bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract ES6-2: PI3K in breast cancer, glutamine changes and methionine addiction
Authors: Toker A
Published: May 2019

Mutations in the PI 3-kinase and AKT signaling pathway are highly prevalent in breast cancer. In luminal, estrogen receptor-positive breast cancer patients, oncogenic mutations in PIK3CA, the gene that encodes the catalytic subunit of class 1a PI3K occur with a frequency of approximately 40%. By contrast, inactivating mutations and loss of heterozygosity in the tumor suppressors PTEN and INPP4B that normally terminate PI3K signaling, are found more frequently in basal-like, triple negative breast tumors. Regardless, in all cases the net result is hyperactivation of PI3K/AKT signaling leading to induction of phenotypes associated with malignancy. In spite of the frequency of genetic lesions in the PI3K pathway and the development of potent and specific small molecule inhibitors targeting the PI3K pathway, results from clinical trials with these inhibitors have been disappointing most often due to dose-limiting on-target toxicities. Consequently, numerous combination trials with PI3K inhibitors and other targeted therapies are underway. Separate pre-clinical and clinical efforts have also been initiated targeting PI3K oncogene addition with therapies that impact cellular states and programs, including metabolic pathways and enzymes. The concept that metabolic reprogramming is a feature of all cancer cells, and not merely a byproduct of accelerated growth, goes back to the days of Otto Warburg who in the 1920s proposed that increased levels of aerobic glycolysis followed by lactate fermentation occurs in tumor cells undergoing rapid growth. This so-called 'Warburg effect' spurred the recent development of numerous drugs that target glycolysis in human tumors, many of which are in clinical trials. Equally promising are strategies that target non-essential amino acid metabolism. The concept of metabolic starvation, whereby one or more metabolite is limiting or removed has gained traction in the field, with the finding that certain non-essential amino acids, particularly glutamine, can be synthesized by normal cells, whereas tumor cells rely on an extracellular supply to the extent that glutamine deprivation sensitizes tumor cells to death. Glutamine is the most widely studied nutrient, other than glucose, in the field of tumor metabolism. The presentation will focus on the intersection of PI3K, AKT and glutamine metabolism in breast cancer, as well as how these pathways modulate methionine dependency in breast cancers that display PI3K pathway hyperactivation. A greater understanding of the mechanisms by which glutamine and methionine sustain cancer cells may lead to the development or repurposing of other successful targeted metabolic therapies and use of the pathway enzymes and metabolites as biomarkers.

Citation Format: Toker A. PI3K in breast cancer, glutamine changes and methionine addiction [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 ES6-2.
Abstract GS1-02: Towards a human breast cell atlas
Authors: Seth TK , Bai S , Hu M , Sei E , Wood A , Wiley J , Chen H , Contreras A , Teshome M , Lim B , Navin NE
Published: May 2019

The human breast tissue consists of lobules connected to a complex network of ducts that are evolutionarily designed to produce and transport milk to nourish offspring. Histopathology has identified 10 major cell types based on morphological features but have provided limited information on cell states - the transcriptional programs of cell types that reflect different biological functions. In this study, we have generated an unbiased 'cell atlas' of the normal human breast to define the cell types and cell states using single cell RNA sequencing methods. We performed 3' microdroplet based single cell RNA sequencing of 31,442 stromal cells from 11 women with pathologically normal breast tissues that were collected from mastectomies. Unbiased expression analysis identified three major cell types: epithelial cells (luminal and basal), fibroblasts and endothelial cells, in addition to several minor cell types: macrophages, T-cells, natural killer cells, pericytes and smooth muscle cells. Analysis of cell states of these cell types revealed different transcriptional programs in luminal epithelial cells (hormone receptor positive and secretory), basal epithelial cells (myoepithelial or basement-like), endothelial cells (lymphatic or vascular), macrophages (M1 or M2) and fibroblasts (three subgroups) and provided insight into progenitors of each cell types. These data provide a valuable reference for the research community and will provide new insights into how normal cell types are transformed in the tumor microenvironment to promote or inhibit the progression of breast cancer.

Citation Format: Seth TK, Bai S, Hu M, Sei E, Wood A, Wiley J, Chen H, Contreras A, Teshome M, Lim B, Navin NE. Towards a human breast cell atlas [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 GS1-02.
Abstract MS2-1: Overtreatment: First, do no harm
Authors: Jagsi R
Published: May 2019

Perhaps more than for any other type of cancer, the management of breast cancer has been supported by a steady trajectory of research that has discovered ways to safely de-escalate therapy and identify patients who may safely forego potentially toxic treatments. This talk will begin with a brief overview of landmark clinical trials that have established the safety of de-escalating breast surgery, axillary surgery, radiotherapy, and systemic therapy for select patients. It will then turn to the research that shows that many women diagnosed with breast cancer today pursue considerably more aggressive treatments than needed to achieve excellent outcomes in terms of survival and recurrence, followed by a focus on the toxicity and costs that can result. Seeking to gain actionable insights on how to prevent shared decision-making from resulting in overtreatment, it will then discuss insights from decision psychology. It will include reflections on the heuristics that can lead patients and physicians alike towards overtreatment, the critical role of patients' underlying proclivities for medical maximizing versus medical minimizing, and the importance of naming and framing to ensure accurate risk communication.

