Evaluation of zero counts to better understand the discrepancies between bulk and single-cell RNA-Seq platforms.

Recent advances in sample preparation and sequencing technology have made it possible to profile the transcriptomes of individual cells using single-cell RNA sequencing (scRNA-Seq). Compared to bulk RNA-Seq data, single-cell data often contain a higher percentage of zero reads, mainly due to lower sequencing depth per cell, which affects mostly measurements of low-expression genes. However, discrepancies between platforms are observed regardless of expression level. Using four paired datasets with multiple samples each, we investigated technical and biological factors that can contribute to this expression shift. Using two separate machine learning models we found that, in addition to expression level, RNA integrity, gene or UTR3 length, and the number of transcripts potentially also influence the occurrence of zeros. These findings could enable the development of novel analytical methods for cross-platform expression shift correction. We also identified genes and biological pathways in our diverse datasets that consistently showed differences when assessed at the single cell versus bulk level to assist in interpreting analysis across transcriptomic platforms. At the gene level, 25 genes (0.12%) were found in all datasets as discordant, but at the pathway level, 7 pathways (2.02%) showed shared enrichment in discordant genes.

AKT/mTOR signaling modulates resistance to endocrine therapy and CDK4/6 inhibition in metastatic breast cancers.

Endocrine therapy (ET) in combination with CDK4/6 inhibition is routinely used as first-line treatment for HR+/HER2- metastatic breast cancer (MBC) patients. However, 30-40% of patients quickly develop disease progression. In this open-label multicenter clinical trial, we utilized a hypothesis-driven protein/phosphoprotein-based approach to identify predictive markers of response to ET plus CDK4/6 inhibition in pre-treatment tissue biopsies. Pathway-centered signaling profiles were generated from microdissected tumor epithelia and surrounding stroma/immune cells using the reverse phase protein microarray. Phosphorylation levels of the CDK4/6 downstream substrates Rb (S780) and FoxM1 (T600) were higher in patients with progressive disease (PD) compared to responders (p = 0.02). Systemic PI3K/AKT/mTOR activation in tumor epithelia and stroma/immune cells was detected in patients with PD. This activation was not explained by underpinning genomic alterations alone. As the number of FDA-approved targeted compounds increases, functional protein-based signaling analyses may become a critical component of response prediction and treatment selection for MBC patients.

Assessment of stained direct cytology smears of breast cancer for whole transcriptome and targeted messenger RNA sequencing.

BACKGROUND: Rather than surgical resection, cytologic specimens are often used as first-line clinical diagnostic procedures due to higher safety, speed, and cost-effectiveness. Archival diagnostic cytology slides containing cancer can be equivalent to tissue biopsies for DNA mutation testing, but the accuracy of transcriptomic profiling by RNA sequencing (RNA-seq) is less understood. METHODS: This study compares the results from whole transcriptome RNA-seq and a targeted RNA-seq assay of stained cytology smears (CS) versus matched tumor tissue samples preserved fresh-frozen (FF) and processed as formalin-fixed paraffin-embedded (FFPE) sections. Cellular cytology scrapes from all 11 breast cancers were fixed and stained using three common protocols: Carnoy's (CS_C) or 95% ethanol (CS_E) fixation and then Papanicolaou stain or air-dried then methanol fixation and DiffQuik stain (CS_DQ). Agreement between samples was assessed using Lin's concordance correlation coefficient. RESULTS: Library yield for CS_DQ was too low, therefore it was not sequenced. The distributions of concordance correlation coefficient of gene expression levels in comparison to FF were comparable between CS_C and CS_E, but expression of genes enriched in stroma was lower in cytosmear samples than in FF or FFPE. Six signatures showed similar concordance to FF for all methods and two were slightly worse in CS_C and CS_E. Genomic signatures were highly concordant using targeted RNA-seq. The allele fraction of selected mutations calculated on cytosmear specimens was highly correlated with FF tissues using both RNA-seq methods. CONCLUSION: RNA can be reliably extracted from cytology smears and is suitable for transcriptome profiling or mutation detection, except for signatures of tumor stroma.

