Hub and spoke framework for study of surgical centralization within United States health systems

BACKGROUND

Hospital consolidation into health systems has mixed effects on surgical quality, potentially related to degree of surgical centralization at high-volume (hub) sites. We developed a novel measure of centralization and evaluated a hub and spoke framework.

METHODS

Surgical centralization within health systems was measured using hospital surgical volumes (American Hospital Association) and health system data (Agency for Healthcare Research and Quality). Hub and spoke hospitals were compared using mixed effects logistic regression and system characteristics associated with surgical centralization were identified using a linear model.

RESULTS

Within 382 health systems containing 3022 hospitals, system hubs perform 63% of cases (IQR 40-84%). Hubs are larger, in metropolitan and urban areas, and more often academically affiliated. Degree of surgical centralization varies ten-fold. Larger, multistate, and investor-owned systems are less centralized. Adjusting for these factors, there is less centralization among teaching systems (p ​< ​0.001).

CONCLUSIONS

A hub-spoke framework applies to most health systems but centralization varies significantly. Future studies of health system surgical care should assess the contributions of surgical centralization and teaching status on differential quality.

The Impact of an Electromagnetic Seed Localization Device Versus Wire Localization on Breast-Conserving Surgery: A Matched-Pair Analysis

BACKGROUND

For breast-conserving surgery (BCS), several alternatives to wire localization (WL) have been developed. The newest, electromagnetic seed localization (ESL), provides three-dimensional navigation using the electrosurgical tool. This study assessed operative times, specimen volumes, margin positivity, and re-excision rates for ESL and WL.

METHODS

Patients who had ESL-guided breast-conserving surgery between August 2020 and August 2021 were reviewed and matched one-to-one with patients who had WL based on surgeon, procedure type, and pathology. Variables were compared between ESL and WL using Wilcoxon rank-sum and Fisher's exact tests.

RESULTS

The study matched 97 patients who underwent excisional biopsy (n = 20) or partial mastectomy with (n = 53) or without (n = 24) sentinel lymph node biopsy (SLNB) using ESL. The median operative time for ESL versus WL for lumpectomy was 66 versus 69 min with SLNB (p = 0.76) and 40 versus 34.5 min without SLNB (p = 0.17). The median specimen volume was 36 cm3 using ESL versus 55 cm3 using WL (p = 0.001). For the patients with measurable tumor volume, excess tissue was greater using WL versus ESL (median, 73.2 vs. 52.5 cm3; p = 0.017). The margins were positive for 10 (10 %) of the 97 ESL patients and 18 (19 %) of the 97 WL patients (p = 0.17). In the ESL group, 6 (6 %) of the 97 patients had a subsequent re-excision compared with 13 (13 %) of the 97 WL patients (p = 0.15).

CONCLUSIONS

Despite similar operative times, ESL is superior to WL, as evidenced by decreased specimen volume and excess tissue excised. Although the difference was not statistically significant, ESL resulted in fewer positive margins and re-excisions than WL. Further studies are needed to confirm that ESL is the most advantageous of the two methods.

Emergency department presentations with suicide and self-harm ideation: a missed opportunity for intervention?

AIMS

Suicidal ideation constitutes a central element of most theories of suicide and is the defining facet separating suicide from other causes of death such as accidents. However, despite a high worldwide prevalence, most research has focused on suicidal behaviours, such as completed suicide and suicide attempts, while the greater proportion who experienced ideation, which frequently precedes suicidal behaviour, have received much less attention. This study aims to examine the characteristics of those presenting to EDs with suicidal ideation and quantify the associated risk of suicide and other causes of death.

METHODS

Retrospective cohort study was performed based on population-wide health administration data linked to data from the Northern Ireland Registry of Self-Harm and centrally held mortality records from April 2012 to December 2019. Mortality data, coded as suicide, all-external causes and all-cause mortality were analysed using Cox proportional hazards. Additional cause-specific analyses included accidental deaths, deaths from natural causes and drug and alcohol-related causes.

RESULTS

There were 1,662,118 individuals aged over 10 years, of whom 15,267 presented to the ED with ideation during the study period. Individuals with ideation had a 10-fold increased risk of death from suicide (hazard ratio [HR_adj] = 10.84, 95% confidence interval [CI] 9.18, 12.80) and from all-external causes (HR_adj = 10.65, 95% CI 9.66, 11.74) and a threefold risk of death from all-causes (HR_adj = 3.01, 95% CI 2.84, 3.20). Further cause-specific analyses indicated that risk of accidental death (HR_adj = 8.24, 95% CI 6.29, 10.81), drug-related (HR_adj = 15.17, 95% CI 11.36, 20.26) and alcohol-related (HR_adj = 10.57, 95% CI 9.07, 12.31) has also significantly increased. There were few socio-demographic and economic characteristics that would identify which of these patients are most at risk of suicide or other causes of death.

CONCLUSIONS

Identifying people with suicidal ideation is recognized to be both important but difficult in practice; this study shows that presentations to EDs with self-harm or suicide ideation represent an important potential intervention point for this hard-to-reach vulnerable population. However, and unlike individuals presenting with self-harm, clinical guidelines for the management and recommended best practice and care of these individuals are lacking. Whilst suicide prevention may be the primary focus of interventions aimed at those experiencing self-harm and suicide ideation, death from other preventable causes, especially substance misuse, should also be a cause of concern.

Robotic bronchoscopic needle-based confocal laser endomicroscopy to diagnose peripheral lung nodules

BACKGROUND AND OBJECTIVE

Robotic bronchoscopy has demonstrated high navigational success in small peripheral lung nodules but the diagnostic yield is discrepantly lower. Needle based confocal laser endomicroscopy (nCLE) enables real-time microscopic imaging at the needle tip. We aim to assess feasibility, safety and needle repositioning based on real-time nCLE-guidance during robotic bronchoscopy in small peripheral lung nodules.

METHODS

Patients with suspected peripheral lung cancer underwent fluoroscopy and radial EBUS assisted robotic bronchoscopy. After radial EBUS nodule identification, nCLE-imaging of the target area was performed. nCLE-malignancy and airway/lung parenchyma criteria were used to identify the optimal sampling location. In case airway was visualized, repositioning of the biopsy needle was performed. After nCLE tool-in-nodule confirmation, needle passes and biopsies were performed at the same location.

