Treatment Patterns and Clinical Outcomes Among Patients With Metastatic Prostate Cancer Harboring Homologous Recombination Repair Mutations

BACKGROUND

There is currently limited literature assessing the real-world treatment patterns and clinical outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) mutations.

METHODS

Medical charts were abstracted for mCRPC patients with ≥ 1 of 12 HRR somatic gene alterations treated at US oncology centers participating in the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange. Treatment patterns and clinical outcomes were assessed from the initiation of first-line or later (1L+) mCRPC therapy received on or after July 1, 2014.

RESULTS

Among 138 patients included in the study, the most common somatic HRR mutations were CDK12 (47.8%), BRCA2 (22.5%), and ATM (21.0%). Novel hormonal therapy and taxane chemotherapy were most commonly used in 1L; taxane use increased in later lines. Median overall survival (95% confidence interval [CI]) was 36.3 (30.7-47.8) months from initiation of 1L therapy and decreased for subsequent lines. Similarly, there was a trend of decreasing progression-free survival and prostate-specific antigen response from 1L to 4L+ therapy.

CONCLUSIONS

Treatment patterns identified in this study were similar to those among patients with mCRPC regardless of tumor HRR mutation status in the literature.

Helicobacter pylori testing prior to or at gastric cancer diagnosis and survival in a diverse US patient population

BACKGROUND

Gastric cancer (GC) accounts for the greatest disparity in cancer mortality between Black and White Americans. Although clinical trials have shown that Helicobacter pylori (Hp) treatment reduces risk of GC, Hp testing and treatment is not consistently performed in the US, and may offer an opportunity to improve survival.

METHODS

In a diverse retrospective cohort of 99 GC cases diagnosed at Duke University from 2002-2020 (57% Black; 43% white), we examined the association of Hp testing and treatment prior to or at cancer diagnosis with overall survival using Cox regression analyses to calculate adjusted hazards ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Overall, 62% of patients were tested for Hp prior to or at GC diagnosis. Of those, 25% tested positive and were treated < 1 year prior to or at diagnosis, 15% tested positive and were treated ≥ 1 year prior to diagnosis, 6% tested positive without evidence of treatment, and 54% tested negative. Compared to never tested, Hp testing and treatment < 1 year prior to or at diagnosis was associated with a significantly reduced likelihood of death (HR 0.21, 95% CI 0.08-0.58). The benefit of any Hp test and treat prior to or at GC diagnosis was significant even among stage IV patients only (HR, 0.22; 95% CI 0.05-0.96).

CONCLUSIONS

These findings support Hp testing and treatment for patients at risk of or diagnosed with GC, and suggest Hp treatment may provide an opportunity to reduce GC mortality disparities in the US.

The Cooperative Human Tissue Network of the National Cancer Institute: Supporting Cancer Research for 35 Years

The Cooperative Human Tissue Network was created by the NCI in 1987 to support a coordinated national effort to collect and distribute high quality, pathologist-validated human tissues for cancer research. Since then, the network has expanded to provide different types of tissue samples, blood and body fluid samples, immunohistologic and molecular sample preparations, tissue microarrays, and clinical datasets inclusive of biomarkers and molecular testing. From inception through the end of 2021, the network has distributed 1,375,041 biospecimens. It served 889 active investigators in 2021. The network has also taken steps to begin to optimize the representation of diverse communities among the distributed biospecimens. In this article, the authors review the 35-year history of this network, describe changes to the program over the last 15 years, and provide operational and scientific highlights from each of the divisions. Readers will learn how to engage with the network and about the continued evolution of the program for the future.

Genomic analysis of early-stage lung cancer reveals a role for TP53 mutations in distant metastasis

Patients with non-small cell lung cancer (NSCLC) who have distant metastases have a poor prognosis. To determine which genomic factors of the primary tumor are associated with metastasis, we analyzed data from 759 patients originally diagnosed with stage I-III NSCLC as part of the AACR Project GENIE Biopharma Collaborative consortium. We found that TP53 mutations were significantly associated with the development of new distant metastases. TP53 mutations were also more prevalent in patients with a history of smoking, suggesting that these patients may be at increased risk for distant metastasis. Our results suggest that additional investigation of the optimal management of patients with early-stage NSCLC harboring TP53 mutations at diagnosis is warranted in light of their higher likelihood of developing new distant metastases.

Abstract 1061: Exportin 1 (XPO1) inhibition alone or in combination as a novel therapeutic strategy in osteosarcoma

Background: Osteosarcoma is an aggressive bone cancer in which therapeutic advancements have been limited over the last 30 years, in part due to genomic heterogeneity. The combination of high-throughput drug screening platforms that efficiently pinpoint drug sensitivities with patient-derived cross-species models is an innovative approach to address the critical need to identify novel treatment strategies for osteosarcoma patients.

Methods: We performed high-throughput drug screens on patient-derived osteosarcoma cell lines D418 (canine) and 17-3x (human), followed by validation of the top compounds, to identify drug sensitivities and novel therapeutic combinations.

Results: High-throughput drug screens using 2100 bioactive compounds show that osteosarcoma cell lines D418 and 17-3x exhibited sensitivity to standard-of-care chemotherapy drugs, inhibitors of XPO1 nuclear export, and proteasome inhibitors. The XPO1 inhibitor, verdinexor (VER), and the proteasome inhibitor, bortezomib (BORT), induced dose-dependent cytotoxicity in multiple osteosarcoma cell lines (D418, IC50VER: 3187 nM, IC50BORT: 2.8 nM; 17-3x IC50VER: 679 nM, IC50BORT: 10.9 nM). In addition, dual XPO1 and proteasome inhibition synergistically reduced cell proliferation in D418 (synergy score=12.89) and 17-3x (synergy score=17.87) cell lines (p &lt;0.05). Selinexor (SEL), an FDA approved XPO1 inhibitor used in combination with bortezomib to treat multiple myeloma, also demonstrated dose-dependent single-agent activity in patient-derived osteosarcoma cell lines (D418, IC50SEL: 370 nM; 17-3x IC50SEL: 101 nM). With drug screening of 119 oncology compounds in combination with selinexor in 17-3x cells, XPO1 inhibition again shows synergistic activity with proteasome inhibition in osteosarcoma.

Conclusions: Inhibition of XPO1-mediated nuclear export is a promising therapeutic strategy in osteosarcoma. These effects may be further potentiated when used in combination with other agents, such as proteasome inhibitors. Additional drug screening and validation assays are underway to identify novel synergistic agents for use in combination with XPO1 inhibitors in osteosarcoma.

Citation Format: Laurie Graves, Gabrielle Rupprecht, Erdem Altunel, Etienne M. Flamant, Sneha Rao, Dharshan Sivara, Alexander L. Lazarides, Sarah M. Hoskinson, Maya U. Sheth, Serene Cheng, So Young Kim, Kathryn E. Ware, Anika Agarwal, Mark M. Cullen, Casey Syal, Laura E. Selmic, Jeffrey I. Everitt, Shannon J. McCall, Cindy Eward, Trinayan Kashyap, Marie Maloof, Christopher J. Walker, Yosef Landesman, Lars Wagner, William C. Eward, David S. Hsu, Jason A. Somarelli. Exportin 1 (XPO1) inhibition alone or in combination as a novel therapeutic strategy in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1061.

Pre-existing Castration-resistant Prostate Cancer–like Cells in Primary Prostate Cancer Promote Resistance to Hormonal Therapy

BACKGROUND

Hormonal therapy targeting the androgen receptor inhibits prostate cancer (PCa), but the tumor eventually recurs as castration-resistant prostate cancer (CRPC).

OBJECTIVE

To understand the mechanisms by which subclones within early PCa develop into CRPC.

DESIGN, SETTING, AND PARTICIPANTS

We isolated epithelial cells from fresh human PCa cases, including primary adenocarcinoma, locally recurrent CRPC, and metastatic CRPC, and utilized single-cell RNA sequencing to identify subpopulations destined to become either CRPC-adeno or small cell neuroendocrine carcinoma (SCNC).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We revealed dynamic transcriptional reprogramming that promotes disease progression among 23226 epithelial cells using single-cell RNA sequencing, and validated subset-specific progression using immunohistochemistry and large cohorts of publically available genomic data.

RESULTS AND LIMITATIONS

We identified a small fraction of highly plastic CRPC-like cells in hormone-naïve early PCa and demonstrated its correlation with biochemical recurrence and distant metastasis, independent of clinical characteristics. We show that progression toward castration resistance was initiated from subtype-specific lineage plasticity and clonal expansion of pre-existing neuroendocrine and CRPC-like cells in early PCa.

CONCLUSIONS

CRPC-like cells are present early in the development of PCa and are not exclusively the result of acquired evolutionary selection during androgen deprivation therapy. The lethal CRPC and SCNC phenotypes should be targeted earlier in the disease course of patients with PCa.

