HER2 Breast Cancer Patients Research Articles

P113 - Survival comparison of HER2 breast cancer patients according to HR status: analysis of a single Portuguese centre

P113 - Survival comparison of HER2 breast cancer patients according to HR status: analysis of a single Portuguese centre

A nomogram to predict the high-risk RS in HR+/HER2-breast cancer patients older than 50\xa0years of age

BackgroundThe 21-gene recurrence score (RS) testing can predict the prognosis for luminal breast cancer patients. Meanwhile, patients > 50 years with RS > 25 have improved survival with adjuvant chemotherapy. The current study aimed to develop a nomogram with routine parameters to predict RS.MethodsWe included patients diagnosed with hormone receptor (HR)-positive, human epidermal growth factor receptor-2 (HER2)-negative who underwent the 21-gene RS testing and aged > 50 years. The primary outcome was high-risk RS (> 25). Univariate and multivariate analyses were performed to identify significant predictors. A predictive nomogram based on logistic model was developed and evaluated with receiver operating characteristic (ROC) curves. The nomogram was internally validated for discrimination and calibration with bootstrapping method, and externally validated in another cohort. We then assessed the nomogram in different subgroups of patients and compared it with several published models.ResultsA total of 1100 patients were included. Five clinicopathological parameters were used as predictors of a high-risk RS, including tumor grade, histologic subtype, ER expression, PR expression, and Ki-67 index. The area under the curve (AUC) was 0.798 (95% CI 0.772–0.825) and optimism adjusted AUC was 0.794 (95% CI 0.781–0.822). External validation demonstrated an AUC value of 0.746 (95% CI 0.685–0.807), which had no significant difference with the training cohort (P = 0.124). Calibration plots indicated that the nomogram-predicted results were well fitted to the actual outcomes in both internal and external validation. The nomogram had better discriminate ability in patients who had tumors > 2 cm (AUC = 0.847, 95% CI 0.804–0.890). When compared with four other existing models, similar AUC was observed between our nomogram and the model constructed by discriminate Lee et al.ConclusionsWe developed a user-friendly nomogram to predict the high-risk RS in luminal breast cancer patients who were older than 50 years of age, which could guide treatment decision making for those who have no access to the 21-gene RS testing.

Omission of Chemotherapy in HR+/HER2− Early Invasive Breast Cancer Based on Combined 6-IHC Score?

PurposeCurrent methods of judging whether HR+/HER2− breast cancer (BC) require adjuvant therapy, such as Ki67 and multigene prognostic tests, cannot balance accuracy with the price most patients can afford. MethodsA retrospective analysis of 330 HR+/HER2− BC patients was conducted. Six BC-related genes (Cathepsin L2, MMP11, CyclinB1, Aurora A, Survivin, and Ki67) were screened using univariate and multivariate COX regression, and correlate clinical follow-up with immunohistochemical expression (designated as 6-IHC). All the included patients were divided randomly at a 7:3 ratio into training and testing cohorts. The cutoff prognosis index (PI) of 6-IHC was determined by multivariate Cox risk regression analysis after calculating the PI of each patient in training cohort and confirmed in testing cohort. Kaplan-Meier (KM) method was used to analyze Disease-free survival (DFS) and overall survival (OS). Six-IHC score and other factors associated with survival benefit of adjuvant chemotherapy were compared with Ki67 index. ResultsThe receiver operating characteristic curve analysis showed that the patients can be divided into 6-IHC score “High” and “Low” risk groups. The 8-year DFS and OS of the KM curves showed that chemotherapy did not significantly improve the DFS in the 6-IHC score “Low” risk group (P= 0.830), but significantly improved the DFS in the 6-IHC score “High” risk group (P = 0.012). ConclusionsCombined 6-IHC score could be a reliable tool in predicting cancer-specific recurrences and survival in HR+/HER2-breast cancer patients, with additional advantages over using immunohistochemical expression of Ki67.

Expression and Prognostic Characteristics of m6 A RNA Methylation Regulators in Breast Cancer.