Citation Format: Jagsi R. Overtreatment: First, do no harm [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 MS2-1.
Abstract MS2-2: Missed opportunities - The perils of under-treatment
Authors: Freedman R
Published: May 2019

Although we have seen improvements in breast cancer survival over time, the pace of improvement has varied among patients with breast cancer, and disparities in breast cancer outcomes have widened for some sub-groups. In particular, black women, those without easy access to medical care, and those at the extremes of age (youngest and oldest patients), are at higher risk for sub-optimal treatment and consequent sub-optimal breast cancer outcomes. These disparities have evolved during an era of significant treatment advances in breast cancer such as hormonal therapy and HER2-directed therapy, with a concern that under-treatment has contributed to differences in breast cancer-specific survival. Though there are cases when over-treatment and over-diagnosis result in undue toxicity, worsened quality of life, and possible detrimental outcomes, there are also many cases where patients are simply under-treated. This under-treatment manifests in a number of ways, and not only in a lack of treatment receipt all together, but also in receipt of lower intensity, non-standard, delayed, or incomplete treatment, which may be most apparent in the setting of longer-term treatments such as hormonal therapy or maintenance HER2-directed therapy. The reasons for under-treatment are complex, highly variable, and may include clear and appropriate medical contraindications but also poor treatment adherence, social stressors which limit treatment completion, the high cost of care, and limited access to high-quality care. In addition, under-treatment likely occurs due to a lack of available prospective evidence to support ideal treatments in different patient sub-groups with the need to uncomfortably extrapolate and apply data from clinical trials where many subgroups are under-represented. We need to urgently improve the evidence base for populations at risk for under-treatment so that we can better understand the side effects and outcomes experienced for both standard treatments and alternative treatment strategies. We will never realize improved survival from breast cancer for all patients until we can assure that each patient is individually receiving the right therapy at the right time with the right amount and for the right duration.

Citation Format: Freedman R. Missed opportunities - The perils of under-treatment [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 MS2-2.
Abstract OT2-07-08: Withdrawn
Authors: Paplomata E , Borges V , Loi S , Abramson V , Hamilton E , Hurvitz S , Lin N , Walker L , Murthy RK
Published: May 2019

This abstract was withdrawn by the authors.

Citation Format: Paplomata E, Borges V, Loi S, Abramson V, Hamilton E, Hurvitz S, Lin N, Walker L, Murthy RK. Withdrawn [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 OT2-07-08.
Abstract P1-05-03: Isoform specific targeting of insulin receptor
Authors: LaPara K , Chan JY , Zdechlik A , Ljunggren K , Schmidt D , Hackel B , Yee D
Published: May 2019

The insulin receptor (InsR) exists in both an A and B isoform. InsR-B differs from InsR-A by the inclusion of exon 11, which encodes 12 amino acid residues at the C-terminus of the InsR alpha-subunit. Increased InsR-A expression is associated with mitogenic signaling pathways while InsR-B is linked to insulin-mediated metabolic functions. Predominant InsR-A expression may therefore be important in growth and fetal development of embryos, whereas predominant InsR-B expression has a role in metabolic insulin action in adult life. Increased InsR-A expression is seen in breast cancer. In endocrine resistant breast cancer, InsR-A is expressed at high levels (Gradishar, et al. Clin Cancer Res 22:301 2016 PMID: 26324738). Thus, developing InsR-A specific inhibitors could be a useful therapy for breast cancer. We have previously published InsR specific binders using a T7 phage gene 2 protein (Gp2), a small protein scaffold (Chan, et al. Mol Cancer Ther 16:1324 2017 PMID: 28468775), with the long-term goal of creating effective InsR inhibitors and diagnostics. Using yeast display and directed evolution, we identified three Gp2 variants (Gp2 #1, #5, and #10) with low nanomolar affinity and specific binding to cell surface InsR. We have shown that these Gp2 variants inhibited insulin-mediated monolayer proliferation in both endocrine-sensitive and resistant breast cancer, but did not downregulate InsR expression. To further characterize the specificity of Gp2 variants, we used two techniques. HEK293T cells were infected with lentiviral vectors expressing either InsR-A tagged with mCherry or InsR-B tagged with eGFP. Using these cells, we performed “mock panning” and showed the Gp2 #5 variant bound both InsR-A and InsR-B, but had higher affinity for InsR-B. We also incorporated Gp2 #5 into the capsid of a tropism-null adeno-associated virus (AAV). Using this Gp2-AAV, we infected HEK293T-InsR-A or InsR-B cells at a number of different multiplicities of infection. These data were consistent with panning data and showed specific Gp2-AAV infection of cells expressing high levels of InsR-B, but not InsR-A. Thus, our data show that Gp2 variants we created have a higher affinity for InsR-B than InsR-A. Despite this preferred affinity, these Gp2 binders have sufficient binding to InsR-A to disrupt the biological effects of insulin in breast cancer cells. Thus, even relatively low affinity binding to InsR-A can disrupt its function. Further development of InsR-A Gp2 binders may be developed and provide more specific targeting of the breast cancer specific isoform of InsR.

