A pleiotropy scan to discover new susceptibility loci for pancreatic ductal adenocarcinoma

Pleiotropic variants (i.e., genetic polymorphisms influencing more than one phenotype) are often associated with cancer risk. A scan of pleiotropic variants was successfully conducted ten years ago in relation to pancreatic ductal adenocarcinoma susceptibility. However, in the last decade, genetic association studies performed on several human traits have greatly increased the number of known pleiotropic variants. Based on the hypothesis that variants already associated with a least one trait have a higher probability of association with other traits, 61,052 variants reported to be associated by at least one genome wide association study (GWAS) with at least one human trait were tested in the present study consisting of two phases (discovery and validation), comprising a total of 16,055 pancreatic ductal adenocarcinoma (PDAC) cases and 212,149 controls. The meta-analysis of the two phases showed two loci (10q21.1-rs4948550 (P=6.52×10-5) and 7q36.3-rs288762 (P=3.03×10-5) potentially associated with PDAC risk. 10q21.1-rs4948550 shows a high degree of pleiotropy and it is also associated with colorectal cancer risk while 7q36.3-rs288762 is situated 28,558 base pairs upstream of the Sonic Hedgehog (SHH) gene, which is involved in the cell differentiation process and PDAC etiopathogenesis. In conclusion, none of the single nucleotide polymorphisms (SNPs) showed a formally statistically significant association after correction for multiple testing. However, given their pleiotropic nature and association with various human traits including colorectal cancer, the two SNPs showing the best associations with PDAC risk merit further investigation through fine mapping and ad hoc functional studies.

Impact of encorafenib on survival of patients with BRAFV600E-mutant metastatic colorectal cancer in a real-world setting

PURPOSE

Patients with BRAFV600E-mutant metastatic colorectal cancer (mCRC) have a dismal prognosis. The best strategies in these patients remain elusive. Against this background, we report the clinical course of patients with BRAFV600E-mutant mCRC to retrieve the best treatment strategy.

PATIENTS AND METHODS

Clinico-pathological data were extracted from the electronic health records. Kaplan-Meier method was used to estimate overall (OS) and progression-free survival (PFS). Objective response rate (ORR) was assessed according to RECIST 1.1.

RESULTS

In total, 51 patients were enrolled. FOLFOXIRI was administered to 12 patients; 29 patients received FOLFOX or FOLFIRI as first-line treatment. Median OS was 17.6 months. Median PFS with FOLFOXIRI (13.0 months) was significantly prolonged (HR 0.325) as compared to FOLFOX/FOLFIRI (4.3 months). However, this failed to translate into an OS benefit (p = 0.433). Interestingly, addition of a monoclonal antibody to chemotherapy associated with superior OS (HR 0.523). A total of 64.7% patients received further-line therapy, which included a BRAF inhibitor in 17 patients. Targeted therapy associated with very favourable OS (25.1 months).

CONCLUSION

Patients with BRAFV600E-mutated mCRC benefit from the addition of an antibody to first-line chemotherapy. Further-line treatment including a BRAF inhibitor has a dramatic impact on survival.

Genotypic and phenotypic spectrum of cytosolic phosphoenolpyruvate carboxykinase deficiency

OBJECTIVES

Pathogenic biallelic variants in PCK1 coding for the cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) cause PEPCK-C deficiency, a rare disorder of gluconeogenesis presenting with hypoglycemia, lactic acidosis, and hepatopathy. To date, there has been no systematic analysis of its phenotypic, biochemical, and genetic spectrum.

METHODS

All currently published individuals and a novel patient with genetically confirmed PEPCK-C deficiency were included. Clinical, biochemical, and genetic findings were analyzed. Protein and in-silico prediction score modeling was applied to analyze potential variant effects.

RESULTS

Thirty-two individuals from 25 families were found, including one previously unreported patient. The typical biochemical pattern was hypoglycemia triggered by catabolic situations, elevated urinary concentrations of tricarboxylic acid cycle metabolites, mildly elevated alanine and aspartate aminotransferase and elevated lactate concentrations in serum. Plasma glutamine concentrations were elevated in some patients and may be a suitable marker for newborn screening. With adequate treatment, biochemical abnormalities usually normalized following a hypoglycemic episode. Symptom onset usually occurred in infancy with a broad range from neonatal age to adulthood. Regardless of the genotype, different phenotypes with a broad clinical spectrum were found. To date, eight genotypes with nine different PCK1 variants were identified, of which alleles with the recurrent variant c.925G > A; p.(Gly309Arg) are predominant and appear to be endemic in the Finnish population. Protein modeling suggests altered manganese- and substrate-binding as superordinate pathomechanisms.

CONCLUSIONS

Environmental factors appear to be the main determinant for the phenotype in patients with biallelic variants in PCK1. Based on the biochemical pattern, PEPCK-C deficiency is a recognizable cause of childhood hypoglycemia. It is a treatable disease and early diagnosis is important to prevent metabolic derailment and morbidity. Newborn screening can identify at least a sub-cohort of affected individuals through elevated glutamine concentrations in dry blood.

During early stages of cancer, neutrophils initiate anti-tumor immune responses in tumor-draining lymph nodes

Tumor-draining lymph nodes (LNs) play a crucial role during cancer spread and in initiation of anti-cancer adaptive immunity. Neutrophils form a substantial population of cells in LNs with poorly understood functions. Here, we demonstrate that, during head and neck cancer (HNC) progression, tumor-associated neutrophils transmigrate to LNs and shape anti-tumor responses in a stage-dependent manner. In metastasis-free stages (N0), neutrophils develop an antigen-presenting phenotype (HLA-DR⁺CD80⁺CD86⁺ICAM1⁺PD-L1^-) and stimulate T cells (CD27⁺Ki67^highPD-1^-). LN metastases release GM-CSF and via STAT3 trigger development of PD-L1⁺ immunosuppressive neutrophils, which repress T cell responses. The accumulation of neutrophils in T cell-rich zones of LNs in N0 constitutes a positive predictor for 5-year survival, while increased numbers of neutrophils in LNs of N1-3 stages predict poor prognosis in HNC. These results suggest a dual role of neutrophils as essential regulators of anti-cancer immunity in LNs and argue for approaches fostering immunostimulatory activity of these cells during cancer therapy.

B-Helper Neutrophils in Regional Lymph Nodes Correlate with Improved Prognosis in Patients with Head and Neck Cancer

Simple Summary

Neutrophils exhibit multiple functions during cancer progression and are believed to regulate adaptive immune responses to cancer. In addition to their interactions with T cells in this context, these cells are also believed to interact with B cells. Neutrophils have been found in the marginal zone of the spleen, where they exhibit helper cell characteristics, supporting B cell proliferation and activation. Here, we investigate the effect of neutrophils on B cells in the regional lymph nodes (RLN) of head-and-neck cancer (HNC) patients. We have identified that, in RLNs, neutrophils express a helper cell phenotype that was associated with the increased activation and proliferation of B cells. Importantly, the high abundance of neutrophils in the B cell follicles of regional lymph nodes is associated with significantly improved HNC patient survival.

Abstract

The role of neutrophils during cancer formation and elimination is diverse. Here, for the first time, we investigate neutrophil helper cells (N_BH), their influence on B cell activity in the regional lymph nodes (RLN) of head-and-neck cancer patients and the effect of this neutrophil/B cell interaction on patient prognosis. Circulating and RLN neutrophils of patients with stage I–IV head-and-neck squamous cell carcinoma were investigated with flow cytometry and qPCR. In addition, neutrophil/B cell co-localization in RLNs was evaluated using immunohistochemistry. B cell proliferation was assessed and correlated with the distance to neutrophils. Patient survival was evaluated. Neutrophils with the helper cell phenotype were identified in the RLN of HNC patients. B cells in close proximity to such N_BH showed significantly higher proliferation rates, together with elevated activation-induced cytidine deaminase (AID) expression. Notably, patient survival was significantly higher in individuals with high N_BH frequencies in the B follicles of RLNs. Neutrophils in RLN can support T cell-independent activation of the adaptive immune system through B cell stimulation, capturing helper cell phenotype character. The presence of such helper neutrophils in the RLNs of HNC patients positively correlates with patient prognosis.