MEASUREMENTS AND MAIN RESULTS

Twenty patients were included (final diagnosis n = 17 (lung) cancer) with a median lung nodule size of 14.5 mm (range 8-28 mm). No complications occurred. In 19/20 patients, good quality nCLE-videos were obtained. In 9 patients (45%), real-time nCLE-imaging revealed inadequate positioning of the needle and repositioning was performed. After repositioning, nCLE-imaging provided tool-in-nodule-confirmation in 19/20 patients. Subsequent ROSE demonstrated representative material in 9/20 patients (45%) and overall diagnostic yield was 80% (16/20). Of the three patients with malignant nCLE-imaging but inadequate pathology, two were diagnosed with malignancy during follow-up.

CONCLUSION

Robotic bronchoscopic nCLE-imaging is feasible and safe. nCLE-imaging in small, difficult-to-access lung nodules provided additional real-time feedback on the correct needle positioning with the potential to optimize the sampling location and diagnostic yield.

60 POWER-AGERS: IMPLEMENTING PROGRESSIVE RESISTANCE TRAINING TO MANAGE SARCOPENIA AMONG COMMUNITY DWELLING OLDER ADULTS

Background

The prevalence of sarcopenia among community dwelling older adults is between 10-40%. Progressive Resistance Training (PRT) improves sarcopenia and functional performance among older-adults. A PRT programme was introduced to a Day Hospital service as part of a sarcopenia management quality improvement initiative.

Methods

The PRT programme was implemented on a phased basis. Phase 1 evaluated the feasibility, safety and participant satisfaction. Phase 2 then collected pre and post outcome measures (gait-speed, grip strength and 5-Times-Sit-to-Stand [5TSTS]), and a patient perception questionnaire. The intervention consisted of a physiotherapist-lead PRT programme (weekly in phase 1 and biweekly in phase 2). Recent community dwelling Day Hospital attendees were recruited by the physiotherapist to participate. The class consisted of a circuit of 4-6 exercises targeting upper and lower limbs, along with an educational component. Exercises were progressively overloaded on an individual basis.

Results

Ten participants attended the PRT programmes (phase 1 [n=5], phase 2 [n=5]). Most were female (n=6), mean age was 84 years. None had prior formal experience of PRT. The phase 1 PRT group was deemed feasible and safe in an outpatient setting. All phase 1 participants (n=5) felt it was beneficial and rated it 5/5. All phase 2 participants had improvements in sarcopenia markers (grip strength [range=1kg-9kg], gait-speed [range=0.04m/s-0.19m/s], and 5TSTS [range=5.1sec-11sec]). All participants reported that the programmes improved their confidence in PRT and that they were interested in continuing PRT in the future.

Conclusion

This supports that PRT a clinical setting with community dwelling older adults is safe, feasible and effective in improving sarcopenia markers. Furthermore, the high rate of satisfaction supports its use with this population. Further research is required to examine the impact of combined nutritional education with strength training as an intervention for older adults with sarcopenia.

43 EXPLORING STAFF PERCEPTIONS AND ATTITUDES TO CARE AND CAREBOTS: THE CASE OF AN ORIGINAL AIR-DISINFECTION ROBOT IN IRELAND

Background

The pandemic heightened the sense of security and safety in care settings, with cleanliness and infection control becoming an even more important aspect of care delivery. Although the impact of new welfare technology on health and social care has been discussed in recent years, few studies have reported the implementation processes or human-robot interactions in care facilities in different cultural settings. The aims of this interdisciplinary research therefore were to understand needs and aspects that have to be considered for implementing an assistive robot, and to explore user perceptions, and the process by which the robots are adopted in Ireland and Japan.

Methods

An original air-disinfection robot (V-Air) was developed by Akara Robotics, as part of research project “Harmonisation towards the establishment of Person-centred, Robotics-aided Care System” (Toyota Foundation, D18-ST-0005). Prior to its instalment in a rehabilitation centre in Dublin, semi-structured interviews were conducted, and observations carried out with seven care professionals, as they interacted with V-Air. The robot was then trialled for eight weeks (March-May 2022) in selected areas of the facility. After four weeks, the users filled out the System Usability Score and were asked questions at the end of the trial. Their scores and answers to the questions revealed staff perceptions and attitudes to care robots.

Results

Overall, the users had positive perceptions of V-Air and its usability. Initial differences existed in staff’s confidence levels, depending on prior experiences with technologies. Collective sensemaking was observed, particularly, around care delivery processes and robot functionalities. The adoption process was facilitated by several factors such as the timing of introduction, user-centred design, concept of care and organisational support.

Conclusion

The findings suggest that the introduction of care robots in care settings can offer an additional layer of organisational safety, while highlighting the significance of the iterative process in adopting assistive technologies.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Polygenic risk modeling for prediction of epithelial ovarian cancer risk

Polygenic risk scores (PRS) for epithelial ovarian cancer (EOC) have the potential to improve risk stratification. Joint estimation of Single Nucleotide Polymorphism (SNP) effects in models could improve predictive performance over standard approaches of PRS construction. Here, we implemented computationally efficient, penalized, logistic regression models (lasso, elastic net, stepwise) to individual level genotype data and a Bayesian framework with continuous shrinkage, "select and shrink for summary statistics" (S4), to summary level data for epithelial non-mucinous ovarian cancer risk prediction. We developed the models in a dataset consisting of 23,564 non-mucinous EOC cases and 40,138 controls participating in the Ovarian Cancer Association Consortium (OCAC) and validated the best models in three populations of different ancestries: prospective data from 198,101 women of European ancestries; 7,669 women of East Asian ancestries; 1,072 women of African ancestries, and in 18,915 BRCA1 and 12,337 BRCA2 pathogenic variant carriers of European ancestries. In the external validation data, the model with the strongest association for non-mucinous EOC risk derived from the OCAC model development data was the S4 model (27,240 SNPs) with odds ratios (OR) of 1.38 (95% CI: 1.28-1.48, AUC: 0.588) per unit standard deviation, in women of European ancestries; 1.14 (95% CI: 1.08-1.19, AUC: 0.538) in women of East Asian ancestries; 1.38 (95% CI: 1.21-1.58, AUC: 0.593) in women of African ancestries; hazard ratios of 1.36 (95% CI: 1.29-1.43, AUC: 0.592) in BRCA1 pathogenic variant carriers and 1.49 (95% CI: 1.35-1.64, AUC: 0.624) in BRCA2 pathogenic variant carriers. Incorporation of the S4 PRS in risk prediction models for ovarian cancer may have clinical utility in ovarian cancer prevention programs.