PATIENT SUMMARY

Here, we report the presence of pre-existing castration-resistant prostate cancer (CRPC)-like cells in primary prostate cancer, which represents a novel castration-resistant mechanism different from the adaptation mechanism after androgen deprivation therapy (ADT). Patients whose tumors harbor increased pre-existing neuroendocrine and CRPC-like cells may become rapidly resistant to ADT and may require aggressive early intervention.

Characterization of a castrate-resistant prostate cancer xenograft derived from a patient of West African ancestry

BACKGROUND

Prostate cancer is a clinically and molecularly heterogeneous disease, with highest incidence and mortality among men of African ancestry. To date, prostate cancer patient-derived xenograft (PCPDX) models to study this disease have been difficult to establish because of limited specimen availability and poor uptake rates in immunodeficient mice. Ancestrally diverse PCPDXs are even more rare, and only six PCPDXs from self-identified African American patients from one institution were recently made available.

METHODS

In the present study, we established a PCPDX from prostate cancer tissue from a patient of estimated 90% West African ancestry with metastatic castration resistant disease, and characterized this model's pathology, karyotype, hotspot mutations, copy number, gene fusions, gene expression, growth rate in normal and castrated mice, therapeutic response, and experimental metastasis.

RESULTS

This PCPDX has a mutation in TP53 and loss of PTEN and RB1. We have documented a 100% take rate in mice after thawing the PCPDX tumor from frozen stock. The PCPDX is castrate- and docetaxel-resistant and cisplatin-sensitive, and has gene expression patterns associated with such drug responses. After tail vein injection, the PCPDX tumor cells can colonize the lungs of mice.

CONCLUSION

This PCPDX, along with others that are established and characterized, will be useful pre-clinically for studying the heterogeneity of prostate cancer biology and testing new therapeutics in models expected to be reflective of the clinical setting.

Implementation of a Molecular Tumor Registry to Support the Adoption of Precision Oncology Within an Academic Medical Center: The Duke University Experience

Comprehensive genomic profiling to inform targeted therapy selection is a central part of oncology care. However, the volume and complexity of alterations uncovered through genomic profiling make it difficult for oncologists to choose the most appropriate therapy for their patients. Here, we present a solution to this problem, The Molecular Registry of Tumors (MRT) and our Molecular Tumor Board (MTB).

PATIENTS AND METHODS

MRT is an internally developed system that aggregates and normalizes genomic profiling results from multiple sources. MRT serves as the foundation for our MTB, a team that reviews genomic results for all Duke University Health System cancer patients, provides notifications for targeted therapies, matches patients to biomarker-driven trials, and monitors the molecular landscape of tumors at our institution.

RESULTS

Among 215 patients reviewed by our MTB over a 6-month period, we identified 176 alterations associated with therapeutic sensitivity, 15 resistance alterations, and 51 alterations with potential germline implications. Of reviewed patients, 17% were subsequently treated with a targeted therapy. For 12 molecular therapies approved during the course of this work, we identified between two and 71 patients who could qualify for treatment based on retrospective MRT data. An analysis of 14 biomarker-driven clinical trials found that MRT successfully identified 42% of patients who ultimately enrolled. Finally, an analysis of 4,130 comprehensive genomic profiles from 3,771 patients revealed that the frequency of clinically significant therapeutic alterations varied from approximately 20% to 70% depending on the tumor type and sequencing test used.

CONCLUSION

With robust informatics tools, such as MRT, and the right MTB structure, a precision cancer medicine program can be developed, which provides great benefit to providers and patients with cancer.

Next-Generation Sequencing Concordance Analysis of Comprehensive Solid Tumor Profiling between a Centralized Specialty Laboratory and the Decentralized Personal Genome Diagnostics, Inc., Elio Tissue Complete Kitted Solution

Genomic tumor profiling by next-generation sequencing (NGS) allows for large-scale tumor testing to inform targeted cancer therapies and immunotherapies, and to identify patients for clinical trials. These tests are often underutilized in patients with late-stage solid tumors and are typically performed in centralized specialty laboratories, thereby limiting access to these complex tests. Personal Genome Diagnostics Inc., elio tissue complete NGS solution is a comprehensive DNA-to-report kitted assay and bioinformatics solution. Comparison of 147 unique specimens from >20 tumor types was performed using the elio tissue complete solution and Foundation Medicine's FoundationOne test, which is of similar size and gene content. The analytical performance of all genomic variant types was evaluated. In general, the overall mutational profile is highly concordant between the two assays, with agreement in sequence variants reported between panels demonstrating >95% positive percentage agreement for single-nucleotide variants and insertions/deletions in clinically actionable genes. Both copy number alterations and gene translocations showed 80% to 83% positive percentage agreement, whereas tumor mutation burden and microsatellite status showed a high level of concordance across a range of mutation loads and tumor types. The Personal Genome Diagnostics Inc., elio tissue complete assay is comparable to the FoundationOne test and will allow more laboratories to offer a diagnostic NGS assay in house, which will ultimately reduce time to result and increase the number of patients receiving molecular genomic profiling and personalized treatment.

RNA splicing and aggregate gene expression differences in lung squamous cell carcinoma between patients of West African and European ancestry

OBJECTIVES

Despite disparities in lung cancer incidence and mortality, the molecular landscape of lung cancer in patients of African ancestry remains underexplored, and race-related differences in RNA splicing remain unexplored.

MATERIALS AND METHODS

We identified differentially spliced genes (DSGs) and differentially expressed genes (DEGs) in biobanked lung squamous cell carcinoma (LUSC) between patients of West African and European ancestry, using ancestral genotyping and Affymetrix Clariom D array. DSGs and DEGs were validated independently using the National Cancer Institute Genomic Data Commons. Associated biological processes, overlapping canonical pathways, enriched gene sets, and cancer relevance were identified using Gene Ontology Consortium, Ingenuity Pathway Analysis, Gene Set Enrichment Analysis, and CancerMine, respectively. Association with LUSC survival was conducted using The Cancer Genome Atlas.

RESULTS

4,829 DSGs and 267 DEGs were identified, including novel targets in NSCLC as well as genes identified previously to have relevance to NSCLC. RNA splicing events within 3 DSGs as well as 1 DEG were validated in the independent cohort. 853 DSGs and 29 DEGs have been implicated as potential drivers, oncogenes and/or tumor suppressor genes. Biological processes enriched among DSGs and DEGs included metabolic process, biological regulation, and multicellular organismal process and, among DSGs, ion transport. Overlapping canonical pathways among DSGs included neuronal signaling pathways and, among DEGs, cell metabolism involving biosynthesis. Gene sets enriched among DSGs included KRAS Signaling, UV Response, E2 F Targets, Glycolysis, and Coagulation. 355 RNA splicing events within DSGs and 18 DEGs show potential association with LUSC patient survival.

CONCLUSION

These DSGs and DEGs, which show potential biological and clinical relevance, could have the ability to drive novel biomarker and therapeutic development to mitigate LUSC disparities.

Biobanking in the COVID-19 Era and Beyond: Part 2. A Set of Tool Implementation Case Studies

The COVID-19 era has brought about a number of novel challenges for the global biobanking community. An array of diverse tools (e.g., standards, best practices, and plans) exists to support quality and fitness-for-purpose in biobank operations. The International Society for Biological and Environmental Repositories (ISBER) COVID-19 Response Task Force has set out to identify needs and gaps in these tools and make recommendations for the next generation of available tools, having closely examined the COVID-19-related challenges. While conducting this work to examine the relationships between tools and biobank adaptability, a subgroup of the task force conducted a parallel effort to develop and describe individual COVID-19 era case studies based on a number of operating biobanks. Each case study presents a different combination of implemented tools. Observations and lessons learned from these case studies are provided, and experiences with tool implementation are discussed. This information is supplemented by data relating to tool usefulness that was obtained through an ISBER survey discussed in a companion article. The knowledge gained from this study will be combined with other task force efforts to make recommendations to better position the biobanking community in their response to future emergencies.

A Comparative Oncology Drug Discovery Pipeline to Identify and Validate New Treatments for Osteosarcoma

Simple Summary

Osteosarcoma is a rare bone cancer that occurs primarily in children. The discovery of new treatments for osteosarcoma and other rare cancer types has been severely limited by access to patient samples to study these often-complex diseases. Here we capitalize on naturally-occurring cancers in pet dogs to study the biology of these rare cancers. Using living cells from canine and human patients to test thousands of drugs simultaneously, we identify a unique combination of drugs that disrupts protein degradation and protein trafficking in cancer cells. This drug combination represents a promising new treatment to treat both dogs and people with osteosarcoma.