Comprehensive Analysis of Metabolic Isozyme Targets in Cancer.

Metabolic reprogramming is a hallmark of malignant transformation, and loss of isozyme diversity (LID) contributes to this process. Isozymes are distinct proteins that catalyze the same enzymatic reaction but can have different kinetic characteristics, subcellular localization, and tissue specificity. Cancer-dominant isozymes that catalyze rate-limiting reactions in critical metabolic processes represent potential therapeutic targets. Here, we examined the isozyme expression patterns of 1,319 enzymatic reactions in 14 cancer types and their matching normal tissues using The Cancer Genome Atlas mRNA expression data to identify isozymes that become cancer-dominant. Of the reactions analyzed, 357 demonstrated LID in at least one cancer type. Assessment of the expression patterns in over 600 cell lines in the Cancer Cell Line Encyclopedia showed that these reactions reflect cellular changes instead of differences in tissue composition; 50% of the LID-affected isozymes showed cancer-dominant expression in the corresponding cell lines. The functional importance of the cancer-dominant isozymes was assessed in genome-wide CRISPR and RNAi loss-of-function screens: 17% were critical for cell proliferation, indicating their potential as therapeutic targets. Lists of prioritized novel metabolic targets were developed for 14 cancer types; the most broadly shared and functionally validated target was acetyl-CoA carboxylase 1 (ACC1). Small molecule inhibition of ACC reduced breast cancer viability in vitro and suppressed tumor growth in cell line- and patient-derived xenografts in vivo. Evaluation of the effects of drug treatment revealed significant metabolic and transcriptional perturbations. Overall, this systematic analysis of isozyme expression patterns elucidates an important aspect of cancer metabolic plasticity and reveals putative metabolic vulnerabilities. SIGNIFICANCE: This study exploits the loss of metabolic isozyme diversity common in cancer and reveals a rich pool of potential therapeutic targets that will allow the repurposing of existing inhibitors for anticancer therapy. See related commentary by Kehinde and Parker, p. 1695.

Data augmentation based on waterfall plots to increase value of response data generated by small single arm Phase II trials.

Waterfall plots have been increasingly used to visualize tumor response measurements in Phase II clinical trials. Despite the growing popularity of waterfall plots, quantitative summaries and distribution features of the data indicating antitumor activities are typically not reported. Statistical summaries from the raw and augmented data may provide valuable information for understanding such features. This issue has not been discussed adequately in the literature or fully recognized within the oncology community. In this article, we propose to augment the data using a statistical distribution system. Summary statistics of the data set corresponding to waterfall plot can be calculated using the original sample of the tumor changes or the augmentation sample, which may lead to additional insights into the treatment effect. We demonstrate the proposed method in numerical studies and in a Phase II clinical trial investigating the efficacy of a treatment for ovarian carcinoma. We recommend the proposed statistical analyses for making inferences in addition to the waterfall plot visualization.

Intra- and Interlaboratory Reproducibility of the Sensitivity to Endocrine Therapy Assay for Stage II/III Breast Cancer.