Increased longevity due to sexual activity in mole-rats is associated with transcriptional changes in the HPA stress axis

Sexual activity and/or reproduction are associated with a doubling of life expectancy in the long-lived rodent genus Fukomys. To investigate the molecular mechanisms underlying this phenomenon, we analyzed 636 RNA-seq samples across 15 tissues. This analysis suggests that changes in the regulation of the hypothalamic–pituitary–adrenal stress axis play a key role regarding the extended life expectancy of reproductive vs. non-reproductive mole-rats. This is substantiated by a corpus of independent evidence. In accordance with previous studies, the up-regulation of the proteasome and so-called ‘anti-aging molecules’, for example, dehydroepiandrosterone, is linked with enhanced lifespan. On the other hand, several of our results are not consistent with knowledge about aging of short-lived model organisms. For example, we found the up-regulation of the insulin-like growth factor 1/growth hormone axis and several other anabolic processes to be compatible with a considerable lifespan prolongation. These contradictions question the extent to which findings from short-lived species can be transferred to longer-lived ones.

DLL3 (delta-like protein 3) expression correlates with stromal desmoplasia and lymph node metastases in medullary thyroid carcinomas

Medullary thyroid carcinomas (MTC) are rare and aggressive neuroendocrine tumors of the thyroid. About 70% of MTC are sporadic; approximately 50% of those harbor somatic RET mutation. DLL3 is widely expressed in many neuroendocrine tumors and has been evaluated as a potential therapeutic target. Since stromal desmoplasia in sporadic MTC has been identified as a reliable predictor of aggressive behavior and development of lymph node metastases, a possible correlation of DLL3 expression with the presence of stromal desmoplasia was of particular interest. 59 paraffin-embedded samples of sporadic MTC with (44 cases) and without (15 cases) stromal desmoplasia and known lymph node status were included. DLL3 expression was determined by immunohistochemistry; no expression (0%), low expression (1-49%) and high expression (≥50%) were correlated with clinicopathological data. The proportion of DLL3 positivity was significantly correlated with both stromal desmoplasia (P < 0.0001) and lymph node metastases (P < 0.0001). MTC without stromal desmoplasia consistently lack DLL3 expression. This is the first study to focus on MTC regarding DLL3 expression and the relationship to various factors. Our results demonstrate that expression of DLL3 in MTC represents a reliable surrogate marker for stromal desmoplasia and lymph node metastases and might be an indicator for aggressive clinical behavior. DLL3 expression in ≥50% of tumor cells virtually excludes MTC without stromal desmoplasia. DLL3 was discussed as a potential therapeutic target in malignant tumors of other locations with positive immunohistochemical reaction and might therefore be a new therapeutic option in MTC, as well.

Machine learning reveals a PD-L1-independent prediction of response to immunotherapy of non-small cell lung cancer by gene expression context

OBJECTIVE

Current predictive biomarkers for PD-1 (programmed cell death protein 1)/PD-L1 (programmed death-ligand 1)-directed immunotherapy in non-small cell lung cancer (NSCLC) mostly focus on features of tumour cells. However, the tumour microenvironment and immune context are expected to play major roles in governing therapy response. Against this background, we set out to apply context-sensitive feature selection and machine learning approaches on expression profiles of immune-related genes in diagnostic biopsies of patients with stage IV NSCLC.

METHODS

RNA expression levels were determined using the NanoString nCounter platform in formalin-fixed paraffin-embedded tumour biopsies obtained during the diagnostic workup of stage IV NSCLC from two thoracic oncology centres. A 770-gene panel covering immune-related genes and control genes was used. We applied supervised machine learning methods for feature selection and generation of predictive models.

RESULTS

Feature selection and model creation were based on a training cohort of 55 patients with recurrent NSCLC treated with PD-1/PD-L1 antibody therapy. Resulting models identified patients with superior outcomes to immunotherapy, as validated in two subsequently recruited, separate patient cohorts (n = 67, hazard ratio = 0.46, p = 0.035). The predictive information obtained from these models was orthogonal to PD-L1 expression as per immunohistochemistry: Selecting by PD-L1 positivity at immunohistochemistry plus model prediction identified patients with highly favourable outcomes. Independence of PD-L1 positivity and model predictions were confirmed in multivariate analysis. Visualisation of the models revealed the predictive superiority of the entire 7-gene context over any single gene.

CONCLUSION

Using context-sensitive assays and bioinformatics capturing the tumour immune context allows precise prediction of response to PD-1/PD-L1-directed immunotherapy in NSCLC.

Testing for hybridisation of the Critically Endangered Iguana delicatissima on Anguilla to inform conservation efforts

The Caribbean Island of Anguilla in the north-eastern Lesser Antilles is home to one of the last populations of the Critically Endangered Lesser Antillean iguana Iguana delicatissima. This population is highly threatened primarily because of hybridisation with non-native Iguana iguana. This study assesses the degree of hybridisation between Anguilla’s Iguana species firstly using morphological characteristics and then genetic analysis to validate the genetic integrity of morphologically identified I. delicatissima. We also examined the genetic diversity of Anguilla’s I. delicatissima population, and that of a population on the nearby island of Îlet Fourchue, St Barthélemy. Forty-five iguanas were captured in Anguilla and 10 in St Barthélemy, and sequences from 3 nuclear and 1 mtDNA genes were obtained for each. Of the 45 iguanas captured in Anguilla, 22 were morphologically identified as I. delicatissima, 12 as I. iguana and the remainder were identified as hybrids. Morphological assignments were all confirmed by genetic analyses except for one I. iguana and one hybrid individual. These two individuals appeared likely to have originated following ancestral hybridisation events several generations ago. A significant paucity of genetic diversity was found within Anguillan and St Barthélemy I. delicatissima populations, with a single haplotype being identified for each of the three nuclear genes and the mtDNA sequence. This study highlights the urgency for immediate action to conserve Anguilla’s remnant I. delicatissima population. Protection from hybridisation will require translocation to I. iguana-free offshore cays, with supplementary individuals being sourced from neighbouring islands to enhance the genetic diversity of the population.

The mismatch repair system is not affected in medullary thyroid carcinoma independent of stromal desmoplasia or ret proto-oncogene mutation

INTRODUCTION

Medullary thyroid carcinoma (MTC) is an aggressive neuroendocrine neoplasia of the thyroid with 10 year overall survival of 50% and limited therapeutic options. High tumor mutational burden because of microsatellite instability (MSI) seems to be a predictor of response to immune checkpoint inhibitor therapy in different tumors. Therefor in 2017 the U.S. Food and Drug Administration (FDA) permitted the therapy of solid tumors with proven Microsatellite instability (MSI) with PD1 antibody Pembrolizumab independently of their origin. As little is known about MSI in MTC and new therapeutic strategies would be eligible we tried to find out, if therapy with PD1-inhibitors could be promising.

MATERIAL AND METHODS

We performed MSI-analyses of 38 cases of MTC. Included were MTCs with and without stromal desmoplasia and with/without lymph node metastases. We also checked the immunhistochemical expression of PD-L-1 and performed next generation sequencing for genetic alterations.

RESULTS

All cases revealed stable conditions of the microsatellites and showed immunohistochemically positive staining of the four mismatch repair proteins. PD-L-1- Immunostaining was negative in all cases.

DISCUSSION

Our data show there is no MSI in MTCs, irrespectively of their status of desmoplasia, metastases and/or ret-mutation. Therefore a positive effect of PD1 inhibitors, because of MSI-associated high tumor mutational burden, seems to be unlikely.

Abstract P5-05-03: Estrogen receptor beta elicits anti-cancer effects in triple negative breast cancer through suppression of NFκB signaling

Background: Triple Negative Breast Cancer (TNBC) affects approximately 15-20% of BC patients, yet accounts for a disproportionately higher rate of BC morbidity and mortality, in part due to lack of targeted therapies. Using well-validated antibodies, Estrogen Receptor Beta (ERβ) protein has been shown to be expressed in approximately 25% of TNBCs and is associated with improved patient outcomes. Using multiple ERβ +/- TNBC cell lines and PDX models, we have demonstrated that ligand-mediated activation of ERβ by estradiol (E2) decreases cell proliferation, invasion, and migration in vitro, as well as primary tumor growth and metastatic spread in vivo.