Abstract

Background: Osteosarcoma is a rare but aggressive bone cancer that occurs primarily in children. Like other rare cancers, treatment advances for osteosarcoma have stagnated, with little improvement in survival for the past several decades. Developing new treatments has been hampered by extensive genomic heterogeneity and limited access to patient samples to study the biology of this complex disease. Methods: To overcome these barriers, we combined the power of comparative oncology with patient-derived models of cancer and high-throughput chemical screens in a cross-species drug discovery pipeline. Results: Coupling in vitro high-throughput drug screens on low-passage and established cell lines with in vivo validation in patient-derived xenografts we identify the proteasome and CRM1 nuclear export pathways as therapeutic sensitivities in osteosarcoma, with dual inhibition of these pathways inducing synergistic cytotoxicity. Conclusions: These collective efforts provide an experimental framework and set of new tools for osteosarcoma and other rare cancers to identify and study new therapeutic vulnerabilities.

A Precision Medicine Drug Discovery Pipeline Identifies Combined CDK2 and 9 Inhibition as a Novel Therapeutic Strategy in Colorectal Cancer

Colorectal cancer is the third most common cancer in the United States and responsible for over 50,000 deaths each year. Therapeutic options for advanced colorectal cancer are limited, and there remains an unmet clinical need to identify new treatments for this deadly disease. To address this need, we developed a precision medicine pipeline that integrates high-throughput chemical screens with matched patient-derived cell lines and patient-derived xenografts (PDX) to identify new treatments for colorectal cancer. High-throughput screens of 2,100 compounds were performed across six low-passage, patient-derived colorectal cancer cell lines. These screens identified the CDK inhibitor drug class among the most effective cytotoxic compounds across six colorectal cancer lines. Among this class, combined targeting of CDK1, 2, and 9 was the most effective, with IC₅₀s ranging from 110 nmol/L to 1.2 μmol/L. Knockdown of CDK9 in the presence of a CDK2 inhibitor (CVT-313) showed that CDK9 knockdown acted synergistically with CDK2 inhibition. Mechanistically, dual CDK2/9 inhibition induced significant G₂-M arrest and anaphase catastrophe. Combined CDK2/9 inhibition in vivo synergistically reduced PDX tumor growth. Our precision medicine pipeline provides a robust screening and validation platform to identify promising new cancer therapies. Application of this platform to colorectal cancer pinpointed CDK2/9 dual inhibition as a novel combinatorial therapy to treat colorectal cancer.

Targeting cellular heterogeneity with CXCR2 blockade for the treatment of therapy-resistant prostate cancer

Hormonal therapy targeting androgen receptor (AR) is initially effective to treat prostate cancer (PCa), but it eventually fails. It has been hypothesized that cellular heterogeneity of PCa, consisting of AR⁺ luminal tumor cells and AR^- neuroendocrine (NE) tumor cells, may contribute to therapy failure. Here, we describe the successful purification of NE cells from primary fresh human prostate adenocarcinoma based on the cell surface receptor C-X-C motif chemokine receptor 2 (CXCR2). Functional studies revealed CXCR2 to be a driver of the NE phenotype, including loss of AR expression, lineage plasticity, and resistance to hormonal therapy. CXCR2-driven NE cells were critical for the tumor microenvironment by providing a survival niche for the AR⁺ luminal cells. We demonstrate that the combination of CXCR2 inhibition and AR targeting is an effective treatment strategy in mouse xenograft models. Such a strategy has the potential to overcome therapy resistance caused by tumor cell heterogeneity.

Reduced MFAP5 expression in stroma of gallbladder adenocarcinoma and its potential diagnostic utility

The diagnosis of invasive adenocarcinoma of the gallbladder can sometimes be challenging. The presence of true desmoplastic reaction facilitates the diagnosis of invasion. However, desmoplasia-like changes can be observed in benign gallbladder conditions, and recognition of desmoplasia may be challenging based on morphology. In this study, we tested the expression pattern of microfibril-associated protein 5 (MFAP5), a promising immunohistochemical marker for desmoplasia, in benign gallbladders with desmoplasia-like reaction and gallbladders with invasive adenocarcinoma. We also evaluated the diagnostic utility of MFAP5 in challenging cases with an interobserver agreement study. The results showed that all benign cases retained intact/positive MFAP5 staining pattern in periglandular connective tissue, whereas 79.3% (23 out of 29) of cases of adenocarcinomas demonstrated diffuse and complete loss of MFAP5 staining in the tumor stroma. Interobserver agreement was improved by 2.66 times when images of MFAP5 immunohistochemistry were provided. In conclusion, MFAP5 expression is downregulated in the desmoplastic stroma of gallbladder adenocarcinoma and may provide a useful diagnostic marker in difficult cases.

Prior tonsillectomy is associated with an increased risk of esophageal adenocarcinoma

BACKGROUND

Esophageal cancer is a deadly cancer with 5-year survival <20%. Although multiple risk factors for esophageal adenocarcinoma (EAC) including obesity, GERD and smoking have been identified, these risk factors do not fully explain the rising incidence of EAC. In this study, we evaluated the association between prior history of tonsillectomy and EAC. Our goal was to determine whether tonsillectomies were more frequent in patients with EAC (cases) than in our thoracic surgery controls.

METHODS

Cases included 452 esophagectomy cases, including 396 with EAC and 56 who underwent esophagectomy for Barrett's esophagus (BE) with high grade dysplasia (HGD). 1,102 thoracic surgery patients with surgical indications other than dysplastic BE or esophageal cancer represented the controls for our analysis. The association of tonsillectomy and HGD/EAC were primarily evaluated by using univariate tests and then verified by logistic regression analysis. Baseline demographics, medical history, and thoracic surgery controls were compared by using χ2 tests or 95% CIs. Significant risk factors were considered as covariates in the multivariate models while evaluating the association between tonsillectomy and HGD/EAC. P-values or odds ratios were estimated with 95% confidence limits to identify significances which was more appropriate.

RESULTS

Tonsillectomy was more common in cases than controls and was found to have a significant association with esophageal cancer (19.9% vs. 12.7%; p-value = 0.0003). This significant association persisted after controlling for other known risk factors/covariates.

CONCLUSION

A prior history of tonsillectomy was significantly associated with HGD/EAC and may represent an independent risk factor for the development of EAC. However, the underlying biology driving this association remains unclear.

Abstract B071: Genomic differences between non-small cell lung cancer (NSCLC) in African American and white patients

Background: Racial disparities in lung cancer exist, as African Americans (AAs) have the highest incidence of lung cancer and rate of lung cancer-related death and develop lung cancer at an earlier age compared with other racial groups. Multiple structural determinants of health affect poorer survival in AAs. In addition, evidence suggests that differences in tumor biology also contribute to disparities in clinical outcomes. This work addresses the urgent need to define further the molecular landscape of non-small cell lung cancer (NSCLC) in the AA population in order to drive novel biomarker and therapeutic development and ultimately improve clinical outcomes.

Methods: We have analyzed differentially expressed genes (DEGs) and differentially spliced genes (DSGs) between resected formalin-fixed, paraffin-embedded lung squamous cell carcinoma specimens from 20 AA and 20 white patients (self-reported race) using Affymetrix Clariom D Assay, human and Transcriptome Analysis Console Software. To obtain genetically estimated indicators of race, we performed ancestral genotyping. After excluding specimens from biracial patients and those with positive versus negative area under the curve less than 0.6, we used a cohort of 14 specimens from AA patients and 13 specimens from white patients for analysis.

Results: Transcriptome analysis revealed 450 DEGs and 7,089 DSGs, in which we identified 13,763 unique splicing events, between NSCLC in AA and white patients. The nuclear receptors meta pathway and the olfactory receptor pathway are over-represented with such DEGs. Seven of the DEGs also exhibit differential expression between lung squamous cell carcinoma in AA and white patients in The Cancer Genome Atlas (TCGA). Twenty-eight of the DEGs also exhibit differential expression between prostate cancer in AA and white patients. Among the 7,089 DSGs between NSCLC in AA and white patients, 599 also exhibit differential splicing between prostate cancer in AA and white patients, 33 also exhibit differential splicing in breast and liver cancer, and 6 also exhibit differential splicing in breast, liver and prostate cancer. Validation of prioritized genomic differences using polymerase chain reaction and investigation of the functional significance of prioritized genomic differences to lung cancer cell biology using CRISPR-Cas9 technology is currently under way.

Conclusions: This study identifies novel aggregate gene expression and splicing differences between NSCLC in AA and white patients. Interestingly, the number of DSGs far exceeds the number of DEGs in the same tissues and a number of DEGs and DSGs exhibit differential aggregate gene expression and splicing, respectively, in additional solid tumor types. Upon further study, these mechanisms have the potential to serve as novel targets for the development of biomarkers or therapeutic agents for lung cancer, and to reduce the mortality burden from lung cancer among AAs.