Abstract P1-24-02: Genetic variants and tumor microenvironment in inflammatory breast cancer: Clues for targeted therapies

Background: Inflammatory breast cancer (IBC) is characterized by a young age at diagnosis, high metastatic potential, and poor overall survival. To better understand the etiology of this aggressive disease, we performed a retrospective study to evaluate genomic alterations and tumor microenvironment in IBC patients. Methods: Targeted next generation sequencing (NGS) was performed using blood cell-free DNA (cfDNA) (n=32), paired DNA from tumor tissues (n=29) and DNA from whole blood or normal tissue (n=20). We also characterized the tumor infiltrating lymphocytes (TILs) in tumor tissue biopsies by studying several markers (CD4, CD8, FoxP3, CD20, PD-1 and PD-L1) through immunohistochemistry (IHC) staining. Results: Our results shown a high incidence of germline variants in patients with IBC that could be associated with an increased risk of developing the disease. Germline variants were found more frequently in patients with TN (38.9%) than non-TN IBC (28.6%). IHC staining revealed that in 7 of 24 (29%) patients, tumor biopsies were positive for PD-L1 and PD-1 expression on TILs. Patients with PD-L1&PD-1 positive biopsies had a lower OS (31 months) than patients with PD-L1&PD-1 negative (38 months) tumors, though the difference was not statistically significant. PD-L1&PD-1 positive tumors had significantly more CD8+ (cytotoxic T-cells), CD20+ (B-cells) and FoxP3+ (Tregs) cells than PD-L1&PD-1 negative ones. Furthermore, most IBC patients showed to have deficiencies in the homologous recombination repair (HRR) pathway (BRCA1, BRCA2, PALB2, RAD51C, ATM, BARD1) making them sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. All tumor biopsies showed positive staining for p-FAK1(Tyr 397). Conclusion: A subset of IBC patients (29%) expressed both PD-L1 and PD-1 on tumor immune cells infiltrates, providing rationale for testing PD-1/PD-L1 blocking therapies. IBC patients could have benefits from PD-1/PD-L1 blocking therapies alone or in combination with PARP or FAK (Tyr397) kinase inhibitors, both having the capacity of altering the tumor microenvironment.

Citation Format: Maria F. Arisi, Yulan Gong, Rajeswari Nagarathinam, Lorenzo Gerratana, Jianming Pei, Kathy Q. Cai, Jennifer Winn, Zachary Hasse, Elias Obeid, Julio Noriega, Christopher Sebastiano, Eric Ross, R. Katherine Alpaugh, Massimo Cristofanilli, Sandra V Fernandez. Genetic variants and tumor microenvironment in inflammatory breast cancer: Clues for targeted therapies [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-24-02.

Optimizing Outcomes With the 1550/1927 nm Dual Wavelength Non-Ablative Fractional Laser: Experienced User Recommendations

BACKGROUND

Fractional laser treatment was introduced in 2004 as a non-invasive technique to treat sun-damaged and aging skin. Since then, numerous ablative and non-ablative photothermolysis technologies and devices have been introduced, increasing the options for clinicians and patients but also increasing the complexity regarding which system to use and the techniques to optimize outcomes. No two devices are the same and the user-manuals preset dosimetry does not address many clinical situations, which can create confusion for new and inexperienced users.

METHODS

An online survey addressing use of a 1550 nm /1927 nm dual wavelength, non-ablative, fractional laser was sent to eight (8) US board certified dermatologists with extensive experience in the use of the device. The survey included 39 questions, addressing experience, best practices and recommendations for use.

RESULTS

The survey data suggests that the device can be used to treat patients of all ages and skin types for indications including photoaging and photodamage, periorbital wrinkles, freckles, (ephelides), solar lentigines, poikiloderma, scarring due to acne or surgery. It can be used on both facial and non-facial areas, including neck, chest, hands, arms, abdomen, legs, and buttocks. Unexpected and adverse effects were rarely reported and those that did were mild and transient.

CONCLUSIONS

This position paper provides practical real-world guidelines resulting from a small survey of experienced users, for new and early uses of the novel 1550 nm /1927 nm dual wavelength, non-ablative, fractional laser. J Drugs Dermatol. 2021;20(11):1150-1157. doi:10.36849/JDD.6181.

Anti-cancer efficacy including Rb-deficient tumors and VHL-independent HIF1α proteasomal destabilization by dual targeting of CDK1 or CDK4/6 and HSP90

A prevalent characteristic of solid tumors is intra-tumoral hypoxia. Hypoxia-inducible factor 1α (HIF1α) predominantly mediates the adaptive response to O₂ oscillation and is linked to multiple malignant hallmarks. Here we describe a strategy to robustly target HIF1α by dual inhibition of CDK(s) and heat shock protein 90 (HSP90). We show that CDK1 may contribute to HSP90-mediated HIF1α stabilization. CDK1 knockdown enhances the decrease of HIF1α by HSP90 inhibition. Dual inhibition of CDK1 and HSP90 significantly increases apoptosis and synergistically inhibits cancer cell viability. Similarly, targeting CDK4/6 using FDA-approved inhibitors in combination with HSP90 inhibition shows a class effect on HIF1α inhibition and cancer cell viability suppression not only in colorectal but also in various other cancer types, including Rb-deficient cancer cells. Dual inhibition of CDK4/6 and HSP90 suppresses tumor growth in vivo. In summary, combined targeting of CDK(s) (CDK1 or CDK4/6) and HSP90 remarkably inhibits the expression level of HIF1α and shows promising anti-cancer efficacy with therapeutic potential.

1458 Compliance of Abdominal X-ray Requesting with iRefer Guidelines in CDDFT

Aim

100% of Abdominal x-ray (AXR) requests in the trust should be compliant with iRefer guidelines. Therefore, with this audit we hope to evaluate the compliance of our hospitals with said guidelines.

Method

This audit was retrospective with AXRs taken between 23 – 29th of November 2020 being analysed for compliance creating our first loop. On the 1st of December we placed our intervention. This came in the form of educational posters in the four areas that request the majority of AXRs. Following this, a further weeks’ worth of AXRs were assessed for compliance between 2nd – 8th of December 2020.

