P-296 Examining the link between environmental toxin exposure and uterine leiomyoma: a systematic review

Study question

Is there an association between exposure to certain environmental toxins and the prevalence of uterine leiomyoma in women?

Summary answer

Some evidence was obtained to suggest an association between phthalate esters, bisphenol A, heavy metals, persistent organic pollutants and the prevalence of uterine fibroids.

What is known already

Environmental toxins are naturally occurring, or human made chemicals that can act as endocrine disrupting chemicals (EDCs) by binding and activating estrogen receptors in the body. Uterine fibroids, often called leiomyoma are non-cancerous growths occurring in the uterus. Though often asymptomatic, they can cause pain, infertility, pregnancy complications and are a leading cause for hysterectomy. The aetiology of leiomyoma is not fully understood but both estrogen and progesterone have been implicated in their growth. We aimed to investigate the epidemiological evidence for the association between EDCs and the prevalence of fibroids. 

Study design, size, duration

We undertook a systematic review and in keeping with PRISMA guidelines, a structured search of Medline, Embase, Scopus, and Web of Science was conducted (to October 2020). Case-control, cross-sectional, cohort and experimental studies were included. 

Participants/materials, setting, methods

The included studies analyzed the association between one or more toxins and the occurrence, or growth of leiomyoma in humans, including human cell lines. The types of toxins, patient characteristics, association and outcome, body concentration of toxin and confounding variables were extracted and analyzed. Quality assessment was performed using the Newcastle-Ottawa Scale.

Main results and the role of chance

In total, 34 studies were included. The majority (76%) of studies revealed a significant association between the exposure studied and the prevalence of uterine leiomyoma. In examining body burden in cases vs controls, phthalate esters showed an association with increased odds of uterine leiomyoma, except in one case where a negative association was observed. In vitro experimental studies examining the effect of alkyl-phenols such as bisphenol A (BPA), octylphenol (OP) and nonylphenol (NP) demonstrated that these environmental estrogens can act to promote the proliferation of leiomyoma cells through a number of mechanisms, typically including the estrogen receptor alpha (ERa) signalling pathway. There were conflicting results for the association between alkyl-phenols and fibroids in case-control studies. A positive association between cadmium was demonstrated in only two studies. There were conflicting results for the association between lead, mercury, arsenic and uterine fibroids. Several metabolites of organophosphate esters, alternative plasticizers, and persistent organic pollutants were associated with an increased risk of uterine fibroids. 

Limitations, reasons for caution

Separating these exposures from the multiple other factors that could affect the outcome of leiomyoma is challenging, but an important issue for future research. 

Wider implications of the findings

The link between some environmental toxins and uterine fibroids discussed is in agreement with previous literature. However, our review provides a more in depth analysis on specific dosage effects, odds ratios, and potential gene mechanisms of the exposures. This information could contribute to more accurate preventative measures.

Trial registration number

not applicable

P–296 Examining the link between environmental toxin exposure and uterine leiomyoma: a systematic review

Study question

Is there an association between exposure to certain environmental toxins and the prevalence of uterine leiomyoma in women?

Summary answer

Some evidence was obtained to suggest an association between phthalate esters, bisphenol A, heavy metals, persistent organic pollutants and the prevalence of uterine fibroids.

What is known already

Environmental toxins are naturally occurring, or human made chemicals that can act as endocrine disrupting chemicals (EDCs) by binding and activating estrogen receptors in the body. Uterine fibroids, often called leiomyoma are non-cancerous growths occurring in the uterus. Though often asymptomatic, they can cause pain, infertility, pregnancy complications and are a leading cause for hysterectomy. The aetiology of leiomyoma is not fully understood but both estrogen and progesterone have been implicated in their growth. We aimed to investigate the epidemiological evidence for the association between EDCs and the prevalence of fibroids.

Study design, size, duration

We undertook a systematic review and in keeping with PRISMA guidelines, a structured search of Medline, Embase, Scopus, and Web of Science was conducted (to October 2020). Case-control, cross-sectional, cohort and experimental studies were included.