Citation Format: April E. Deveaux, Dadong Zhang, Muthana Al Abo, Nadine J. Barrett, Rick A. Kittles, Kouros Owzar, Shannon J. McCall, Jeffrey Crawford, Steven R. Patierno, Jeffrey M. Clarke, Jennifer A. Freedman. Genomic differences between non-small cell lung cancer (NSCLC) in African American and white patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B071.

Abstract B035: Identification of a tumor cell adaptive stress response signaling pathway, which drives aggressive breast cancer phenotype and therapeutic resistance, in African American patients with locally advanced breast cancer subtypes

Introduction: The higher incidence of biologically aggressive and treatment-resistant breast cancer (BCa) subtypes, which includes triple negative (TN), basal, and inflammatory breast cancer (IBC), contributes to worse survival outcomes in African American/AA patients, 42% higher death rate compared to White BCa. Amongst locally advanced BCa, IBC is a model of aggressive, most lethal, frequently basal/TN, accounting for 10% AA BCa and disparity in outcomes exist after adjusting for socioeconomic and diagnosis factors. IBC exhibits a unique phenotype wherein malignant cells do not form solid masses and instead, present as hyperproliferative tumor cell clusters, termed tumor emboli, in the skin and lymphatics. Our key finding was the identification of a tumor cell adaptive stress response pathway linking the mitogen activated ser/thr kinase/MNK, X-linked inhibitor of anti-apoptotic protein, XIAP, and nuclear transcription factor, NFkB, mediated proliferative, invasive and immunosuppressive signaling. Our goal was to determine the role of the adaptive stress response pathway, which we have identified to contribute to aggressiveness of TNBC and IBC, in AA breast tumor biology. Methods: Expression of MNK, XIAP and NFkB target gene sets, a 40-gene oxidative stress response that correlates with response to cell death stimuli and a 79-gene IBC signature (identified from comparative analysis of IBC and non-IBC biospecimens) were evaluated in The Cancer Genome Atlas (TCGA) breast cancer datasets (1109 tumor; 113 normal) stratified according to race and molecular subtypes (luminal A, B, Her2, basal). The mean expression for each gene in these signatures were also assessed among different subtypes and race using R. Gene Ontology (GO) analysis was performed using GATHER online tool. XIAP immunohistochemistry (IHC) conducted in BCa samples (n=93) from Duke and MDACC biorepositories. Results: TCGA analysis of the IBC-related signatures identified genes differentially expressed (&gt;2-fold change; Wilcoxon rank sum test, FDR&lt;0.05) among BCa subtypes and between AA vs White within a subtype. Additionally, the oxidative stress response metagene was significantly upregulated in AA basal (p=0.037) whereas there were fewer differences in immune-related genes within AA subtypes suggesting attenuated immune response. IHC, to date, shows high XIAP in high grade, ER-negative and in majority of AA BCa and in IBC samples independent of molecular subtypes and grade. Conclusions: We report a heightened adaptive stress response gene signature and identify genes in the MNK:XIAP:NFkB pathway and IBC-related signatures in AA BCa, suggesting potential biomarkers and drug discovery targets. High XIAP expression in high grade BCa, frequent in AA patients, is of therapeutic relevance as XIAP, the most potent caspase inhibitor, is linked to chemo- and immunotherapy resistance and XIAP inhibitors are in clinical trials. Supported by DOD-Breakthrough-W81XWH-17-1-0297; Duke SOM bridge funds; NCI-1P20-CA202925-01A12.

Citation Format: Gayathri R Devi, Muthana Al Abo, Larisa Gearhart-Serna, Joseph Geradts, Shannon J McCall, Savitri Krishnamurthy. Identification of a tumor cell adaptive stress response signaling pathway, which drives aggressive breast cancer phenotype and therapeutic resistance, in African American patients with locally advanced breast cancer subtypes [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B035.

Abstract A114: Characterization of a metastatic prostate cancer xenograft derived from a patient of African ancestry

Background: Prostate cancer (PCa) is a clinically and molecularly heterogeneous disease, with differences in incidence and mortality among and between racial groups, which grade and stage only partially predict. Prostate cancer patient-derived xenografts (PCPDXs) are essential for studying PCa biology and testing new therapeutics in models that we expect to be reflective of the clinical setting. To date, PCPDXs have been difficult to establish due to lack of solid tumor content and poor uptake rates in mice. In the present study, we established and characterized the first PCPDX from a highly aggressive and metastatic tumor sample from a patient of African ancestry.

Methods: We collected the PCa sample from the patient at the time of surgery after initiating stage-specific standard-of-care treatment. Tissue was minced and implanted into the kidney capsule of 8- to 10-week-old SCID mice. Once the explant was established, tissue was collected and formalin-fixed, paraffin-embedded for histologic evaluation. An initial section was stained using hematoxylin and eosin and another section was stained by PIN4 (p63, CKBE12, racemase) for immunohistochemical (IHC) analysis to confirm diagnosis of PCa. To obtain genetically estimated indicators of race, we performed ancestral genotyping. We evaluated response to chemical castration with 10mg/kg enzalutamide administered 5 days per week by oral gavage. Tumor growth was measured with calipers every day.

Results: We established a PCPDX from a core prostate sample taken from a patient diagnosed with adenocarcinoma of the prostate (Gleason 10), metastatic to lymph nodes and penis undergoing a pelvic exenteration. Ancestral genotyping estimated 90% African ancestry. IHC staining showed this model to be highly tumorigenic and PSA negative. Passaged tumors took in 15 out of 15 SCID mice and reached 10mm3 within 3 weeks. This model does not show a significant decrease in growth in response to treatment with the androgen receptor inhibitor, enzalutamide. Further characterization using IHC, RNA and whole-exome sequencing, castration, drug treatment, and assays for metastatic potential are currently under way.

Conclusions: Establishing this PCPDX provides a unique model of metastatic, androgen-independent PCa in a patient of African ancestry. Prior to this study, there had yet to be a PCPDX model derived from a patient of African ancestry. We established this PCPDX from a Gleason 10 PCa, supporting previous data of success in grafting this type of aggressive PCa into a mouse. It has a very high take rate and growth rate relative to other PCa models. Such a model will enable interrogation of PCa from a patient of African ancestry. Once a larger panel of PCPDXs from racially diverse patients is established, we will be able to achieve a more complete characterization of this disease and use such models to develop new biomarkers and therapeutic agents. Ultimately, these tools will improve outcomes for all men with aggressive PCa and reduce PCa disparities for patients of African ancestry.

Citation Format: Brendon M. Patierno, Wayne Glover, Wen-Chi Foo, Jason A. Somarelli, Kathryn E. Ware, Lingfan Xu, Yanjing Li, Xufeng Chen, Daniel J. George, Rick A. Kittles, Andrew J. Armstrong, Shannon J. McCall, Jiaoti Huang, Jennifer A. Freedman, Steven R. Patierno, David S. Hsu. Characterization of a metastatic prostate cancer xenograft derived from a patient of African ancestry [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A114.

Anaphylaxis in pregnancy: a population-based multinational European study

Anaphylaxis in pregnancy is a rare but severe complication for both mother and infant. Population-based data on anaphylaxis in pregnancy are lacking from mainland European countries. This multinational study presents the incidence, causative agents, management and maternal and infant outcomes of anaphylaxis in pregnancy. This descriptive multinational study used a combination of retrospective (Finnish medical registries) and prospective population-based studies (UK, France, Belgium and the Netherlands) to identify cases of anaphylaxis. Sixty-five cases were identified among 4,446,120 maternities (1.5 per 100,000 maternities; 95%CI 1.1-1.9). The incidence did not vary between countries. Approximately three-quarters of reactions occurred at the time of delivery. The most common causes were antibiotics in 27 women (43%), and anaesthetic agents in 11 women (17%; including neuromuscular blocking drugs, 7), which varied between countries. Anaphylaxis had very poor outcomes for one in seven mothers and one in seven babies; the maternal case fatality rate was 3.2% (95%CI 0.4-11.0) and the neonatal encephalopathy rate was 14.3% (95%CI 4.8-30.3). Across Europe, anaphylaxis related to pregnancy is rare despite having a multitude of causative agents and different antibiotic prophylaxis protocols.

State of the Art: Toward Improving Outcomes of Lung and Liver Tumor Biopsies in Clinical Trials-A Multidisciplinary Approach

PURPOSE

National Cancer Institute (NCI)-sponsored clinical trial network studies frequently require biopsy specimens for pharmacodynamic and molecular biomarker analyses, including paired pre- and post-treatment samples. The purpose of this meeting of NCI-sponsored investigators was to identify local institutional standard procedures found to ensure quantitative and qualitative specimen adequacy.

METHODS

NCI convened a conference on best biopsy practices, focusing on the clinical research community. Topics discussed were (1) criteria for specimen adequacy in the personalized medicine era, (2) team-based approaches to ensure specimen adequacy and quality control, and (3) risk considerations relevant to academic and community practitioners and their patients.