Methods: To determine the mechanisms by which ERβ elicits these anti-cancer effects, we elucidated the ERβ transcriptome and cistrome via Microarray and ChIPseq, respectively, in TNBC cells stably expressing ERβ in a doxycycline-inducible manner. We also performed gene expression and luciferase assays to assess the impact of ERβ on NFκB signaling, followed by ChIP-PCR and ChIPseq to assess how ERβ modifies chromatin architecture near NFκB target genes.

Results: Pathway analysis of ERβ-regulated genes identified NFκB signaling as one of the most suppressed pathways in response to E2 treatment. Indeed, numerous NFκB target genes were among the most down-regulated genes following E2 treatment but only in the presence of ERβ expression. Chromatin Immunoprecipitation followed by sequencing (ChIPseq) revealed that ERβ primarily associated with estrogen response elements (EREs), but was also enriched around NFκB binding sites following E2 treatment. In fact, 12% of all ERβ binding sites were enriched for NFκB response elements and ERβ was shown to physically associate with NFκB protein. Using an NFκB reporter construct and qPCR, ERβ was shown to block TNFα-mediated induction of NFκB signaling and NFκB target gene expression. Globally, RNAseq identified 200 genes to be significantly regulated by TNFα in TNBC cells, of which 81 were significantly altered in the presence of E2+TNFα. ChIPseq demonstrated that ligand-mediated activation of ERβ significantly diminished an activating histone mark (H3K27Ac) at many of these NFκB target genes while enhancing a repressive mark (H3K27Me3). These modifications are also associated with recruitment of the histone methyltransferase, EZH2, to enhancer elements of these NFκB target genes. Drug-mediated blockade of HDAC and EZH2 activity reversed suppression of NFκB target gene expression by ERβ.

Conclusions: Our data suggest that ERβ may elicit its anti-cancer effects in part via formation of a novel co-repressor complex consisting of ERβ, NFκB, and EZH2. These data are in keeping with prior observations of the importance of NFκB signaling as it relates to TNBC cell proliferation and invasion, and that decreased expression of NFκB target genes is associated with improved outcomes in TNBC patients. Currently, a Mayo Breast SPORE prospective study is underway to investigate the role of estradiol in ERβ expressing TNBC and to further evaluate the cross-talk between ERβ and NFκB signaling in TNBC.

Citation Format: Aspros K, Nelson A, Ye Z, Sun Z, Chernukhin I, Carroll J, Ingle J, Goetz M, Hawse J. Estrogen receptor beta elicits anti-cancer effects in triple negative breast cancer through suppression of NFκB signaling [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-03.

Molecular dissection of effector mechanisms of RAS-mediated resistance to anti-EGFR antibody therapy

Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR), cetuximab and panitumumab, are a mainstay of metastatic colorectal cancer (mCRC) treatment. However, a significant number of patients suffer from primary or acquired resistance. RAS mutations are negative predictors of clinical efficacy of anti-EGFR antibodies in patients with mCRC. Oncogenic RAS activates the MAPK and PI3K/AKT pathways, which are considered the main effectors of resistance. However, the relative impact of these pathways in RAS-mutant CRC is less defined. A better mechanistic understanding of RAS-mediated resistance may guide development of rational intervention strategies. To this end we developed cancer models for functional dissection of resistance to anti-EGFR therapy in vitro and in vivo. To selectively activate MAPK- or AKT-signaling we expressed conditionally activatable RAF-1 and AKT in cancer cells. We found that either pathway independently protected sensitive cancer models against anti-EGFR antibody treatment in vitro and in vivo. RAF-1- and AKT-mediated resistance was associated with increased expression of anti-apoptotic BCL-2 proteins. Biomarkers of MAPK and PI3K/AKT pathway activation correlated with inferior outcome in a cohort of mCRC patients receiving cetuximab-based therapy. Dual pharmacologic inhibition of PI3K and MEK successfully sensitized primary resistant CRC models to anti-EGFR therapy. In conclusion, combined targeting of MAPK and PI3K/AKT signaling, but not single pathways, may be required to enhance the efficacy of anti-EGFR antibody therapy in patients with RAS-mutated CRC as well as in RAS wild type tumors with clinical resistance.

MET Expression in Advanced Non-Small-Cell Lung Cancer: Effect on Clinical Outcomes of Chemotherapy, Targeted Therapy, and Immunotherapy

BACKGROUND

The receptor tyrosine kinase MET is implicated in malignant transformation, tumor progression, metastasis, and acquired treatment resistance. We conducted an analysis of the effect of MET expression and MET genomic aberrations on the outcome of patients with advanced or metastatic pulmonary adenocarcinomas prospectively enrolled in an institutional precision oncology program.

PATIENTS AND METHODS

Standardized immunohistochemistry (IHC) analyses of MET and markers of pathway activation were available in 384 patients, and next-generation sequencing-based MET hotspot mutation analyses were available from 892 patients. Clinical data were retrieved with a median follow-up from initial diagnosis of 37 months.

RESULTS

High MET expression, defined as MET IHC 3+ or MET H-Score in the upper quartile, was observed in 102 of 384 patients (26.6%). MET exon 14 mutations were only detected in 7 of 892 patients (0.78%). High MET expression correlated with activation markers of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathways only in cases without Kirsten rat sarcoma viral oncogene homolog (KRAS), epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) aberrations. There was no association of MET expression with outcome during chemotherapy. High MET expression negatively affected the outcome during EGFR-targeting therapy but was associated with more favorable results with programmed death 1/programmed death ligand 1 (PD-L1)-directed therapy, independent of smoking history, PD-L1 expression or KRAS mutation. Two patients with MET exon 14 mutation and high PD-L1 expression failed to respond to pembrolizumab.

CONCLUSION

MET expression affects the outcomes of targeted therapies in non-small-cell lung cancer, thus supporting the development of biomarker-informed combination strategies. The interaction of MET expression and MET mutation with immune checkpoint inhibitor therapy is novel and merits further investigation.

Phosphorylation of p70 Ribosomal Protein S6 Kinase β-1 is an Independent Prognostic Parameter in Metastatic Colorectal Cancer

BACKGROUND

Deregulation of signal transduction pathways plays a critical role in oncogenesis of colorectal cancer (CRC) and directly affects sensitivity to targeted therapies. Against this background we developed a comprehensive biomarker profiling program including markers of downstream signaling to study their association with clinical outcomes.

PATIENTS AND METHODS

A prospectively studied cohort of 160 patients with metastatic CRC was included. Standard diagnostic workup included mutational analyses of Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS), and v-Raf murine sarcoma viral oncogene homolog B (BRAF). In addition, markers of mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and mammalian target of rapamycin pathway activation (phosphorylation of extracellular signal-regulated kinase [ERK], AKT, and p70 ribosomal protein S6 kinase β-1 [p70S6K]) were studied using standardized immunohistochemistry.

RESULTS

There was a significant correlation between markers of ERK and AKT activation in the full cohort. In addition, phosphorylation of p70S6K correlated strongly with ERK and AKT phosphorylation and primary tumor localization in the right colon. Subgroup analyses specified these correlations to patients with all-RAS wild type tumors. In contrast, tumors harboring RAS mutations predominantly exhibited ERK phosphorylation. Interestingly, patients with CRC showing high p70S6K phosphorylation (highest quartile) had a significantly inferior overall survival (hazard ratio [HR], 2.4; P = .002) irrespective of RAS mutational status. This effect remained significant in multivariate analysis (P = .002). A patient subgroup characterized by high p70S6K phosphorylation and right-sided primary tumors had a particularly poor prognosis with a dramatically inferior overall survival (HR, 5.2; P < .001). Patients with right-sided primary tumor and low p70S6K phosphorylation had responses to anti-epidermal growth factor receptor antibody-based therapies and overall survival similar to patients with left-sided primary tumors.

CONCLUSION

High phosphorylation of p70S6K is a novel, independent biomarker for poor prognosis, in particular in patients with right-sided primary tumors.