BACKGROUND: The sensitivity to endocrine therapy assay (SET2,3) predicts treatment outcomes in Stage II-III breast cancer. SET2,3 measures transcription related to estrogen and progesterone receptors (SETER/PR index) and the molecular subtype (RNA4: ESR1, PGR, ERBB2, AURKA) from formalin-fixed paraffin-embedded (FFPE) tissue sections. METHODS: We designed a nested study across 3 pathology laboratories, each testing 60 breast cancers twice in controlled batches. Laboratories macrodissected and directly homogenized the unstained FFPE tumor sections, then performed the QuantiGene Plex bead-based hybridization assay. SET2,3 was calculated centrally using predefined statistical R-scripts and applying pre-defined cutpoints. Concordance correlation coefficient (CCC) was calculated from continuous measurements and Kappa statistic from categorical results. A mixed-effects model estimated contributions to bias (fixed effects) and variance (random effects) from the replicated design. RESULTS: Intralaboratory (CCC 0.96-0.99) and interlaboratory (CCC 0.98-0.99) SET2,3 results were concordant, with rates of agreement for high/low categorization within (Kappa 0.83-0.93) and between laboratories (Kappa 0.87-0.88). The relative contributions to overall variance of SET2,3 measurements were 96.90% from biological differences between cancers, 0.67% from interlaboratory variability, and 2.44% from residual causes including intralaboratory replicates. Similar results were obtained with SETER/PR, the baseline prognostic index calculated using pathological or clinical tumor and nodal staging information, and the 4 individual genes (ESR1, PGR, ERBB2, and AURKA). CONCLUSION: Intra- and interpathology laboratory measurements of SET2,3 and its components were highly reproducible when tested from FFPE tumor sections.

Diffuse Alveolar Hemorrhage after Receiving Oral Levonorgerstrel for Emergency Contraception: A Case Report.

INTRODUCTION: Drug-induced diffuse alveolar hemorrhage (DAH) has been associated with the administration of various medications, among which levonorgestrel (LN) has not been reported until now. CASE PRESENTATION: This case study describes a 42-year-old woman who presented with hemoptysis, hypoxemia, and radiological depiction of ground glass opacities, 3 days after she had received emergency contraceptive medication containing levonorgestrel. Emergent bronchoscopy was performed, and BAL was diagnostic of diffuse alveolar hemorrhage (DAH). A thorough diagnostic approach was followed, in order to detect the underlying pathological condition that induced DAH. The absence of other identifiable pathological conditions in this patient raised suspicion of LN's potential causative role. CONCLUSION: DAH has not been reported as an adverse effect of LN until now. However, LN has been found to exert immunomodulatory effects and to present potential for manifestations of vasculitis as well as severe hypersensitivity reactions. These mechanisms may have been implicated in the development of DAH in our patient, who presented no other pathological conditions.

Treatment scheduling effects on the evolution of drug resistance in heterogeneous cancer cell populations.

The effect of scheduling of targeted therapy combinations on drug resistance is underexplored in triple-negative breast cancer (TNBC). TNBC constitutes heterogeneous cancer cell populations the composition of which can change dynamically during treatment resulting in the selection of resistant clones with a fitness advantage. We evaluated crizotinib (ALK/MET inhibitor) and navitoclax (ABT-263; Bcl-2/Bcl-xL inhibitor) combinations in a large design consisting of 696 two-cycle sequential and concomitant treatment regimens with varying treatment dose, duration, and drug holiday length over a 26-day period in MDA-MB-231 TNBC cells and found that patterns of resistance depend on the schedule and sequence in which the drugs are given. Further, we tracked the clonal dynamics and mechanisms of resistance using DNA-integrated barcodes and single-cell RNA sequencing. Our study suggests that longer formats of treatment schedules in vitro screening assays are required to understand the effects of resistance and guide more realistically in vivo and clinical studies.

Whole-genome sequencing of phenotypically distinct inflammatory breast cancers reveals similar genomic alterations to non-inflammatory breast cancers.

