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S3. Representative images of cells grown in 3D Matrigel for 14D and treated with ABT-263 (1.0 uM). S4. Whole cell lysates from cells treated with ABT-263 (1.0uM) for 0=24 hours.

An estimated 40,000 deaths will be attributed to breast cancer in 2016, underscoring the need for improved therapies. Evading cell death is a major hallmark of cancer, driving tumor progression and therapeutic resistance. To evade apoptosis, cancers use antiapoptotic Bcl-2 proteins to bind to and neutralize apoptotic activators, such as Bim. Investigation of antiapoptotic Bcl-2 family members in clinical breast cancer datasets revealed greater expression and more frequent gene amplification of MCL1 as compared with BCL2 or BCL2L1 (Bcl-xL) across three major molecular breast cancer subtypes, Luminal (A and B), HER2-enriched, and Basal-like. While Mcl-1 protein expression was elevated in estrogen receptor α (ERα)-positive and ERα-negative tumors as compared with normal breast, Mcl-1 staining was higher in ERα+ tumors. Targeted Mcl-1 blockade using RNAi increased caspase-mediated cell death in ERα+ breast cancer cells, resulting in sustained growth inhibition. In contrast, combined blockade of Bcl-2 and Bcl-xL only transiently induced apoptosis, as cells rapidly acclimated through Mcl-1 upregulation and enhanced Mcl-1 activity, as measured in situ using Mcl-1/Bim proximity ligation assays. Importantly, MCL1 gene expression levels correlated inversely with sensitivity to pharmacologic Bcl-2/Bcl-xL inhibition in luminal breast cancer cells, whereas no relationship was seen between the gene expression of BCL2 or BCL2L1 and sensitivity to Bcl-2/Bcl-xL inhibition. These results demonstrate that breast cancers rapidly deploy Mcl-1 to promote cell survival, particularly when challenged with blockade of other Bcl-2 family members, warranting the continued development of Mcl-1–selective inhibitors for targeted tumor cell killing.Implications: Mcl-1 levels predict breast cancer response to inhibitors targeting other Bcl-2 family members, and demonstrate the key role played by Mcl-1 in resistance to this drug class. Mol Cancer Res; 15(3); 259–68. ©2016 AACR.

Purpose:We wanted to determine the prognosis and the phenotypic characteristics of hormone receptor–positive advanced breast cancer tumors harboring an ERBB2 mutation in the absence of a HER2 amplification.Experimental Design:We retrospectively collected information from the American Association of Cancer Research-Genomics Evidence Neoplasia Information Exchange registry database from patients with hormone receptor–positive, HER2-negative, ERBB2-mutated advanced breast cancer. Phenotypic and co-mutational features, as well as response to treatment and outcome were compared with matched control cases ERBB2 wild type.Results:A total of 45 ERBB2-mutant cases were identified for 90 matched controls. The presence of an ERBB2 mutation was not associated with worse outcome determined by overall survival (OS) from first metastatic relapse. No significant differences were observed in phenotypic characteristics apart from higher lobular infiltrating subtype in the ERBB2-mutated group. ERBB2 mutation did not seem to have an impact in response to treatment or time-to-progression (TTP) to endocrine therapy compared with ERBB2 wild type. In the co-mutational analyses, CDH1 mutation was more frequent in the ERBB2-mutated group (FDR < 1). Although not significant, fewer co-occurring ESR1 mutations and more KRAS mutations were identified in the ERBB2-mutated group.Conclusions:ERBB2-activating mutation was not associated with a worse OS from time of first metastatic relapse, or differences in TTP on treatment as compared with a series of matched controls. Although not significant, differences in coexisting mutations (CDH1, ESR1, and KRAS) were noted between the ERBB2-mutated and the control group.

Purpose: The genetic differences between human papilloma virus (HPV)–positive and –negative head and neck squamous cell carcinomas (HNSCC) remain largely unknown. To identify differential biology and novel therapeutic targets for both entities, we determined mutations and copy-number aberrations in a large cohort of locoregionally advanced HNSCC.Experimental Design: We performed massively parallel sequencing of 617 cancer-associated genes in 120 matched tumor/normal samples (42.5% HPV-positive). Mutations and copy-number aberrations were determined and results validated with a secondary method.Results: The overall mutational burden in HPV-negative and HPV-positive HNSCC was similar with an average of 15.2 versus 14.4 somatic exonic mutations in the targeted cancer-associated genes. HPV-negative tumors showed a mutational spectrum concordant with published lung squamous cell carcinoma analyses with enrichment for mutations in TP53, CDKN2A, MLL2, CUL3, NSD1, PIK3CA, and NOTCH genes. HPV-positive tumors showed unique mutations in DDX3X, FGFR2/3 and aberrations in PIK3CA, KRAS, MLL2/3, and NOTCH1 were enriched in HPV-positive tumors. Currently targetable genomic alterations were identified in FGFR1, DDR2, EGFR, FGFR2/3, EPHA2, and PIK3CA. EGFR, CCND1, and FGFR1 amplifications occurred in HPV-negative tumors, whereas 17.6% of HPV-positive tumors harbored mutations in fibroblast growth factor receptor genes (FGFR2/3), including six recurrent FGFR3 S249C mutations. HPV-positive tumors showed a 5.8% incidence of KRAS mutations, and DNA-repair gene aberrations, including 7.8% BRCA1/2 mutations, were identified.Conclusions: The mutational makeup of HPV-positive and HPV-negative HNSCC differs significantly, including targetable genes. HNSCC harbors multiple therapeutically important genetic aberrations, including frequent aberrations in the FGFR and PI3K pathway genes. Clin Cancer Res; 21(3); 632–41. ©2014 AACR.See related commentary by Krigsfeld and Chung, p. 495