Abstract OT3-05-07: PATINA: A randomized open label phase III trial to evaluate the efficacy and safety of palbociclib + anti HER2 therapy + endocrine therapy vs anti HER2 therapy + endocrine therapy after induction treatment for hormone receptor positive, HER2 positive metastatic breast cancer

Background

Pre-clinical data and initial results from clinical studies point to the added benefit of CDK4/6 inhibition when combined with anti-HER2 tx. The current study is designed to evaluate the added benefit of palbociclib when given in combination with anti-HER2 and endocrine tx maintenance in the 1st†line setting of metastatic HER2+HR+ breast cancer.

Trial design

PATINA is an international, open-label, pivotal Phase III study. Primary objective is to demonstrate that the combination of palbociclib with anti-HER2 plus endocrine tx is superior to anti-HER2 plus endocrine tx in prolonging PFS. Sample size is 496 pts. The study starts after completion of 6-8 cycles of chemotherapy-containing anti-HER2 tx for metastatic breast cancer in the 1st line setting. Pts are eligible provided they are without evidence of disease progression by local assessment (i.e. CR, PR or SD). To account for the need for less intense tx regimens for a subset of pts diagnosed with HER2+ER+ disease, clinicians may recommend the combination of trastuzumab with either a taxane or vinorelbine prior to study initiation. Clinicians might also choose a non-pertuzumab option for pts previously treated with pertuzumab in the neo(adjuvant) setting. Secondary objectives include measures of tumor control (OR, CBR, DOR), OS, safety and QOL. The translational science main objective is to compare PFS estimates according to PIK3CA mutation status assessed by cfDNA analysis. Endocrine tx options are AI or fulvestrant. Premenopausal pts must receive ovarian suppression. The study has a 90% power to detect a hazard ratio of 0.667 in favor of the palbociclib arm. Pts approached to participate in AFT-38 will be asked to indicate on the informed consent forms whether remaining biospecimens and clinical data from the control arm of the study can be shared with the Mastering Breast Cancer (MBC) Initiative. The overarching purpose of the MBC is to create a mechanism for understanding the natural history of metastatic breast cancer by cataloguing longitudinally studied tumor-specific markers and treatment effects.

ClinicalTrials.gov Identifier: NCT02947685

Citation Format: Metzger-Filho O, Mandrekar S, Loibl S, Ciruelos E, Gianni L, Lim E, Miller K, Huang C, Koehler M, Francis P, Valagussa P, Goel S, Prat A, Goetz M, Loi S, Krop I, Carey L, Lanzillotti J, Winer E, Tripathy D, DeMichele A. PATINA: A randomized open label phase III trial to evaluate the efficacy and safety of palbociclib + anti HER2 therapy + endocrine therapy vs anti HER2 therapy + endocrine therapy after induction treatment for hormone receptor positive, HER2 positive metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-05-07.

Abstract PD1-04: CSMD1 SNPs selectively affect anastrozole response in postmenopausal breast cancer patients

BACKGROUND: Based on prospective clinical trials, there is no evidence for differences in efficacy between the 3 aromatase inhibitors (AIs) anastrozole, exemestane, and letrozole. The purpose of this study was to identify germline genetic variants associated with response to AIs and to help identify novel mechanisms associated with drug disease efficacy.

METHODS: A genome-wide association study (GWAS) was performed for 624 patients (Steroids 2015;99:32-38) to identify SNPs associated with estrogen level change in women with estrogen receptor (ER) positive breast cancer treated with anastrozole. Replication of associated SNPs was performed in a GWAS from the MA.27 trial that compared adjuvant anastrozole and exemestane treatment of post-menopausal women with ER+ breast cancer. Functional studies were subsequently performed to determine SNP effects and underlying mechanisms.

RESULTS: Our initial GWAS identified SNPs within CSMD1 that were associated with changes in estrogen levels during anastrozole therapy. An additional SNP in CSMD1 was also associated with breast cancer events in CCTG MA.27. Functionally, we showed that CSMD1 regulates CYP19 expression in a SNP-, and in an anastrozole- dependent fashion. These phenomena were not observed for either letrozole or exemestane. In MA.27, an anastrozole- specific effect was also seen with the minor allele having a protective effect on time to distant metastasis (HR=0.49, p=0.00259), but this was not the case for exemestane (HR=0.71, p=0.111). Our in vitro functional studies indicated that overexpression of CSMD1 sensitized anastrozole or letrozole resistant cells to anastrozole but not to the other two AIs. The SNP in CSMD1 that was associated with increased CSMD1 and CYP19 expression levels increased anastrozole sensitivity, but not letrozole or exemestane in lymphoblastoid cell lines (LCLs) homozygous for either WT or variant CSMD1 SNP genotypes. Based on these observations, we explored whether anastrozole has additional mechanisms beyond its function as a CYP19 inhibitor. Utilizing an estrogen response element (ERE) luciferase reporter assay in a CYP19 CRISPR knockout breast cancer T47D cell line and a surface plasmon resonance (SPR) assay, we found that anastrozole can also function as an ERα agonist, and can bind to, and result in, proteasome dependent ERα degradation, especially in the presence of E2. Treatment of these CYP19 CRISPR knockout cells with anastrozole in the presence of increasing concentrations of E2 results in greater sensitivity compared with anastrozole alone, while the addition of E2, as expected, does not improve letrozole or exemestane sensitivity. These same observations were also seen in letrozole and anastrazole resistant cells.

CONCLUSIONS: Our findings suggest that anastrozole might be more effective than letrozole or exemestane in patients with the CSMD1 SNP. Furthermore, anastrozole can function as an ERα agonist, binding to ERα and resulting in its degradation, especially in the presence of E2. These findings should help to make it possible to develop precision endocrine therapies for women who are candidates for AIs.

Citation Format: Cairns J, Ingle J, Dudenkov T, Kalari K, Buzdar A, Kubo M, Robson M, Ellis M, Goss P, Shepherd L, Goetz M, Weinshilboum R, Wang L. CSMD1 SNPs selectively affect anastrozole response in postmenopausal breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD1-04.

ADHD and Present Hedonism: time perspective as a potential diagnostic and therapeutic tool

The article draws primarily from the behavioral findings (mainly psychiatric and psychological observations) and points out the important relationships between attention-deficit/hyperactivity disorder (ADHD) symptoms and time orientation. Specifically, the authors argue that there is a significant overlap between the symptoms of ADHD and Present Hedonism. Present Hedonism is defined by Zimbardo's time perspective theory and assessed by Zimbardo Time Perspective Inventory. Developmental data on Present Hedonism of males and females in the Czech population sample (N=2201) are also presented. The hypothesis of relationship between ADHD and Present Hedonism is mainly derived from the prevalence of addictive behavior (mainly excessive Internet use, alcohol abuse, craving for sweets, fatty foods, and fast foods), deficits in social learning, and increased aggressiveness both in ADHD and in the population scoring high on Present Hedonism in the Zimbardo Time Perspective Inventory. We conclude that Zimbardo's time perspective offers both: 1) a potential diagnostic tool - the Zimbardo Time Perspective Inventory, particularly its Present Hedonism scale, and 2) a promising preventive and/or therapeutic approach by the Time Perspective Therapy. Time Perspective Therapy has so far been used mainly to treat past negative trauma (most notably, posttraumatic stress disorder); however, it also has value as a potential therapeutic tool for possible behavioral compensation of ADHD.

Abstract S6-05: A phase II trial of neoadjuvant palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, in combination with anastrozole for clinical stage 2 or 3 estrogen receptor positive HER2 negative (ER+HER2-) breast cancer (BC)

Background

ER+ BC is associated with activated CDK4/6. The CDK4/6 inhibitor palbociclib (P) markedly improves time to progression in advanced ER+HER2- BC. We conducted a neoadjuvant phase II trial to determine the activity of P in primary breast cancer as a prelude to adjuvant studies.