PurposeN6-methyladenosine (m6A) is the most prevalent modification in mRNA methylation which has a wide effect on biological functions. This study aims to figure out the efficacy of m6A RNA methylation regulator-based biomarkers with prognostic significance in breast cancer.Patients and MethodsThe 23 RNA methylation regulators were firstly analyzed through ONCOMINE, then relative RNA-seq transcriptome and clinical data of 1,096 breast cancer samples and 112 normal tissue samples were acquired from The Cancer Gene Atlas (TCGA) database. The expressive distinction was also showed by the Gene Expression Omnibus (GEO) database. The gene expression data of m6A RNA regulators in human tissues were acquired from the Genotype-Tissue Expression (GTEx) database. The R v3.5.1 and other online tools such as STRING, bc-GeneExminer v4.5, Kaplan-Meier Plotter were applied for bioinformatics analysis.ResultsResults from ONCOMINE, TCGA, and GEO databases showed distinctive expression and clinical correlations of m6A RNA methylation regulators in breast cancer patients. The high expression of YTHDF3, ZC3H13, LRPPRC, and METTL16 indicated poor survival rate in patients with breast cancer, while high expression of RBM15B pointed to a better survival rate. Both univariate and multivariate Cox regression analyses revealed that age and risk scores were related to overall survival (OS). Univariate analysis also delineated that stage, tumor (T) status, lymph node (N) status, and metastasis (M) status were associated with OS. From another perspective, Kaplan-Meier Plotter platform showed that the relatively high expression of YTHDF3 and LRPPRC and the relatively low expression of RBM15B, ZC3H13, and METTL16 in breast cancer patients had worse Relapse-Free Survival (RFS). Breast Cancer Gene-Expression Miner v4.5 showed that LRPPRC level was negatively associated with ER and PR expression, while METTL16, RBM15B, ZC3H13 level was positively linked with ER and PR expression. In HER-2 (+) breast cancer patients, the expression of LRPPRC, METTL16, RBM15B, and ZC3H13 were all lower than the HER-2 (−) group.ConclusionThe significant difference in expression levels and prognostic value of m6A RNA methylation regulators were analyzed and validated in this study. This signature revealed the potential therapeutic value of m6A RNA methylation regulators in breast cancer.

Diagnostic value of serum HER2 levels in breast cancer: a systematic review and meta-analysis

BackgroundMeasurement of serum human epidermal growth factor receptor-2 (HER-2/neu) levels might play an essential role as a diagnostic/screening marker for the early selection of therapeutic approaches and predict prognosis in breast cancer patients. We aimed to undertake a systematic review and meta-analysis focusing on the diagnostic/screening value of serum HER-2 levels in comparison to routine methods.MethodsWe performed a systematic search via PubMed, Scopus, Cochrane-Library, and Web of Science databases for human diagnostic studies reporting the levels of serum HER-2 in breast cancer patients, which was confirmed using the histopathological examination. Meta-analyses were carried out for sensitivity, specificity, accuracy, area under the ROC curve (AUC), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR).ResultsFourteen studies entered into this investigation. The meta-analysis indicated the low sensitivity for serum HER2 levels (Sensitivity: 53.05, 95%CI 40.82–65.28), but reasonable specificity of 79.27 (95%CI 73.02–85.51), accuracy of 72.06 (95%CI 67.04–77.08) and AUC of 0.79 (95%CI 0.66–0.92). We also found a significant differences for PPV (PPV: 56.18, 95%CI 44.16–68.20), NPV (NPV: 76.93, 95%CI 69.56–84.31), PLR (PLR: 2.10, 95%CI 1.69–2.50) and NLR (NLR: 0.58, 95%CI 0.44–0.71).ConclusionOur findings revealed that although serum HER-2 levels showed low se nsitivity for breast cancer diagnosis, its specificity, accuracy and AUC were reasonable. Hence, it seems that the measurement of serum HER-2 levels can play a significant role as a verification test for initial negative screening test results, especially in low-income regions due to its cost-effectiveness and ease of implementation.