RESULTS AND RECOMMENDATIONS

Key recommendations from the convened consensus panel included (1) establishment of infrastructure for multidisciplinary biopsy teams with a formalized information capture process, (2) maintenance of standard operating procedures with regular team review, (3) optimization of tissue collection and yield methodology, (4) incorporation of needle aspiration and other newer techniques, and (5) commitment of stakeholders to use of guideline documents to increase awareness of best biopsy practices, with the goal of universally improving tumor biopsy practices.

Next generation sequencing of PD-L1 for predicting response to immune checkpoint inhibitors

BACKGROUND

PD-L1 immunohistochemistry (IHC) has been traditionally used for predicting clinical responses to immune checkpoint inhibitors (ICIs). However, there are at least 4 different assays and antibodies used for PD-L1 IHC, each developed with a different ICI. We set to test if next generation RNA sequencing (RNA-seq) is a robust method to determine PD-L1 mRNA expression levels and furthermore, efficacy of predicting response to ICIs as compared to routinely used, standardized IHC procedures.

METHODS

A total of 209 cancer patients treated on-label by FDA-approved ICIs, with evaluable responses were assessed for PD-L1 expression by RNA-seq and IHC, based on tumor proportion score (TPS) and immune cell staining (ICS). A subset of serially diluted cases was evaluated for RNA-seq assay performance across a broad range of PD-L1 expression levels.

RESULTS

Assessment of PD-L1 mRNA levels by RNA-seq demonstrated robust linearity across high and low expression ranges. PD-L1 mRNA levels assessed by RNA-seq and IHC (TPS and ICS) were highly correlated (p < 2e-16). Sub-analyses showed sustained correlation when IHC results were classified as high or low by clinically accepted cut-offs (p < 0.01), and results did not differ by tumor type or anti-PD-L1 antibody used. Overall, a combined positive PD-L1 result (≥1% IHC TPS and high PD-L1 expression by RNA-Seq) was associated with a 2-to-5-fold higher overall response rate (ORR) compared to a double negative result. Standard assessments of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) showed that a PD-L1 positive assessment for melanoma samples by RNA-seq had the lowest sensitivity (25%) but the highest PPV (72.7%). Among the three tumor types analyzed in this study, the only non-overlapping confidence interval for predicting response was for "RNA-seq low vs high" in melanoma.

CONCLUSIONS

Measurement of PD-L1 mRNA expression by RNA-seq is comparable to PD-L1 expression by IHC both analytically and clinically in predicting ICI response. RNA-seq has the added advantages of being amenable to standardization and avoidance of interpretation bias. PD-L1 by RNA-seq needs to be validated in future prospective ICI clinical studies across multiple histologies.

The incidence, characteristics, management and outcomes of anaphylaxis in pregnancy: a population-based descriptive study

OBJECTIVE

The aim of this study was to estimate the incidence of anaphylaxis in pregnancy and describe the management and outcomes in the UK.

DESIGN

A population-based descriptive study using the UK Obstetric Surveillance System (UKOSS).

SETTING

All consultant-led maternity units in the UK.

POPULATION

All pregnant women who had anaphylaxis between 1 October 2012 and 30 September 2015. Anaphylaxis was defined as a severe, life-threatening generalised or systemic hypersensitivity reaction.

METHODS

Prospective case notification using UKOSS.

MAIN OUTCOME MEASURES

Maternal mortality, severe maternal morbidity, neonatal mortality and severe neonatal morbidity.

RESULTS

There were 37 confirmed cases of anaphylaxis in pregnancy, giving an estimated incidence of 1.6 (95% CI: 1.1-2.2) per 100 000 maternities. Four cases of anaphylaxis were in women with known penicillin allergies: two received co-amoxiclav and two cephalosporins. Twelve women had anaphylaxis following prophylactic use of antibiotics at the time of a caesarean delivery. Prophylactic use of antibiotics for Group B streptococcal infection accounted for anaphylaxis in one woman. Two women died (5%), 14 (38%) women were admitted to intensive care and seven women (19%) had one or more additional severe maternal morbidities, which included three haemorrhagic events, two cardiac arrests, one thrombotic event and one pneumonia. No infants died; however, in those infants whose mother had anaphylaxis before delivery (n = 18) there were seven (41%) neonatal intensive care unit admissions, three preterm births and one baby was cooled for neonatal encephalopathy.

CONCLUSIONS

Anaphylaxis is a rare severe complication of pregnancy and frequently the result of a reaction to antibiotic administration. This study highlights the seriousness of the outcomes of this condition for the mother. The low incidence is reassuring given the large proportion of the pregnant population that receive prophylactic antibiotics during delivery.

TWEETABLE ABSTRACT

Anaphylaxis is a rare severe complication of pregnancy and frequently the result of a reaction to antibiotic administration.

A Landscape of Therapeutic Cooperativity in KRAS Mutant Cancers Reveals Principles for Controlling Tumor Evolution

Combinatorial inhibition of effector and feedback pathways is a promising treatment strategy for KRAS mutant cancers. However, the particular pathways that should be targeted to optimize therapeutic responses are unclear. Using CRISPR/Cas9, we systematically mapped the pathways whose inhibition cooperates with drugs targeting the KRAS effectors MEK, ERK, and PI3K. By performing 70 screens in models of KRAS mutant colorectal, lung, ovarian, and pancreas cancers, we uncovered universal and tissue-specific sensitizing combinations involving inhibitors of cell cycle, metabolism, growth signaling, chromatin regulation, and transcription. Furthermore, these screens revealed secondary genetic modifiers of sensitivity, yielding a SRC inhibitor-based combination therapy for KRAS/PIK3CA double-mutant colorectal cancers (CRCs) with clinical potential. Surprisingly, acquired resistance to combinations of growth signaling pathway inhibitors develops rapidly following treatment, but by targeting signaling feedback or apoptotic priming, it is possible to construct three-drug combinations that greatly delay its emergence.

Targeting the human epidermal growth factor receptor 2 (HER2) oncogene in colorectal cancer

Human epidermal growth factor receptor 2 (HER2) is an oncogenic driver, and a well-established therapeutic target in breast and gastric cancers. Using functional and genomic analyses of patient-derived xenografts, we previously showed that a subset (approximately 5%) of metastatic colorectal cancer (CRC) tumors is driven by amplification or mutation of HER2. This paper reviews the role of HER2 amplification as an oncogenic driver, a prognostic and predictive biomarker, and a clinically actionable target in CRC, considering the specifics of HER2 testing in this tumor type. While the role of HER2 as a biomarker for prognosis in CRC remains uncertain, its relevance as a therapeutic target has been established. Indeed, independent studies documented substantial clinical benefit in patients treated with biomarker-driven HER2-targeted therapies, with an impact on response rates and duration of response that compared favorably with immunotherapy and other examples of precision oncology. HER2-targeted therapeutic strategies have the potential to change the treatment paradigm for a clinically relevant subgroup of metastatic CRC patients.

Comparative Molecular Analysis of Gastrointestinal Adenocarcinomas

We analyzed 921 adenocarcinomas of the esophagus, stomach, colon, and rectum to examine shared and distinguishing molecular characteristics of gastrointestinal tract adenocarcinomas (GIACs). Hypermutated tumors were distinct regardless of cancer type and comprised those enriched for insertions/deletions, representing microsatellite instability cases with epigenetic silencing of MLH1 in the context of CpG island methylator phenotype, plus tumors with elevated single-nucleotide variants associated with mutations in POLE. Tumors with chromosomal instability were diverse, with gastroesophageal adenocarcinomas harboring fragmented genomes associated with genomic doubling and distinct mutational signatures. We identified a group of tumors in the colon and rectum lacking hypermutation and aneuploidy termed genome stable and enriched in DNA hypermethylation and mutations in KRAS, SOX9, and PCBP1.

Metastatic Renal Cell Carcinoma as Solitary Subcentimeter Polypoid Gastric Mucosal Lesions: Clinicopathologic Analysis of Five Cases

Background

The stomach is an uncommon site for metastatic carcinoma. Approximately 6% of renal cell carcinomas (RCCs) may metastasize to the stomach. The majority of the reported metastatic RCCs in the stomach presented as large masses or ulcers greater than a centimeter in size. It is very rare to encounter metastatic RCC as a solitary small polypoid gastric mucosal lesion.

Methods

In this study, we collected surgical pathology cases of gastric metastasis from RCC that measured 1.0 cm or less at the time of endoscopy. The clinicopathological characteristics were analyzed.