Results

Between 23-29/11/20 there were 67 AXRs requested. Eight of these were excluded according to our exclusion criteria, leaving a total of 59 AXRs to be assessed. After reviewing the request cards for these AXRs, 17 were non-compliant (28.8%). Following the intervention, AXR requests were re-audited. Between 2-8/12/20 there were 69 AXRs requested. Six were excluded leaving a total of 63 AXRs to be assessed. After review, 22 were non-compliant (34.9%)

Conclusions

In both loops of this audit, the standard of 100% compliance with iRefer guidelines was not met. There was a high percentage of non-compliance in both loops with a rate of 28.8% and 34.9% respectively – a decrease in compliance. One possible reason to account for this was due the changeover of Junior Doctors within the trust on 2/12/20. Our interventional posters were placed in only half of the Trusts hospitals which may also account for the decrease in compliance.

Genetic Variants and Tumor Immune Microenvironment: Clues for Targeted Therapies in Inflammatory Breast Cancer (IBC)

To better understand the etiology of inflammatory breast cancer (IBC) and identify potential therapies, we studied genomic alterations in IBC patients. Targeted, next-generation sequencing (NGS) was performed on cell-free DNA (cfDNA) (n = 33) and paired DNA from tumor tissues (n = 29) from 32 IBC patients. We confirmed complementarity between cfDNA and tumor tissue genetic profiles. We found a high incidence of germline variants in IBC patients that could be associated with an increased risk of developing the disease. Furthermore, 31% of IBC patients showed deficiencies in the homologous recombination repair (HRR) pathway (BRCA1, BRCA2, PALB2, RAD51C, ATM, BARD1) making them sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. We also characterized the tumor-infiltrating lymphocytes (TILs) in tumor tissue biopsies by studying several markers (CD4, CD8, FoxP3, CD20, PD-1, and PD-L1) through immunohistochemistry (IHC) staining. In 7 of 24 (29%) patients, tumor biopsies were positive for PD-L1 and PD-1 expression on TILs, making them sensitive to PD-1/PD-L1 blocking therapies. Our results provide a rationale for considering PARP inhibitors and PD-1/PDL1 blocking immunotherapy in qualifying IBC patients.

Abstract 2374: Identification of altered miRNA-gene interactions in AOM/DSS induced colitis-associated dysplasia

Although significant progress has been made in delineating the pathways that contribute to ulcerative colitis (UC)-associated tumorigenesis, the early molecular alterations that fuel disease progression remain poorly understood. microRNAs (miRs) have emerged as important modulators of inflammatory pathways and their aberrant expression has been associated with initiation and progression of malignancy. The goal of this study is to identify gene-miR interactions that occur early in experimental UC and contribute to the development of colitis-associated dysplasia. The mRNA and miR expression profile of laser microdissected colon specimens (inflamed mucosa vs. dysplasia) from Swiss Webster mice with AOM/DSS-induced colitis was interrogated using the Mouse Gene Expression Microarrays 4x44K v2 (Agilent®) and miRNA Mouse platform (NanoString®). Data were analyzed using R/Bioconductor and nSolverTM (NanoString®). Differentially expressed miRs (n=12, p&lt;0.001) were validated by RT-qPCR (n=9) and used for target prediction (TargetScan v. 7.2). The differential expression of the predicted target genes (mRNA array) vs. miRs was compared and filtered to include only those with contrasting changes in expression (e.g. downregulated miR and upregulated mRNA). The resulting list of 98 genes was subjected to pathway enrichment analysis using EnrichR. Network interactions were calculated using STRING and visualized on Cytoscape v.3.8.0. Gene ontology analyses revealed 23 terms associated with the pathogenesis and progression of UC, including TNFα signaling via NF-kB, G1 to S cell cycle control, Wnt and Hedgehog signaling. Analyses of miR targets revealed that miR-30c, miR-145a and miR-1a controlled the largest number of predicted target genes (35%, 26% and 18%, respectively). These data suggest an important role of these top miRs (putative tumor suppressors) in UC-associated tumorigenesis, based on their downregulation in dysplasias and corresponding upregulation of their oncogenic targets (Sox9, Ccnd2 and Cdk6). Consistent with our findings, Sox9 contributes to carcinogenesis through its effect on stem cells. The Ccnd2/Cdk6 complex is considered a central component of signaling pathways that regulate cell cycle G1/S transition during neoplastic development. Therefore, early interaction of these miRs with their respective target genes may contribute to the transition of inflamed colonic mucosa to dysplasia in mice with experimental colitis. Additional in vitro validation of the predicted interactions remains in progress. (Supported by a generous donation from Aurora and Timothy Hughes).

Citation Format: Mariana F. Fragoso, Geysson J. Fernandez, Lisa Vanderveer, Harry S. Cooper, Wen-Chi Chang, Michael Slifker, Karthik Devarajan, Yan Zhou, Eric Ross, Margie L. Clapper. Identification of altered miRNA-gene interactions in AOM/DSS induced colitis-associated dysplasia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2374.

Changes in regeneration-responsive enhancers shape regenerative capacities in vertebrates

Vertebrates vary in their ability to regenerate, and the genetic mechanisms underlying such disparity remain elusive. Comparative epigenomic profiling and single-cell sequencing of two related teleost fish uncovered species-specific and evolutionarily conserved genomic responses to regeneration. The conserved response revealed several regeneration-responsive enhancers (RREs), including an element upstream to inhibin beta A (inhba), a known effector of vertebrate regeneration. This element activated expression in regenerating transgenic fish, and its genomic deletion perturbed caudal fin regeneration and abrogated cardiac regeneration altogether. The enhancer is present in mammals, shares functionally essential activator protein 1 (AP-1)-binding motifs, and responds to injury, but it cannot rescue regeneration in fish. This work suggests that changes in AP-1-enriched RREs are likely a crucial source of loss of regenerative capacities in vertebrates.

Rapid recurrence in head and neck cancer: Underappreciated problem with poor outcome

BACKGROUND

Rapid recurrence, defined as gross tumor recurrence after primary operation but prior to initiating postoperative radiation therapy (PORT), is underappreciated in head and neck cancer (HNC).

METHODS

CT simulation images in patients with HNC managed surgically with adjuvant therapy at a single center between 2010 and 2017 were retrospectively reviewed.

RESULTS

A total of 194 patients with HNC were included. Rapid recurrence occurred in 39 patients (20%) with a median time from operation to CT simulation of 37 days. On multivariable analysis (MVA), extranodal extension (ENE) was the only predictor of rapid recurrence (P = .03). While rapid recurrence, ENE, and perineural invasion were all associated with poor overall survival (OS) on MVA, rapid recurrence was the strongest predictor (hazard ratio [HR] 5.47).