Citation Format: LaPara K, Chan JY, Zdechlik A, Ljunggren K, Schmidt D, Hackel B, Yee D. Isoform specific targeting of insulin receptor [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 P1-05-03.
Abstract P1-05-06: Endothelial nitric oxide synthase gene intron4 VNTR polymorphism in patients with breast cancer
Authors: Gunaldi M , Isiksacan N , Pehlivan S , Binboga S
Published: May 2019

Background: Endothelial nitric oxide synthase (eNOS), also known as NOS3 is an enzyme that in humans is encoded by the NOS3 gene located in the 7q35-7q36 region of chromosome 7. Nitric oxide (NO) is synthesized from L-arginine by eNOS in the vascular endothelium and plays crucial roles in cellular proliferation. In the present study, it is hypothesized that polymorphisms of the Intron4b/a variable number of tandem repeat (VNTR) polymorphism Intron4b/a in the eNOS gene may be associated with an increased risk in the developing breast cancer.

Methods: We included 38 (38 F/Female) patients with breast cancer and 70 (44M/26F) healthy controls. The VNTR polymorphism in intron4 (intron4b/a) was analyzed by PCR. The results were statistically analyzed by calculating the odds ratios (OR) and 95% confidence intervals using the χ2 test.

Results: The distributions of genotype and allele frequency was compared among the groups. The bb, ab and aa genotypes were observed in 29 [76.3%], 9 [23.7%], 0 [0%] patients with breast cancer and in 33 [47.1%], 15 [21.4%], 22[31.5%] healthy controls respectively. The b and a alleles were observed in 67 [88.2%], 9 [11.8%] patients with breast cancer and in 81 [57.8%], 59 [42.2%] healthy controls respectively. The susceptibility to patients with breast cancer had significantly higher frequencies in bb genotype (p=0.004 OR=3.613). The patients with breastcancer had significantly lower frequencies in aa genotype (p=0.001,OR=1.458). The frequency of the a allele was significantly lower in the patients with breast cancer (p=0.001, OR=4.070).

Comparison of eNOS / VNTR polymorphism between patients with Breast and healthy control subjects.eNOS VNTRBreastHealthy ControlsOR*%95 CI*pGenotypesn=38 (%)n=70 (%)   BB29 (76.3)33 (47.1)3.613 a1.494-8.735 a0.004 a   3.065 b1.440-6.520 b0.004 bAB9 (23.7)15 (21.4)0.879 a0.343-2.252 a0.812 a   0.9020.388-2.096 b0.832 bAA0 (0)22 (31.5)1.458 a1.244-1.709 a0.001 a   12.375 b2.764-55.396 b0.001 bAllele     B67 (88.2)81 (57.8)5.422 a2.505-11.740 a0.001 aA9 (11.8)59 (42.2)4.070 b2.199-7.533 b0.001 b* Fisher's Exact Test a, comparison of genotype and allele frequencies between breast and healthy control groups

Conclusion: We conclude that there was sensible correlation between eNOS gene intron 4b/a VNTR polymorphism and the risk of breast cancer and bb genotype frequency was significantly higher in these patients than healthy controls.

Citation Format: Gunaldi M, Isiksacan N, Pehlivan S, Binboga S. Endothelial nitric oxide synthase gene intron4 VNTR polymorphism in patients with breast cancer [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 P1-05-06.
Abstract P1-06-10: Combined tandem affinity purification mass-spectrometry technique with genome-editing CRISPR-Cas9 knockout screening to identify potential subunits in the BRCA1 complex
Authors: Zhao H , Jiang H , Sun W , Shao Z , Hu X
Published: May 2019

Background: Genomic instability is one of tumor characteristics. Enhancing the DNA damage load or impairing the ability of DNA damage repair has been therapeutics of cancer. Breast cancer type 1 susceptibility gene (BRCA1) has been studied a lot about the DNA damage and repair in breast cancer and ovarian cancer. BRCA1 mutation increases the risk of developing breast cancer by an eighth to tenth. The C terminal domain of BRCA1 can associates with three proteins Abraxas, Bach1 and CtIP in a phosphorylation-dependent manner forming mutually exclusive complexes, namely BRCA1-A, B, and C complexes. The BRCA1-A complex is necessary in DNA damage repair, and study implicates the complex play roles in chemotherapy resistance.

Methods: We explored tandem affinity purification mass-spectrometry (TAP-MAS) technique to identify potential subunits associated with NBA1(one component of BRCA1-A complex). Then we made the genome-editing CRISPR-Cas9 sgRNA library into lentivirus to infect U2OS cells. And 5 Gy dose of Ionizing radiation (IR) was used to induce DNA damage on the cell. After 14 days cultivation, we extracted the DNA from the cells, performed polymerase chain reaction (PCR) and analyzed the correlation between potential genes and DNA damage-repair passage by bioinformatics methods. We generated 200 breast cancer patient tissue samples in our cancer center and performed immunostaining assay.