Abstract 367: The role of A20 - Cdc20 axis promotes tumorigenesis and metastasis in triple negative breast cancer

Abstract Triple negative breast cancer (TNBC) has a higher mitotic index compared to other types of breast cancer yet Ki-67 values are still being used, despite an unclear mechanism. Here we found that the gene Cell-Division Cycle 20 (CDC20), an essential mitotic factor, was highly expressed in TNBC cell lines by using a NCBI GEO database. CDC20 was also negatively correlated with TNBC metastasis and recurrence. CDC20 deficiency results in the decreasing of TNBC cancer cell growth and migration, and mitosis inhibitors blocked TNBC cancer cells growth and metastasis. Interestingly, CDC20 stability is regulated by tumor necrosis factor, alpha-induced protein 3 (TNFAIP3 /A20). CDC20 expression show positive correlation with A20 in TNBC patient samples but not HR positive or HER2 breast cancer patients. A20 deficiency also inhibits cell migration and invasion through the decreasing of CDC20 protein level. Our findings uncover a critical role of the A20-CDC20 axis in tumor growth and metastasis of TNBC and suggest A20 or CDC20 is a novel therapeutic target in TNBC. Citation Format: Chaeun Song. The role of A20 - Cdc20 axis promotes tumorigenesis and metastasis in triple negative breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 367.

Monitoring Value of Serum HER2 as a Predictive Biomarker in Patients with Metastatic Breast Cancer.

PurposeThe aim of this study was to investigate the monitoring value of serum HER2 in patients with metastatic breast cancer.Patients and MethodsWe firstly evaluated the association of serum HER2 levels with tissue HER2 expression and imaging results in 420 breast cancer patients admitted into Tianjin Medical University Cancer Institute and Hospital between April 2016 and December 2018. Secondly, we analyzed serum HER2 levels in breast cancer patients with different metastatic degrees.ResultsThere is a higher correlation between serum HER2 and tissue HER2 in breast cancer patients with stage III (κ=0.670, p<0.001) and stage IV (κ=0.464, p<0.001). Serum HER2 levels were significantly associated with imaging results (κ=0.478, p<0.001). The ROC curve analysis showed that serum HER2 was superior to other serum markers for predicting metastatic breast cancer. Multinomial logistic regression revealed that the patients with higher serum HER2 levels would be more likely to have breast cancer metastasis.ConclusionSerum HER2 levels in breast cancer patients can partly reflect tissue HER2 expression and tumor imaging changes, and serum HER2 may be used as a biomarker for evaluating metastatic status in patients with breast cancer.

Abstract B63: Clearance of ctDNA in triple-negative and Her2-positive breast cancer patients during neoadjuvant treatment is correlated with pathologic complete response

Abstract Introduction: Previous studies have shown that levels of circulating tumor DNA (ctDNA) during therapy and post-surgery can stratify patients who exhibit effective responses versus those showing minimal residual disease. In this study, we performed longitudinal tracking of plasma TP53 and PIK3CA mutations prespecified from NGS analysis of tumor tissue specimens of HER2-positive and triple-negative (TN) breast cancer (BC) patients in order to demonstrate that ctDNA clearance during neoadjuvant treatment (NAT) correlates with effective response to treatment. Initially, we examined the degree to which clearance of TP53 and PIK3CA mutations in ctDNA during NAT correlated with pathologic complete response (pCR) in the resected specimen. Our findings suggest that effective ctDNA clearance may predict pCR. Moreover, these findings prompt further investigative trials that explore more fully the value of ctDNA monitoring to identify those patients who may avoid surgery following NAT. Patients and Methods: In initial analyses, tumor tissue samples from 18 TN or HER2 BC patients whoreceived NAT and showed significant response were analyzed for TP53 and PI3KCA mutations (Qiasymphony DNA midi and DNA Tissue Kits, respectively, QIAGEN). Plasma samples were obtained from all of these patients at diagnosis, after the 1st treatment cycle, during the middle of treatment, and prior to surgery. All TP53 and PIK3CA ctDNA analyses were carried out using the plasma SafeSEQ technology (Sysmex Inostics) and were only carried out on patient samples in which a specific TP53 or PIK3CA mutation had been initially identified in that patient’s tissue. All patients underwent a surgical excision after NAT. Results: Of the 18 patients, only 8 were found to have either a TP53 or a PIK3CA mutation (6 TP53 and 2 PI3KCA mutations). PI3KCA mutations were only detected in HER2-positive patients, whereas TP53 mutations were detected predominantly in TN patients (88%). After the 1st cycle of NAT, no mutations were detected in 6 (75%) patients while the 2 remaining (25%) demonstrated mutation clearance at the middle of treatment. Interestingly, one patient showed a TP53 baseline mutation (TP53 p.R273L) that was no longer detected after the 1st cycle of NAT, but a new mutation was detected at the time of surgery (TP53 p.R267W). Seven out of these 8 patients showing mutation clearance in ctDNA (88%) reached a pCR. Conclusions: ctDNA detected in plasma of patients with TN or HER2-positive BC showed a sharp decrease from the first cycle of NAT, reaching undetectable levels until the time of surgery and correlating with pCR. However, new mutations not previously present appeared, which may reflect the adaptation of the tumor to treatment. We are currently extending our analyses to reanalyze with an alternative NGS platform those tissue specimens for which no mutations were detected. Also, additional patient plasma and tissue specimens are undergoing analysis to evaluate the relationship between molecular MRD as determined by ctDNA and pCR. Citation Format: Nikaoly Ciriaco, Esther Zamora, Santiago Escrivá, Rosa Somoza, Javier Hernández-Losa, Santiago Ramón y Cajal, Martín Espinosa-Bravo, Vicente Peg. Clearance of ctDNA in triple-negative and Her2-positive breast cancer patients during neoadjuvant treatment is correlated with pathologic complete response [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B63.