CONCLUSION

Rapid recurrence occurs at an underappreciated rate and is associated with poor survival outcomes. Patients with ENE are at highest risk and may benefit from diagnostic imaging evaluations immediately prior to PORT.

Primary tumor characteristics and next-generation sequencing mutations as biomarkers for melanoma immunotherapy response

INTRODUCTION

Considerable advances in melanoma have been realized through immunotherapy. The principal aim was to determine whether primary tumor characteristics or next-generation sequencing (NGS) could serve as markers of immunotherapy response.

METHODS AND RESULTS

The study cohort consisted of 67 patients who received immunotherapy for recurrent or metastatic melanoma and for whom primary tumor biopsies and pathology reports were available. A subset of 59 patient tumors were profiled using an NGS panel of 50 cancer-related genes. Objective response rate to immunotherapy was assessed using RECIST v1.1 criteria. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. Lymphovascular invasion (LVI) strongly correlated with an increased proportion of immunotherapy responders (p = .002). PFS interval (p = .003) and OS (p = .036) were significantly higher in patients with LVI. NRAS mutation was more strongly correlated with an increased proportion of immunotherapy responders (p =.050). PFS was significantly higher in patients with NRAS mutation (p = .042); no difference in OS (p = .111).

DISCUSSION

This analysis demonstrates an association between lymphovascular invasion and immunotherapy response. Additionally, NGS mutation analysis demonstrated a potential association between NRAS mutations and immunotherapy response.

Clustered Microcysts at Breast US: Outcomes and Updates for Appropriate Management Recommendations

Background Clustered microcysts are common, especially in perimenopausal women, and are seen in up to 6% of US examinations. However, there are limited published data on appropriate assessment and management recommendations for clustered microcysts on breast US images. Purpose To determine outcomes of lesions identified as clustered microcysts on breast US images to help guide appropriate management recommendations. Materials and Methods Lesions classified as clustered microcysts at breast US were retrospectively identified in women at two hospitals (a large tertiary care academic hospital and a National Comprehensive Cancer Network-designated comprehensive cancer center) within one metropolitan health system from 2005 through 2015. If US-guided tissue sampling was performed, results were obtained from the pathology or cytology reports. If sampling was not performed, only lesions with at least 24 months of imaging follow-up or any imaging follow-up with interval resolution or decrease in size were included in the study. Data were evaluated using standard statistics, Fisher exact tests, and Wilcoxon rank sum tests. Results A total of 189 women (median age, 52 years [interquartile range, 46-59 years]) with 196 lesions classified as clustered microcysts on US images were included in this study. During the surveillance period of at least 24 months and at tissue diagnosis, malignancy was not found in any of the 196 lesions (0%) (95% confidence interval: 0.0%, 1.9%). A total of 158 of 196 (80%) lesions were followed with imaging, and 38 of 196 (20%) lesions underwent percutaneous sampling. During the follow-up period, 28 of 158 (18%) lesions spontaneously resolved, 13 of 158 (8%) decreased in size, and one of 158 lesions (0.6%) increased at 18-month follow-up but then became stable. One hundred sixteen of 158 lesions (73%) demonstrated no change at follow-up imaging, 38 of 196 (19%) lesions underwent percutaneous sampling, and 38 of 38 (100%) revealed benign results. Conclusion No malignancies were identified in this series. These results further support the existing literature that lesions characterized as clustered microcysts demonstrate a very low risk of malignancy and can be classified as benign. Biopsy may be safely avoided. © RSNA, 2020 See also the editorial by Berg in this issue.

Signatures of Divergence, Invasiveness, and Terrestrialization Revealed by Four Apple Snail Genomes

The family Ampullariidae includes both aquatic and amphibious apple snails. They are an emerging model for evolutionary studies due to the high diversity, ancient history, and wide geographical distribution. Insight into drivers of ampullariid evolution is hampered, however, by the lack of genomic resources. Here, we report the genomes of four ampullariids spanning the Old World (Lanistes nyassanus) and New World (Pomacea canaliculata, P. maculata, and Marisa cornuarietis) clades. The ampullariid genomes have conserved ancient bilaterial karyotype features and a novel Hox gene cluster rearrangement, making them valuable in comparative genomic studies. They have expanded gene families related to environmental sensing and cellulose digestion, which may have facilitated some ampullarids to become notorious invasive pests. In the amphibious Pomacea, novel acquisition of an egg neurotoxin and a protein for making the calcareous eggshell may have been key adaptations enabling their transition from underwater to terrestrial egg deposition.

On spatial conditional extremes for ocean storm severity

We describe a model for the conditional dependence of a spatial process measured at one or more remote locations given extreme values of the process at a conditioning location, motivated by the conditional extremes methodology of Heffernan and Tawn. Compared to alternative descriptions in terms of max-stable spatial processes, the model is advantageous because it is conceptually straightforward and admits different forms of extremal dependence (including asymptotic dependence and asymptotic independence). We use the model within a Bayesian framework to estimate the extremal dependence of ocean storm severity (quantified using significant wave height, H S ) for locations on spatial transects with approximate east-west (E-W) and north-south (N-S) orientations in the northern North Sea (NNS) and central North Sea (CNS). For H S on the standard Laplace marginal scale, the conditional extremes "linear slope" parameter α decays approximately exponentially with distance for all transects. Furthermore, the decay of mean dependence with distance is found to be faster in CNS than NNS. The persistence of mean dependence is greatest for the E-W transect in NNS, potentially because this transect is approximately aligned with the direction of propagation of the most severe storms in the region.

RNP-Granule Assembly via Ataxin-2 Disordered Domains Is Required for Long-Term Memory and Neurodegeneration

Human Ataxin-2 is implicated in the cause and progression of amyotrophic lateral sclerosis (ALS) and type 2 spinocerebellar ataxia (SCA-2). In Drosophila, a conserved atx2 gene is essential for animal survival as well as for normal RNP-granule assembly, translational control, and long-term habituation. Like its human homolog, Drosophila Ataxin-2 (Atx2) contains polyQ repeats and additional intrinsically disordered regions (IDRs). We demonstrate that Atx2 IDRs, which are capable of mediating liquid-liquid phase transitions in vitro, are essential for efficient formation of neuronal mRNP assemblies in vivo. Remarkably, ΔIDR mutants that lack neuronal RNP granules show normal animal development, survival, and fertility. However, they show defects in long-term memory formation/consolidation as well as in C9ORF72 dipeptide repeat or FUS-induced neurodegeneration. Together, our findings demonstrate (1) that higher-order mRNP assemblies contribute to long-term neuronal plasticity and memory, and (2) that a targeted reduction in RNP-granule formation efficiency can alleviate specific forms of neurodegeneration.