BACKGROUND: Inflammatory breast cancer (IBC) has a highly invasive and metastatic phenotype. However, little is known about its genetic drivers. To address this, we report the largest cohort of whole-genome sequencing (WGS) of IBC cases. METHODS: We performed WGS of 20 IBC samples and paired normal blood DNA to identify genomic alterations. For comparison, we used 23 matched non-IBC samples from the Cancer Genome Atlas Program (TCGA). We also validated our findings using WGS data from the International Cancer Genome Consortium (ICGC) and the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We examined a wide selection of genomic features to search for differences between IBC and conventional breast cancer. These include (i) somatic and germline single-nucleotide variants (SNVs), in both coding and non-coding regions; (ii) the mutational signature and the clonal architecture derived from these SNVs; (iii) copy number and structural variants (CNVs and SVs); and (iv) non-human sequence in the tumors (i.e., exogenous sequences of bacterial origin). RESULTS: Overall, IBC has similar genomic characteristics to non-IBC, including specific alterations, overall mutational load and signature, and tumor heterogeneity. In particular, we observed similar mutation frequencies between IBC and non-IBC, for each gene and most cancer-related pathways. Moreover, we found no exogenous sequences of infectious agents specific to IBC samples. Even though we could not find any strongly statistically distinguishing genomic features between the two groups, we did find some suggestive differences in IBC: (i) The MAST2 gene was more frequently mutated (20% IBC vs. 0% non-IBC). (ii) The TGF ß pathway was more frequently disrupted by germline SNVs (50% vs. 13%). (iii) Different copy number profiles were observed in several genomic regions harboring cancer genes. (iv) Complex SVs were more frequent. (v) The clonal architecture was simpler, suggesting more homogenous tumor-evolutionary lineages. CONCLUSIONS: Whole-genome sequencing of IBC manifests a similar genomic architecture to non-IBC. We found no unique genomic alterations shared in just IBCs; however, subtle genomic differences were observed including germline alterations in TGFß pathway genes and somatic mutations in the MAST2 kinase that could represent potential therapeutic targets.

Targeted RNAseq assay incorporating unique molecular identifiers for improved quantification of gene expression signatures and transcribed mutation fraction in fixed tumor samples.

BACKGROUND: Our objective was to assess whether modifications to a customized targeted RNA sequencing (RNAseq) assay to include unique molecular identifiers (UMIs) that collapse read counts to their source mRNA counts would improve quantification of transcripts from formalin-fixed paraffin-embedded (FFPE) tumor tissue samples. The assay (SET4) includes signatures that measure hormone receptor and PI3-kinase related transcriptional activity (SETER/PR and PI3Kges), and measures expression of selected activating point mutations and key breast cancer genes. METHODS: Modifications included steps to introduce eight nucleotides-long UMIs during reverse transcription (RT) in bulk solution, followed by polymerase chain reaction (PCR) of labeled cDNA in droplets, with optimization of the polymerase enzyme and reaction conditions. We used Lin's concordance correlation coefficient (CCC) to measure concordance, including precision (Rho) and accuracy (Bias), and nonparametric tests (Wilcoxon, Levene's) to compare the modified (NEW) SET4 assay to the original (OLD) SET4 assay and to whole transcriptome RNAseq using RNA from matched fresh frozen (FF) and FFPE samples from 12 primary breast cancers. RESULTS: The modified (NEW) SET4 assay measured single transcripts (p< 0.001) and SETER/PR (p=0.002) more reproducibly in technical replicates from FFPE samples. The modified SET4 assay was more precise for measuring single transcripts (Rho 0.966 vs 0.888, p< 0.01) but not multigene expression signatures SETER/PR (Rho 0.985 vs 0.968) or PI3Kges (Rho 0.985 vs 0.946) in FFPE, compared to FF samples. It was also more precise than wtRNAseq of FFPE for measuring transcripts (Rho 0.986 vs 0.934, p< 0.001) and SETER/PR (Rho 0.993 vs 0.915, p=0.004), but not PI3Kges (Rho 0.988 vs 0.945, p=0.051). Accuracy (Bias) was comparable between protocols. Two samples carried a PIK3CA mutation, and measurements of transcribed mutant allele fraction was similar in FF and FFPE samples and appeared more precise with the modified SET4 assay. Amplification efficiency (reads per UMI) was consistent in FF and FFPE samples, and close to the theoretically expected value, when the library size exceeded 400,000 aligned reads. CONCLUSIONS: Modifications to the targeted RNAseq protocol for SET4 assay significantly increased the precision of UMI-based and reads-based measurements of individual transcripts, multi-gene signatures, and mutant transcript fraction, particularly with FFPE samples.