Predictor of trastuzumab-induced cardiotoxicity in breast cancer (BC) patients: HER2/neu 655 polymorphisms, biochemical and clinical features.

1033 Background: The introduction of trastuzumab in the treatment scheme of the HER2 BC patients has improved the evolution of the disease. Nevertheless, some of this patients develop cardiotoxicity. We studied some of our population of HER2 positive BC patients treated with trastuzumab trying to find predictors for developing cardiotoxicity, specifically the association of the HER2 Ile655Val A˃G polymorphism with trastuzumab-induced cardiotoxicity and with survival and some biochemical and clinical features. Methods: For the study breast cancer patients were recruited from San Cecilio University Hospital in Granada (Spain) who were treated with trastuzumab. HER2 Ile655Val A˃G polimorphism was performed in 93 patients using Taqman SNP technology. We analyzed the relation of polymorphisms with disease free survival (DFS) and overall survival (OS). We also could asses 66 patients who had biochemical measurement of NTpro BNP during the treatment with trastuzumab and cardiovascular risk factors including diabetes, hypertension, smoking, hypercholesterolemia and body mass index (BMI). Cardiotoxicity was defined as a ≥ 10% decrease of the left ventricular ejection fraction (LVEF) from baseline, a LVEF below 40% or any clinical manifestation of heart insufficiency. NT-proBNP cut-off points were considered to stablish normal or abnormal values adjusted by patient age. Results: Genotype frequencies of HER2/neu 655 met Hardy-Weinberg equilibrium (p = 0.363). Logistic regression analysis adjusted by hormonal status and anthracycline treatment showed higher cardiotoxicity risk for AG vs AA Her2-Ile655 polimorphism (OR = 3.00, CI95% 1.07-8.41, p = 0.037) or for AG vs AA+GG Her2-Ile655 polimorphism (OR = 3.21, CI95% 1.15-8.96, p = 0.026). We did not find association between HER2neu Ile655Val polymorphism and DFS or OS. NT-proBNP baseline higher than the range (OR 5.9, 95% CI 1.2 - 28.5, p = 0.028) and diabetes mellitus (OR 22.0, 95% CI 5.7 - 85.4, p = 0.000) were found to be related with the development of cardiotoxicity. Conclusions: HER2-Ile655 A˃G polymorphism is significantly associated with higher risk of trastuzumab-induced cardiotoxicity but it is not correlated with DFS neither OS. Diabetes or baseline high NT-proBNP levels are predictors for the development of trastuzumab-induced cardiotoxicity. These parameters should be considered for a closer follow up and for preventive actions as accurate glycaemic control for patients who will receive trastuzumab.

Predicting Effects of Clinicopathological Variables on Her2 Gene Amplification by Chromogenic in situ Hybridization (CISH) in IHC Her2 (2+) Breast Cancer Patients; A Study from Iran.