Supplementary Figure from Natural History and Characteristics of ERBB2-mutated Hormone Receptor–positive Metastatic Breast Cancer: A Multi-institutional Retrospective Case–control Study from AACR Project GENIE

Supplementary Table from Natural History and Characteristics of ERBB2-mutated Hormone Receptor–positive Metastatic Breast Cancer: A Multi-institutional Retrospective Case–control Study from AACR Project GENIE

Background Cancer resequencing studies have revealed epigenetic enzymes as common targets for recurrent mutations. The monomethyltransferase MLL3 is among the most recurrently mutated enzymes in ER+ breast cancer. The H3K4me1 marks created by MLL3 can define enhancers. In ER+ breast cancer, ERα genome‐binding sites are primarily distal enhancers. Thus, we hypothesize that mutation of MLL3 will alter the genomic binding and transcriptional regulatory activity of ERα. Methods We investigated the genomic consequences of knocking down MLL3 in an MLL3/PIK3CA WT ER+ breast cancer cell line. Results Loss of MLL3 led to a large loss of H3K4me1 across the genome, and a shift in genomic location of ERα‐binding sites, which was accompanied by a re‐organization of the breast cancer transcriptome. Gene set enrichment analyses of ERα‐binding sites in MLL3 KD identified endocrine therapy resistance terms, and we showed that MLL3 KD cells are resistant to tamoxifen and fulvestrant. Many differentially expressed genes are controlled by the small collection of new locations of H3K4me1 deposition and ERα binding, suggesting that loss of functional MLL3 leads to new transcriptional regulation of essential genes. Motif analysis of RNA‐seq and ChIP‐seq data highlighted SP1 as a critical transcription factor in the MLL3 KD cells. Differentially expressed genes that display a loss of ERα binding upon MLL3 KD also harbor increased SP1 binding. Conclusions Our data show that a decrease in functional MLL3 leads to endocrine therapy resistance. This highlights the importance of genotyping patient tumor samples for MLL3 mutation upon initial resection, prior to deciding upon treatment plans., MLL3 is the 6th most commonly mutated gene in ER+ breast cancer patients, however its role in regulating the transcriptional activity of ERα in breast cancer is still unclear. Our data imply that mutations in MLL3 lend to endocrine therapy resistance through an altered genomic enhancer and ERα binding landscape resulting in an altered transcriptome, and therefore genotyping should be done prior to deciding upon course of treatment.

Background:Third generation EGFR TKIs have emerged as a first line treatment of choice for aNSCLC patients with qualifying EGFR mutations due to high and durable response rates; however most patients will progress on therapy and may receive further treatment. Second line (2L) options include other EGFR TKIs, chemotherapy (C) and chemoimmunotherapy (C-IO). An optimal treatment strategy and utility of biomarkers in this 2L setting remain uncharacterized. In this study, we aim to describe the real-world treatment patterns and outcomes of patients with aNSCLC after treatment with first line (1L) EGFR TKIs to elucidate the potential for biomarker-guided approaches. Methods:We selected patients with non-squamous aNSCLC treated with 1L EGFR TKIs on or after April 1, 2018 (based on 1L approval of osimertinib) within the US-based de-identified Flatiron Health-Foundation Medicine (FMI) real world clinico-genomic database. Real world overall survival (rwOS) and progression free survival (rwPFS) curves and estimates of median survival time were generated using the Kaplan-Meier method. PD-L1 and tumor mutational burden (TMB) were summarized overall and by 2L treatment regimen. Results:Among 428 patients who received 1L EGFR TKI treatment, 386 (90%) received osimertinib, 30 (7%) received afatinib and 11 (3%) received erlotinib. For patients with known 2L treatment information (n=139, 32%) most received EGFR TKI alone (n=43, 31%), followed by C-IO (n=38, 27%), and C alone (n=14, 10%). Median rwOS following 2L treatment with EGFR TKI, C-IO, and C was 21.0 (95% CI 17.4-28.7) months, 9.9 (95% CI 7.7-19.8) months, and 17.4 (95% CI 4.3-NA) months respectively. Median rwPFS for the EGFR-TKI, C-IO, and C cohorts was 5.1 (95% CI 3.4-12.5) months, 5.5 (95% CI 3.3-7.0) months, and 3.5 (95% CI 1.9-NA) months. 416 (97%) of 428 patients harbored an EGFR mutation detected by FoundationOne®CDx, including 361 (84%) patients with at least one EGFR mutation in NCCN Guidelines. Among patients with available PD-L1 status (n=254, 59%), PD-L1 positivity (≥1% tumor proportion score) was more common among patients who received 2L C-IO (88%) compared to patients overall (59%). 30 (7%) of 428 patients had high TMB (≥10 mut/Mb); prevalence of high TMB was similar regardless of 2L therapy choice. Conclusions:This real-world data analysis confirmed that among patients with aNSCLC treated with EGFR TKIs, the vast majority received 1L osimertinib. Among 2L treatment options, additional EGFR TKI use was the most common and patients in this cohort had robust outcomes, with a median rwOS of 21 mos. Further analyses will describe the clinical characteristics of patients receiving different 2L treatment strategies and evaluate the association of PD-L1 status and select EGFR mutations with outcomes across therapeutic classes. Citation Format: Ericka Ebot, Jie He, David Fabrizio, Ivy Altomare, Neha Jain, Davey Daniel, Thomas Stricker, Edward Arrowsmith. Real world treatment patterns and outcomes in patients with advanced non-small cell lung cancer (aNSCLC) post-EGFR tyrosine kinase inhibitor (TKI) therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 933.