Participants/materials, setting, methods

The included studies analyzed the association between one or more toxins and the occurrence, or growth of leiomyoma in humans, including human cell lines. The types of toxins, patient characteristics, association and outcome, body concentration of toxin and confounding variables were extracted and analyzed. Quality assessment was performed using the Newcastle-Ottawa Scale.

Main results and the role of chance

In total, 34 studies were included. The majority (76%) of studies revealed a significant association between the exposure studied and the prevalence of uterine leiomyoma. In examining body burden in cases vs controls, phthalate esters showed an association with increased odds of uterine leiomyoma, except in one case where a negative association was observed. In vitro experimental studies examining the effect of alkyl-phenols such as bisphenol A (BPA), octylphenol (OP) and nonylphenol (NP) demonstrated that these environmental estrogens can act to promote the proliferation of leiomyoma cells through a number of mechanisms, typically including the estrogen receptor alpha (ERa) signalling pathway. There were conflicting results for the association between alkyl-phenols and fibroids in case-control studies. A positive association between cadmium was demonstrated in only two studies. There were conflicting results for the association between lead, mercury, arsenic and uterine fibroids. Several metabolites of organophosphate esters, alternative plasticizers, and persistent organic pollutants were associated with an increased risk of uterine fibroids.

Limitations, reasons for caution

Separating these exposures from the multiple other factors that could affect the outcome of leiomyoma is challenging, but an important issue for future research.

Wider implications of the findings: The link between some environmental toxins and uterine fibroids discussed is in agreement with previous literature. However, our review provides a more in depth analysis on specific dosage effects, odds ratios, and potential gene mechanisms of the exposures. This information could contribute to more accurate preventative measures.

Trial registration number

Not applicable

Appraisal of systematic reviews on interventions for postpartum depression: systematic review

BACKGROUND

Postpartum depression (PPD) is a highly prevalent mental health problem that affects parental health with implications for child health in infancy, childhood, adolescence and beyond. The primary aim of this study was to critically appraise available systematic reviews describing interventions for PPD. The secondary aim was to evaluate the methodological quality of the included systematic reviews and their conclusions.

METHODS

An electronic database search of MEDLINE, Embase, and the Cochrane Library from 2000 to 2020 was conducted to identify systematic reviews that examined an intervention for PPD. A Measurement Tool to Assess Systematic Reviews was utilized to independently score each included systematic review which was then critically appraised to better define the most effective therapeutic options for PPD.

RESULTS

Of the 842 studies identified, 83 met the a priori criteria for inclusion. Based on the systematic reviews with the highest methodological quality, we found that use of antidepressants and telemedicine were the most effective treatments for PPD. Symptoms of PPD were also improved by traditional herbal medicine and aromatherapy. Current evidence for physical exercise and cognitive behavioural therapy in treating PPD remains equivocal. A significant, but weak relationship between AMSTAR score and journal impact factor was observed (p = 0.03, r = 0.24; 95% CI, 0.02 to 0.43) whilst no relationship was found between the number of total citations (p = 0.27, r = 0.12; 95% CI, - 0.09 to 0.34), or source of funding (p = 0.19).

CONCLUSION

Overall the systematic reviews on interventions for PPD are of low-moderate quality and are not improving over time. Antidepressants and telemedicine were the most effective therapeutic interventions for PPD treatment.

Brain-derived neurotrophic factor (BDNF) expression and function in the mammalian reproductive Tract

BACKGROUND

Neurotrophins of the nerve growth factor family are soluble polypeptides that are best known for their role in nerve growth, survival and differentiation in the central nervous system. A growing body of literature shows that neurotrophins and their receptors are also expressed throughout the reproductive tract.

OBJECTIVE AND RATIONALE

Neurotrophins are key regulatory proteins in reproductive physiology during development and throughout adult life. Of the neurotrophins, the literature describing the expression and function of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, neurotrophin receptor kinase-2 (NTRK2), has been expanding rapidly. We therefore conducted a systematic inductive qualitative review of the literature to better define the role of the BDNF in the reproductive tract. We postulate that BDNF and NTRK2 are central regulatory proteins throughout the reproductive system.