Results: By the TAP-MAS technique of NBA1 tagged with HA and Flag, we found 93 potential subunits except those known subunits in BRCA1-A complex. Combined with CRISPR-Cas9 sgRNA library screening, we scored the relativity of DNA damage and repair passageway of identified 93 potential subunits. We found that nucleoside-triphosphatase, cancer-related (NTPCR) as a new potential subunit of BRCA1-A complex (P value=0.0034) had the highest score. Endogenous and exogenous co-IP validated NTPCR physically associates with subunits within BRCA1-A complex. Besides, we found that NTPCR associated with the same domain of NBA1 as the other subunits in BRCA1-A complex. Immunohistochemistry of patient tissue samples indicated that high levels of NTPCR expression was correlated with poor prognosis in multivariate analysis (HR: 4.990; 95%CI: 1.433-17.378; p value: 0.012).

Conclusion: NTPCR is a new subunit in BRCA1-A complex. And high expression of NTPCR is a negative prognostic factor in breast cancer patients.

Citation Format: Zhao H, Jiang H, Sun W, Shao Z, Hu X. Combined tandem affinity purification mass-spectrometry technique with genome-editing CRISPR-Cas9 knockout screening to identify potential subunits in the BRCA1 complex [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 P1-06-10.
Abstract P1-11-05: Withdrawn
Authors: Bundred NJ , Foden P , Riches K , Morris J , Evans A , Todd C , Bramley M , Skene A , Watterson D , Purushotham A , Keeley V
Published: May 2019

This abstract was withdrawn by the authors.

Citation Format: Bundred NJ, Foden P, Riches K, Morris J, Evans A, Todd C, Bramley M, Skene A, Watterson D, Purushotham A, Keeley V. Withdrawn [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 P1-11-05.
Abstract P1-11-13: Depomedroxyprogesterone therapy for hot flashes in survivors of ER-expressing breast cancer: Impact on recurrence and survival
Authors: Ertz-Archambault N , Rogoff L , Kosiorek H , Ernst B , Anderson K , Pockaj B , Gray R , Northfelt D
Published: May 2019

Background

Survivors of ER-expressing operable breast cancer (ER+BC) generally do not receive hormone replacement therapy for menopausal symptoms due to concern about provoking recurrence of disease. Single dose depomedroxyprogesterone acetate (MPA) 400 mg IM has previously been shown (Loprinzi CL, et al. J Clin Oncol 2006;24:1409) to be the most effective non-estrogen therapy available for menopausal hot flashes (HF) but long-term evidence of safety in survivors of ER+BC is lacking.

Methods

Consecutive patients previously diagnosed with ER+BC who received MPA for HF between January 2007 and December 2012 were retrospectively identified in the breast cancer patient database at Mayo Clinic Arizona. Medical records were audited for breast cancer outcomes in these cases and in contemporaneous control patients with ER+BC who did not receive MPA, matched for age, stage of disease, and year of diagnosis. Statistical comparisons of local-regional recurrence and event-free survival were performed.

Results

92 patients who received MPA were identified and matched 1:1 with contemporaneous controls. Median follow-up duration was 5.7 years in cases and 4.5 years in controls. Estimated local-regional recurrence free survival at 10 years was 85% (95% CI, 72-100%) in cases and 95% (95% CI, 86-100%) in controls. Matched pairs hazard ratio was 1.0 (95% CI, 0.06-16.0) for local-regional recurrence free survival. Estimated event-free survival at 10 years was 81% (95% CI, 69-97%) in cases and 76% (95% CI, 64-92%) in controls. Matched pairs hazard ratio was 0.38 (95% CI, 0.10-1.41) for event-free survival. The majority (77%) of case patients experienced satisfactory relief of hot flashes from MPA injection.

Conclusion

In this retrospective case-control study we were unable to identify a detrimental effect of MPA therapy for HF in survivors of ER+BC. MPA may be acceptable for management of HF in this population.

Citation Format: Ertz-Archambault N, Rogoff L, Kosiorek H, Ernst B, Anderson K, Pockaj B, Gray R, Northfelt D. Depomedroxyprogesterone therapy for hot flashes in survivors of ER-expressing breast cancer: Impact on recurrence and survival [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 P1-11-13.
Abstract P1-16-07: Progression-free survival is a surrogate of survival in maintenance therapy for metastatic breast cancer: Randomized trial level analysis
Authors: Song E , Yao H , Yu Y , Ou Q , Wang Y
Published: May 2019

Background:The validity of progression-free survival (PFS) as a surrogate end point for overall survival (OS) in maintenance therapy trials of metastatic breast cancer (MBC) is uncertain. We aimed to compare treatment effect sizes and the strength of associations between OS and PFS in trials of maintenance therapy for MBC.

Methods: We searched for randomized trials investigating maintenance chemotherapy, endocrine therapy or immunotherapy after first-line chemotherapy in MBC and selected those reporting results for both OS and PFS. Treatment effect size differences between OS and PFS by a ratio of hazard ratios (rHRs) with 95% confidence intervals [CIs] were evaluated using random effects analysis. Surrogacy were analyzed using a weighted linear regression model, correlations were evaluated by squared correlation R2.

