of oncotype Dx in early breast cancer

Background: Oncotype Dx (ODX) prognosticates the risk of recurrence and predicts the benefit of adjuvant chemotherapy in estrogen-receptor-positive breast cancer (BC). However, its cost makes it prohibitive for many health care systems. Our objective was to develop a model that uses routine clinical and pathological parameters to identify ODX high risk patients which require adjuvant chemotherapy.

Methods: We retrospectively reviewed ODX and pathology reports from 190 early BC patients treated between 2014 and 2016 in a specialized cancer center. Our population was divided into a training (n:133) and validation set (n:57). In the training set, among available clinico-pathological variables (age, T, ER, PR, Ki67, Elston-Ellis grade) a multiple linear regression model was carried out to select those significantly associated with ODX. Coefficients of statistically significant variables were used to build an equation. The equation was applied in the training set. These results were confronted to ODX categories. The best threshold for selecting high risk patients was identified in the training set and tested in the validation set.

Results: Among the tested variables, tumor size (pT), progesterone receptor (PR), Ki67 and Ellston-Ellis grade were significantly associated with ODX RS (Table 1). The linear predictor is: (0.2544 x pT) – (0.0739 x PR) + (0.0861 x Ki67) + (5.4232 x Elston grade). The threshold score for this equation was set on 14 to discriminate high from low-intermediate risk patients. The test was able to correctly classify high risk patients with a sensitivity of 78%, a specificity of 72% and a negative predictive value of 98%.

Conclusion: With further refinement ODX could be omitted in patients classified as high risk by our predictor therefore restricting and optimizing the use of ODX to a smaller population of patients. The observed ODX distribution in our patients is similar to previously reported series suggesting that this equation could be informative in similar clinical settings. Additional external testing using new datasets is ongoing.

Citation Format: Ruiz R, Namuche F, Flores C, Aguilar A, Gomez HL. Optimizing the use of oncotype Dx in early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-06-12.

Abstract P6-09-11: Ki67 cut offs and oncotype DX recurrence score in early breast cancer

Background: The gene expression profiling assay OncotypeDx (ODX) predicts the likelihood of estrogen receptor (ER) positive breast cancer (BC) recurrence and assesses the likely benefit from both hormonal therapy and chemotherapy. Many clinical scores that estimate the risk category of ODX are being tested. Ki67 is frequently incorporated into these assessments, although there is no standard cut-off for its use.

Methods: We retrospectively reviewed the electronic medical records of 190 patients with early stage ER+ BC for whom ODX recurrence score (RS) was available. Patients were diagnosed and treated at a specialized cancer center between 2014 and 2016. Our objective was to find out the degree to which an optimal ki67 cut-off correlates with ODX risk category. We also aim to determine an association between classical clinicopathological variables (St. Gallen (SG) 2015) could predict ODX risk category. Chi square test was used.

Results: The characteristics of patients according to ODX risk category are shown in Table 2. Mean age at diagnosis was 59 years (range 28-89). Mean tumor diameter was 15mm, 84.2% were intermediate grade and 4.7% patients had lymph node involvement. Mean expression of ER, PR and Ki67 were 87%, 53% and 22%, respectively. According to ODX 62.1% patients were low risk, 30.5% were intermediate risk and 7.4% were high risk. An overall concordance of 46.8% (73/190) was found between SG 2015 and the risk category of ODX (75.7% for low, 33.3% for intermediate and 23.9% for high RS). When changing SG Ki67 cutoffs to ≤20% (for low Ki67) and ≥30% (for high Ki67), an overall concordance of 56.3% (107/190) was found (69.6% for low, 47.3% for intermediate and 23.9% for high RS) and this was statistically significant (p=0.00) (Table 3).

Conclusion: In our population there is no a direct correlation between classical clinicopathological variables and ODX score. Despite being a specialized center, the utility of classical clinicopathological variables for predicting ODX risk category is limited.