Background & Objective:The her2 amplification plays an important role in breast cancer management. Therefore, there is a need for using supplementary molecular methods in IHC equivocal cases. Present study has been conducted to determine the effects of clinicopathological variables on her2 gene amplification by chromogenic in situ hybridization (CISH) in IHC Her2 (2+) breast cancer individuals.Methods:A cross-sectional study was conducted in Zaferanyeh Laboratory collaborated with Shahid Beheshti University of Medical Sciences (Tehran-Iran; 2015-2018). All pathological data related invasive breast cancer patients with equivocal IHC results were included. CISH method was performed as a supplementary technique. The associations between histopathologic variables, status of Ki-67 index, progesterone and estrogen receptors (PR & ER) with her2 amplification by CISH were investigated and analyzed. The level of significance was considered as P-value < 0.05.Results:Totally, 239 patients with mean age of 53.2 years were studied. CISH identified her2 gene amplification in 51 subjects (21.3%). The type of tumor (invasive ductal carcinoma), the tumor grade, and the value of Ki-67 index were directly correlated with her2 amplification. Significant negative associations were also observed between CISH results and ER and PR expression.Conclusion:As her2 gene amplification was identified in 21.3% of invasive breast cancer patients with equivocal IHC results, it is supposed that applying CISH method may consider as a potentially valuable supplementary method. Results have also shown that higher grades of tumor, invasive ductal carcinoma, absences of hormone receptors and high Ki-67 index significantly correlated with the her2 amplification.

TRASTUZUMAB INDUCED CARDIOTOXICITY: WITHOUT PRIOR ANTHRACYCLINES, DECREASE IN LEFT VENTRICULAR EJECTION FRACTION IS NEGLIGIBLE

In a randomized, double-blind, placebo-controlled trial, we enrolled HER-2 breast cancer patients into two arms depending on the anthracycline exposure prior to trastuzumab, and randomized them into placebo, lisinopril, and carvedilol. We reported the outcomes on prevention of cardiotoxicity.

Abstract P3-08-68: Application of 21-gene recurrence score in patients with T1-2, N0-1 ER-positive/HER2 negative breast cancer: Survival analysis in relation to clinical risk score

Abstract Background: Incorporating 21-gene recurrence score (RS) into daily practice have saved chemotherapy in about more than two-third of ER(+)/HER2(-) patients. In those with node-positive disease, 21-gene RS showed a clinically meaningful benefit in terms of reducing chemotherapy. We investigated the rate of chemotherapy and a short-term clinical outcome in patients with T1-2, N0-1 ER(+)/HER2(-) breast cancer after we actively applied 21-gene RS in our daily practice. Method: We identified T1-2, N0-1, ER(+)/HER2(-) breast cancer patients who underwent breast surgery followed by adjuvant treatment from January 2014 to December 2018. The clinical risk score (CRS) was defined as low and high based on histologic grade, tumor size, and nodal status as used in MINDACT trial. The rate of chemotherapy and survival outcomes were analyzed according to CRS and whether 21-gene RS was performed or not. Also, the patients were classified into 3 groups: Group A, endocrine alone without 21-gene RS; Group B, endocrine or chemo-endocrine guided by 21-gene RS; Group C, chemo-endo without 21-gene RS. In the patients between 2014 and 2016, we investigated the recurrence-free survival (RFS). Results: In a total of 1,008 patients, there were 446 (44.2%) for group A, 352 (34.9%) for group B, and 210 (20.8%) for group C, showing that 21-gene RS was done in about one-third of all. The rate of high CRS was 18.2% (81 of 446) in the group A, 42.3% (149 of 352) in the group B, and 71.0% (149 of 210) in the group C (P&amp;lt;0.001). In the low-CRS group, 36 (17.7%) of 203 patients with 21-gene RS received chemotherapy and 61 (14.3%) of 365 patients without 21-gene RS received chemotherapy (P=0.268). However, in the high-CRS group, 46 (30.9%) of 149 patients with 21-gene RS received chemotherapy although 149 (64.8%) of 230 patients without 21-gene RS received chemotherapy (P&amp;lt;0.001). In the patients eligible for survival analyses, a median follow-up was 36 months. In women treated with endocrine alone, there were no difference of RFS between the patients with or without 21-gene RS (P=0.147). Also, the RFS did not differ between two groups with or without 21-gene RS, regardless of CRS (log-rank test, P=0.657 in the high-CRS group, and P=0.803 in the low-CRS group, respectively). Conclusions: These results supported that the application of 21-gene RS reduced the rate of chemotherapy in N0-1 patients with high CRS. Further study with a long-term follow up is needed to clarify an oncologic safety of a reduced the chemo-endocrine rate brought by 21-gene RS in terms of survival outcomes. Key words: breast neoplasm, adjuvant treatment, 21-gene recurrence score, chemotherapy Citation Format: Soong June Bae, Sung Gwe Ahn, Soeun Park, Chi Hwan Cha, Dooreh Kim, Janghee Lee, Joon Jeong. Application of 21-gene recurrence score in patients with T1-2, N0-1 ER-positive/HER2 negative breast cancer: Survival analysis in relation to clinical risk score [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-68.