SEARCH METHODS

An electronic search of Medline (PubMed) and Web of Science for articles relating to BDNF and the reproductive system was carried out between January 2018 and February 2019.

OUTCOMES

In the ovary, BDNF expression and levels have been linked with follicle organisation during ovarian development, follicle recruitment and growth and oocyte maturation. In the endometrium, BDNF is involved in cell proliferation and neurogenesis. In contrast, literature describing the role of BDNF in other reproductive tissues is sparse and BDNF-NTRK2 signalling in the male reproductive tract has been largely overlooked. Whilst estradiol appears to be the primary regulator of BDNF expression, we also identified reports describing binding sites for glucocorticoid and myocyte enhancer factor-2, a calcium-response element through activation of an N-methyl-D-aspartate (NMDA) receptor, and aryl hydrocarbon receptor nuclear transporter protein-4 (ARNT) response elements in promoter regions of the BDNF gene. Expression is also regulated by multiple microRNAs and post-translational processing of precursor proteins and intracellular shuttling. BDNF-NTRK2 signalling is modulated through tissue specific receptor expression of either the full-length or truncated NTRK2 receptor; however, the functional importance remains to be elucidated. Dysregulation of BDNF expression and circulating concentrations have been implicated in several reproductive disorders including premature ovarian failure, endometriosis, pre-eclampsia, intra-uterine growth restriction (IUGR) and several reproductive cancers.

WIDER IMPLICATIONS

We conclude that BDNF and its receptors are key regulatory proteins central to gonadal development, ovarian regulation and uterine physiology, as well as embryo and placenta development. Furthermore, dysregulation of BDNF-NTRK2 in reproductive diseases suggests their potential role as candidate clinical markers of disease and potential therapeutic targets.

A review of long-term pesticide monitoring studies to assess surface water quality trends

Aquatic pesticide pollution from both agricultural and urban pest control is a concern in many parts of the world. Making an accurate assessment of pesticide exposure is the starting point to protecting aquatic ecosystems. This in turn requires the design of an effective monitoring program. Monitoring is also essential to evaluate the efficacy of mitigation measures aimed to curb pesticide pollution. However, empirical evidence for their efficacy can be confounded by additional influencing factors, most prominently variable weather conditions. This review summarizes the experiences gained from long-term (>5 years) pesticide monitoring studies for detecting trends and provides recommendations for their improvement. We reviewed articles published in the scientific literature, with a few complements from selected grey literature, for a total of 20 studies which fulfill our search criteria. Overall, temporal trends of pesticide use and hydrological conditions were the two most common factors influencing aquatic pesticide pollution. Eighteen studies demonstrated observable effects to surface water concentrations from changes in pesticide application rates (e.g., use restriction) and sixteen studies from interannual variability in hydrological conditions during the application period. Accounting for seasonal- and streamflow-related variability in trend analysis is important because the two factors can obscure trends caused by changes in pesticide use or management practices. Other mitigation measures (e.g., buffer strips) were only detectable in four studies where concentrations or loads were reduced by > 45%. Collecting additional agricultural (e.g., pesticide use, mitigation measures) and environmental (e.g., precipitation, stream flow) data, as well as establishing a baseline before the implementation of mitigation measures have been consistently reported as prerequisites to interpret water quality trends from long-term monitoring studies, but have rarely been implemented in the past.

Enhancing departmental preparedness for COVID-19 using rapid-cycle in-situ simulation

In response to coronavirus disease 2019 (COVID-19), a rapid-cycle in-situ simulation (ISS) programme was developed to facilitate identification and resolution of systems-based latent safety threats. The simulation involved a possible COVID-19 case in respiratory failure, using a mannequin modified to aerosolize phosphorescent secretions. Thirty-six individuals participated in five ISS sessions over 6 weeks, and a further 20 individuals observed these sessions. Debriefing identified latent safety threats from four domains: personnel, personal protective equipment, supply/environment and communication. These threats were addressed and resolved in later iterations. Ninety-four percent of participants felt more prepared to care for a potential case of COVID-19 after the ISS.