Treatment decisions in primary myelofibrosis (PMF) are guided by numerous prognostic systems. Patient-specific comorbidities have influence on treatment-related survival and are considered in clinical contexts but have not been routinely incorporated into current prognostic models. We hypothesized that patient-specific comorbidities would inform prognosis and could be incorporated into a quantitative score. All patients with PMF or secondary myelofibrosis with available DNA and comprehensive electronic health record (EHR) data treated at Vanderbilt University Medical Center between 1995 and 2016 were identified within Vanderbilt’s Synthetic Derivative and BioVU Biobank. We recapitulated established PMF risk scores (eg, Dynamic International Prognostic Scoring System [DIPSS], DIPSS plus, Genetics-Based Prognostic Scoring System, Mutation-Enhanced International Prognostic Scoring System 70+) and comorbidities through EHR chart extraction and next-generation sequencing on biobanked peripheral blood DNA. The impact of comorbidities was assessed via DIPSS-adjusted overall survival using Bonferroni correction. Comorbidities associated with inferior survival include renal failure/dysfunction (hazard ratio [HR], 4.3; 95% confidence interval [95% CI], 2.1-8.9; P = .0001), intracranial hemorrhage (HR, 28.7; 95% CI, 7.0-116.8; P = 2.83e-06), invasive fungal infection (HR, 41.2; 95% CI, 7.2-235.2; P = 2.90e-05), and chronic encephalopathy (HR, 15.1; 95% CI, 3.8-59.4; P = .0001). The extended DIPSS model including all 4 significant comorbidities showed a significantly higher discriminating power (C-index 0.81; 95% CI, 0.78-0.84) than the original DIPSS model (C-index 0.73; 95% CI, 0.70-0.77). In summary, we repurposed an institutional biobank to identify and risk-classify an uncommon hematologic malignancy by established (eg, DIPSS) and other clinical and pathologic factors (eg, comorbidities) in an unbiased fashion. The inclusion of comorbidities into risk evaluation may augment prognostic capability of future genetics-based scoring systems.

Annotation and interpretation of full scan electrospray mass spectra of metabolites is complicated by the presence of a wide variety of ions. Not only protonated, deprotonated, and neutral loss ions but also sodium, potassium, and ammonium adducts as well as oligomers are frequently observed. This diversity challenges automatic annotation and is often poorly addressed by current annotation tools. In many cases, annotation is integrated in metabolomics workflows and is based on specific chromatographic peak-picking tools. We introduce mzAdan, a nonchromatography-based multipurpose standalone application that was developed for the annotation and exploration of convolved high-resolution ESI-MS spectra. The tool annotates single or multiple accurate mass spectra using a customizable adduct annotation list and outputs a list of [M+H]+ candidates. MzAdan was first tested with a collection of 408 analytes acquired with flow injection analysis. This resulted in 402 correct [M+H]+ identifications and, with combinations of sodium, ammonium, and potassium adducts and water and ammonia losses within a tolerance of 10 mmu, explained close to 50% of the total ion current. False positives were monitored with mass accuracy and bias as well as chromatographic behavior which led to the identification of adducts with calcium instead of the expected potassium. MzAdan was then integrated in a workflow with XCMS for the untargeted LC-MS data analysis of a 52 metabolite standard mix and a human urine sample. The results were benchmarked against three other annotation tools, CAMERA, findMAIN, and CliqueMS: findMAIN and mzAdan consistently produced higher numbers of [M+H]+ candidates compared with CliqueMS and CAMERA, especially with co-eluting metabolites. Detection of low-intensity ions and correct grouping were found to be essential for annotation performance. Graphical abstract Electronic supplementary material The online version contains supplementary material available at 10.1007/s00216-020-03019-3.

The 17q23 amplicon is associated with poor outcome in ER+ breast cancers, but the causal genes to endocrine resistance in this amplicon are unclear. Here, we interrogate transcriptome data from primary breast tumors and find that among genes in 17q23, PRR11 is a key gene associated with a poor response to therapeutic estrogen suppression. PRR11 promotes estrogen-independent proliferation and confers endocrine resistance in ER+ breast cancers. Mechanistically, the proline-rich motif-mediated interaction of PRR11 with the p85α regulatory subunit of PI3K suppresses p85 homodimerization, thus enhancing insulin-stimulated binding of p110-p85α heterodimers to IRS1 and activation of PI3K. PRR11-amplified breast cancer cells rely on PIK3CA and are highly sensitive to PI3K inhibitors, suggesting that PRR11 amplification confers PI3K dependence. Finally, genetic and pharmacological inhibition of PI3K suppresses PRR11-mediated, estrogen-independent growth. These data suggest ER+/PRR11-amplified breast cancers as a novel subgroup of tumors that may benefit from treatment with PI3K inhibitors and antiestrogens., The 17q23 amplicon is associated with poor outcome in ER+ breast cancers, but the causal genes responsible endocrine resistance in this region are unclear. In this study, the authors demonstrate that PRR11 located at 17q23, is critical for conferring endocrine resistance through activation of PI3K signalling and therefore propose PI3K inhibition as a treatment for PRR11-amplified breast cancers.