Circulating miR-21 is Down-Regulated Following Adjuvant Chemotherapy in Breast Cancer Patients

Breast cancer is one of the most prevalent known cancers in women with the incidence rate of annually 7000 cases in Iran. MicroRNAs (miRNAs) are a group of non-coding RNAs with 20–25 nucleotides length, which can effect on cancer development. There is low information about the influence of anti-cancer drugs on the expression levels of miRNAs. The present study is the first investigation to evaluate the down-regulation of circulating microRNA-21 (miR-21) expression in breast cancer patients after treatment with Doxorubicin and 5-fu drugs. The expression levels of miR-21 in paired blood plasma samples of 40 new cases of breast cancer patients, were analyzed by Real-Time Polymerase Chain Reaction (RT-PCR) with 2 repeats for each sample. miR-21 rates were evaluated before and after the treatment with Doxorubicin and 5-FU medicines and data were analyzed using t-test. Comparisons between plasma miRNAs before and after the chemotherapy suggested that the treatment has down regulated the circulating miR-21 expression in both HER2+ (Human Epidermal growth factor Receptor 2 positive) and HER2—breast cancer patients. According to the obtained results, it can be suggested that Doxorubicin and 5-FU drugs significantly decrease the circulating miR-21 expression, which might play a key role in anti-tumor effects (0.15 Fold change, P-value < 0.0001).

Targeted Treatment Trastuzumab is found to greatly Improve Long Term Survival of HER2 Breast Cancer Patients

Targeted Treatment Trastuzumab is found to greatly Improve Long Term Survival of HER2 Breast Cancer Patients

20P - Diagnostic value of serum HER-2 level in compression with tissue HER-2 in breast cancer: A systematic review and meta-analysis

BackgroundMeasurement of serum human epidermal growth factor receptor-2 (HER-2/neu) levels for breast cancer is still controversial and not recommended in any clinical procedures. However, it seems that HER-2 measuring can plays an important role as a diagnostic marker for early selection of therapeutic approach as well as predict of prognosis in breast cancer patients. We aimed to undertake a systematic review and meta-analysis focuses on the diagnostic value of serum HER-2 level measures by ELISA in compare to other methods due to its ease of implementation and cost-effectiveness for HER-2 positive two plus in IHC. MethodsWe performed a systematic search via PubMed, Scopus, Cochrane Library and Web of Science databases for human diagnostic studies reported the levels of serum HER2 in breast cancer patients, which was confirmed using histopathological examination such as immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Meta-analyses were carried out for sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR). ResultsFourteen studies entered into the study. The meta-analysis indicated that serum HER2 levels had sensitivity 53.05 (95%CI 40.82-65.28), specificity 79.27 (95%CI 73.02-85.51), accuracy 72.06 (95%CI 67.04-77.08), PPV 56.18 (95%CI 44.16-68.20), NPV 76.93 (95%CI 69.56-84.31), PLR 2.10 (95%CI 1.69-2.50) and NLR 0.58 (95%CI 0.44-0.71). ConclusionsOur findings revealed that, although serum HER2 levels showed a low sensitivity for breast cancer diagnosis, its specificity is significantly high in this regard. Hence, it seems that measurement of serum HER2 levels can play a significant role as a verification test for initial negative screening test results, especially in low-income regions due to its cost-effectiveness and ease of implementation in comparison with monitoring of tissue HER-2. Legal entity responsible for the studyAmir Shamshirian and Reza Alizadeh-Navaei. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

CDK12 drives breast tumor initiation and trastuzumab resistance via WNT and IRS1-ErbB-PI3K signaling.