Results: We analyzed data from 16 trials and 3,898 patients that received maintenance chemotherapy, endocrine therapy or immunotherapy for MBC. In the all trial-level analysis, treatment effect sizes were 28% greater for PFS than for OS (combined rHR, 0.72; 95% CI, 0.62 to 0.85, P < 0.001), and the correlation coefficient R2 between PFS and OS was 18% (95% CI, 12% to 26%). Differences were greater with PFS than OS for trials of maintenance chemotherapy compared with observation (rHR, 0.72; 95% CI, 0.59 to 0.80, P < 0.001), and the correlation coefficient R2between treatment effects on PFS and on OS ranged from 12% (95% CI, 8% to 16%) when all trials were considered to 40% (95%CI, 30% to 54%) after exclusion of one highly influential trial by sensitivity analysis. Differences were also great for trials of maintenance endocrine therapy vs. observation (rHR, 0.54; 95% CI, 0.44 to 0.66), and immunotherapy vs. observation (rHR, 0.85; 95% CI, 0.80 to 0.91).

Conclusion: PFS was greater than OS in the treatment effect sizes, which is a valid surrogate end point for OS to assess treatment effect in MBC maintenance therapy trials.

PROSPERO registry: No. CRD42017071858; Support: ChiCTR-IIR-17014036, SYS-C-201801.

Citation Format: Song E, Yao H, Yu Y, Ou Q, Wang Y. Progression-free survival is a surrogate of survival in maintenance therapy for metastatic breast cancer: Randomized trial level analysis [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 P1-16-07.
Abstract P1-20-06: Association of circulating tumor DNA with clinical outcomes in metastatic breast cancer patients
Authors: Tan AR , Symanowski J , Kim EN , Hosking M , Morris CD , Plagnol V , Farhangfar CJ , Ersek JL
Published: May 2019

Background: Circulating tumor DNA (ctDNA) can be used as a non-invasive method to detect and quantify genomic alterations (GA) in blood. We evaluated the relationship between ctDNA features, radiographic disease progression (RDP) and progression-free survival (PFS) in patients (pts) with metastatic breast cancer (MBC).

Methods: A retrospective analysis of 32 female MBC pts with plasma ctDNA tested prior to a radiology scan was performed. Plasma ctDNA tests were run by Inivata using a 36-gene panel for detecting point mutations, short insertions/deletions, and copy number variations. ctDNA features were tabulated for each pt and included number of genomic alterations (numGA), maximum mutant allele frequency (maxMAF), and sum of mutant allele frequency (sumMAF). Univariate and multivariable logistic regression (LR) models were used to explore ctDNA features associated with RDP. Univariate and multivariable Cox proportional hazards models were used to identify ctDNA features that were associated with PFS. All models included ctDNA features as continuous variables.

Results: Frequency of subtypes were 38% HR+HER2-, 28% HR+HER2+, 28% triple-negative, and 6% HR-HER2+. 97% had prior chemotherapy; 92% of HR+HER2-negative pts had prior endocrine therapy. 20 of 32 samples (69%) had GAs. The most common GAs were TP53 (50%), ESR1 (25%), PIK3CA (19%), and GATA3 (9.4%). Median numGA was 1 (0-12); median maxMAF was 1.9 (0-65.5); median sumMAF was 2.2 (0-157.2). Univariate LR analysis identified numGA (p=0.025), maxMAF (p=0.034), and sumMAF (p=0.049) to be significantly associated with RDP; numGA (p=0.056) and maxMAF (p=0.109) were retained in the final multivariable LR model. Univariate Cox regression analysis showed that numGA (HR=1.32, p<0.001), maxMAF (HR=1.03, p=0.011), and sumMAF (HR=1.02, p=0.002) were significantly associated with PFS; numGA (HR= 1.30, p=0.001) and maxMAF (HR= 1.02, p=0.045) were retained in the final multivariable Cox model.

Conclusions: Blood ctDNA profiling contributes to the prediction of RDP and PFS in MBC pts. High number of alterations and high allele fraction of these alterations were associated with worse clinical outcomes. These data provide an overview of the ctDNA dynamics in treated MBC pts.

Citation Format: Tan AR, Symanowski J, Kim EN, Hosking M, Morris CD, Plagnol V, Farhangfar CJ, Ersek JL. Association of circulating tumor DNA with clinical outcomes in metastatic breast cancer patients [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 P1-20-06.
Abstract P2-01-20: LAP2alpha, a novel tumor marker candidate is related to metastasis of breast cancer
Authors: Hu Y , Qiu J , Zhou M , Li X , Huang Y
Published: May 2019

Background: To date, there is no suitable serum marker for diagnosis and prognosis of breast cancer. In our early research, a new tumor marker candidate of breast cancer whose molecular weight was 5.6 kDa was screened from serum using mass spectrometry technology. It was decoded to be a fragment of isoform alpha of lamina-associated polypeptide 2 (LAP2α). The survival analysis revealed that LAP2α was over-expressed in breast cancer patients and indicated poor prognosis.