Toward the Molecular Deciphering of Pomacea canaliculata Immunity: First Proteomic Analysis of Circulating Hemocytes

Pomacea canaliculata is a freshwater snail with interesting biological features that include invasiveness, human parasite hosting, and adult regeneration. Its immune system may represent the target for strategies aimed at controlling the spread of the snail population and its hosting of the human parasite Angiostrongylus cantonensis. Moreover, immune functions likely have a role in the snail's ability to wound heal and regenerate. Despite its importance in multiple processes, very little is known about the molecular basis of P. canaliculata immunity. Aiming to contribute to filling this gap, the ultrastructure of circulating hemocytes in healthy snails is studied and the first proteomic analysis of these cells is performed, evidencing 83 unique proteins, 96% of which have identifiable homologs in other species. Fifteen proteins are retrieved as potentially involved in immune-related signaling pathways, such as hemocyanin, C1q-like protein, and HSP90 together with cytoskeleton and cytoskeleton-related proteins involved in cell motility and membrane dynamics. This first proteome study on non-stimulated hemocytes provides a valid reference for future investigations on the molecular changes under stressful circumstances, like pathogen exposure, wounding, or environmental changes.

Adherence to postresection colorectal cancer surveillance at National Cancer Institute-designated Comprehensive Cancer Centers

Guidelines recommend surveillance after resection of colorectal cancer (CRC), but rates of adherence to surveillance are variable and have not been studied at National Cancer Institute (NCI)‐designated Comprehensive Cancer Centers. The aim of this study was to determine rates of adherence to standard postresection CRC surveillance recommendations including physician visits, carcinoembryonic antigen (CEA), computed tomography (CT), and colonoscopy after CRC resection at three NCI‐designated centers.

Data on patients with resected CRC from 2010 to 2017 were reviewed. Adherence to physician visits was defined as having at least two visits within 14 months after surgical resection. CEA adherence was defined as having at least four CEA levels drawn within 14 months. CT and colonoscopy adherence were defined as completing each between 10 and 14 months from surgical resection. Chi‐square test and logistic regression analyses were performed for overall adherence and adherence to individual components.

A total of 241 CRC patients were included. Overall adherence was 23%. While adherence to physician visits was over 98%, adherence to CEA levels, CT, and colonoscopy were each less than 50%. Center was an independent predictor of adherence to CEA, CT, and/or colonoscopy. Stage III disease predicted CT adherence, while distance traveled of 40 miles or less predicted colonoscopy adherence.

Overall adherence to postresection CRC guideline‐recommended care is low at NCI‐designated centers. Adherence rates to surveillance vary by center, stage, and distance traveled for care. Understanding factors associated with adherence is critical to ensure CRC patients benefit from postresection surveillance.

Plk2 Loss Commonly Occurs in Colorectal Carcinomas but not Adenomas: Relationship to mTOR Signaling

Plk2 is a target of p53. Our previous studies demonstrated that with wild-type p53, Plk2 impacts mTOR signaling in the same manner as TSC1, and Plk2-deficient tumors grew larger than control. Other investigators have demonstrated that Plk2 phosphorylates mutant p53 in a positive feedback loop. We investigated Plk2’s tumor suppressor functions in relationship to mTOR signaling. Archival specimens from 12 colorectal adenocarcinomas were stained for markers including Plk2, phosphorylated mTOR (serine 2448) and ribosomal S6 (Serine 235/236). We show that Plk2 is expressed in normal colon, with a punctate staining pattern in supranuclear cytoplasm. In colorectal adenocarcinoma, Plk2 demonstrates complete or partial loss of expression. Strong expression of phosphorylated mTOR is observed in the invasive front. Phosphorylated S6 expression partially correlates with phosphorylated mTOR expression but appears more diffuse in some cases. p53 and Ki67 expression is diffuse, in the subset of cases examined. In order to determine whether Plk2 is lost prior to the development of invasive cancer, 8 colon polyps from 6 patients were evaluated for Plk2 expression. All polyps are positive for Plk2. A Cancer Genome Atlas search identified Plk2 mutations to be infrequent in colorectal adenocarcinomas. Neither Plk2 methylation (in the gene body) nor copy number variations correlated with changes in mRNA expression levels. Loss of Plk2 expression along with accentuated expression of phosphorylated mTOR and phosphorylated S6 at the invasive front in some colorectal carcinomas is consistent with previous findings that an interaction between Plk2 and TSC1 / mTOR signaling molecules plays a role in tumor suppression. Plk2 protein expression is lost at the same stage in colorectal carcinogenesis as p53. The p53 dependence of Plk2 loss and tumor suppressor function in relationship to mTOR signaling may have therapeutic implications.

A Novel Cross-Disciplinary Multi-Institute Approach to Translational Cancer Research: Lessons Learned from Pennsylvania Cancer Alliance Bioinformatics Consortium (PCABC)

Background

The Pennsylvania Cancer Alliance Bioinformatics Consortium (PCABC, http://www.pcabc.upmc.edu ) is one of the first major project-based initiatives stemming from the Pennsylvania Cancer Alliance that was funded for four years by the Department of Health of the Commonwealth of Pennsylvania. The objective of this was to initiate a prototype biorepository and bioinformatics infrastructure with a robust data warehouse by developing a statewide data model (1) for bioinformatics and a repository of serum and tissue samples; (2) a data model for biomarker data storage; and (3) a public access website for disseminating research results and bioinformatics tools. The members of the Consortium cooperate closely, exploring the opportunity for sharing clinical, genomic and other bioinformatics data on patient samples in oncology, for the purpose of developing collaborative research programs across cancer research institutions in Pennsylvania. The Consortium's intention was to establish a virtual repository of many clinical specimens residing in various centers across the state, in order to make them available for research. One of our primary goals was to facilitate the identification of cancer-specific biomarkers and encourage collaborative research efforts among the participating centers.