A149 COMPARING THE REAL-WORLD EFFECTIVENESS OF 4L VERSUS 2L SPLIT COLONOSCOPY PREPARATIONS: PRELIMINARY DATA OF A SINGLE CENTRE EXPERIENCE THROUGH THE BRITISH COLUMBIA COLONOSCOPY SCREENING PROGRAM

Background

The British Columbia Colon Screening Program (CSP) is a population-based program offering biennial fecal immunochemical test (FIT) to individuals age 50–74 years with follow-up colonoscopy for a positive FIT as well as individuals with a personal history of neoplastic polyps or a high risk family history of colorectal cancer. Over 20,000 colonoscopies are performed annually. In December 2018, program colonoscopists in Vancouver, Canada agreed to switch from a 2L polyethylene glycol (PEG) preparation to a 4L PEG preparation after studies suggested superiority of the higher volume preparation in achieving adequate bowel cleansing and improving adenoma detection rates (ADR). High quality bowel cleansing is critical to minimize repeat procedures and maximize neoplasia detection.

Aims

To compare the quality of bowel preparation and neoplasia detection rates using the 4L high volume split preparation (HVSP) versus the 2L low volume split preparation (LVSP) in patients undergoing colonoscopy in the BC CSP.

Methods

A retrospective review of consecutive patients undergoing colonoscopy through the CSP at St. Paul’s Hospital from Dec 2017-Apr 2018 and Dec 2018-Apr 2019 was conducted. Inclusion criteria included: age 50–74, patients undergoing colonoscopy for any reason through the BC CSP. Variables collected included: patient demographics, bowel preparation qualty and pathologic findings. ADR and sessile serrated polyp detection rate (SSDR) were analyzed.

Results

462 colonoscopies were included, 280 in the LVSP group and 182 in the HVSP group. 8/280 (2.9%) had poor bowel preparation in the LVSP group, while 10/182 (5.5%) had poor bowel preparation in the HVSP group. The ADR and SSDR were 53.6% in LVSP vs. 50.0% in HVSP and 8.2% in LVSP vs. 8.8% in HVSP, respectively.

Conclusions

In this preliminary evaluation, the high volume PEG-based split preparation did not reduce the proportion of inadequate bowel preparations. Further evaluation of a larger number of colonoscopies is planned.

Funding Agencies

None

A168 IS ROUTINE SCREENING FOR HEREDITARY COLORECTAL CANCER FEASIBLE IN AN OUTPATIENT GASTROENTEROLOGY PRACTICE?

Background

Lynch syndrome (LS) is the most common cause of hereditary colorectal cancer (CRC), with a reported prevalence of 2–5% of all CRC cases. A study by Kastrinos et al. found that a simple 3 item survey identified 77% of individuals at high risk for hereditary CRC. Implementation of this questionnaire at a gastroenterology office may help identify patients at risk for LS and other hereditary CRC.

Aims

To assess whether implementation of a validated questionnaire to screen for hereditary CRC is feasible in an outpatient gastroenterology clinic.

Methods

Adult gastroenterology outpatients who consented to participate in the study completed the screening questionnaire. Those who had previously been assessed by the Hereditary Cancer Program were excluded. Each subject was asked the following three questions: (1) Do you have a first-degree relative with CRC or LS-related cancer diagnosed before age 50? (2) Have you had CRC or polyps diagnosed before age 50? (3) Do you have ≥3 relatives with CRC?. Answering yes to any question was considered a positive screen.

Results

A total of 288 patients were screened, with 12 (4.2%) screening positive for question 1, 28 (9.7%) screening positive for question 2, and 8 (2.8%) screening positive for question 3. In total, 14.2% of individuals surveyed screened positive.