Cyclin-dependent kinase 12 (CDK12) has emerged as an effective therapeutic target due to its ability to regulate DNA damage repair in human cancers, but little is known about the role of CDK12 in driving tumorigenesis. Here, we demonstrate that CDK12 promotes tumor initiation as a novel regulator of cancer stem cells (CSCs) and induces anti-HER2 therapy resistance in human breast cancer. High CDK12 expression caused by concurrent amplification of CDK12 and HER2 in breast cancer patients is associated with disease recurrence and poor survival. CDK12 induces self-renewal of breast CSCs and invivo tumor-initiating ability, and also reduces susceptibility to trastuzumab. Furthermore, CDK12 kinase activity inhibition facilitates anticancer efficacy of trastuzumab in HER2+ tumors, and mice bearing trastuzumab-resistant HER2+ tumor show sensitivity to an inhibitor of CDK12. Mechanistically, the catalytic activity of CDK12 is required for the expression of genes involved in the activation of ErbB-PI3K-AKT or WNT-signaling cascades. These results suggest that CDK12 is a major oncogenic driver and an actionable target for HER2+ breast cancer to replace or augment current anti-HER2 therapies.

Abstract 3412: Genomic signature of trastuzumab neoadjuvant therapy predictive of patient survival in HER2-positive breast cancer

Abstract Although the adjuvant use of trastuzumab has significantly improved survival, therapy resistance still plagues HER2-positive breast cancer patients. A recent clinical trial study showed that tumors exposed to single dose trastuzumab have increased Immune index and PD-1 expression1, suggesting that trastuzumab not only blocks HER2 signaling but also alters the tumor immune microenvironment. In order to identify genomic signature(s) of tumors that correlate with trastuzumab-induced tumor immune response, we analyzed eight HER2-positive breast tumors samples from patients treated with 2 or more cycles of neoadjuvant trastuzumab. First, we assessed the tumor immune environment using immunohistochemistry (IHC) with a specific interest in PD-1, a T cell immune checkpoint marker. Second, we conducted DNA/RNA sequencing and identified gene mutations and expression signatures. Lastly, we used the gene signature to evaluate survival outcomes of breast cancer patients using the TCGA dataset. DNA sequencing detected that two tumors contained deleterious TP53 mutations, two tumors activating PIK3CA mutations, and one tumor a GATA1 inactivating mutation, closely reflecting the prevalent gene mutation frequencies previously reported in breast cancer. Unsupervised clustering of the RNA sequencing data revealed two distinct clades in this patient cohort. The pathway analysis showed the gene list that distinguished the two clades included inflammatory genes such as TNFα and CXCL10 as well as immune checkpoint genes, CTLA-4 and iCOS. IHC staining for immune cell markers was consistent with the RNA sequencing results showing the presence of a large number of T cells positive for CD4, CD8, or PD-1 in tumors expressing pro-inflammatory genes. Supervised clustering of the two clades identified a gene signature composed of 59 upregulated and 24 downregulated genes in the “pro-inflammatory” clade. The gene signature effectively stratified HER2 breast cancer patients in the TCGA dataset with a striking Hazard Ratio of 7.3 (n=182, p = 0.0026, 95% C.I. 2.01-27.23) and patients with the “pro-inflammatory” tumors had significantly favorable survival outcomes. This patient stratification by the gene signature was uniquely specific to HER2-positive breast cancer, indicating a functional relevance of the gene signature related to HER2 cancer biology and/or therapy. These results support the idea that trastuzumab elicits local immune response, which contributes to therapeutic efficacy. Furthermore, patients with tumors containing the “pro-inflammatory” gene signature may benefit from immune checkpoint inhibitor therapy in combination with trastuzumab. 1Varadan et al (2016) Clin Cancer Res 22(13):3249-99 Citation Format: Natalia Briones, Salvatore Facista, Rebecca Halperin, Paul Heaton, Daruka Mahadevan, Wiiliam Hendricks, Suwon Kim. Genomic signature of trastuzumab neoadjuvant therapy predictive of patient survival in HER2-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3412.