Multi-Omics Investigation of Innate Navitoclax Resistance in Triple-Negative Breast Cancer Cells.

Cancer cells employ various defense mechanisms against drug-induced cell death. Investigating multi-omics landscapes of cancer cells before and after treatment can reveal resistance mechanisms and inform new therapeutic strategies. We assessed the effects of navitoclax, a BCL2 family inhibitor, on the transcriptome, methylome, chromatin structure, and copy number variations of MDA-MB-231 triple-negative breast cancer (TNBC) cells. Cells were sampled before treatment, at 72 h of exposure, and after 10-day drug-free recovery from treatment. We observed transient alterations in the expression of stress response genes that were accompanied by corresponding changes in chromatin accessibility. Most of these changes returned to baseline after the recovery period. We also detected lasting alterations in methylation states and genome structure that suggest permanent changes in cell population composition. Using single-cell analyses, we identified 2350 genes significantly upregulated in navitoclax-resistant cells and derived an 18-gene navitoclax resistance signature. We assessed the navitoclax-response-predictive function of this signature in four additional TNBC cell lines in vitro and in silico in 619 cell lines treated with 251 different drugs. We observed a drug-specific predictive value in both experiments, suggesting that this signature could help guiding clinical biomarker studies involving navitoclax.

Increasing accrual of minority patients in breast cancer clinical trials.

BACKGROUND: Black and Hispanic patients participate in clinical trials at lower rates than white patients nationally; lack of diversity in clinical trials prevents appropriate safety and efficacy testing of new treatments in these populations. METHODS: The Oncology Welcomes New Haven into Trials (OWN IT) initiative at the Yale Cancer Center used a multi-tiered approach to improve breast cancer minority clinical trial accrual through community focus groups, ongoing community outreach, institutional executive council representation, grand rounds presentation, and didactic lectures with healthcare providers. Eligibility criteria of breast cancer trials at Smilow Cancer Center were reviewed using clinicaltrials.gov. Also, an anonymous, 5-min survey was conducted at regular visits with Smilow Breast Center patients to gauge awareness of and access to clinical trials. Survey data were compared to the Yale Cancer Center Clinical Trials Office, Connecticut Tumor Registry, and U.S. Census records. Two-tailed Fisher's tests were used for all analyses. RESULTS: There was a significant increase in the number of minority patients who participated in clinical trials at Smilow Cancer Center from 2016 (95/750) to 2018 (155/944) (p = 0.0325). Two hundred patients participated in the survey; response rate 92%. There was no significant difference in the rate at which patients were invited to participate in clinical trials or the rate at which they declined to participate based on race or ethnicity. Black and Hispanic patients were significantly less likely to be aware of clinical trials than white patients (p < .001). The review of eligibility criteria showed that over half of the studies reviewed had restrictions regarding increased liver function tests, and many restricted the participation of patients with other chronic conditions. CONCLUSIONS: Low participation in clinical trials among black and Hispanic patients is likely multifaceted. This study indicated that there are likely structural factors at work which can be modified with institutional effort. The role of patient education regarding clinical trials and accrual should be studied further as should eligibility criteria as a potential barrier to participation.

Germline variant burden in cancer genes correlates with age at diagnosis and somatic mutation burden.

Cancers harbor many somatic mutations and germline variants, we hypothesized that the combined effect of germline variants that alter the structure, expression, or function of protein-coding regions of cancer-biology related genes (gHFI) determines which and how many somatic mutations (sM) must occur for malignant transformation. We show that gHFI and sM affect overlapping genes and the average number of gHFI in cancer hallmark genes is higher in patients who develop cancer at a younger age (r = -0.77, P = 0.0051), while the average number of sM increases in increasing age groups (r = 0.92, P = 0.000073). A strong negative correlation exists between average gHFI and average sM burden in increasing age groups (r = -0.70, P = 0.017). In early-onset cancers, the larger gHFI burden in cancer genes suggests a greater contribution of germline alterations to the transformation process while late-onset cancers are more driven by somatic mutations.