Rationale: We have a limited understanding of the molecular underpinnings of early adenocarcinoma (ADC) progression. We hypothesized that the behavior of early ADC can be predicted based on genomic determinants. Objectives: To identify genomic alterations associated with resected indolent and aggressive early lung ADCs. Methods: DNA was extracted from 21 ADCs in situ (AISs), 27 minimally invasive ADCs (MIAs), and 54 fully invasive ADCs. This DNA was subjected to deep next-generation sequencing and tested against a custom panel of 347 cancer genes. Measurements and Main Results: Sequencing data was analyzed for associations among tumor mutation burden, frequency of mutations or copy number alterations, mutation signatures, intratumor heterogeneity, pathway alterations, histology, and overall survival. We found that deleterious mutation burden was significantly greater in invasive ADC, whereas more copy number loss was observed in AIS and MIA. Intratumor heterogeneity establishes early, as in AIS. Twenty-one significantly mutated genes were shared among the groups. Mutation signature profiling did not vary significantly, although the APOBEC signature was associated with ADC and poor survival. Subclonal KRAS mutations and a gene signature consisting of PIK3CG, ATM, EPPK1, EP300, or KMT2C mutations were also associated with poor survival. Mutations of KRAS, TP53, and NF1 were found to increase in frequency from AIS and MIA to ADC. A cancer progression model revealed selective early and late drivers. Conclusions: Our results reveal several genetic driver events, clonality, and mutational signatures associated with poor outcome in early lung ADC, with potential future implications for the detection and management of ADC.

Importance Early-onset atrial fibrillation (AF) can be the initial manifestation of a more serious underlying inherited cardiomyopathy or arrhythmia syndrome. Objective To examine the results of genetic testing for early-onset AF. Design, Setting, and Participants This prospective, observational cohort study enrolled participants from an academic medical center who had AF diagnosed before 66 years of age and underwent whole genome sequencing through the National Heart, Lung, and Blood Institute’s Trans-Omics for Precision Medicine program. Participants were enrolled from November 23, 1999, to June 2, 2015. Data analysis was performed from October 24, 2020, to March 11, 2021. Exposures Rare variants identified in a panel of 145 genes that are included on cardiomyopathy and arrhythmia panels used by commercial clinical genetic testing laboratories. Main Outcomes and Measures Sequencing data were analyzed using an automated process followed by manual review by a panel of independent, blinded reviewers. The primary outcome was classification of rare variants using American College of Medical Genetics and Genomics criteria: benign, likely benign, variant of undetermined significance, likely pathogenic, or pathogenic. Disease-associated variants were defined as pathogenic/likely pathogenic variants in genes associated with autosomal dominant or X-linked dominant disorders. Results Among 1293 participants (934 [72.2%] male; median [interquartile range] age at enrollment, 56 [48-61] years; median [interquartile range] age at AF diagnosis, 50 [41-56] years), genetic testing identified 131 participants (10.1%) with a disease-associated variant, 812 (62.8%) with a variant of undetermined significance, 92 (7.1%) as heterozygous carriers for an autosomal recessive disorder, and 258 (20.0%) with no suspicious variant. The likelihood of a disease-associated variant was highest in participants with AF diagnosed before the age of 30 years (20 of 119 [16.8%; 95% CI, 10.0%-23.6%]) and lowest after the age of 60 years (8 of 112 [7.1%; 95% CI, 2.4%-11.9%]). Disease-associated variants were more often associated with inherited cardiomyopathy syndromes compared with inherited arrhythmias. The most common genes wereTTN(n = 38),MYH7(n = 18),MYH6(n = 10),LMNA(n = 9), andKCNQ1(n = 8). Conclusions and Relevance In this cohort study, genetic testing identified a disease-associated variant in 10% of patients with early-onset AF (the percentage was higher if diagnosed before the age of 30 years and lower if diagnosed after the age of 60 years). Most pathogenic/likely pathogenic variants are in genes associated with cardiomyopathy. These results support the use of genetic testing in early-onset AF.

The prevalence of thyroid carcinoma is increasing and represents the most common endocrine malignancy, with papillary thyroid carcinoma (PTC) being the most frequent subtype. The genetic alterations identified in PTCs fail to distinguish tumors with different clinical behaviors, such as extra-thyroidal extension and lymph node metastasis. We hypothesize that the immune microenvironment may play a critical role in tumor invasion and metastasis. Computational immunogenomic analysis was performed on 568 PTC samples in The Cancer Genome Atlas using CIBERSORT, TIMER and TIDE deconvolution analytic tools for characterizing immune cell composition. Immune cell infiltrates were correlated with histologic type, mutational type, tumor pathologic T stage and lymph node N stage. Dendritic cells (DCs) are highly associated with more locally advanced tumor T stage (T3/T4, odds ratio (OR) = 2.6, CI = 1.4–4.5, P = 5.4 × 10−4). Increased dendritic cells (OR = 3.4, CI = 1.9–6.3, P = 5.5 × 10−5) and neutrophils (OR = 10.5, CI = 2.7–44, P = 8.7 × 10−4) significantly correlate with lymph node metastasis. In addition, dendritic cells positively correlate with tall cell morphology (OR = 4.5, CI = 1.6–13, P = 4.9 × 10−3) and neutrophils negatively correlate with follicular morphology (OR = 1.3 × 10−3, CI = 5.3 × 10−5–0.031, P = 4.1 × 10−5). TIDE analysis indicates an immune-exclusive phenotype that may be mediated by increased galectin-3 found in PTCs. Thus, characterization of the PTC immune microenvironment using three computational platforms shows that specific immune cells correlate with mutational type, histologic type, local tumor extent and lymph node metastasis. Immunologic evaluation of PTCs may provide a better indication of biologic behavior, resulting in the improved diagnosis and treatment of thyroid cancer.