Methods

To assess molecular changes induced by anastrozole (A) or P+A, patients (pts) were treated initially with A alone (1mg PO daily) for 28 days in cycle 0 (C0) before the addition of P (125mg PO daily on D1-21 each cycle) on C1D1. P+A was administered for 4 28-day cycles followed by C5 with A alone for 2-4 weeks (wks) before surgery. P was added in C5 for 10-12 days immediately prior to surgery in the last 20 pts enrolled to assess molecular changes induced by A, either alone or in combination with P immediately prior to surgery, in resected tumor. Goserelin was added in premenopausal pts.

Research tumor biopsies were obtained at baseline, C1D1, and C1D15. Central Ki67 analysis was performed at all timepoints, those with Ki67 &gt;10% at C1D15 went off study treatment.

The primary endpoint was complete cell cycle arrest (CCA), defined as Ki67 &lt;2.7%, at C1D15. Patient stratification was based on PIK3CA mutation status with an initial focus on PIK3CA wild type (WT) disease. Pts with PIK3CA mutant (Mut) tumors enrolled to a separate cohort. A sample size of 33 pts in the PIK3CA WT cohort was chosen based on the Fleming's single-stage phase II design to test the hypothesis that P+A leads to &gt; 50% improvement over A in CCA rate on C1D15 biopsy (44% with A alone based on historical data, vs 66% with P+A, power = 0.8, alpha=0.05). The primary endpoint is met if &gt;20 pts achieved CCA in this cohort.

Correlative endpoints included assessment of markers of proliferation, apoptosis, senescence, Rb, gene expression microarray, intrinsic subtype, and next generation sequencing of 83-gene panels, which will be reported at the meeting.

Results

Between 4/23/2013 and 4/24/2015, 50 pts (33 PIK3CA WT, 11 PIK3CA Mut, 2 pending, 4 tissue quantity or quality not sufficient for sequencing (QNS)) were enrolled to the study. Median age was 57.5 (range: 34.1–79.6) years. Four pts, all with WT PIK3CA, went off study due to Ki67 &gt;10% on C1D15 biopsy, 26 pts completed treatment and surgery, 1 refused surgery, 3 withdrew study treatment in C1, and 16 continued to receive study drug (2 in C0, 3 in C1, 4 in C2, 5 in C3, 1 in C4, and 1 in C5). Among the 40 pts currently evaluable for the primary endpoint (C1D15 Ki67), CCA occurred in 34 (85%) pts, including 9 of 9 (100%) PIK3CA Mut, 22 of 28 (78.5%) WT, and 3 of 3 QNS pts. Preliminary analysis of available data indicated a significantly lower Ki67 value after 2 wks of P+A (C1D15) compared to that on A alone (C1D1) (p=0.034, n=18).

Conclusion

This study met the primary endpoint demonstrating that P+A is a highly effective anti-proliferative combination. The sequential biopsy design clearly demonstrated that P+A increased cell cycle control over A alone. P+A was effective regardless of PIK3CA mutation status and these results support the evaluation of this combination in the adjuvant setting for ER+HER2- BC.

Citation Format: Ma CX, Gao F, Northfelt D, Goetz M, Forero A, Naughton M, Ademuyiwa F, Suresh R, Anderson KS, Margenthaler J, Aft R, Hobday T, Moynihan T, Gillanders W, Cyr A, Eberlein TJ, Hieken T, Krontiras H, Hoog J, Han J, Guo Z, Vij K, Mardis E, Al-Kateb H, Sanati S, Ellis MJ. A phase II trial of neoadjuvant palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, in combination with anastrozole for clinical stage 2 or 3 estrogen receptor positive HER2 negative (ER+HER2-) breast cancer (BC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S6-05.

Abstract P5-04-01: ERβ elicits tumor suppressive effects in triple negative breast cancer through the induction of cystatins and suppression of TGFβ signaling

Background: Triple negative breast cancer (TNBC) accounts for approximately 20% of all breast cancer diagnoses. Clinical management of TNBC is limited to surgery, chemotherapy and radiation due to lack of estrogen receptor alpha and HER2 expression. Recently, we have shown that approximately 40% of TNBCs express estrogen receptor beta (ERβ) and have begun to explore the possibility that this receptor could be utilized as a novel therapeutic target for this disease.

Methods: To examine the biological functions of ERβ in TNBC, novel ERβ expressing TN cell lines (MDA-MB-231 and Hs578T) were developed. In vitro experiments were employed to determine alterations in the global gene expression profiles, biological pathways, proliferation rates, and cell cycle progression following estrogen or ERβ-specific agonist treatment. Cell line xenografts were also established in athymic ovariectomized nude mice to examine tumoral responses to ERβ targeting agents and to investigate gene and protein expression patterns as well as potential serum biomarkers indicative of therapeutic response. Additionally, using the resources of the Mayo Clinic Breast Cancer Genome Guided Therapy Study (BEAUTY), we have identified, and begun to analyze, ERβ+ and ERβ- patient derived xenografts (PDX) established from women with TNBC.

Results: Our studies have revealed that both estrogen and multiple ERβ-specific agonists elicit significant anti-proliferative effects in ERβ+ TNBC cells primarily through a G1/S phase cell cycle arrest. These anti-proliferative effects appear to be mediated by cystatins, a family of small secreted cysteine protease inhibitors which are highly induced following estrogen and ERβ-specific agonist treatment. Conditioned media isolated from estrogen or ERβ-specific agonist treated cells decreased the proliferation rates of multiple non-ERβ expressing cell lines; effects that were completely reversed when cystatins were depleted from the media. In addition, we have shown that activation of ERβ, and the subsequent induction of cystatin gene expression, leads to suppression of canonical TGFβ signaling through multiple mechanisms including suppression of TGFβR2 expression, induction of Smad7 expression and blockade of TGFβ ligand-mediated activation of this pathway both in vitro and in vivo. Finally, ERβ+ TNBC PDXs exhibit significantly decreased tumor growth rates in estrogen-treated mice compared to ERβ- TN breast tumors.

Conclusions: Our in vitro and in vivo data show that estrogen and ERβ-specific agonists elicit anti-cancer effects in ERβ+ TNBC. These effects appear to be mediated, in part, by cystatins through their inhibitory effects on canonical TGFB signaling, a pathway known to drive TNBC progression. Importantly, these data lay the foundation for studies aimed at examining the ability to therapeutically target ERβ in TNBC patients.

Citation Format: Reese J, Bruinsma E, Subramaniam M, Suman V, Pitel K, Kalari K, Yu J, Wang L, Goetz M, Ingle J, Hawse J. ERβ elicits tumor suppressive effects in triple negative breast cancer through the induction of cystatins and suppression of TGFβ signaling. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-01.

Abstract P5-13-04: A phase II neoadjuvant trial of MK-2206, an AKT inhibitor, in combination with anastrozole for clinical stage 2 or 3 PIK3CA mutant estrogen receptor positive HER2 negative (ER+HER2-) breast cancer (BC)

Background

Activating mutations in PIK3CA occur in approximately 40% ER+BC. MK-2206 (M), a pan-AKT inhibitor, induced apoptosis of ER+ BC under estrogen deprivation in preclinical studies. We conducted this neoadjuvant trial to determine the pathologic complete response (pCR) rate of M plus anastrozole (A) for PIK3CA mutant (Mut) ER+ BC.

Methods

This single arm open label study of M+A used a 2-stage Simon phase II design (stage 1, n=16; stage 2, n=13, alpha=0.10, power=0.90) to test whether pCR rate &lt;1% (based on historical data with A alone), against the alternative that pCR rate ≥15% in PIK3CA Mut ER+ BC. At least 1 pCR in stage 1 was required to proceed to stage 2.

Eligible patients (pts) with clinical stage II or III ER+HER2- BC were pre-registered and proceeded to a research tumor biopsy for PIK3CA sequencing, followed by treatment with daily A monotherapy for 28 days (cycle 0). Pts with PIK3CA Mut BC were subsequently registered, underwent a second biopsy, and started M (150mg PO weekly) with daily A on cycle 1 day 1 (C1D1) for a maximum of four 28-day cycles followed by surgery. Goserelin was added for premenopausal pts. A tumor biopsy on C1D17, 17 days post the start of M, was performed. Those with C1D17 Ki67 &gt;10% discontinued study treatment. pCR was defined as no invasive cancer in the breast and the lymph nodes. Tumor specimens collected at all timepoints are being analyzed for markers of proliferation, apoptosis, and PI3K pathway activity, gene expression microarray, intrinsic subtypes, and next generation sequencing of 83 genes.