Analysis of Pre- and Posttreatment Tissues from the SWOG S0800 Trial Reveals an Effect of Neoadjuvant Chemotherapy on the Breast Cancer Genome.

PURPOSE: We performed whole-exome sequencing (WES) of pre- and posttreatment cancer tissues to assess the somatic mutation landscape of tumors before and after neoadjuvant taxane and anthracycline chemotherapy with or without bevacizumab. EXPERIMENTAL DESIGN: Twenty-nine pretreatment biopsies from the SWOG S0800 trial were subjected to WES to identify mutational patterns associated with response to neoadjuvant chemotherapy. Nine matching samples with residual cancer after therapy were also analyzed to assess changes in mutational patterns in response to therapy. RESULTS: In pretreatment samples, a higher proportion of mutation signature 3, a BRCA-mediated DNA repair deficiency mutational signature, was associated with higher rate of pathologic complete response (pCR; median signature weight 24%, range 0%-38% in pCR vs. median weight 0%, range 0%-19% in residual disease, Wilcoxon rank sum, Bonferroni P = 0.007). We found no biological pathway level mutations associated with pCR or enriched in posttreatment samples. We observed statistically significant enrichment of high functional impact mutations in the "E2F targets" and "G2-M checkpoint" pathways in residual cancer samples implicating these pathways in resistance to therapy and a significant depletion of mutations in the "myogenesis pathway" suggesting the cells harboring these variants were effectively eradicated by therapy. CONCLUSIONS: These results suggest that genomic disturbances in BRCA-related DNA repair mechanisms, reflected by a dominant mutational signature 3, confer increased chemotherapy sensitivity. Cancers that survive neoadjuvant chemotherapy frequently have alterations in cell-cycle-regulating genes but different genes of the same pathways are affected in different patients.

The impact of RNA extraction method on accurate RNA sequencing from formalin-fixed paraffin-embedded tissues.

BACKGROUND: Utilization of RNA sequencing methods to measure gene expression from archival formalin-fixed paraffin-embedded (FFPE) tumor samples in translational research and clinical trials requires reliable interpretation of the impact of pre-analytical variables on the data obtained, particularly the methods used to preserve samples and to purify RNA. METHODS: Matched tissue samples from 12 breast cancers were fresh frozen (FF) and preserved in RNAlater or fixed in formalin and processed as FFPE tissue. Total RNA was extracted and purified from FF samples using the Qiagen RNeasy kit, and in duplicate from FFPE tissue sections using three different kits (Norgen, Qiagen and Roche). All RNA samples underwent whole transcriptome RNA sequencing (wtRNAseq) and targeted RNA sequencing for 31 transcripts included in a signature of sensitivity to endocrine therapy. We assessed the effect of RNA extraction kit on the reliability of gene expression levels using linear mixed-effects model analysis, concordance correlation coefficient (CCC) and differential analysis. All protein-coding genes in the wtRNAseq and three gene expression signatures for breast cancer were assessed for concordance. RESULTS: Despite variable quality of the RNA extracted from FFPE samples by different kits, all had similar concordance of overall gene expression from wtRNAseq between matched FF and FFPE samples (median CCC 0.63-0.66) and between technical replicates (median expression difference 0.13-0.22). More than half of genes were differentially expressed between FF and FFPE, but with low fold change (median |LFC| 0.31-0.34). Two out of three breast cancer signatures studied were highly robust in all samples using any kit, whereas the third signature was similarly discordant irrespective of the kit used. The targeted RNAseq assay was concordant between FFPE and FF samples using any of the kits (CCC 0.91-0.96). CONCLUSIONS: The selection of kit to purify RNA from FFPE did not influence the overall quality of results from wtRNAseq, thus variable reproducibility of gene signatures probably relates to the reliability of individual gene selected and possibly to the algorithm. Targeted RNAseq showed promising performance for clinical deployment of quantitative assays in breast cancer from FFPE samples, although numerical scores were not identical to those from wtRNAseq and would require calibration.