Purpose: We wanted to determine the prognosis and the phenotypic characteristics of hormone receptor–positive advanced breast cancer tumors harboring an ERBB2 mutation in the absence of a HER2 amplification. Experimental Design: We retrospectively collected information from the American Association of Cancer Research-Genomics Evidence Neoplasia Information Exchange registry database from patients with hormone receptor–positive, HER2-negative, ERBB2-mutated advanced breast cancer. Phenotypic and co-mutational features, as well as response to treatment and outcome were compared with matched control cases ERBB2 wild type. Results: A total of 45 ERBB2-mutant cases were identified for 90 matched controls. The presence of an ERBB2 mutation was not associated with worse outcome determined by overall survival (OS) from first metastatic relapse. No significant differences were observed in phenotypic characteristics apart from higher lobular infiltrating subtype in the ERBB2-mutated group. ERBB2 mutation did not seem to have an impact in response to treatment or time-to-progression (TTP) to endocrine therapy compared with ERBB2 wild type. In the co-mutational analyses, CDH1 mutation was more frequent in the ERBB2-mutated group (FDR < 1). Although not significant, fewer co-occurring ESR1 mutations and more KRAS mutations were identified in the ERBB2-mutated group. Conclusions: ERBB2-activating mutation was not associated with a worse OS from time of first metastatic relapse, or differences in TTP on treatment as compared with a series of matched controls. Although not significant, differences in coexisting mutations (CDH1, ESR1, and KRAS) were noted between the ERBB2-mutated and the control group.

Objective: Here we present 2 cases of papillary thyroid microcarcinomas (PMCs) that had metastasized at presentation. The 2015 American Thyroid Association and the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) criteria do not recommend biopsy of the majority of subcentimeter thyroid nodules, as PMCs are mostly indolent with excellent prognosis. However, the paradigm of active surveillance presents a conundrum on how to identify the rare patient with distant metastatic disease while avoiding unnecessary intervention in the majority. Methods: After initial discovery of incidental lesions on chest computed tomography, core or wedge biopsies of the lung lesion were performed. Thyroid nodules on ultrasound were classified by TI-RADS. Tumor DNA was sequenced, annotated, filtered on 119 known cancer genes, and filtered for variants with an exome allele frequency of G mutation (p.Thr574Ser) in the TSHR gene in patient 1 and a codon 61 mutation in the NRAS gene in patient 2. Both patients were iodine-avid, with complete structural remission in one patient and ongoing treatment with evidence of structural response in the other. Conclusion: The 2 presentations demonstrate unexpected and concerning behavior of PMCs. Both thyroid tumors were subcentimeter in diameter, meaning they would have escaped detection using traditional risk-stratification algorithms in active surveillance. Further knowledge of tumor genetics and microenvironment may assist in predicting tumor behavior in PMCs. Abbreviations: ATA American Thyroid Association CT computed tomography PMC papillary thyroid microcarcinoma PTC papillary thyroid carcinoma TI-RADS Thyroid Imaging Reporting and Data System

Treatment for myelodysplastic syndromes (MDS) remains insufficient due to clonal heterogeneity and clinical complexity. Dysregulation of apoptosis is observed across MDS subtypes regardless of mutations and represents an attractive therapeutic opportunity. Venetoclax (VEN), a selective inhibitor of anti-apoptotic protein B-cell lymphoma-2 (BCL2), has yielded impressive responses in older patients with acute myeloid leukemia (AML). BCL2 family anti-apoptotic proteins BCL-XL and induced myeloid cell leukemia 1 (MCL1) are implicated in leukemia survival, and upregulation of MCL1 is seen in VEN-resistant AML and MDS. Here, we determined the in vitro sensitivity of MDS patient samples to selective inhibitors of BCL2, BCL-XL and MCL1. While VEN response positively correlated with increasing blast counts, all MDS subtypes responded to the MCL1 inhibitor, S63845. Treatment with combined VEN+S63845 was synergistic in all MDS subtypes and reduced MDS engraftment in MISTRG6 mice supporting the pursuit of clinical trials with combined BCL2+MCL1 inhibition in MDS.

Background: FGFR1 amplification (amp) occurs in ˜15% of breast cancers (BC) and associates with poor prognosis and resistance to endocrine therapy. CCND1 regulates cell cycle progression and is amplified in 15-20% of BC. Co-amp of FGFR1 occurs in 30-40% of CCND1amp tumors, suggesting the possibility of oncogene cooperativity. CDK4/6 inhibitors, which block the action of cyclin D1/CDK4 complexes at the G1-to-S transition, are approved for treatment of ER+ BC and FGFR inhibitors are in early phase clinical trials. Results: Between 11/2013 and 03/2017, 191 BCs from 188 patients with metastatic (M) or refractory locoregional recurrent (RLRR) BC at Vanderbilt (VICC) were profiled by targeted next gen sequencing (Foundation OneTM). These are included within the 2131 publicly available BC sequencing results in GENIE (Foundation OneTM and MSK-IMPACT). Among the GENIE cohort, rates were: FGFR1amp 7% (n=156), CCND1amp 12% (n=261) and CCND1/FGFR1co-amp 3% (n=58). Additional cases showed FGFR1 missense mutations (n=16) and deep deletions (n=5). When the analysis was limited to the VICC cohort allowing restriction to ER+ BC, FGFR1amp (16%) and CCND1amp (23%) rates are similar to rates in primary BC in TCGA (13% FGFR1 [p = 0.44] and 19% CCND1 [p = 0.24]). In GENIE, the most frequent co-mutations in FGFR1amp tumors were TP53 (31%), PIK3CA (21%), GATA3 (13%), CDH1 (11%) and MAP3K1 (10%). However, TP53 and PIK3CA mutations were less common among FGFR1amp tumors than FGFR1non-amp cases (p 0.016). Histopathologic correlation on tumors from our institution show a majority of FGFR1 and/or CCND1 amp BC (64%) were ER+/HER2–; 33% of ER+/FGFR1amp tumors were PR–. Distinctive histologic features associated with FGFR1 and/or CCND1 amp were lobular histology (17%) and neuroendocrine differentiation (14%), 0-10%TILs (94%) and high proliferative rate (46%). Conclusion: FGFR1amp and CCND1amp rates in TCGA are similar to those seen in MBC/LRRBC (GENIE) suggesting FGFR1 can function as both a driver mutation and de novo mechanism of endocrine resistance early in tumorigenesis. Frequent co-amp with CCND1 and lower rates of TP53 and PIK3CAmut also support a driver role for FGFR1amp and FGFR1/CCND1co-amp. The observation of neuroendocrine features in a subset of these tumors suggests lineage plasticity. This may be a consequence of genomic alterations promoting anti-estrogen resistance and is consistent with recently published BC outcome data associating neuroendocrine differentiation with higher grade ER+ tumors, frequent 8p amp, which includes FGFR1, and worse disease-free and overall survival. The frequency of FGFR1amp suggests genotype specific trials with FGFR inhibitors would be highly feasible. Whether FGFR1/CCND1 co-amplified tumors are candidates for treatment with a combination of FGFR and CDK4/6 inhibitors requires further investigation. Citation Format: Gonzalez-Ericsson PI, Estrada MV, Formisano L, Jansen VM, Mayer IA, Rexer BN, Abramson VG, Levy M, Balko JM, Stricker TP, Arteaga CL, Sanders ME. Genenomic landscape of breast cancers with FGFR1 amplification and FGFR1/CCND1 co-amplification revealed by targeted capture next generation sequencing [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 PD4-07.