Results

Five patients with subcentimeter metastatic RCC involving the gastric mucosa were identified. The clinical presentation for upper endoscopic examination was non-specific. Two of the five patients did not have a known history of RCC. In the three patients with a previous history of RCC, the interval from primary RCC diagnosis to the detection of gastric mucosal metastasis was 5, 6, and 10 years, respectively. Endoscopically, all the lesions were solitary, ranging in size from 0.4 to 1 cm. Histologically, all five cases were of the clear cell type consisting of a bland clear cell proliferation within the lamina propria. Although the tumor cells were relatively bland, the presence of clear cytoplasm, nuclear membrane irregularity, occasional enlarged hyperchromatic atypical nuclei, and destructive growth in the center of the lesion should promote immunohistochemical workup. Immunohistochemically, the RCC cells exhibited at least patchy immunoreactivity for cytokeratin and RCC markers. In two cases, there were many CD68 positive foamy histiocytes intermingled with the tumor cells.

Conclusion

Metastatic RCC can rarely present as subcentimeter polypoid gastric mucosal lesions. The remote or unknown history of RCC, the non-specific endoscopic appearance, and the bland histological features may lead to a potential diagnostic pitfall. It is of importance to raise the awareness of such an unusual presentation of metastatic RCC in the stomach and to include metastatic RCC in the differential diagnosis for gastric mucosal polyps with clear cell morphology.

The College of American Pathologists Biorepository Accreditation Program: Results from the First 5 Years

The College of American Pathologists (CAP) developed the Biorepository Accreditation Program (BAP) in 2012. This program integrates best practices from the International Society for Biological and Environmental Biorepositories, the National Cancer Institute, the Organisation for Economic Cooperation and Development, the Center for Medicare and Medicaid Services, and the CAP Laboratory Accreditation Program. The goal of this elective program is to provide requirements for standardization in biorepository processes that will result in high-quality specimens that can be used to support research, drug discovery, and personalized medicine. CAP uses a peer inspection model to ensure the inspectors have proper expertise and to promote educational efforts through information sharing. Lead inspectors are comprised of pathologists, PhDs, and managers of biorepositories and they are often supported by CAP staff inspectors. Accreditation is a 3-year continuous cycle of quality with a peer inspection occurring at the start of year 1 and a self-inspection and CAP desk assessment at the start of year 2 and 3. At this time 53 biorepositories are fully CAP BAP accredited and 13 are in the process of obtaining accreditation. There are currently 273 established standards with requirement lists customized based on the scope of activities performed by a biorepository. A total of 90 inspections were completed between May 2012 and December 2016. Sixty-one were initial inspections and 29 were reinspections. A total of 527 deficiencies were identified in the areas of Equipment/Instrumentation (22%), Information Technology (18%), Specimen Handling and QC (15%), Quality Management (16%), Personnel (11%), Safety (10%), Facilities (6%), and Regulatory (2%). Assessment of common deficiencies identifies areas of focus for continuous improvement and educational opportunities. Overall success of the program is high based on the current enrollment of 66 biorepositories, anecdotal participant feedback and increasing national recognition of the BAP in federal documents.

PIK3CA mutations enable targeting of a breast tumor dependency through mTOR-mediated MCL-1 translation

Therapies that efficiently induce apoptosis are likely to be required for durable clinical responses in patients with solid tumors. Using a pharmacological screening approach, we discovered that combined inhibition of B cell lymphoma-extra large (BCL-X_L) and the mammalian target of rapamycin (mTOR)/4E-BP axis results in selective and synergistic induction of apoptosis in cellular and animal models of PIK3CA mutant breast cancers, including triple-negative tumors. Mechanistically, inhibition of mTOR/4E-BP suppresses myeloid cell leukemia-1 (MCL-1) protein translation only in PIK3CA mutant tumors, creating a synthetic dependence on BCL-X_L This dual dependence on BCL-X_L and MCL-1, but not on BCL-2, appears to be a fundamental property of diverse breast cancer cell lines, xenografts, and patient-derived tumors that is independent of the molecular subtype or PIK3CA mutational status. Furthermore, this dependence distinguishes breast cancers from normal breast epithelial cells, which are neither primed for apoptosis nor dependent on BCL-X_L/MCL-1, suggesting a potential therapeutic window. By tilting the balance of pro- to antiapoptotic signals in the mitochondria, dual inhibition of MCL-1 and BCL-X_L also sensitizes breast cancer cells to standard-of-care cytotoxic and targeted chemotherapies. Together, these results suggest that patients with PIK3CA mutant breast cancers may benefit from combined treatment with inhibitors of BCL-X_L and the mTOR/4E-BP axis, whereas alternative methods of inhibiting MCL-1 and BCL-X_L may be effective in tumors lacking PIK3CA mutations.

Melanoma Therapeutic Strategies that Select against Resistance by Exploiting MYC-Driven Evolutionary Convergence

Diverse pathways drive resistance to BRAF/MEK inhibitors in BRAF-mutant melanoma, suggesting that durable control of resistance will be a challenge. By combining statistical modeling of genomic data from matched pre-treatment and post-relapse patient tumors with functional interrogation of >20 in vitro and in vivo resistance models, we discovered that major pathways of resistance converge to activate the transcription factor, c-MYC (MYC). MYC expression and pathway gene signatures were suppressed following drug treatment, and then rebounded during progression. Critically, MYC activation was necessary and sufficient for resistance, and suppression of MYC activity using genetic approaches or BET bromodomain inhibition was sufficient to resensitize cells and delay BRAFi resistance. Finally, MYC-driven, BRAFi-resistant cells are hypersensitive to the inhibition of MYC synthetic lethal partners, including SRC family and c-KIT tyrosine kinases, as well as glucose, glutamine, and serine metabolic pathways. These insights enable the design of combination therapies that select against resistance evolution.

Immune Activation in Early-Stage Non-Small Cell Lung Cancer Patients Receiving Neoadjuvant Chemotherapy Plus Ipilimumab

Purpose: To determine the immunologic effects of neoadjuvant chemotherapy plus ipilimumab in early-stage non-small cell lung cancer (NSCLC) patients.Experimental Design: This is a single-arm chemotherapy plus phased ipilimumab phase II study of 24 treatment-naïve patients with stage IB-IIIA NSCLC. Patients received neoadjuvant therapy consisting of 3 cycles of paclitaxel with either cisplatin or carboplatin and ipilimumab included in the last 2 cycles.Results: Chemotherapy alone had little effect on immune parameters in PBMCs. Profound CD28-dependent activation of both CD4 and CD8 cells was observed following ipilimumab. Significant increases in the frequencies of CD4⁺ cells expressing activation markers ICOS, HLA-DR, CTLA-4, and PD-1 were apparent. Likewise, increased frequencies of CD8⁺ cells expressing the same activation markers, with the exception of PD-1, were observed. We also examined 7 resected tumors and found higher frequencies of activated tumor-infiltrating lymphocytes than those observed in PBMCs. Surprisingly, we found 4 cases of preexisting tumor-associated antigens (TAA) responses against survivin, PRAME, or MAGE-A3 present in PBMC at baseline, but neither increased frequencies nor the appearance of newly detectable responses following ipilimumab therapy. Ipilimumab had little effect on the frequencies of circulating regulatory T cells and MDSCs.Conclusions: This study did not meet the primary endpoint of detecting an increase in blood-based TAA T-cell responses after ipilimumab. Collectively, these results highlight the immune activating properties of ipilimumab in early-stage NSCLC. The immune profiling data for ipilimumab alone can contribute to the interpretation of immunologic data from combined immune checkpoint blockade immunotherapies. Clin Cancer Res; 23(24); 7474-82. ©2017 AACR.

TGF-β-induced stromal CYR61 promotes resistance to gemcitabine in pancreatic ductal adenocarcinoma through downregulation of the nucleoside transporters hENT1 and hCNT3

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer in part due to inherent resistance to chemotherapy, including the first-line drug gemcitabine. Although low expression of the nucleoside transporters hENT1 and hCNT3 that mediate cellular uptake of gemcitabine has been linked to gemcitabine resistance, the mechanisms regulating their expression in the PDAC tumor microenvironment are largely unknown. Here, we report that the matricellular protein cysteine-rich angiogenic inducer 61 (CYR61) negatively regulates the nucleoside transporters hENT1 and hCNT3. CRISPR/Cas9-mediated knockout of CYR61 increased expression of hENT1 and hCNT3, increased cellular uptake of gemcitabine and sensitized PDAC cells to gemcitabine-induced apoptosis. In PDAC patient samples, expression of hENT1 and hCNT3 negatively correlates with expression of CYR61 . We demonstrate that stromal pancreatic stellate cells (PSCs) are a source of CYR61 within the PDAC tumor microenvironment. Transforming growth factor-β (TGF-β) induces the expression of CYR61 in PSCs through canonical TGF-β-ALK5-Smad2/3 signaling. Activation of TGF-β signaling or expression of CYR61 in PSCs promotes resistance to gemcitabine in PDAC cells in an in vitro co-culture assay. Our results identify CYR61 as a TGF-β-induced stromal-derived factor that regulates gemcitabine sensitivity in PDAC and suggest that targeting CYR61 may improve chemotherapy response in PDAC patients.