PYK2 promotes HER2-positive breast cancer invasion

BackgroundMetformin, a biguanide, is one of the most commonly prescribed treatments for type 2 diabetes and has recently been recommended as a potential drug candidate for advanced cancer therapy. Although Metformin has antiproliferative and proapoptotic effects on breast cancer, the heterogenous nature of this disease affects the response to metformin leading to the activation of pro-invasive signalling pathways that are mediated by the focal adhesion kinase PYK2 in pure HER2 phenotype breast cancer.MethodsThe effect of metformin on different breast cancer cell lines, representing the molecular heterogenicity of the disease was investigated using in vitro proliferation and apoptosis assays. The activation of PYK2 by metformin in pure HER2 phenotype (HER2+/ER−/PR-) cell lines was investigated by microarrays, quantitative real time PCR and immunoblotting. Cell migration and invasion PYK2-mediated and in response to metformin were determined by wound healing and invasion assays using HER2+/ER−/PR- PYK2 knockdown cell lines. Proteomic analyses were used to determine the role of PYK2 in HER2+/ER−/PR- proliferative, migratory and invasive cellular pathways and in response to metformin. The association between PYK2 expression and HER2+/ER−/PR- patients’ cancer-specific survival was investigated using bioinformatic analysis of PYK2 expression from patient gene expression profiles generated by the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) study. The effect of PYK2 and metformin on tumour initiation and invasion of HER2+/ER−/PR- breast cancer stem-like cells was performed using the in vitro stem cell proliferation and invasion assays.ResultsOur study showed for the first time that pure HER2 breast cancer cells are more resistant to metformin treatment when compared with the other breast cancer phenotypes. This drug resistance was associated with the activation of PTK2B/PYK2, a well-known mediator of signalling pathways involved in cell proliferation, migration and invasion. The role of PYK2 in promoting invasion of metformin resistant HER2 breast cancer cells was confirmed through investigating the effect of PYK2 knockdown and metformin on cell invasion and by proteomic analysis of associated cellular pathways. We also reveal a correlation between high level of expression of PYK2 and reduced survival in pure HER2 breast cancer patients. Moreover, we also report a role of PYK2 in tumour initiation and invasion-mediated by pure HER2 breast cancer stem-like cells. This was further confirmed by demonstrating a correlation between reduced survival in pure HER2 breast cancer patients and expression of PYK2 and the stem cell marker CD44.ConclusionsWe provide evidence of a PYK2-driven pro-invasive potential of metformin in pure HER2 cancer therapy and propose that metformin-based therapy should consider the molecular heterogeneity of breast cancer to prevent complications associated with cancer chemoresistance, invasion and recurrence in treated patients.

Increased Mortality Risk among Early Stage Hormone Receptor Positive Breast Cancer Patients Who Did Not Receive Adjuvant or Neoadjuvant Therapy

Background: Hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) is the most common biologic subtype of breast cancer. Although adjuvant therapy has demonstrated a survival benefit in clinical trials, its use is poorly understood in the real-world among elderly breast cancer patients since age is a barrier to receiving adjuvant therapy. An examination of treatment patterns and outcomes associated with receipt of adjuvant/neoadjuvant therapy among elderly HR + HER2-breast cancer patients was undertaken. Methods: There were 18,470 HR + HER2-breast cancer patients from the linked SEER-Medicare database. Patients were diagnosed with stage I-III disease between 1/1/2007-12/31/2011, ≥66 years, enrolled in Medicare Parts A, B and D, and underwent breast cancer surgery after diagnosis. Time-varying Cox proportional hazards regression assessed overall survival. Results: There were 13,670 (74%) patients treated with adjuvant/neoadjuvant therapy and 4800 (26%) untreated. Compared to treated patients, untreated patients were older, had earlier stage, lower grade, smaller tumors, poorer performance, higher comorbidity score, and less use of a 21-gene recurrence score (RS) assay (p n RS assay was associated with lower risks. The Cox model showed a 48% higher risk of death in untreated compared to treated patients. In a subset of 8967 patients with stage I disease, tumor size Conclusions: Older patients with favorable clinical characteristics (earlier stage, smaller tumor, lower grade) are less likely to be treated and have a higher risk of death compared to adjuvant/neoadjuvant treated patients. An unmet need among older breast cancer patients persists.

Comparison of Tumor - Infiltrating Lymphocytes Between Primary and Metastatic Tumors in Her2+ and HER2-Breast Cancer Patients

The impact of tumor infiltrating lymphocytes (TILs) on survival was confirmed in various cancer types. Our study aims to investigate the prognostic role of TILs on survival in patients with primary and metastatic tumors in breast cancer patients. We retrospectively identified 29 patients with human epidermal growth factor receptor - 2 (HER2+) and HER2 - early breast cancer diagnosed between 2012 and 2018 at Institute of Oncology Prof. Dr. Al. Trestioreanu Bucharest and who subsequently experienced regional or distant recurrence confirmed by tumor biopsy/resection.