Insights into mutational burden of the airway epithelium, the field of cancerization, may play important role in stratifying individuals at different levels of risk for lung cancer. We hypothesized that cytologically normal bronchial epithelium of patients with lung cancer and those at high risk for lung cancer harbor driver mutations. We performed next generation sequence-based targeted CAPP-Seq (CAncer Personalized Profiling by deep Sequencing) and whole exome sequencing (WES) of DNA from the bronchial epithelial cells from the bronchial brushings of individuals at-risk for lung cancer and patients with lung cancer as well as matched lung tumor tissues. We used the Tammemagi risk model to calculate the risk for lung cancer. Both CAPPSeq and WES data analyses showed higher mutation burden in lung tumor tissues compared to bronchial brushings. Using targeted CAPPSeq, a total of 129 nonsynonymous mutations were identified in bronchial brushings. Among individuals without lung cancer, 9 oncogenic driver mutations were identified in 5 out of 13 high risk and 2 out of 7 low risk individuals. Among individuals with cancer, 13 out of 22 brushings harbored 11 driver mutations, of which mutations in TP53 and PTEN were identified in both tumor and brushing matched samples. Mutations detected in the brushings of individuals with and without cancer were TP53, PIK3CA, NOTCH1, KRAS, MET, CUL3, and NF1. Using WES on the DNA from the same brushings (low risk, n=9; high risk, n=8 and lung cancer, n=17), we identified 19478 mutations total, and 90 of that were also identified by CAPPSeq. WES identified 80% of the mutations that were identified by CAPPSeq with >5% variant allelic frequencies (VAF). Mutations identified by CAPPSeq had VAF as low as 0.2% and vast majority of the mutations identified by WES had VAF >5%. Out of 9 mutations in TP53 identified in the brushings by CAPPSeq, 4 were identified by WES. Mutation in KMT2D, a histone methylation enzyme and believed to be a tumor suppressor, was identified by WES in the brushings and the tumor tissues of patients with lung cancer as well as in one high risk brushings. Mutational signature profiling identified tobacco mutational signature in the bronchial epithelium and tobacco, APOBEC and DNA-DSB repair signatures in the tumor tissues. Copy number variation (CNV) data analysis revealed significantly higher CNV levels in tumor samples than brushing samples. Genome-wide CNA profiling identified regions significantly influenced by CNV, such as deletions in chromosome region 19p13.3, which was previously reported to be related to lung cancer. We identified mutations in cancer driver genes in the bronchial brushings of individuals with and without lung cancer. This field of cancerization effect may provide a tool for risk assessment for lung cancer. This research was funded by U01CA196405 to PPM. Citation Format: SM Jamshedur Rahman, Shilin Zhao, Shih-Kai Chu, Yong Zou, Angela B. Hui, Thomas P. Stricker, Chen Heidi, Maximilian Diehn, Pierre P. Massion. Mutational landscape of the bronchial epithelium of individuals at high risk for lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2536.

While thyroid cancer is primarily indolent, forming well-differentiated carcinomas (DTCs), a subset of patients develop dedifferentiated tumors that are aggressive. The evolution of dedifferentiated carcinomas is complex, producing two subtypes: poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC). ATCs lack markers of differentiated thyroid tissue and have a median survival of 5 months. In contrast, PDTCs retain follicular cell differentiation and have 5-year disease-specific survival of 66%. It's possible that PDTCs and ATCs arise de novo; however, co-occurrences within DTCs have been observed. Consequently, it has been proposed that PDTCs are a transitional stage in the DTC dedifferentiation process, eventually leading to ATC. Dedifferentiation of many cancer types is associated with the accumulation of second hit driver mutations. However, despite large sequencing endeavors, few additional mutations between PDTCs and ATCs have been identified. It is likely that the drivers of dedifferentiation to ATC may be extrinsic to the mutational landscape. Thus, we hypothesize that the tumor microenvironment plays a central role in driving dedifferentiation of DTCs. We performed RNA sequencing on a cohort of 262 thyroid resection specimens encompassing a broad range of thyroid cancers and used DESeq2 to generate fold-change gene expression estimates for poor outcome samples (defined by transformation to PDTC or ATC, recurrence, distant metastasis, or death from disease). Functional enrichment analysis (WebGestalt) identified extracellular matrix (ECM) and regulation of leukocyte activation gene sets as enriched in poor outcome. In the ECM gene set, FAP, PDPN, TGFB1, FN1, COL11A1, LAMB3, POSTN, VCAN, and WNT2, amongst others, were significantly enriched. The neutrophil activating chemokine CXCL5 showed a striking 43-fold increase in poor outcome cases. Interestingly, segregating by histology shows that these stromal markers are upregulated in ATCs but not PDTCs, suggesting that distinct populations of fibroblasts may be present in ATCs. Similarly, the tumor immune cell prediction algorithm TIMER (Tumor Immune Estimation Resource) predicts increased macrophage and neutrophil infiltrate within ATCs relative to PDTCs. Together, these results support a model in which a heterogenous population of fibroblasts drive tumor aggression and granulocyte infiltrate in ATCs but not PDTCs. Single cell resolution will be instrumental to further clarify this model and elucidate the signals that support ATC aggression. Importantly, the distinct differences in stromal markers between PDTCs and ATCs in our cohort suggest that these may be pathologically distinct outcomes rather than existing on a spectrum of dedifferentiation with PDTCs eventually fated to become ATCs. Citation Format: Matthew A. Loberg, George Xu, Thomas P. Stricker, Quanhu Sheng, Barbara A. Murphy, Vivian L. Weiss. Dedifferentiated thyroid cancers have unique expression profiles of stromal cell markers and TIMER predicted immune cell infiltrate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2708.