Results

Of the 51 pts pre-registered, 35 pts did not register due to no PIK3CA mutation (n=22), inadequate specimen for testing (n=6), physician/pt decision (n=7). The remaining 16 pts (median age: 58, range: 40-77 years) received combination therapy. Three pts did not complete 4 cycles due to C1D17 Ki67 &gt;10% (n=2) and intolerability (grade (Gr) 4 transaminase elevation in C1, n=1). Other severe toxicities possibly related to M included Gr 3 rash (25%) and pruritus (12.5%). Of the 13 pts completed study therapy and underwent surgery, all had residual disease in the breast and 7 also had positive nodes. Table 1 summarized changes in Ki67 during treatment.

ComparisonsnAbsolute changes in Ki67 median (range)Wilcoxon signed rank p-valueC1D1 relative to pre-registration11-17.0% (-49.8 to 4.1%)0.0020C1D17 relative to pre-registration14-16.4% (-51.4 to 4.1%)0.0004C1D17 relative to C1D112-1.5% (-18.6 to 15.8%)0.9697C1D1, biopsy post 28 days of A alone; C1D17 biopsy post 17 days on combination therapy

Although Ki67 levels post A monotherapy (C1D1) or M+A (C1D17) were significantly lower than that of pre-registration samples, Ki67 did not differ between C1D17 and C1D1 samples. Other correlative studies are ongoing and results will be presented.

Conclusion

Despite the small sample size, biomarker analysis on serial biopsy specimens demonstrated that M+A is unlikely to be more effective than A alone in PIK3CA Mut ER+ BC. This trial demonstrated the feasibility of genomic sequencing for pt selection and the value of a small, well-designed proof-of-principle neoadjuvant trial for the evaluation of targeted agents.

Citation Format: Ma CX, Suman VJ, Goetz M, Northfelt D, Burkard M, Ademuyiwa F, Naughton M, Margenthaler J, Aft R, Gray R, Tavaarwerk A, Wilke L, Haddad T, Moynihan T, Loprinzi C, Hieken T, Hoog J, Guo Z, Han J, Vij K, Mardis E, Sanati S, Al-Kateb H, Doyle L, Erlichman C, Ellis MJ. A phase II neoadjuvant trial of MK-2206, an AKT inhibitor, in combination with anastrozole for clinical stage 2 or 3 PIK3CA mutant estrogen receptor positive HER2 negative (ER+HER2-) breast cancer (BC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-04.

Recurrent pyogenic cholangitis as a differential diagnosis in biliary tract diseases

Recurrent Pyogenic Cholangitis (RPC) or Primary Hepatolithiasis is a common disease of the biliary tract in Asia, whereas it is usually not seen in Europeans. With increasing global mobility, the disease will be encountered in Europe more frequently, too. It should therefore be considered as a differential diagnosis in patients from endemic countries with recurrent symptoms of cholestasis/cholangitis and bile duct dilations, strictures and hepatolithiasis. In this case report, we present the history of a 37-year old patient from Sri Lanka and describe typical aspects of RPC. The patient presented at our hospital with scleral jaundice and pruritus. In the past she had been treated for septic cholangitis. Diagnosis in our patient was made after laboratory tests, MRT/MRCP and ERC. She was treated interventionally by ERC and is now monitored on a regular basis.

[OTSC-assisted resection of a duodenal neuroendocrine tumor: a case report]

The over the scope clip (OTSC) is mainly used for closure of gastrointestinal endoluminal defects and treatment of gastrointestinal bleeding. Its use for resection of subepithelial tumors or full-thickness resection is still under investigation. Duodenal neuroendocrine tumors (NET) are rare neoplasms. Endoscopic resection is appropriate up to a size of 20  mm, however positive deep margins are a frequent challenge in these subepithelial tumors. We report on a 60-year-old male patient who had undergone endoscopic mucosal resection with R1 deep margins of a NET (G1) in the duodenal bulb. To avoid local surgical resection in this multimorbid patient, we performed OTSC-assisted deep resection. Complete resection (R0) was achieved, and no complications occurred. Our report suggests that OTSC-assisted resection of subepithelial tumors is a possible and safe option, especially for patient's and in locations with a high perioperative risk.

High-definition endoscopy with iScan and Lugol's solution for the detection of inflammation in patients with nonerosive reflux disease: histologic evaluation in comparison with a control group

Nonerosive reflux disease (NERD) is commonly diagnosed in patients with symptoms of reflux. The aim of the present study was to determine whether high-definition endoscopy (HD) plus equipped with the iScan function or chromoendoscopy with Lugol's solution might permit the differentiation of NERD patients from those without reflux symptoms, proven by targeted biopsies of endoscopic lesions. A total of 100 patients without regular intake of proton pump inhibitors and with a normal conventional upper endoscopy were prospectively divided into NERD patients and controls. A second upper endoscopy was performed using HD+ with additional iScan function and then Lugol's solution was applied. Biopsy specimens were taken from the gastroesophageal junction in all patients. A total of 65 patients with reflux symptoms and 27 controls were included. HD(+) endoscopy with iScan revealed subtle mucosal breaks in 52 patients; the subsequent biopsies confirmed esophagitis in all cases. After Lugol's solution, 58 patients showed mucosal breaks. Sensitivity for the iScan procedure was 82.5%, whereas that for Lugol's solution was 92.06%. Excellent positive predictive values of 100% and 98.3%, respectively, were noted. The present study suggests that the majority of patients with NERD and typical symptoms of reflux disease can be identified by iScan or Lugol's chromoendoscopy as minimal erosive reflux disease (ERD) patients.

Transpapillary retrieval of a proximally migrated stent using a three-prong polyp retrieval device in a 2-years-old girl

Endoscopic retrieval of proximally migrated biliary stents is sometimes challenging. We report on the successful use of a three-prong colon polyp retrieval device in a two year old child.

Antifeedant action ofZ-dihydromatricaria acid from soldier beetles (Chauliognathus spp.)

The acetylenic acid,Z-dihydromatricaria acid (DHMA), previously isolated from the defensive secretion ofChauliognathus lecontei, and now shown to occur also inC. pennsylvanicus, is a potent feeding deterrent to jumping spiders (Phidippus spp.). A simple bioassay withPhidippus is described, which is generally applicable to studies dealing with the isolation and evaluation of feeding deterrency of natural products from insects. By use of this assay,Phidippus were shown to be sensitive to as little as 1 μg DHMA, an amount equivalent to less than 2% of the DHMA content ofC. pennsylvanicus.

Abstract PD1-2: PIK3CA mutations and/or low PTEN predict resistance to combined anti-HER2 therapy with lapatinib and trastuzumab and without chemotherapy in TBCRC006, a neoadjuvant trial of HER2-positive breast cancer patients

We have recently reported that in patients with HER2-positive breast cancer, neoadjuvant targeted therapy with lapatinib and trastuzumab to more completely block the HER receptor layer, combined with endocrine therapy (in ER-positive tumors) and without chemotherapy led to a substantial 27% pathologic complete response (pCR) rate in the breast. Activation of downstream signaling pathways may lead to resistance to therapies targeting the HER pathway receptors. Aberrant activation of the PI3K pathway via decreased levels of PTEN and/or the presence of activating PIK3CA mutations has been implicated in resistance to targeted anti-HER2 therapy, but results of clinical trials are all confounded by the co-administration of chemotherapy and are inconsistent. We sought to clarify the role of these variables in predicting pCR, a surrogate for long-term outcome, in patients treated with potent targeted therapy alone in a prospective Phase II neoadjuvant trial in patients with HER2-positive breast cancer.

Patients with large tumors (median 6 cm) were given 12 weeks of lapatinib plus trastuzumab followed by surgery (Rimawi et al. JCO, 2013). Serial tissue biopsies were obtained from study participants. For this study, we focused on baseline pre-treatment characteristics. PTEN protein levels were measured by IHC and scored using the H-score. PIK3CA mutations were identified on extracted DNA using multiplex PCR with targeted next generation sequencing (the Ion Torrent 50-gene cancer mutation panel).