Conclusions

Utilization of a simple 3-question survey as part of regular patient intake in a gastroenterology office resulted in 14.2% of individuals screening high-risk for hereditary CRC. This is similar to the 15% screen positive rate in the original study of individuals with CRC. Further research is needed to determine whether a physician’s knowledge of the questionnaire results will change management and whether a positive screen leads to a confirmed diagnosis of LS and other hereditary colorectal cancers.

Funding Agencies

None

A165 ASSESSING ATTENDANCE OF SUBSTANCE USER ENDOSCOPIES (A.S.U.R.E)

Background

In Canada, British Columbia (BC) is the leading province in opioid deaths with 30.6 per 100,000 population. Since substance users are stigmatized in health care, patient care requires specific, individualized management strategies, which often creates a gap between the patient and health care service. Diagnostic studies remain a challenge due to lack of funding and the unique requirements necessary to treat this patient population efficiently. Thus, new methods of prevention must be cultivated to ensure ideal patient care.

Aims

To investigate the proportion of patients on restricted narcotics that failed to attend scheduled gastroenterology and hepatology appointments at our center.

Methods

A retrospective chart review from 01/05 – 07/19 and data analysis of patients (≥ 19 yrs.) referred to a Downtown Gastroenterology office was performed. Data was collected from an electronic medical record system and filtered through a keyword search for ‘Methadone’, ‘Suboxone’, ‘Dilaudid’, and ‘Morphine’ to create a sample size of patients with recent/ongoing use of narcotic agents. Patients with chronic pain, or terminal illness prescribed these drugs were not included. Demographic information, type of appointment scheduled and failure to attend were recorded.

Results

Acquired data yielded 2630 patients of which 350 patient were included. Mean age was 47 years (61% male). 35% of the patients were current narcotics users, the rest being previous users of these agents. Scheduled appointments and non-attendance are shown in Tables 2 and 3. Most patients (70%) were referred for various general GI complaints with HCV accounting for 23% of the consults. Despite the use of confirmation lines, 20% of HCV referred patients and 29% of non-HCV referred patients did not attend their first appointment.

Conclusions

Current and prior narcotic users failed to attend more than one quarter of scheduled gastroenterology/hepatology appointments. Ideal management of care for GI disease can’t be obtained without contact with those that provide the service. Creative, innovative management strategies are required to ensure ideal care for this unique group of patients.

Funding Agencies

None

A154 ASSESSING COLON SCREENING PROGRAM COLONOSCOPIES IN A NON-HOSPITAL ENDOSCOPY CLINIC

Background

Colorectal cancer is the most commonly diagnosed cancer in British Columbia, affecting 1 in 6 persons. The BC Colon Screening Program (CSP) screens individuals 50–74 years of age with biennial FIT (cut-off 10 mcg/g) with follow-up colonoscopy for positive results. In Vancouver, colonoscopies are performed in a hospital environment; however non-hospital endoscopy clinics have been used in other jurisdictions.

Aims

To investigate the quality of procedure, rate of complications and need to repeat procedures in a hospital setting for colonoscopies performed on CSP patients in a non-hospital setting.

Methods

A retrospective chart review for all CSP colonoscopies performed from 04/19 to 07/19 in a non-hospital endoscopy clinic. Data was collected from an electronic medical record system and included adenoma detection rates; any repeat procedures required in a hospital setting and adverse event rates. Criteria for a repeat in hospital colonoscopy were inadequate bowel preparation, body mass index exceeding the allowable threshold for a non-hospital colonoscopy and identification of a difficult to remove polyp such as a polyp > 20 mm or in a difficult location.

Results

801 FIT positive patients (ages 50–74) underwent colonoscopy in the non-hospital endoscopy clinic. The mean age was 60 years (51% female). The mean time between referral date and procedure date was 192 days. The neoplasia detection rate was 60.2%, there was one (0.1%) adverse event (post-polypectomy bleed) and 21 (2.6%) patients required a repeat colonoscopy in a hospital setting.

Conclusions

Colonoscopy to follow-up a positive FIT in an non-hospital endoscopy clinic was safe and effective with a low number of repeat, in hospital colonoscopies required.