Methods

The PCABC has developed unique partnerships so that every region of the state can effectively contribute and participate. It includes over 80 individuals from 14 organizations, and plans to expand to partners outside the State. This has created a network of researchers, clinicians, bioinformaticians, cancer registrars, program directors, and executives from academic and community health systems, as well as external corporate partners - all working together to accomplish a common mission. The various sub-committees have developed a common IRB protocol template, common data elements for standardizing data collections for three organ sites, intellectual property/tech transfer agreements, and material transfer agreements that have been approved by each of the member institutions. This was the foundational work that has led to the development of a centralized data warehouse that has met each of the institutions’ IRB/HIPAA standards.

Results

Currently, this “virtual biorepository” has over 58,000 annotated samples from 11,467 cancer patients available for research purposes. The clinical annotation of tissue samples is either done manually over the internet or semi-automated batch modes through mapping of local data elements with PCABC common data elements. The database currently holds information on 7188 cases (associated with 9278 specimens and 46,666 annotated blocks and blood samples) of prostate cancer, 2736 cases (associated with 3796 specimens and 9336 annotated blocks and blood samples) of breast cancer and 1543 cases (including 1334 specimens and 2671 annotated blocks and blood samples) of melanoma. These numbers continue to grow, and plans to integrate new tumor sites are in progress. Furthermore, the group has also developed a central web-based tool that allows investigators to share their translational (genomics/proteomics) experiment data on research evaluating potential biomarkers via a central location on the Consortium's web site.

Conclusions

The technological achievements and the statewide informatics infrastructure that have been established by the Consortium will enable robust and efficient studies of biomarkers and their relevance to the clinical course of cancer.

A prokineticin-like protein responds to immune challenges in the gastropod pest Pomacea canaliculata

The golden apple snail Pomacea canaliculata is an invasive pest originating from South America. It has already been found in Asia, the southern United States and more recently in the EU. Aiming to target the immune system of the snail as a way to control its spreading, we have developed organ-specific transcriptomes and looked for molecules controlling replication and differentiation of snail hemocytes. The prokineticin domain-containing protein Astakine 1 is the only cytokine known thus far capable of regulating invertebrate hematopoiesis, and we analyzed the transcriptomes looking for molecules containing a prokineticin domain. We have identified a prokineticin-like protein (PlP), that we called Pc-plp and we analyzed by real-time PCR (qPCR) its expression. In control snails, highest levels of Pc-plp were detected in the digestive gland, the ampulla (i.e., a hemocyte reservoir) and the pericardial fluid (i.e., the hematopoietic district). We tested Pc-plp expression after triggering hematopoiesis via multiple hemolymph withdrawals, or during bacterial challenge through LPS injection. In both cases a reduction of Pc-plp mRNA was observed. The multiple hemolymph withdrawals caused a significant decrease of Pc-plp mRNA in pericardial fluid and circulating hemocytes, while the LPS injection promoted the Pc-plp mRNA drop in anterior kidney, mantle and gills, organs that may act as immune barrier in molluscs. Our data indicate an important role for prokineticin domain-containing proteins as immunomodulators also in gastropods and their dynamic expression may serve as a biosensor to gauge the effectiveness of immunological interventions aimed at curtailing the spreading of the gastropod pest P. canaliculata.

Microbial source tracking in shellfish harvesting waters in the Gulf of Nicoya, Costa Rica

Current microbial water quality monitoring is generally limited to culture-based measurements of fecal indicator bacteria (FIB). Given the many possible sources of fecal pollution within a watershed and extra-intestinal FIB reservoirs, it is important to determine source(s) of fecal pollution as a means to improve water quality and protect public health. The principal objective of this investigation was to characterize the microbial water quality of shellfish harvesting areas in the Gulf of Nicoya, Costa Rica during 2015. In order to achieve this objective, the specificity and sensitivity of 11 existing microbial source tracking (MST) PCR assays, associated with cows (BacCow), dogs (BacCan, DogBac), domestic wastewater (PMMoV), general avian (GFD), gulls (Gull2), horses (HorseBac, HoF), humans (HF183, HPyV), and pigs (PF), were evaluated using domestic wastewater and animal fecal samples collected from the region. The sensitivity of animal-associated assays ranged from 13 to 100%, while assay specificity ranged from 38 to 100%. The specificity of pepper mild mottle virus (PMMoV) and human polyomavirus (HPyV) was 100% for domestic wastewater, as compared to 94% specificity of the HF183 Bacteroidales marker. PMMoV was identified as a useful domestic wastewater-associated marker, with concentrations as high as 1.1 × 10⁵ copies/ml and 100% sensitivity and specificity. Monthly surface water samples collected from four shellfish harvesting areas were analyzed using culture-based methods for Escherichia coli as well as molecular methods for FIB and a suite of MST markers, which were selected for their specificity in the region. While culturable E. coli results suggested possible fecal pollution during the monitoring period, the absence of human/domestic wastewater-associated markers and low FIB concentrations determined using molecular methods indicated sufficient microbial water quality for shellfish harvesting. This is the first study to our knowledge to test the performance of MST markers in Costa Rica as well as in Central America. Given the lack of wastewater treatment and the presence of secondary sources of FIB, this study highlights the importance of an MST toolbox approach to characterize water quality in tropical regions. Furthermore, it confirms and extends the geographic range of PMMoV as an effective tool for monitoring domestic wastewater pollution.

Widespread maintenance of genome heterozygosity in Schmidtea mediterranea

Loss of heterozygosity through inbreeding or mitotic errors leads to reductions in progeny survival and fertility. Loss of heterozygosity is particularly exacerbated in geographically isolated populations, which are prone to inbreeding depression and faster rates of extinction. The regenerative capacities of the hermaphroditic biotype of the planarian Schmidtea mediterranea allowed us to perform a systematic genetic test of Mendelian segregation and study the loss of heterozygosity in the Spiralian superclade in general and planarians in particular. We discovered that ~300 Mb (~37.5%) of the genome retains heterozygosity even after ten generations of inbreeding, and show that these chromosomal regions have low diversity and recombination rates in wild populations. Our genetic and genomic analyses establish S. mediterranea as a genetically tractable system. The research also opens the door to study the evolutionary basis of non-Mendelian mechanisms, the adaptive advantages of chromosome structural heterozygotes and their potential relationship to the robust regenerative capacities of planarians.