Of 64 evaluable patients, tissue was available on 59 for PTEN IHC, and sufficient DNA was available on 33 for the mutation panel. PTEN median H-score was 100 (range 0-300). PTEN status when dichotomized by the median was correlated with pCR (32% in high PTEN vs. 9% in low PTEN, p = 0.04). Activating PIK3CA mutations were identified in 12 out of 33 tumors (36%; 3 mutations in the helical and 9 in the catalytic domain) and were independent of ER status. None of the patients whose tumors harbored a PIK3CA mutation achieved pCR (p = 0.06). There was no association between PTEN status and PIK3CA mutation suggesting they are independent variables (p = 0.44). When PIK3CA mutations were considered together with PTEN status, there were 31 cases with data on both. The overall pCR rate in this cohort was 16% (lower than pCR rate observed in the overall trial). However, 0/17 cases (0%) with a mutation and/or PTEN low expression (&lt;100 H score) had a pCR compared to 5/14 cases (36%) with PI3KCA wild type and high PTEN levels (p = 0.01).

We conclude that PI3K pathway activation downstream of HER2 as a result of either low PTEN or activating PIK3CA mutation results in resistance to the combination of lapatinib and trastuzumab. This is the first report on patient tissue samples from a neoadjuvant trial using the combination of lapatinib and trastuzumab without chemotherapy. If validated in a larger cohort, our findings suggest that patients with HER2 positive tumors and who also harbor aberrant downstream PI3K pathway activation may benefit from the addition of PI3K/Akt/mTOR inhibitors to potent HER2 blockade.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD1-2.

Abstract P2-16-05: Efficacy of ABT-888 (veliparib) in patients with BRCA-associated breast cancer

Background: The potential for exploiting BRCA deficiencies with DNA repair inhibitors has both pre-clinical and clinical support. ABT-888 (veliparib), a DNA repair inhibitor initially thought to target Poly(ADP-Ribose) Polymerases (PARP), has demonstrated in vitro inhibition of BRCA1 and BRCA2 deficient mouse embryonic stell cells, with a larger effect on BRCA1 cells. We report on the pre-planned interim analysis of the efficacy of single agent veliparib in patients with either BRCA1 or BRCA2-associated stage IV breast cancer. Methods: BRCA 1 or 2 carrier patients with stage IV breast cancer, with measurable disease, without prior exposure to a PARP inhibitor or a platinum compound in the metastatic setting, were eligible. Velapirib was administered orally, at doses of 400 mg twice daily. Dose adjustments based on toxicity were permitted. Patients progressing on velapirib alone received carboplatin at an AUC of 5, IV, given Q 21 days, and velapirib 150 mg twice daily (the maximum tolerated dose [MTD] of the combination from our completed Phase I study: J Clin Oncol 30, 2012 [suppl; abstr 1024]). Patients were to be accrued from 7 NCI NO1- supported consortia. Initially 10 patients were to be accrued to each stratum (BRCA1 and BRCA2) to provide evidence of single agent activity. If there was sufficient activity to warrant consideration of velapirib as single agent therapy (defined as 2 or more confirmed partial [PR] or better responses out of 10 per stratum), an additional 12 patients would be accrued per stratum. Results: 20 evaluable patients (11 BRCA1 and 9 BRCA2 [1 in screening]) have been accrued, the majority with lung or liver as visceral metastatic sites of disease. Median age (range) is 46 (29-68) years. Tumors from 9 patients were hormone receptor positive. BRCA1 cohort: 4 of 11 patients are off treatment at a median of 2 months (1-4); 1 patient stopped velapirib due to toxicity (grade 2 rash/pruritus, grade 2 vomiting), 3 stopped for progressive disease (one with an unconfirmed PR). Seven patients are still on single agent veliparib with 1 unconfirmed PR, and 1 patient with two evaluations showing stable disease. BRCA2 cohort: 2 patients are off treatment at 2 months for progressive disease, 7 are still on treatment with 1 confirmed PR, and 3 unconfirmed PRs. Data on patients receiving combination of velapirib and carboplatin after progression is too early. Treatment-related toxicity is being updated and has so far been reported from 14 patients: 1 patient had grade 3 fatigue, 1 patient with liver metastasis had both grade 3 alanine aminotransferase elevation and grade 3 abdominal pain. Grade 2 toxicities occurring in more than 1 patient included nausea/vomiting (6 patients), chills (2 patients), and fatigue (2 patients). Conclusion: Velapirib has single agent activity in both BRCA1 and BRCA2-associated stage IV breast cancer patients, and is well-tolerated. Mature response, treatment, and toxicity data will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-05.

Echinococcosis mimicking autoimmune or malignant bile duct disease

Indeterminate strictures of the bile ducts are common diagnostic dilemmas in gastroenterology, and differential diagnosis includes inflammatory and neoplastic diseases. Alveolar echinococcosis (AE) is rarely considered as a differential diagnosis, although it is endemic in the Northern hemisphere. In this case report on a 50-year-old male patient, the lack of cystic lesions or calcifications on CT, and suggestive ERCP findings made a hilar cholangiocellular carcinoma the most probable differential diagnosis, and only explorative laparotomy provided the definite diagnosis of AE. AE should therefore be included in the differential diagnosis of indeterminate biliary strictures even in the absence of typical stigmata in imaging studies.

[Microscopy of the gastrointestinal tract: confocal endomicroscopy - clinical and scientific benefits]

Endomicroscopy is a novel method that allows microscopy of the gastrointestinal mucosa during ongoing endoscopy. This necessitates the application of fluorescent contrast agents. Indications for endomicroscopy include inflammatory and (pre-)neoplastic diseases that are often only incompletely assessed by random biopsies. Multiple trials have established the value of endomicroscopy of the upper and lower gastrointestinal tract. Follow-up studies have evaluated intravital microscopy of the biliary tract, the liver or pancreas. Endomicroscopy for the first time enables microscopic imaging of the intact tissue virtually free of artifacts. This allows an unprecedented approach to the patient in gastrointestinal science and molecular imaging. CLE therefore links clinical patient care with translational science.

In vivo molecular imaging with cetuximab, an anti-EGFR antibody, for prediction of response in xenograft models of human colorectal cancer

BACKGROUND AND STUDY AIMS

Molecular imaging has mainly been studied for detection of lesions using diagnostic probes. The aim of the current trial was to evaluate in vivo confocal laser endomicroscopy (CLE) with cetuximab, an antibody targeting the epidermal growth factor receptor (EGFR), for detection and moreover early prediction of response to molecular chemotherapy in models of human colorectal cancer (CRC).

METHODS

Xenografts with cetuximab-sensitive (HT29) and cetuximab-resistant (SW620) human CRC cell lines were induced in 44 mice. CLE was performed 48 h after injection of a fluorescently labelled cetuximab test dose, and compared with isotype antibody or untreated controls on d0, and d30 (HT29) or d15 (SW620). Initial fluorescence intensity was examined in relation to clinical readouts (tumor growth, thriving, mortality) during cetuximab treatment vs. controls. Results were validated in vivo with wide-field molecular imaging in three HT29 mice and ex vivo using fluorescence-activated cell sorting (FACS) and immunohistochemistry.

RESULTS

All HT29 xenografts showed specific fluorescence in vivo after cetuximab injection on d0 and d30. Fluorescence at d0 was significantly stronger in cetuximab-treated HT29 tumors than in HT29 controls (P = 0.0017) or cetuximab-treated SW620 tumors (P = 0.0027), and accorded with significantly slower tumor progression (P = 0.0009), better overall survival (P = 0.02), and better physical condition (P < 0.0001). Cetuximab sensitivity could be predicted from fluorescence intensity at d0 with high positive predictive value.

CONCLUSIONS

Molecular CLE was for the first time linked to early prediction of response to targeted therapy in models of human CRC. Therapeutic antibodies can be used as molecular beacons in CLE and wide-field techniques. These results may indicate a promising principle for early patient stratification.