Funding Agencies

None

A163 MICROCOSTING: ASSESSING HEALTH ECONOMICS IN GI

Background

Micro-costing is a method of collecting precise cost measurements and proves effective in determining economic requirements needed to support health interventions. At St. Paul’s GI Clinic, over 12000 procedures are performed yearly, 80% of which are colonoscopies. Specific standards in the form of appropriate documentation are recommended through Global Rating Scale (GRS) and require yearly auditing to ensure appropriate compliance with these standards. These audits require a time commitment of staff to assess charts. The cost of performing these assessments is not known.

Aims

To determine the cost of annual data collection suggested by GRS for documentation of procedures.

Methods

A retrospective chart review and data analysis of patients (≥ 19 years old) admitted to St. Paul’s GI Clinic for a colonoscopy and/or esophagogastroduodenoscopy (EGD). Data is extracted from the St. Paul’s medical database from August 1st 2018 – August 1st 2019. Since it is a ‘time-and-motion’ study, a stopwatch is used to time the collection of data from each chart. The mean time per-case is derived and used to conduct an appropriate economic analysis, such as total working hours, per-minute salary calculations and equipment costs. The purpose is to determine a yearly cost and identify what the main cost drivers were (time/labor).

Results

As per our annual review format suggested by GRS, 260 procedure reports were reviewed, 150 colonoscopies and 110 EGDs (random sampling of 10 per physician for each type of procedure). A spread sheet outlining key data assessment points for mandatory standard reporting points has been used yearly and was used for this study as well. Mean evaluation time (including recording presence or absence of each item on our standard reporting form): 1 minute and 40 seconds to review the report for a colonoscopy and 1 minute and 33 seconds to review the report for an EGD. A total of 2 hours 51 minutes 16 seconds to review all the EGD reports and 4 hours 8 minutes and 46 seconds for the colonoscopy reports.

Conclusions

It would cost $126 annually to pay a research student, who makes $18/ hour, to collect this quality assurance data required for auditing completeness of physician colonoscopy and EGD procedure documentation according to standards.

Funding Agencies

None

A rare presentation of angioedema with isolated retropharyngeal and supraglottic involvement

Angiotensin converting-enzyme (ACE) inhibitors are commonly prescribed drugs with multiple indications including congestive heart failure, hypertension, and diabetic nephropathy. ACE inhibitor induced angioedema is commonly seen across emergency departments and clinics, with transient swelling of lips, tongue, and other facial structures being the common presentation. Isolated airway obstruction as a result of pharyngeal and laryngeal swelling without facial swelling is a rare presentation. We present a case of a patient on lisinopril therapy for one year who experienced severe airway compromise without the classic symptoms of ACE inhibitor induced angioedema. He required emergent cricothyroidotomy to secure his airway, as fiberoptic laryngoscopy showed 90% obstruction and inability to visualize true vocal cords. His ACE inhibitor therapy was discontinued, and he was discharged home within a few days with no residual symptoms.

Abstract B095: Mapping the genetic features of immune checkpoint responsiveness using AAV-CRISPR mediated in vivo screen