Ductular and proliferative response of esophageal submucosal glands in a porcine model of esophageal injury and repair

Esophageal injury is a risk factor for diseases such as Barrett's esophagus (BE) and esophageal adenocarcinoma. To improve understanding of signaling pathways associated with both normal and abnormal repair, animal models are needed. Traditional rodent models of esophageal repair are limited by the absence of esophageal submucosal glands (ESMGs), which are present in the human esophagus. Previously, we identified acinar ductal metaplasia in human ESMGs in association with both esophageal injury and cancer. In addition, the SOX9 transcription factor has been associated with generation of columnar epithelium and the pathogenesis of BE and is present in ESMGs. To test our hypothesis that ESMGs activate after esophageal injury with an increase in proliferation, generation of a ductal phenotype, and expression of SOX9, we developed a porcine model of esophageal injury and repair using radiofrequency ablation (RFA). The porcine esophagus contains ESMGs, and RFA produces a consistent and reproducible mucosal injury in the esophagus. Here we present a temporal assessment of this model of esophageal repair. Porcine esophagus was evaluated at 0, 6, 18, 24, 48, and 72 h and 5 and 7 days following RFA and compared with control uninjured esophagus. Following RFA, ESMGs demonstrated an increase in ductal phenotype, echoing our prior studies in humans. Proliferation increased in both squamous epithelium and ESMGs postinjury with a prominent population of SOX9-positive cells in ESMGs postinjury. This model promises to be useful in future experiments evaluating mechanisms of esophageal repair.NEW & NOTEWORTHY A novel porcine model of injury and repair using radiofrequency ablation has been developed, allowing for reproducible injury to the esophagus to study repair in an animal model with esophageal submucosal glands, a key anatomical feature and missing in rodent models but possibly harboring progenitor cells. There is a strong translational component to this porcine model given the anatomical and physiological similarities between pigs and humans.

Porcine Esophageal Submucosal Gland Culture Model Shows Capacity for Proliferation and Differentiation

BACKGROUND & AIMS

Although cells comprising esophageal submucosal glands (ESMGs) represent a potential progenitor cell niche, new models are needed to understand their capacity to proliferate and differentiate. By histologic appearance, ESMGs have been associated with both overlying normal squamous epithelium and columnar epithelium. Our aim was to assess ESMG proliferation and differentiation in a 3-dimensional culture model.

METHODS

We evaluated proliferation in human ESMGs from normal and diseased tissue by proliferating cell nuclear antigen immunohistochemistry. Next, we compared 5-ethynyl-2'-deoxyuridine labeling in porcine ESMGs in vivo before and after esophageal injury with a novel in vitro porcine organoid ESMG model. Microarray analysis of ESMGs in culture was compared with squamous epithelium and fresh ESMGs.

RESULTS

Marked proliferation was observed in human ESMGs of diseased tissue. This activated ESMG state was recapitulated after esophageal injury in an in vivo porcine model, ESMGs assumed a ductal appearance with increased proliferation compared with control. Isolated and cultured porcine ESMGs produced buds with actively cycling cells and passaged to form epidermal growth factor-dependent spheroids. These spheroids were highly proliferative and were passaged multiple times. Two phenotypes of spheroids were identified: solid squamous (P63+) and hollow/ductal (cytokeratin 7+). Microarray analysis showed spheroids to be distinct from parent ESMGs and enriched for columnar transcripts.

CONCLUSIONS

Our results suggest that the activated ESMG state, seen in both human disease and our porcine model, may provide a source of cells to repopulate damaged epithelium in a normal manner (squamous) or abnormally (columnar epithelium). This culture model will allow the evaluation of factors that drive ESMGs in the regeneration of injured epithelium. The raw microarray data have been uploaded to the National Center for Biotechnology Information Gene Expression Omnibus (accession number: GSE100543).

Factors associated with maternal mortality at advanced maternal age: a population-based case-control study

OBJECTIVE

This study aimed to examine the factors associated with maternal mortality among women aged ≥35 years.

DESIGN

Unmatched population based case-control study.

SETTING

United Kingdom.

POPULATION

Between 2009 and 2012, 105 cases of maternal deaths aged ≥35 years were extracted from the surveillance database of the MBRRACE-UK confidential enquiries into maternal deaths in the UK. In addition, 766 controls aged ≥35 years were identified from the UK Obstetric Surveillance System (2005-2012).

METHODS

Risk factors known to be associated with maternal mortality and morbidity and for which data were available were examined for their association with maternal mortality among women ≥35 years using logistic regression analysis.

MAIN OUTCOME MEASURES

Odds ratios and 95% confidence intervals associated with maternal death.

RESULTS

Five factors were found to be significantly associated with increased odds of death among women aged ≥35 years: smoking during pregnancy (adjusted odds ratio (aOR) 2.06, 95% CI 1.13-3.75), inadequate use of antenatal care (aOR 23.62, 95% CI 8.79-63.45), medical co-morbidities (aOR 5.92, 95% CI 3.56-9.86) and previous pregnancy problems (aOR 2.06, 95% CI 1.23-3.45). The odds associated with death increased by 12% per year increase in age (aOR 1.12, 95% CI 1.02-1.22).

CONCLUSION

Age was associated with maternal mortality even after adjusting for other known risk factors. Importantly, this study showed an association between maternal mortality and smoking among women aged 35 years or older. It emphasises the importance of public health action to reduce smoking levels and address trends in rising maternal age.

TWEETABLE ABSTRACT

Smoking is a risk factor for maternal death for those aged over 35 years.

Professional Practice Evaluation for Pathologists: The Development, Life, and Death of the Evalumetrics Program

CONTEXT

- In 2008, the Joint Commission (JC) implemented a standard mandating formal monitoring of physician professional performance as part of the process of granting and maintaining practice privileges.

OBJECTIVE

- To create a pathology-specific management tool to aid pathologists in constructing a professional practice-monitoring program, thereby meeting the JC mandate.

DESIGN

- A total of 105 College of American Pathologists (CAP)-defined metrics were created. Metrics were based on the job descriptions of pathologists' duties in the laboratory, and metric development was aided by experience from the Q-Probes and Q-Tracks programs. The program was offered in a Web-based format, allowing secure data entry, customization of metrics, and central data collection for future benchmarking.

RESULTS

- The program was live for 3 years, with 347 pathologists subscribed from 61 practices (median, 4 per institution; range, 1-35). Subscribers used 93 of the CAP-defined metrics and created 109 custom metrics. The median number of CAP-defined metrics used per pathologist was 5 (range, 1-43), and the median custom-defined metrics per pathologist was 2 (range, 1-5). Most frequently, 1 to 3 metrics were monitored (42.7%), with 20% each following 4 to 6 metrics, 5 to 9 metrics, or greater than 10 metrics. Anatomic pathology metrics were used more commonly than clinical pathology metrics. Owing to low registration, the program was discontinued in 2016.

CONCLUSIONS

- Through careful vetting of metrics it was possible to develop a pathologist-specific management tool to address the JC mandate. While this initial product failed, valuable metrics were developed and implementation knowledge was gained that may be used to address new regulatory requirements for emerging value-based payment systems.

Physician Satisfaction With Clinical Laboratory Services: A College of American Pathologists Q-Probes Study of 81 Institutions

CONTEXT

-Assessment of customer satisfaction is a vital component of the laboratory quality improvement program.

OBJECTIVE

-To survey the level of physician satisfaction with hospital clinical laboratory services.

DESIGN

-Participating institutions provided demographic information and survey results of physician satisfaction, with specific features of clinical laboratory services individually rated on a scale of 5 (excellent) to 1 (poor).

RESULTS

-Eighty-one institutions submitted 2425 surveys. The median overall satisfaction score was 4.2 (10th percentile, 3.6; 90th percentile, 4.6). Of the 16 surveyed areas receiving the highest percentage of excellent/good ratings (combined scores of 4 and 5), quality of results was highest along with test menu adequacy, staff courtesy, and overall satisfaction. Of the 4 categories receiving the lowest percentage values of excellent/good ratings, 3 were related to turnaround time for inpatient "STAT" (tests performed immediately), outpatient STAT, and esoteric tests. The fourth was a new category presented in this survey: ease of electronic order entry. Here, 11.4% (241 of 2121) of physicians assigned below-average (2) or poor (1) scores. The 5 categories deemed most important to physicians included quality of results, turnaround times for inpatient STAT, routine, and outpatient STAT tests, and clinical report format. Overall satisfaction as measured by physician willingness to recommend their laboratory to another physician remains high at 94.5% (2160 of 2286 respondents).

CONCLUSIONS

-There is a continued trend of high physician satisfaction and loyalty with clinical laboratory services. Physician dissatisfaction with ease of electronic order entry represents a new challenge. Test turnaround times are persistent areas of dissatisfaction, representing areas for improvement.