The AACR Project GENIE is an international data-sharing consortium focused on generating an evidence base for precision cancer medicine by integrating clinical-grade cancer genomic data with clinical outcome data for tens of thousands of cancer patients treated at multiple institutions worldwide. In conjunction with the first public data release from approximately 19,000 samples, we describe the goals, structure, and data standards of the consortium and report conclusions from high-level analysis of the initial phase of genomic data. We also provide examples of the clinical utility of GENIE data, such as an estimate of clinical actionability across multiple cancer types (>30%) and prediction of accrual rates to the NCI-MATCH trial that accurately reflect recently reported actual match rates. The GENIE database is expected to grow to >100,000 samples within 5 years and should serve as a powerful tool for precision cancer medicine. Significance: The AACR Project GENIE aims to catalyze sharing of integrated genomic and clinical datasets across multiple institutions worldwide, and thereby enable precision cancer medicine research, including the identification of novel therapeutic targets, design of biomarker-driven clinical trials, and identification of genomic determinants of response to therapy. Cancer Discov; 7(8); 818–31. ©2017 AACR. See related commentary by Litchfield et al., p. 796. This article is highlighted in the In This Issue feature, p. 783

Rationale In peptide quantification by liquid chromatography/mass spectrometry (LC/MS), the optimization of multiple reaction monitoring (MRM) parameters is essential for sensitive detection. We have compared different approaches to build MRM assays, based either on flow injection analysis (FIA) of isotopically labelled peptides, or on the knowledge and the prediction of the best settings for MRM transitions and collision energies (CE). In this context, we introduce MRMOptimizer, an open-source software tool that processes spectra and assists the user in selecting transitions in the FIA workflow. Methods MS/MS spectral libraries with CE voltages from 10 to 70 V are automatically acquired in FIA mode for isotopically labelled peptides. Then MRMOptimizer determines the optimal MRM settings for each peptide. To assess the quantitative performance of our approach, 155 peptides, representing 84 proteins, were analysed by LC/MRM-MS and the peak areas were compared between: (A) the MRMOptimizer-based workflow, (B1) the SRMAtlas transitions set used ‘as-is’; (B2) the same SRMAtlas set with CE parameters optimized by Skyline. Results 51% of the three most intense transitions per peptide were shown to be common to both A and B1/B2 methods, and displayed similar sensitivity and peak area distributions. The peak areas obtained with MRMOptimizer for transitions sharing either the precursor ion charge state or the fragment ions with the SRMAtlas set at unique transitions were increased 1.8- to 2.3-fold. The gain in sensitivity using MRMOptimizer for transitions with different precursor ion charge state and fragment ions (8% of the total), reaches a ~ 11-fold increase. Conclusions Isotopically labelled peptides can be used to optimize MRM transitions more efficiently in FIA than by searching databases. The MRMOptimizer software is MS independent and enables the post-acquisition selection of MRM parameters. Coefficients of variation for optimal CE values are lower than those obtained with the SRMAtlas approach (B2) and one additional peptide was detected. Copyright © 2017 John Wiley & Sons, Ltd.

An estimated 40,000 deaths will be attributed to breast cancer in 2016, underscoring the need for improved therapies. Evading cell death is a major hallmark of cancer, driving tumor progression and therapeutic resistance. To evade apoptosis, cancers use antiapoptotic Bcl-2 proteins to bind to and neutralize apoptotic activators, such as Bim. Investigation of antiapoptotic Bcl-2 family members in clinical breast cancer datasets revealed greater expression and more frequent gene amplification of MCL1 as compared with BCL2 or BCL2L1 (Bcl-xL) across three major molecular breast cancer subtypes, Luminal (A and B), HER2-enriched, and Basal-like. While Mcl-1 protein expression was elevated in estrogen receptor α (ERα)-positive and ERα-negative tumors as compared with normal breast, Mcl-1 staining was higher in ERα+ tumors. Targeted Mcl-1 blockade using RNAi increased caspase-mediated cell death in ERα+ breast cancer cells, resulting in sustained growth inhibition. In contrast, combined blockade of Bcl-2 and Bcl-xL only transiently induced apoptosis, as cells rapidly acclimated through Mcl-1 upregulation and enhanced Mcl-1 activity, as measured in situ using Mcl-1/Bim proximity ligation assays. Importantly, MCL1 gene expression levels correlated inversely with sensitivity to pharmacologic Bcl-2/Bcl-xL inhibition in luminal breast cancer cells, whereas no relationship was seen between the gene expression of BCL2 or BCL2L1 and sensitivity to Bcl-2/Bcl-xL inhibition. These results demonstrate that breast cancers rapidly deploy Mcl-1 to promote cell survival, particularly when challenged with blockade of other Bcl-2 family members, warranting the continued development of Mcl-1–selective inhibitors for targeted tumor cell killing. Implications: Mcl-1 levels predict breast cancer response to inhibitors targeting other Bcl-2 family members, and demonstrate the key role played by Mcl-1 in resistance to this drug class. Mol Cancer Res; 15(3); 259–68. ©2016 AACR.