Immune checkpoint blockade has achieved tremendous clinical success across many tumor types, but fails to induce clinical responses in many patients. The mechanisms underlying checkpoint resistance remain poorly characterized. Recent studies have applied next generation sequencing techniques to catalog the mutational burden of patient tumors, which provides a wealth of data to determine common mutations. To map the genetic features of response to checkpoint blockade immunotherapy as well as correlating the clinical efficacy with certain mutations, we developed a novel direct in vivo CRISPR screening approach for high-throughput profiling of functional cancer drivers in an autochthonous manner by injecting AAVs carrying an sgRNA library targeting the top 50 TCGA pan-cancer recurrently mutated tumor suppressor genes (mTSG) into the immunocompetent Cas9 transgenic mice. All mice that received the AAV-mTSG library developed liver cancer and died within four months. We then utilized MIP sequencing of sgRNA target sites to chart the mutational landscape of these tumors, revealing the functional consequence of multiple variants in driving liver tumorigenesis as well as identifying specific gene pairs that were co-occurring across mice. Using this approach, we also mapped the mutation landscape changes under the pressures of immune checkpoint inhibitors, anti-PD1 or anti-CTLA4. We monitored liver tumor growth in AAV-mTSG injected LSL-Cas9;LSL-Fluc mice by using intravital bioluminescent imaging system (IVIS) in combination with dissection check before drug administration. Using IVIS data, we grouped them into 3 size-matched cohorts to receive anti-PD1 or anti-CTLA4 treatments or PBS control. According to the survival data, the mice with mTSG-induced liver tumor benefit from anti-PD1 or anti-CLTA4 treatment. By comparing the mutation frequencies of liver tumors in the mice receiving either checkpoint inhibitors or PBS treatment, we mapped the mutation landscape changes associated with anti-PD1 or anti-CTLA4 treatment. We are performing validation studies on top targets such as Arid1a, Stk11, and B2M. Using this approach, we systematically mapped the correlation of these top 50 driver mutations with cancer immune evasion and immunotherapy responsiveness, providing a valuable reference for patient stratification when considering immunotherapy as well as novel targets for synergistic interventions.

Citation Format: Guangchuan Wang, Ryan Chow, Zhigang Bai, Lupeng Ye, Sidi Chen. Mapping the genetic features of immune checkpoint responsiveness using AAV-CRISPR mediated in vivo screen [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B095.

Novel frequency analysis of signal-averaged electrocardiograms is predictive of adverse outcomes in implantable cardioverter defibrillator patients

BACKGROUND

Current noninvasive risk stratification methods offer limited prediction of arrhythmic events when selecting patients for ICD implantation. Our laboratory has recently developed a signal processing metric called Layered Symbolic Decomposition frequency (LSDf) that quantifies the percentage of hidden QRS wave frequency components in signal-averaged ECG (SAECG) recordings. The purpose of this pilot study was to determine whether LSDf can be predictive of ventricular arrhythmia or death in an ICD patient cohort.

METHODS AND RESULTS

Fifty-two ICD patients were recruited from 2008 to 2009. These were followed for a mean of 8.5 ± 0.4 years for the primary outcome of first appropriately treated ventricular arrhythmia (VT/VF) or death. Thirty-four subjects met the primary outcome. LSDf was significantly lower, and 12-lead QRS duration was significantly greater in patients meeting the primary outcome (12.14 ± 3.97% vs. 16.45 ± 3.73%; p = 0.001) and (111.59 ± 14.96 ms vs. 97.69 ± 13.51 ms; p = 0.012) respectively. A 13.25% LSDf threshold (0.74 sensitivity and 0.85 specificity) was selected based on an ROC curve. Kaplan-Meier survival analysis was conducted; patients above the 13.25% threshold demonstrated significantly better survival outcomes (log-rank p < 0.001). In Cox multivariate regression analysis, the LSDf threshold (13.25%) was compared to LVEF (28.5%), 12-lead QRSd (100 ms), age, % male sex, NYHA classification, and antiarrhythmic usage. LSDf was a predictor of the primary outcome (p = 0.005) and an independent predictor for solely ventricular arrhythmia (p = 0.002).

CONCLUSION

Layered Symbolic Decomposition frequency analysis in SAECG recordings may be a viable predictor of negative ICD survival outcomes.

miR-151a induces partial EMT by regulating E-cadherin in NSCLC cells

miR-151a and its host gene, focal adhesion kinase, FAK, are located in a region of chromosome 8q that is frequently amplified in solid tumors, including lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and metastasis remains the major challenge in battling lung cancer mortality. Here, we demonstrate that miR-151a is overexpressed in non-small cell lung cancer (NSCLC) patient specimens, as compared to healthy lung. In addition, miR-151a overexpression promotes proliferation, epithelial-to-mesenchymal transition (EMT) and induces tumor cell migration and invasion of NSCLC cells. Blocking miR-151a expression using anti-miR-151a approaches significantly reduced NCSLC cell proliferative and motility potential. Furthermore, we determined that miR-151a significantly regulates E-cadherin expression. Finally, functional rescue experiments determined that overexpression of E-cadherin in miR-151a NSCLC cell lines potently repressed miR-151a-induced partial EMT and cell migration of NSCLC cells. In conclusion, our findings suggest that miR-151a functions as an oncomiR in NSCLC by targeting E-cadherin mRNA and inducing proliferation, migration and partial EMT.