Materials and Methods: Immunohistochemistry (IHC) was utilized to evaluate LAP2α expression in paired primary breast tumor, metastasis of axillary lymph node and ipsilateral normal breast tissue of 29 breast cancer patients. An inhibition plasmid vector of LAP2α-small hairpin RNA (LAP2α-shRNA) was constructed and transfected into MCF-7 cells. The abilities of cell proliferation and metastasis were assessed both in vitro and in vivo. The association of LAP2α with epithelial-to-mesenchymal transition (EMT) was determined by western blot.

Results: LAP2α expression of paired tissue descended in order of metastasis of axillary lymph node (21/29, 72.4%), primary breast tumor (11/29, 37.9%) and ipsilateral normal breast tissue (4/29, 13.8%) (P<0.05 in comparisons between each two groups). CCK-8 experiments on transfected and control cells showed that inhibition of LAP2α could not influence cell proliferation. Transwell and matrigel-transwell assays indicated that inhibition of LAP2α could significantly reduce cell migration and invasion abilities. In vivo experiments utilizing subcutaneous xenograft model and tail vein-injection mouse model revealed that the down-regulation of LAP2α might suppress tumorigenesis and metastasis of breast cancer. Western blot suggested that down regulation of LAP2α increased the E-cadherin expression level but repressed N-cadherin and vimentin expression levels.

Conclusions: A novel tumor marker candidate, LAP2α is related to metastasis of breast cancer both in clinical samples and tissue culture experiments. Inhibition of LAP2α could suppress aggressiveness and metastasis of breast cancer probably via EMT suppression.

Funding: The Natural Science Foundation of Zhejiang Province of China (No. LY14H160030 and LY13H160011), the National Program on Key Basic Research Project of China (973 Program; No. 2014CB542003), the National Natural Science Foundation of China (No. 30801341) and Zheng Shu Elite Scholarship for Clinical Medicine.

Citation Format: Hu Y, Qiu J, Zhou M, Li X, Huang Y. LAP2alpha, a novel tumor marker candidate is related to metastasis of breast cancer [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 P2-01-20.
Abstract P2-02-01: Inhibition of creatine kinase metabolism represses invasion and sensitizes estrogen-receptor negative breast cancer cells to standard chemotherapies
Authors: Barch HP , Krutilina R , Brooks DL , Parke D , Seagroves TN
Published: May 2019

Dysregulated tumor cell metabolism is a hallmark of cancer progression and therapeutic resistance. In a screen for Hypoxia-Inducible Factor (HIF)-dependent genes regulating metabolism, we identified creatine kinase, brain isoform (CKB) as down-regulated in HIF-1 knockout mammary tumor cells. CKB is a member of a family of cytosolic and mitochondrial creatine kinases (CKs) that reversibly catalyze the transfer of a high-energy phosphoryl group from ATP to creatine, generating local stores of phosphocreatine in the forward reaction, and re-generating ATP in the reverse reaction. Creatine kinases are up-regulated in a variety of solid tumors, including breast cancers. CK activity is inhibited by cyclocreatine (cCr), a creatine kinase substrate that represses the CK-dependent generation of ATP from phosphocreatine >170-fold. Knockdown of CKB in tumor cells derived from the polyoma middle T (PyMT) transgenic model of metastatic breast cancer did not impair cell proliferation or wound healing, but potently suppressed invasion in vitro, suggesting utility for treating stage IV disease. When female FVB/Nj mice were injected with wild type PyMT cells in a tail vein assay and then treated with cCr, lung metastasis was repressed to the same extent as CKB gene knockdown. These data were validated using a variety of human estrogen receptor (ER)-negative breast cancer cell lines. CKB loss- and gain-of-function models were created and effects on cell proliferation, survival, wound healing and ATP production were compared to cCr treatment. Overall, whereas deletion of CKB had no effect on cell proliferation or survival in either adherent or suspension conditions, either deletion of CKB or cCr therapy potently reduced intracellular ATP levels, which was associated with reduced invasive potential. In contrast, over-expression of CKB enhanced chemotaxis to EGF and invasion towards serum. Whereas cCr monotherapy is generally cytostatic, combination with either doxorubicin or paclitaxel is synergistic to kill tumor cells. Together, these data suggest that inhibition of CK activity may be effective in treating stage IV breast cancer patients with established metastatic disease. We are currently exploring the cell signaling and cell survival pathways that are altered by CKB gene deletion or cCr treatment to understand how the creatine kinase arm of metabolism promotes tumor progression, metastasis and response to conventional chemotherapies.

Citation Format: Barch HP, Krutilina R, Brooks DL, Parke D, Seagroves TN. Inhibition of creatine kinase metabolism represses invasion and sensitizes estrogen-receptor negative breast cancer cells to standard chemotherapies [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 P2-02-01.
Abstract P2-06-08: Withdrawn
Authors: Vena F , Bayle S , Quereda V , Monastyrskyi A , Duckett D
Published: May 2019

This abstract was withdrawn by the authors.