Citation Format: Namuche F, Ruiz R, Flores C, Gomez HL, Aguilar A. Ki67 cut offs and oncotype DX recurrence score in early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-11.

Technique for precaval and laterocaval nodes excision at extraperitoneal paraaortic lymphadenectomy

STUDY OBJECTIVE

To describe our technique for excision of the pre-caval and laterocaval nodes using an extraperitoneal approach. This technique was developed to make the dissection and excision of the less accessible nodes in an easier and safer way by minimizing the risk of great vessels injury and bleeding.

DESIGN

Step-by-step description of the surgical procedure using video (Canadian Task Force classification III).

SETTING

The procedure was performed at a teaching hospital, Hospital Universitario Donostia (Spain).

PATIENTS

A 52-year-old woman with a body mass index of 33 underwent endoscopic extraperitoneal paraaortic lymphadenectomy for advanced high grade cervical adenocarcinoma FIGO IIB.

INTERVENTIONS

The patient underwent an endoscopic extraperitoneal para-aortic lymphadenectomy. An anatomical dissection is being performed being the upper limit of the dissection the left renal vein. Focus of the video involves the challenging dissection of the right nodes.

MEASUREMENTS AND MAIN RESULTS

Firstly we complete a dissection of all the anatomical aortic limits until the renal vein and exeresis of aortic nodes. A plane just above the cava vein is carefully developed by pushing all the lymph nodes to the roof of the dissection. Special care must be taken close to the aortic bifurcation due to the perforating vessels that can be found more frequently in this location. Once all this space is dissected, nodes attached to the roof are easily pushed down. It is useful to use a clip in the upper part, close to the renal vein, to prevent lymphorrhea. Nodes are excised in four blocks, supramesenteric and inframesenteric aortic and precaval nodes. The proximity to the peritoneal roof and the chance for a peritoneal hole and loss of pneumoperitoneum can be less problematic if the right dissection is performed at the end of the procedure.

CONCLUSION

A complete para-aortic retroperitoneal dissection can be achieved with this extraperitoneal approach. Benefits of this technique are based on the absence of the bowel or other intraperitoneal structures invading the operative field given the barrier-free nature of the retroperitoneal space. Despite the challenge of the access to the right nodes in a retroperitoneal paraaortic lymphadenectomy they can be successfully excised reaching the renal vein including obese patients.

[Triple arthrodesis for correction of cavovarus deformity]

OBJECTIVE

The aim is to correct the underlying cavovarus deformity and to achieve a pain-free and stable hindfoot.

INDICATIONS

Rigid neurologic, posttraumatic, congenital, and idiopathic cavovarus deformities.

CONTRAINDICATIONS

General surgical or anesthesiological risks, infections, critical soft tissue conditions, neurovascular impairment of the lower extremity, noncompliance, patients with severely reduced bone quality, insulin-dependent diabetes mellitus, smoking.

SURGICAL TECHNIQUE

The talonavicular and subtalar joints are exposed using a single medial approach. Joint cartilage is carefully debrided. Hindfoot reposition with complete correction of cavovarus deformity in all three planes. Joints are stabilized using cannulated screws, followed by wound closure.

POSTOPERATIVE MANAGEMENT

A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts on postoperative day 1 using a stabilizing walking boot or cast for 6 weeks with 15 kg partial weight bearing. Clinical and radiographic follow-up 6 weeks postoperatively to assess osseous consolidation at the arthrodesis site. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is gradually initiated.

RESULTS

Between January 2012 and July 2014, triple arthrodesis was performed in 11 patients with a mean age of 62 ± 14 years due to cavovarus deformity. The mean follow-up was 34 ± 8 months (range 24-48 months). In all patients, the cavovarus deformity was substantially corrected. Significant pain relief from 7.1 ± 2.2 (range 5-10) to 1.8 ± 1.5 (range 0-4) on the visual analogue scale was observed.