A t(17;19)(q22;p13.3) Involving TCF3, a t(1;9)(p13;p13), and a 5' IGH Deletion in a Case of Adult B-cell Acute Lymphoblastic Leukemia

TCF3 (19p13.3) abnormalities are relatively common in B-cell acute lymphoblastic leukemia (B-ALL). The t(1;19)(q23;p13) involving PBX1 is the most common of these rearrangements. The t(17;19)(q22;p13.3), resulting in the TCF3-HLF fusion gene, is also seen in B-ALL and is associated with an extremely poor prognosis. Herein, we present the case of a 25-year-old male diagnosed with B-ALL whose initial karyotype showed a t(17;19)(q22p13.3). FISH confirmed TCF3 involvement and also revealed a 5' IGH deletion. After treatment, the patient relapsed, at which point conventional cytogenetic studies showed a t(17;19), loss of the 5' IGH region, and a t(3;10) not seen in initial studies. After hematopoietic stem cell transplantation, the patient relapsed again, at which point conventional cytogenetic studies showed a complex karyotype with t(17;19), t(1;9)(p13;p13), and structural anomalies involving chromosomes 5, 7, and 14, but no IGH abnormalities by FISH. The t(1;9) has been shown to involve PAX5, which plays numerous regulatory roles in B-cell differentiation. Other PAX5 rearrangements have been detected in B-ALL cases of young adults and adolescents, but with unclear clinical significance. To the best of our knowledge, this is the first reported case of t(17;19)-ALL with concomitant 5' IGH deletion and t(1;9)(p13;p13) potentially involving PAX5, albeit at different time points in disease progression. This case provides insight into the clonal evolution of t(17;19)-ALL and the potential involvement of PAX5 and IGH aberrations in the evolution of this malignancy.

Incidence of skeletal-related events over time from solid tumour bone metastases reported in randomised trials using bone-modifying agents

AIMS

Skeletal-related events (SREs) in patients with bone metastases decrease a patient's quality of life and functional status. Although bone-modifying agents have been found to reduce the time to first on-trial SRE and decrease the total incidence of SREs in randomised clinical trials, standard practice in the management of bone metastases has changed concurrently. The purpose of this study was to investigate if advances in bone-targeted therapies have decreased the incidence of individual types of SREs and to delineate the trend of SREs.

MATERIALS AND METHODS

A literature review was conducted in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials to identify phase III, randomised bisphosphonate and other bone-targeted therapy trials from 1980 to September 2011. For all studies, a mean year of enrolment ([start of enrolment + end of enrolment]/2) was calculated. The incidences of SREs were tabulated and expressed as percentages of on-trial patients. Generalised linear mixed models were used to search for the trends of SREs over time for all placebo and intervention arms. Regression coefficients were interpreted as the odds ratio, which was calculated using the exponential of the slope. Ninety-five per cent confidence intervals were also calculated.

RESULTS

In total, 20 eligible studies were identified that reported SRE data from phase III trials, of which 11 were suitable for the quantitative analysis. Most of the articles included patients with breast cancer and the remaining involved patients with prostate, renal cell, bladder and lung cancer or other solid tumours. Enrolment periods for all included data ranged from 1990 to 2009. Statistically significant overall downward trends in pathological fractures and the need for surgery were seen over time. Also significant differences between intervention and placebo were seen with all SREs.

CONCLUSION

The decrease in SREs over time may not only be a result of the development of new generation bone-targeted agents, but also due to better systemic management and awareness of events associated with bone metastases.