Breast cancer intra-tumor heterogeneity contributes to chemotherapy resistance and decreased patient survival, yet no reliable in vitro models exist to study this phenomenon. To address this need we developed an in vitro 3D organoid culture system using primary human breast cancer tissue. A major difficulty in the development of such models is to identify robust in vitro conditions that preserve the breast cancer phenotypes observed in situ. To address this challenge we used quantitative immunofluorescence imaging to compare the cellular phenotypes in the starting tumor tissue with those observed in the tumor organoids cultured in 3D. We utilized a clustering algorithm and utility function to quantitatively assess whether tumor organoids generated in vitro faithfully recapitulated intra- and inter-tumor heterogeneity of the tumor tissue in situ. This approach generated a normalized score that reflects tissue-organoid similarity. To test the sensitivity of our method to overall changes in tissue phenotype we focused on three distinct breast cancer subtypes distinguished by expression of estrogen receptor (ER), progesterone receptor (PR) and amplification of ERBB2/HER2 (HER2). Using our approach, we successfully recapitulated the tumor phenotypes present in ER+, ER+/HER2+ and triple negative breast cancer. We discovered that EGF preserves the TNBC phenotype, whereas AREG is required for recapitulating the phenotype of ER+ and ER+/HER2+ breast cancers. Additionally, our data demonstrate that HER1 ligands drive inter- and intra-tumor heterogeneity. To investigate how intra-tumor heterogeneity contributes to therapy responses we treated organoids with standard agents used clinically to treat each of the distinct subtypes. For all tumor subtypes we observed differential vulnerabilities between patients to drug treatments. Importantly, our analysis identified divergent cellular phenotypes that have various sensitivities to chemotherapies. Taken together, our methodology provides an unprecedented view of intra-tumor heterogeneity and allows for the investigation of chemo-resistance mechanisms. Further, this approach will provide a powerful tool, which will enhance the identification of novel therapies and facilitate personalized medicine. Citation Format: Sowder ME, Ludwik KA, Pasic L, Brenin DR, Stricker TP, Macara IG, Lannigan DA. Breast cancer organoid cultures preserve intra-tumor heterogeneity and reveal intrinsically resistant phenotypes to standard chemotherapies [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 P1-06-05.

Background: Approximately 20% of patients with early ER+ breast cancer (BC) treated with adjuvant antiestrogen therapy eventually relapse with endocrine-resistant metastatic disease. We hypothesized that profiling newly diagnosed ER+ BC that persist following prolonged estradiol deprivation with letrozole would identify genomic alterations associated with endocrine resistance. Methods: We treated 57 postmenopausal women (median 77 years; range 60-86) with ER+/HER2– BC with neoadjuvant letrozole (median 7.5 months; range 3-36) followed by surgery and adjuvant endocrine therapy. Patients were followed with serial ultrasounds and defined as non-responders if they developed recurrent locally or metastatic disease, or had a preoperative endocrine prognostic index (PEPI) ≥4 (composite score of post-treatment ER, Ki67, T and N status). Post-treatment specimens were profiled by RNA-seq and targeted capture NGS of >300 cancer-related genes. We screened for variants with a high probability of disrupting protein function (GERP score >4) and excluded likely germline variants by filtering out every alteration not present in COSMIC, if the variant had an allele frequency >0.1% as per the ExAC dataset. Results: Ten patients (17.5%) had a PEPI 0 score, 31 (54%) were PEPI 1-3, and 16 (28%) were PEPI ≥4. After a median follow-up of 50 months (12-100), 9 patients (15.7%) had recurred with metastatic disease (4 with PEPI 1-3, 5 with PEPI ≥4). We identified 294 variants with a median coverage >250x (206 nonsynonymous, 21 nonsense, 58 indels, 8 splice site). Recurrent mutations included PIK3CA (38%), KMT2C (28%), CDH1 (15%), NF1 (12 %), TP53 (10%), MAP3K1 (7%), ERBB2 (7%) and ESR1 (5%). Recurrent amplifications were identified in MCL1 (31%), GNAS (19%), CCND1 (16%), FYN (14%), AURKA (12%), and ERBB2 (10%), while recurrent deletions were found in DUSP4 (12%), NCOR1 (8%) and NF1 (6%). Compared to alterations reported in untreated ER+ breast cancers in TCGA, we observed a significant increase in KMT2C, NF1, MCL1 and FYN alterations (FDR Conclusions: Genomic profiling of residual ER+ breast cancers treated with prolonged neoadjuvant letrozole revealed a different mutational landscape than primary untreated ER+ BC. These alterations may be associated with poor response to estrogen deprivation in early breast cancer and deserve further study. Citation Format: Guerrero AL, Stricker T, Hutchinson KE, Formisano L, Giltnane J, Fidalgo A, Schwarz LJ, Gavila J, Guillen V, Lluch A, Ruiz A, Arteaga CL. Genomic profiling of residual ER+ breast cancers treated with prolonged neoadjuvant letrozole reveals novel alterations in clinically resistant tumors [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 P2-10-01.