Identification and Validation of a Novel Biologics Target in Triple Negative Breast Cancer.

The goal of this study was to identify a novel target for antibody-drug conjugate (ADC) development in triple negative breast cancer (TNBC), which has limited treatment options, using gene expression datasets and in vitro siRNA/CRISPR and in vivo functional assays. We analyzed 4467 breast cancers and identified GABRP as top expressed gene in TNBC with low expression in most normal tissues. GABRP protein was localized to cell membrane with broad range of receptors/cell (815-53,714) and expressed by nearly half of breast cancers tissues. GABRP gene knockdown inhibited TNBC cell growth and colony formation in vitro and growth of MDA-MB-468 xenografts in nude mice. Commercially available anti-GABRP antibody (5-100 µg/ml) or de novo generated Fabs (20 µg/ml) inhibited TNBC cell growth in vitro. The same antibody conjugated to mertansine (DM1) also showed significant anticancer activity at nanomolar concentrations. Our results indicate that GABRP is a potential novel therapeutic target for ADC development.

SETER/PR: a robust 18-gene predictor for sensitivity to endocrine therapy for metastatic breast cancer.

There is a clinical need to predict sensitivity of metastatic hormone receptor-positive and HER2-negative (HR+/HER2-) breast cancer to endocrine therapy, and targeted RNA sequencing (RNAseq) offers diagnostic potential to measure both transcriptional activity and functional mutation. We developed the SETER/PR index to measure gene expression microarray probe sets that were correlated with hormone receptors (ESR1 and PGR) and robust to preanalytical and analytical influences. We tested SETER/PR index in biopsies of metastastic HR+/HER2- breast cancer against the treatment outcomes in 140 patients. Then we customized the SETER/PR assay to measure 18 informative, 10 reference transcripts, and sequence the ligand-binding domain (LBD) of ESR1 using droplet-based targeted RNAseq, and tested that in residual RNA from 53 patients. Higher SETER/PR index in metastatic samples predicted longer PFS and OS when patients received endocrine therapy as next treatment, even after adjustment for clinical-pathologic risk factors (PFS: HR 0.534, 95% CI 0.299 to 0.955, p = 0.035; OS: HR 0.315, 95% CI 0.157 to 0.631, p = 0.001). Mutated ESR1 LBD was detected in 8/53 (15%) of metastases, involving 1-98% of ESR1 transcripts (all had high SETER/PR index). A signature based on probe sets with good preanalytical and analytical performance facilitated our customization of an accurate targeted RNAseq assay to measure both phenotype and genotype of ER-related transcription. Elevated SETER/PR was associated with prolonged sensitivity to endocrine therapy in patients with metastatic HR+/HER2- breast cancer, especially in the absence of mutated ESR1 transcript.

The impact of communication style on patient satisfaction.

BACKGROUND: Communication between patients and health providers influences patient satisfaction, but it is unknown whether similarity in communication styles results in higher patient satisfaction. METHODS: This study was conducted in the Smilow Cancer Hospital Breast Center. During routine follow-up visits, patients completed a Communication Styles Assessment (CSA), health survey (SF-12), Princess Margaret Hospital Satisfaction with Doctor Questionnaire, and brief demographic form. Physicians and Advanced Practice Providers were also asked to complete the CSA. Patients and providers were blinded to each other's responses. A communication styles concordance score was calculated as the Pearson correlation between 80 binary CSA items for each provider/patient pair. Factors affecting patient satisfaction scores were assessed in mixed-effects models. RESULTS: In total, 330 patients were invited to participate; of these 289 enrolled and 245 returned surveys. One hundred seventy-four completed all survey components, and 18 providers completed the CSA. Among the factors considered, physical health score (effect size = 0.0058, 95% CI 0.00051 to 0.0011, p = 0.032) and employment status (0.12, 95% CI - 0.0094 to 0.25, p = 0.069) had the greatest impact on patient satisfaction. However, patients who were not employed and less physically healthy had significantly elevated satisfaction scores when their communication style was more similar to their provider's (1.52, 95% CI 0.66 to 2.38, p = 0.0016). CONCLUSIONS: Patients who were physically healthy and employed were generally more satisfied with their care. The similarity in communication styles of patients and providers had a greater impact on patient satisfaction for patients who were less physically healthy and not employed.