Citation Format: Vena F, Bayle S, Quereda V, Monastyrskyi A, Duckett D. Withdrawn [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 P2-06-08.
Abstract P2-06-23: New biomarkers for adjuvant bisphosphonate use in triple-negative breast cancer
Authors: Sandholm JA , Petruk N , Selander KS , Tuomela JM
Published: May 2019

We first showed that triple-negative breast cancer (TNBC) patients with low Toll-like receptor 9 (TLR9) expression have significantly worse prognosis than patients with high TLR9 expression. TLR9 is an innate immunity DNA receptor which is also expressed in several cancers, including TNBC. Later, we showed that low-TLR9 cells and tumors are more sensitive to amino-bisphosphonates, especially to zoledronate. Bisphosphonates (BP) inhibit osteoclasts and thereby effectively prevent bone fractures in osteoporosis and in cancer-induced bone disease. BPs also have direct anticancer effects. Interestingly, adjuvant BP use is associated with significantly improved progression-free and overall survival, but only among post-menopausal breast cancer patients. The molecular mechanisms behind this observation is unclear.

CD73 is a 70 kDa glycophosphatidylinositol-anchored cell protein, which converts adenosine monophosphate to adenosine and organic phosphate. High CD73 expression has been shown to have cancer cell invasion-promoting properties. On the other hand, CD73 is associated with poor prognosis in TNBC. Interestingly, TLR9 and CD73 have been shown to have inverse relationship in T cells and during colonic inflammation. Currently, we study the relationship of CD73 and TLR9 in vitroand in vivo upon BP treatment.

Our preliminary results show that TLR9 and CD73 have an inverse relationship also in TNBC cells. We use both nitrogen-containing (zoledronate and alendronate) and pyrophosphate-like (clodronate) BPs together with doxorubicin to study TNBC cell responses. We have seen that zoledronate and alendronate, but not clodronate, inhibited 4T1 murine triple-negative mammary tumor cell proliferation in a dose-dependent manner. Also, high concentrations of zoledronate and alendronate significantly inhibited 4T1 cell migration. Additionally, CD73 shRNA cells are more sensitive to zoledronate and alendronate, showing morphological changes and disruption in actin organization.

Our results suggest that CD73 expression may affect treatment responses to BPs in TNBC. Further, low-CD73 tumors could benefit more of BP therapy, compared with high-CD73 tumors.

Citation Format: Sandholm JA, Petruk N, Selander KS, Tuomela JM. New biomarkers for adjuvant bisphosphonate use in triple-negative breast cancer [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 P2-06-23.
Abstract P2-06-25: A phenotypic screening and machine learning platform efficiently identifies triple negative breast cancer-selective and readily druggable targets
Authors: Gautam P , Jaiswal A , Aittokallio T , Hassan A-A , Wennerberg K
Published: May 2019

Identifying effective oncogenic targets is challenged by the complexity of genetic alterations in cancer and their poorly understood relation to cell function and survival. This, combined with the fact that the majority of the proteome is predicted to be undruggable, may explain why genomic approaches have had only moderate success in identifying and translating oncogenic drug targets. There is a need for methods that rapidly and accurately identify “pharmacologically effective” targets without the requirement for priori knowledge of complex signaling networks. We developed an approach that uses machine learning to relate results from unbiased phenotypic screening of kinase inhibitors to their biochemical activity data. This process, which we call idTRAX (Identification of Drug TaRgets and Anti-targets by Cellular and Molecular Cross-referencing), identifies targets that are pharmacologically responsive and readily druggable. Additionally, the identified targets are not typically overcome by the robustness of signaling networks, because only targets that effectively induce a phenotype upon pharmacological engagement are selected. We applied this methodology to triple negative breast cancer, which still lacks targeted therapy. We screened 19 breast cancer cell lines with ˜500 small-molecule kinase inhibitors with annotated kinase activity data and identified cell-line specific kinase targets, i.e. kinases whose inhibition causes cell line-specific cytotoxicity or cytostaticity. We were able to identify various unique cell line selective kinase addictions along with well-known driver kinase addictions, for example, dependence on FGFR2 in the MFM-223 cell line and AKT kinases in MFM-223, CAL-148, and others. We also found that triple negative breast cancer cell lines exhibit heterogeneous target patterns, indicating the need of personalized medicine approach to tackle them. We further compared candidate targets identified by idTRAX with those reported from RNAi- and CRISPR-based screens. Strikingly, the correlation between targets identified by the pharmacological approach and those identified by knockdown/knockout-based screens was low [average rank correlation (ρ) = 0.0273- 0.1074], suggesting that gene-silencing approaches may not be the most efficient at identifying targets for small-molecule drug discovery or repurposing. Our approach provides a platform for rapidly identifying sample-specific drug targets and potentially guiding personalised therapy regimens.

Citation Format: Gautam P, Jaiswal A, Aittokallio T, Hassan A-A, Wennerberg K. A phenotypic screening and machine learning platform efficiently identifies triple negative breast cancer-selective and readily druggable targets [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 P2-06-25.
Abstract P2-08-48: Features associated with long-term survival in metastatic breast cancer
Authors: Klar NJ , Rosenzweig M , Diergaarde B , Brufsky A
Published: May 2019

Background: 5-10% of women with metastatic breast cancer (MBC) survive ≥5 years. Predictors of long-term survival are not clearly elucidated. We used data from 122 long-term MBC survivors (≥5-year survival from date of MBC diagnosis) and 191 short-term MBC survivors (≤2-year survival from date from MBC diagnosis) to identify clinico-pathologic and socioeconomic features associated with MBC survival.