Local barrier dysfunction identified by confocal laser endomicroscopy predicts relapse in inflammatory bowel disease

OBJECTIVES

Loss of intestinal barrier function plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Shedding of intestinal epithelial cells is a potential cause of barrier loss during inflammation. The objectives of the study were (1) to determine whether cell shedding and barrier loss in humans can be detected by confocal endomicroscopy and (2) whether these parameters predict relapse of IBD.

METHODS

Confocal endomicroscopy was performed in IBD and control patients using intravenous fluorescein to determine the relationship between cell shedding and local barrier dysfunction. A grading system based on appearances at confocal endomicroscopy in humans was devised and used to predict relapse in a prospective pilot study of 47 patients with ulcerative colitis and 11 patients with Crohn's disease.

RESULTS

Confocal endomicroscopy in humans detected shedding epithelial cells and local barrier defects as plumes of fluorescein effluxing through the epithelium. Mouse experiments demonstrated inward flow through some leakage-associated shedding events, which was increased when luminal osmolarity was decreased. In IBD patients in clinical remission, increased cell shedding with fluorescein leakage was associated with subsequent relapse within 12 months after endomicroscopic examination (p<0.001). The sensitivity, specificity and accuracy for the grading system to predict a flare were 62.5% (95% CI 40.8% to 80.4%), 91.2% (95% CI 75.2 to 97.7) and 79% (95% CI 57.7 to 95.5), respectively.

CONCLUSIONS

Cell shedding and barrier loss detected by confocal endomicroscopy predicts relapse of IBD and has potential as a diagnostic tool for the management of the disease.

MedJet--a new CO2-based disposable cleaning device allows safe and effective bowel cleansing during colonoscopy: a pilot study

BACKGROUND AND STUDY AIMS

Complete bowel cleansing is mandatory for effective colon cancer screening and surveillance. The aim of the current pilot study, which was conducted in humans, was to test the safety and efficiency of a newly developed disposable cleaning device, the MedJet, for intraprocedural bowel cleansing.

PATIENTS AND METHODS

Patients with screening or surveillance colonoscopy after previous polypectomy were included. The colonoscope was first inserted to the cecum and the overall cleansing was assessed according to the Ottawa scale. The MedJet device was used if colon cleansing had been incomplete. The MedJet catheter was passed over the working channel of the colonoscope and the colon was cleaned during withdrawal. The MedJet device delivered controlled jets comprising compressed CO2 and minimal amounts of sterile water, which allowed disintegration and removal of residual stool. The efficiency of cleaning was assessed according to the Boston scale.

RESULTS

A total of 32 patients (16 female; mean age 61 years) were treated with the device. No device-related adverse or serious adverse events were noted. MedJet application during withdrawal provided effective and significant improvement in bowel cleansing (P = 0.005). Furthermore, 18 adenomas and 1 colon cancer, which were hidden behind stool remnants, could be identified in 11 patients following use of the MedJet device. However, the withdrawal times were prolonged (11.4±6.0 minutes) due to the additional cleaning procedure. All patients tolerated the procedure well.

CONCLUSIONS

The new MedJet device enabled highly effective and safe bowel cleansing during colonoscopy. The catheter-based system was easy to use and CO2 was applied for cleansing. The procedure was well tolerated by patients.

[With the scalpel against the immune system: HIV infection complicated by an unclear colitis]

A 35-year-old Kenian lady with advanced immunodeficiency due to HIV infection started on an antiretroviral therapy. Five months later, a severe colitis was diagnosed, however, no causal pathogen could be found. In order to avoid imminent perforation, a hemicolectomy became necessary, and immediately the symptoms and inflammation markers normalized rapidly. M. tuberculosis could be proven in culture in a draining abdominal lymph node. We assume that the severe inflammation was caused by an immune restoration inflammatory syndrome (IRIS). Essentials in diagnosis, pathogenesis and therapy of IRIS are discussed.

PD01-06: Endoxifen Exhibits Potent Anti-Tumor Activity and Regulates Different Genes Than Tamoxifen in an Aromatase Expressing MCF7 Model Resistant to Letrozole

Background: First in human studies of Z-endoxifen hydrochloride (E), the active metabolite of tamoxifen (T), are underway in metastatic breast cancer (BC). Previous data have demonstrated the superiority of aromatase inhibitors (AI's) over T in estrogen receptor (ER) + BC. Using an in vivo aromatase expressing model (MCF7/AC1), we compared the antitumor activity of E with T and Letrozole (L), as well as the antitumor activity and global gene expression changes of E with T in an L-resistant model.

Methods: MCF7/AC1 tumors were stimulated with androstenedione. Once tumor size reached 300 mm3, mice (30/group) were randomly assigned to one of five treatment groups: control (daily, po), T (500 μg/day, sc), endoxifen 25 mg/kg/day p.o.(LDE) endoxifen 75 mg/kg/day p.o. (HDE) or letrozole, 10 μg/day s.c for 4 weeks. Tumors were harvested from control, T, and E groups while the L group continued treatment until the development of resistance defined as an increase in tumor volume of at least 300% from day 1. Mice with L-resistant tumors were randomly assigned to T (n=4) or E (n=5) for 4 weeks and then sacrificed. Gene expression in L-resistant tumors was quantified using Affymetrix U133+2 and changes in gene expression profiles [comparing T and E with L-resistant (n=3)] were analyzed. Genes identified as significantly different were confirmed by real-time RT-PCR assays.

Results: At the 4 week time point, both doses of E and L resulted in greater anti-tumor activity than control (Wilcoxon rank sum test: all p &lt; 0.0001); however, tumor burden did not differ between T and control (p=0.095). HDE resulted in significantly less tumor burden than T (p=0.002) but was similar to L. In mice that continued on L, resistance developed at 24 weeks in 9/25 mice. These mice were randomly assigned to either T (n=4) or E (n=5) for 4 weeks. Tumor volume (expressed as a% of its size prior to randomization) was significantly different comparing E (73.3%; range: 69.3 to 80.75%) versus T (148.39%; range: 114.07 to 165.99%) (Wilcoxon rank sum test p=0.016). Compared to control, microarray studies identified 1518 unique probe sets regulated by E (p&lt;0.001) compared to 441 for T including estrogen-regulated genes such as progesterone receptor (PGR) and amphiregulin (AREG) that were significantly down-regulated in the E group [PGR (−6.2 fold, p=0.000008) and AREG (−3.2 fold, p=.0006) but unchanged or up-regulated in the T group (PGR unchanged and AREG +9.2 fold p=0.00002). These findings were confirmed by RT-PCR.

Conclusions: Using the MCF7/AC1 model previously used to show the superiority of AI's over T, HDE demonstrated similar antitumor activity to L and was superior to T. In cells resistant to L, E was superior to T and gene expression changes demonstrate that E down-regulates while T activates estrogen regulated genes. These findings support the ongoing development of E for the treatment of ER+ BC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD01-06.

[Granular-cell tumor (Abrikossoff's tumor): precise preoperative diagnosis is crucial when for minimally-invasive resection]

HISTORY AND ADMISSION FINDINGS

A 38-year-old man was referred to a gastroenterologist because of thoracic pain and dysphagia of uncertain cause.

INVESTIGATIONS

Endoscopy revealed a centrally depressed, coarse submucosal tumor, 1.0 cm in diameter, in the anterior wall of the esophagus at about 35 cm from the teeth. Button-hole biopsy revealed histologically and immunohistochemically a granular cell tumor (Abrikossoff's tumor), positive for S-100 protein. CT-staging was unremarkable, except for a thickening of the distal esophageal wall.

TREATMENT AND COURSE

Minimally invasive submucosal resection was undertaken using the videoscopic/endoscopic rendezvous technique. Histological examination confirmed complete resection of the tumor. The clinical course was uneventful and endoscopy 6 and 12 weeks after the operation showed complete resection of the tumor.

CONCLUSION

An exact preoperative diagnosis beyond a mere description of site and morphology, but also providing the histopathological data creates favorable conditions for planning and performing a minimally invasive resection. Submucosal resection with the videoscopic/endoscopic in rendezvous technique offers the possibility of complete resection, which can often not be achieved in a submucosal tumor by only endoscopic resection.