Examining the cost-effectiveness of baseline left ventricular function assessment among breast cancer patients undergoing anthracycline-based therapy.

BACKGROUND: There is a lack of consensus to guide which breast cancer patients require left ventricular function assessment (LVEF) prior to anthracycline therapy; the cost-effectiveness of screening this patient population has not been previously evaluated. METHODS: We performed a retrospective analysis of the Yale Nuclear Cardiology Database, including 702 patients with baseline equilibrium radionuclide angiography (ERNA) scan prior to anthracycline and/or trastuzumab therapy. We sought to examine associations between abnormal baseline LVEF and potential cardiac risk factors. Additionally, we designed a Markov model to determine the incremental cost-effectiveness ratio (ICER) of ERNA screening for women aged 55 with stage I-III breast cancer from a payer perspective over a lifetime horizon. RESULTS: An abnormal LVEF was observed in 2% (n = 14) of patients. There were no significant associations on multivariate analysis performed on self-reported risk factors. Our analysis showed LVEF screening is cost-effective with ICER of $45,473 per QALY gained. For a willingness-to-pay threshold of $100,000/ QALY, LVEF screening had an 81.9% probability of being cost-effective. Under the same threshold, screening was cost-effective for non-anthracycline cardiotoxicity risk of RR ≤ 0.58, as compared to anthracycline regimens. CONCLUSIONS: Age, preexisting cardiac risk factors and coronary artery disease did not predict a baseline abnormal LVEF. While the prevalence of an abnormal baseline LVEF is low in patients with breast cancer, our results suggest that cardiac screening prior to anthracycline is cost-effective.

Immune profiling of pre- and post-treatment breast cancer tissues from the SWOG S0800 neoadjuvant trial.

BACKGROUND: How the immune microenvironment changes during neoadjuvant chemotherapy of primary breast cancer is not well understood. METHODS: We analyzed pre- and post-treatment samples from 60 patients using the NanoString PanCancer IO360™ assay to measure the expression of 750 immune-related genes corresponding to 14 immune cell types and various immune functions, and assessed TIL counts and PD-L1 protein expression by immunohistochemistry. Treatment associated changes in gene expression levels were compared using t-test with Bonferroni correction. TIL count, PD-L1 protein and immune metagenes were compared using Wilcoxon test. Baseline immune markers were correlated with pathologic complete response (pCR) using estrogen receptor and treatment arm adjusted logistic regression. RESULTS: At baseline, high TIL counts and high expression of chemoattractant cytokines (CCL21, CCL19) and cytotoxic T cell markers were associated with higher pCR rate. High expression of stromal genes (VEGFB, TGFB3, PDGFB, FGFR1, IGFR1), mast and myeloid inflammatory cell metagenes, stem cell related genes (CD90, WNT11, CTNNB1) and CX3CR1, and IL11RA were associated with residual disease (RD). After treatment, in cases with pCR, TIL counts and most immune genes decreased significantly. Among RD cases, TIL counts and PD-L1 expression did not change but cellular stress and hypoxia associated genes (DUSP1, EGR1), and IL6, CD36, CXCL2, CD69 and the IL8/VEGF metagene increased. CONCLUSIONS: Activated T cells in the tumor microenvironment are associated with pCR whereas stromal functions are associated with residual disease. Most immune functions decrease during neoadjuvant chemotherapy but several immunotherapy targets (PD-L1, IL6, IL8) remain expressed in RD suggesting potential therapeutic strategies.