Radiographic and endoscopic regression of metastatic gastric cancer to the colon in the setting of 5-aminosalicylic acid use

Colonic metastases from gastric cancer are a rare phenomenon and sparsely reported in the literature. We report a case of a 59-year-old woman who presented with vague abdominal symptoms and initial computer tomography (CT) imaging suggestive of a colonic apple-core lesion with serial colonoscopic biopsies diagnostic of metastatic signet ring cell gastric adenocarcinoma. This case is unique given the evolving CT and endoscopic findings that suggested a regression in colonic wall thickening in the setting of 5-aminosalicylic acid (5-ASA) use prior to histologic diagnosis.

Mixed Adenoneuroendocrine Carcinoma, Amphicrine Type, of the Small Bowel

OBJECTIVES

Amphicrine-type mixed adenoneuroendocrine carcinomas are exceedingly rare lesions of the gastrointestinal tract, comprising tumor cells simultaneously demonstrating both neuroendocrine and exocrine features. To date, only 14 cases of amphicrine carcinoma have been reported; here we report the first definitive case of amphicrine carcinoma in the small bowel.

METHODS

A 72-year-old woman who sought treatment for nonspecific abdominal complaints was found to have a duodenojejunal junction tumor and underwent radical surgical resection.

RESULTS

Morphologically, the tumor consisted of areas of moderately differentiated adenocarcinoma intermingled with areas characteristic of neuroendocrine tumor. The entire tumor showed strong, diffuse immunoreactivity for synaptophysin. Coexpression of exocrine and neuroendocrine features by neoplastic cells indicates bivalent differentiation, and therefore the tumor was classified as an amphicrine carcinoma of the small bowel.

CONCLUSIONS

Demonstration of amphicrine carcinoma in the small bowel carries implications with regard to the common origin of exocrine and neuroendocrine cells in the gastrointestinal tract.

Primary high-grade neuroendocrine carcinoma emerging from an adenomatous polyp in the setting of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a rare inherited syndrome that is characterised by innumerable adenomas of the colon and rectum, a high risk of colorectal cancer and a variety of extracolonic manifestations. FAP presents as hundreds to thousands of colonic adenomas beginning in adolescence. The syndrome is associated with less than 1% of all colorectal cancer cases, but there is a nearly 100% lifetime risk of colorectal cancer in individuals with FAP. This case demonstrates a 60-year-old man with FAP who developed high-grade neuroendocrine carcinoma with glandular and squamous differentiation, and regional lymph node and liver metastases. Early diagnosis of FAP is of the utmost importance to start screening colonoscopies to assess disease burden, perform polypectomies and to make management decisions. Neuroendocrine carcinomas rarely occur in patients with FAP, and awareness of this association among general medical physicians and pathologists is essential for the diagnosis and care of these patients.

Ductal metaplasia in oesophageal submucosal glands is associated with inflammation and oesophageal adenocarcinoma

AIMS

Recent studies have suggested that oesophageal submucosal gland (ESMG) ducts harbour progenitor cells that may contribute to oesophageal metaplasia. Our objective was to determine whether histological differences exist between the ESMGs of individuals with and without oesophageal adenocarcinoma (EAC).

METHODS AND RESULTS

We performed histological assessment of 343 unique ESMGs from 30 control patients, 24 patients with treatment-naïve high-grade columnar dysplasia (HGD) or EAC, and 23 non-EAC oesophagectomy cases. A gastrointestinal pathologist assessed haematoxylin and eosin-stained ESMG images by using a scoring system that assigns individual ESMG acini to five histological types (mucous, serous, oncocytic, dilated, or ductal metaplastic). In our model, ductal metaplastic acini were more common in patients with HGD/EAC (12.7%) than in controls (3.5%) (P = 0.006). We also identified greater proportions of acini with dilation (21.9%, P < 0.001) and, to a lesser extent, ductal metaplasia (4.3%, P = 0.001) in non-EAC oesophagectomy cases than in controls. Ductal metaplasia tended to occur in areas of mucosal ulceration or tumour.

CONCLUSIONS

We found a clear association between ductal metaplastic ESMG acini and HGD/EAC. Non-EAC cases had dilated acini and some ductal dilation. Because ESMGs and ducts harbour putative progenitor cells, these associations could have significance for understanding the pathogenesis of EAC.

Endogenous elevation of plasma cholecystokinin does not prevent gallstones

BACKGROUND

Regular gall bladder contraction reduces bile stasis and prevents gallstone formation. Intraduodenal administration of exogenous pancreatic secretory trypsin inhibitor-I (PSTI-I, also known as monitor peptide) causes cholecystokinin (CCK) secretion.

DESIGN

We proposed that stimulation of CCK release by PSTI would produce gall bladder contraction and prevent gallstones in mice fed a lithogenic diet. Therefore, we tested the effect of overexpression of rat PSTI-I in pancreatic acinar cells on plasma CCK levels and gall bladder function in a transgenic mouse line (TgN[Psti1]; known hereafter as PSTI-I tg).

RESULTS

Importantly, PSTI tg mice had elevated fasting and fed plasma CCK levels compared to wild-type (WT) mice. Only mice fed the lithogenic diet developed gallstones. Both fasting and stimulated plasma CCK levels were substantially reduced in both WT and PSTI-I tg mice on the lithogenic diet. Moreover, despite higher CCK levels PSTI-I tg animals developed more gallstones than WT animals.

CONCLUSIONS

Together with the previously observed decrease in CCK-stimulated gall bladder emptying in mice fed a lithogenic diet, our findings suggest that a lithogenic diet causes gallstone formation by impaired CCK secretion in addition to reduced gall bladder sensitivity to CCK.

Patterns of failure for stage I ampulla of Vater adenocarcinoma: a single institutional experience

BACKGROUND

Ampullary adenocarcinoma is a rare malignancy associated with a relatively favorable prognosis. Given high survival rates in stage I patients reported in small series with surgery alone, adjuvant chemoradiotherapy (CRT) has traditionally been recommended only for patients with high risk disease. Recent population-based data have demonstrated inferior outcomes to previous series. We examined disease-related outcomes for stage I tumors treated with pancreaticoduodenectomy, with and without CRT.

METHODS

All patients with stage I ampullary adenocarcinoma treated from 1976 to 2011 at Duke University were reviewed. Disease-related endpoints including local control (LC), metastasis-free survival (MFS), disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method.

RESULTS

Forty-four patients were included in this study. Thirty-one patients underwent surgery alone, while 13 also received adjuvant CRT. Five-year LC, MFS, DFS and OS for patients treated with surgery only and surgery with CRT were 56% and 83% (P=0.13), 67% and 83% (P=0.31), 56% and 83% (P=0.13), and 53% and 68% (P=0.09), respectively.

CONCLUSIONS

The prognosis for patients diagnosed with stage I ampullary adenocarcinoma may not be as favorable as previously described. Our data suggests a possible benefit of adjuvant CRT delivery.

Q-Probes studies in anatomic pathology: quality improvement through targeted benchmarking

CONTEXT

The Q-Probes program is a peer-comparison quality assurance service offered by the College of American Pathologists that was created in 1989.

OBJECTIVE

To establish national benchmarks around a specific quality metric at a specific point in time in anatomic pathology (AP).

DESIGN

Q-Probes are based on a voluntary subscription for an individual study. Hospital-based laboratories in the United States, Canada, and 16 other countries have participated. Approximately one-third of all Q-Probes studies address AP metrics. Each Q-Probes study has a primary quality indicator and additional minor indicators.

RESULTS

There have been 52 AP Q-Probes studies addressing process-, outcome-, and structure-related quality assurance issues. These Q-Probes studies often represented the first standardized national benchmark for specific metrics in the disciplines of cytopathology, surgical pathology, and autopsy pathology, and as such have been cited more than 1700 times in peer-reviewed literature. The AP Q-Probes studies that have been repeated over time demonstrate improvement in laboratory performance across an international spectrum.

CONCLUSIONS

The Q-Probes program has produced important national benchmarks in AP, addressing preanalytic, analytic, and postanalytic factors in the disciplines of cytopathology, surgical pathology, and autopsy pathology. Q-Probes study data have been published, cited, and used in the creation of laboratory accreditation standards and other national guidelines.

Mismatch repair gone awry: Management of Lynch syndrome

The hallmark of Lynch syndrome involves germline mutations of genes important in DNA mismatch repair. Affected family kindreds will have multiple associated malignancies, the most common of which is colorectal adenocarcinoma. Recently, evidence has shown that clinical diagnostic criteria provided by the Amsterdam Criteria and the Bethesda Guidelines must be linked with microsatellite instability testing to correctly diagnose Lynch syndrome. We present a case of metachronous colorectal adenocarcinomas in a patient less than 50 years of age, followed by a discussion of Lynch syndrome, with an emphasis on surveillance and prevention of malignancies.