Head regeneration in hemichordates is not a strict recapitulation of development

BACKGROUND

Head or anterior body part regeneration is commonly associated with protostome, but not deuterostome invertebrates. However, it has been shown that the solitary hemichordate Ptychodera flava possesses the remarkable capacity to regenerate their entire nervous system, including their dorsal neural tube and their anterior head-like structure, or proboscis. Hemichordates, also known as acorn worms, are marine invertebrate deuterostomes that have retained chordate traits that were likely present in the deuterostome ancestor, placing these animals in a vital position to study regeneration and chordate evolution. All acorn worms have a tripartite body plan, with an anterior proboscis, middle collar region, and a posterior trunk. The collar houses a hollow, dorsal neural tube in ptychoderid hemichordates and numerous chordate genes involved in brain and spinal cord development are expressed in a similar anterior-posterior spatial arrangement along the body axis.

RESULTS

We have examined anterior regeneration in the hemichordate Ptychodera flava and report the spatial and temporal morphological changes that occur. Additionally, we have sequenced, assembled, and analyzed the transcriptome for eight stages of regenerating P. flava, revealing significant differential gene expression between regenerating and control animals.

CONCLUSIONS

Importantly, we have uncovered developmental steps that are regeneration-specific and do not strictly follow the embryonic program. Developmental Dynamics 245:1159-1175, 2016. © 2016 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Time to Surgery and Breast Cancer Survival in the United States

IMPORTANCE

Time to surgery (TTS) is of concern to patients and clinicians, but controversy surrounds its effect on breast cancer survival. There remains little national data evaluating the association.

OBJECTIVE

To investigate the relationship between the time from diagnosis to breast cancer surgery and survival, using separate analyses of 2 of the largest cancer databases in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Two independent population-based studies were conducted of prospectively collected national data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database and the National Cancer Database (NCDB). The SEER-Medicare cohort included Medicare patients older than 65 years, and the NCDB cohort included patients cared for at Commission on Cancer-accredited facilities throughout the United States. Each analysis assessed overall survival as a function of time between diagnosis and surgery by evaluating 5 intervals (≤30, 31-60, 61-90, 91-120, and 121-180 days) and disease-specific survival at 60-day intervals. All patients were diagnosed with noninflammatory, nonmetastatic, invasive breast cancer and underwent surgery as initial treatment.

MAIN OUTCOMES AND MEASURES

Overall and disease-specific survival as a function of time between diagnosis and surgery, after adjusting for patient, demographic, and tumor-related factors.

RESULTS

The SEER-Medicare cohort had 94 544 patients 66 years or older diagnosed between 1992 and 2009. With each interval of delay increase, overall survival was lower overall (hazard ratio [HR], 1.09; 95% CI, 1.06-1.13; P < .001), and in patients with stage I (HR, 1.13; 95% CI, 1.08-1.18; P < .001) and stage II disease (HR 1.06; 95% CI, 1.01-1.11; P = .01). Breast cancer-specific mortality increased with each 60-day interval (subdistribution hazard ratio [sHR], 1.26; 95% CI, 1.02-1.54; P = .03). The NCDB study evaluated 115 790 patients 18 years or older diagnosed between 2003 and 2005. The overall mortality HR was 1.10 (95% CI, 1.07-1.13; P < .001) for each increasing interval, significant in stages I (HR, 1.16; 95% CI, 1.12-1.21; P < .001) and II (HR, 1.09; 95% CI, 1.05-1.13; P < .001) only, after adjusting for demographic, tumor, and treatment factors.

CONCLUSIONS AND RELEVANCE

Greater TTS is associated with lower overall and disease-specific survival, and a shortened delay is associated with benefits comparable to some standard therapies. Although time is required for preoperative evaluation and consideration of options such as reconstruction, efforts to reduce TTS should be pursued when possible to enhance survival.

Abstract LB-023: Plk2 loss occurs commonly in colorectal carcinomas but not in adenomas

Plk2 is a target of p53. Our previous studies demonstrated that in the wild-type p53 context, Plk2 impacts mTOR signaling in the same manner as TSC1, and human tumor cells deficient in Plk2 grew significantly larger than control tumor cells. Other investigators have demonstrated that Plk2 phosphorylates mutant p53 in a positive feedback loop. We investigated Plk2's tumor suppressor functions as they relate to mTOR signaling.

Archived pathology specimens from 12 colorectal adenocarcinomas (4 early stage and 8 advanced stage) were stained for phosphorylated mTOR (serine 2448), phosphorylated ribosomal S6 (Serine 235/236), Plk2, p53, Ki67, and glucose transporter 1 (Glut1). We show that Plk2 is expressed in normal colon epithelium, with a punctate staining pattern in the supranuclear region. In colorectal adenocarcinoma, Plk2 demonstrates partial loss of expression, complete loss of expression, or disrupted expression manifested as irregular or abnormal localization. Loss of Plk2 expression is more pronounced in the invasive front in some cases. Strong expression of phosphorylated mTOR is observed in the invasive front, which is presumed to be less hypoxic. Phosphorylated S6 and Glut1 expression partially correlate with phosphorylated mTOR expression but appear more diffuse in some cases. p53 and Ki67 expression is diffuse, rather than specific to the tumor invasive front in the subset of cases examined. In order to determine at what stage in carcinogenesis Plk2 is lost, an additional 8 archived pathology specimens (tubular adenomas, sessile serrated polyps and hyperplastic polyps) from 6 patients were evaluated for Plk2 expression. All specimens were found to be positive for Plk2 expression.

We conducted a TCGA search of Plk2 alterations in colorectal adenocarcinomas. Plk2 is mutated in only 8 of 498 (all p53 wild-type) cases. Neither Plk2 methylation (in the gene body not in the regulatory region CpG islands and shores) nor copy number changes correlated with mRNA expression changes and appeared to be independent of p53 status.

Loss of Plk2 expression along with accentuated expression of phosphorylated mTOR, phosphorylated S6, and Glut1 at the invasive front at least in some colorectal carcinomas is consistent with previous findings that an interaction between Plk2 and TSC1 / mTOR signaling molecules plays a role in tumor suppression during hypoxic conditions. Plk2 protein expression was found to be lost at the same stage in colorectal carcinogenesis as p53 genetic loss. The p53 dependence of Plk2 loss and tumor suppressor function as they relate to mTOR signaling may have therapeutic implications.

Citation Format: Elizabeth M. Matthew, Zhaohai Yang, Suraj Peri, Namrata Vijayvergia, Amriti Lulla, Eric Ross, Wafik S. El-Deiry. Plk2 loss occurs commonly in colorectal carcinomas but not in adenomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-023.