Methods: Women initially diagnosed with breast cancer (BC) in or after 1999, and diagnosed with MBC at Magee Women's Cancer Program of UPMC were included (N=313). Data abstracted from medical records included: stage at initial BC diagnosis, body mass index (BMI), Charlson Comorbidity Index (CCI), age, menopausal status at initial BC diagnosis, tumor receptor status at initial BC diagnosis, site of initial metastases, time to recurrence between initial diagnosis and MBC, household income, race, employment status, and partner status. Differences between groups were assessed using t-tests and Chi-square or Fisher's exact tests. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression models.

Results: Long-term survivors were significantly (P<0.05) younger, had more ER positive, PR positive, and Her2 positive disease, lower CCI, more often premenopausal at initial diagnosis, lower rates of visceral metastases, higher household income, and more often partnered than short-term survivors. The association of premenopausal status at initial diagnosis with long-term survival remained significant after adjustment for stage at initial diagnosis, tumor receptor status, and CCI (OR: 1.96, 95% CI 1.02- 3.79). Long-term term survivors were also significantly more often diagnosed with de novo MBC compared to short-term survivors. The association of de novo MBC with long-term survival remained significant after adjustment for age, tumor receptor status, and CCI (OR: 3.0, 95% CI 1.6-5.4). Time to recurrence between initial diagnosis and MBC, BMI, race, and employment status were not associated with survival.

Conclusions: Diagnosis of de novo MBC, ER-, PR- and/or Her2-positive primary tumor, lower rates of visceral metastases, higher household income, younger age, lower CCI, premenopausal status, and having a partner are associated with long-term survival after diagnosis of MBC. This is one of the first studies to show a survival benefit in MBC for patients with de novo MBC, premenopausal status at initial diagnosis, positive partner status, and higher household income.

Citation Format: Klar NJ, Rosenzweig M, Diergaarde B, Brufsky A. Features associated with long-term survival in metastatic breast cancer [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 P2-08-48.
Abstract P2-08-55: Not presented
Authors: Zhang H , Liu T-H , Zhang L-Q , Li J , Cui J , Tian X-Y , Li D-N , Cai J-P
Published: May 2019

This abstract was not presented at the conference.

Citation Format: Zhang H, Liu T-H, Zhang L-Q, Li J, Cui J, Tian X-Y, Li D-N, Cai J-P. Not presented [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 P2-08-55.
Abstract P2-13-06: Long term clinical follow up of real world HER2-positive patients since the introduction of trastuzumab
Authors: Ellegard S , Asowed M , Engvall K , Hallbeck A-L , Elander N , Stål O
Published: May 2019

Background: The prognosis for patients with HER2-positive early breast cancer (EBC) has improved dramatically since the introduction of adjuvant trastuzumab therapy. With the addition of pertuzumab the prognosis has improved further. However, there is a need to study how these results from clinical controlled trials are transferred to the real-world clinical setting. In this study we aim to investigate all patients with early HER2-positive breast cancer in our region since the introduction of adjuvant trastuzumab to evaluate the implementation of trastuzumab treatment regarding treatment coverage, prognosis and survival.

Method: All patients with HER2-positve EBC, diagnosed between 2006 and 2014 in South-east Sweden were included in the study. The patients were identified using the Swedish national breast cancer register and then cross-referenced with data from the pathology department at each hospital in order to obtain complete coverage in a retrospective clinical follow up. In addition, data were collected from medical records for each patient to verify the actual given treatments and survival data.

Results: Preliminary data is available. 611 patients were included with a median follow-up time of 5 years. During the follow-up period the number of patients diagnosed with HER2-positive EBC cancer doubled. 73% of all patients received trastuzumab treatment; however the coverage increased successively from 56% in 2006 to 83% in 2013. ER-positive patients did receive trastuzumab therapy to the same extent as ER-negative patients. Local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS) and breast cancer specific survival (BCSS) at 5 years were 85%, 76%, and 75% for patients not receiving trastuzumab. In the trastuzumab treated group LRFS, DRFS and BCSS was 95%, 85% and 83% respectively. The group not receiving trastuzumab was significantly older, had more frequently node negative disease and was not treated with chemotherapy to the same extent.

Conclusion: A significant amount of early HER2-positive breast cancer patients did not receive adjuvant trastuzumab therapy between 2006 and 2014. In this group fewer patients received chemotherapy and despite less nodal involvement LRFS, DRFS and BCSS were poor for these patients.

Citation Format: Ellegard S, Asowed M, Engvall K, Hallbeck A-L, Elander N, Stål O. Long term clinical follow up of real world HER2-positive patients since the introduction of trastuzumab [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 P2-13-06.
Abstract P2-14-06: Withdrawn
Authors: Athanasiou I , Reed MW , Shrestha A , Cheung K-L , Audisio R , Collins K , Wyld L
Published: May 2019

This abstract was withdrawn by the authors.

Citation Format: Athanasiou I, Reed MW, Shrestha A, Cheung K-L, Audisio R, Collins K, Wyld L. Withdrawn [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 P2-14-06.