HER2 Protein Expression Research Articles

Abstract P4-10-26: Protein-protein interaction of HER2 predicts the prognosis of hormone receptor-positive HER2-negative breast cancer

Abstract Introduction: Patients with Hormone receptor (HR)-positive / HER2-negtive breast cancer have not received targeted therapy for Her2 based on criteria of the protein expression or DNA copy number amplification. However, the clinical meaning of the level of Her2 signaling activity has not been fully elucidated yet. We recently developed a novel technique of single-molecule protein-protein interaction (PPI) profiling to investigate the importance of HER2 signaling activity in this major subgroup of breast cancer. Methods: This study is a study with the biospecimen and registered medical record from the prospective collected cohort of Samsung Medical Center, and all of these biospecimens were provided by Samsung Medical Center BioBank. First, We selected 138 of 8463 patients who were diagnosed with invasive breast cancer by curative surgery between January 2008 and December 2013. Specimens were selected based on modified Allred Immunohistochemistry (IHC) scores; 6 for hormone receptors (ER/PR+) and 1 for Her2. Then, we applied the single-molecule co-immunoprecipitation, a novel technology determining protein-protein interactions (PPIs), to each selected biospecimen. PPI and expression level for HER2 protein of each tumor extract were analyzed with HER2-PPI-Dx kit. All the measurement were performed using a single-molecule fluorescence imaging equipment. Based on HER2 PPI and expression level analysis, we developed an algorithm based on the 72 patients’ samples which can predict the prognosis of these patients. This algorithm was validated with the samples from the other 66 patients. Results: In total, 138 samples from each patients (72 in training set and 66 in validation set) were analyzed. The median follow-up time was 68.0 (range: 7-123) months. Single-molecule measurement for HER2 level showed that clinical specimens showed significant differences in HER2-PPI level even though they had the same IHC score (65-fold from 117 patients with ‘HER2 IHC score: 0’ and 33-fold from 21 patients with ‘HER2-IHC score: 1’, respectively). For the training set, by combining HER2 PPI and HER2 protein expression data, we could select 12 patients (17%) as a high level HER2-PPI group. This high level HER2-PPI group showed the significantly poorer disease free survival (DFS) rate compared to that of the low level group (42% for high-level vs. 83% for low-level, p=0.001). For the validation set with the same cutoff, 17 patients (26%) with identified as high level HER2-PPI group. We still found a significantly poorer DFS rate in this group compared to that of the low level group (82% vs. 88%, p=0.033). For total 138 patients set, we found a significantly poorer DFS rate in this group compared to that of the low level group (p=0.014). Conclusion: Our results showed that HER2 PPI may have an important clinical meaning to identify a high risk of recurrence in the patients with strong HR-positive and HER2-negative breast cancers defined by conventional method. For those patients with high level HER2-PPI, HER2-targeted therapies may be beneficial despite of their HER2-negativity. This will be proved for the future. Citation Format: Hee Jun Choi, Hong Won Lee, Sangmin Kim, Tae-Young Yoon, Hyunwoo Kim, Seul Lee, Seok Jin Nam, Seok Won Kim, Sooyoun Cho, Yeon Hee Park, Jeong Eon Lee. Protein-protein interaction of HER2 predicts the prognosis of hormone receptor-positive HER2-negative breast cancer [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 P4-10-26.

Abstract P3-03-04: Role of ABL kinase signaling in metastatic breast cancer colonization of the brain

Abstract Breast cancer brain metastasis (BCBM) occurs in approximately 50% of late-stage Human Epidermal Growth Factor Receptor 2-positive (HER2+) breast cancer patients. BCBM may result in cognitive decline and cranial neuropathies and is associated with a median survival rate of nine months. Current therapies for BCBM, such as whole brain radiation therapy, can enhance cognitive impairment while targeted therapies and chemotherapy are ineffective. Despite the increased patient survival due to HER2 targeted therapies, patients often relapse due to brain metastases. Recently, our laboratory has discovered a role for Abelson (Abl) family of tyrosine kinases, ABL1 and ABL2, in breast cancer metastasis. Evaluation of 279 HER2+ breast cancer patients demonstrates a correlation between high expression of ABL1 and decreased distant metastasis free survival. Expression of ABL1 and ABL2 increase in brain metastatic breast cancer cells compared to parental cells, suggesting a role for the Abl kinases in breast cancer brain metastasis. I have found that treatment with the allosteric Abl kinase inhibitor GNF5 decreases colonization of the brain by two distinct human HER2+ breast cancer cell lines. Increasing evidence suggests that HER2 is upregulated in breast cancer cells colonizing the brain and may interact with the brain microenvironment to promote outgrowth. Both pharmacologic and genetic inhibition of the Abl kinases decreases HER2 protein expression in brain metastatic HER2+ breast cancer cells, potentially ablating the cell’s ability to proliferate in the brain. These data support a role for Abl kinases in promoting colonization of the brain by breast cancer cells. Due to its blood-brain barrier penetrance and efficacy in pre-clinical mouse models, Abl kinase-specific allosteric inhibitors may provide a novel therapeutic strategy for HER2+ breast cancer brain metastasis. Citation Format: Courtney Michelle McKernan, Ann M Pendergast. Role of ABL kinase signaling in metastatic breast cancer colonization of the brain [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 P3-03-04.

Plasma HER2ECD a promising test for patient prognosis and prediction of response in HER2 positive breast cancer: results of a randomized study - SAKK 22/99

BackgroundThe HER2 extracellular domain shed in blood (HER2ECD) is reported to rise and fall in parallel with HER2+ breast cancer behavior. In this study, we evaluated the clinical relevance of plasma HER2ECD values in patients with metastatic breast cancer treated in the SAKK22/99 trial comparing trastuzumab monotherapy followed by trastuzumab-chemotherapy combination at progression versus upfront combination therapy.MethodsQuantitative assessment of plasma HER2ECD was performed in 133 patients at baseline; after 2–24 h; at 3 weeks; at first response evaluation (8–9 weeks); and at tumor progression. Associations with tumor characteristics, disease course and trial treatment were evaluated.ResultsBaseline HER2ECD levels were stable within 24 h after the first trastuzumab injection. These plasma values correlated positively with the HER2 gene ratio (rs = 0.39, P < 0.001) and HER2 protein expression levels (rs = 0.36, P < 0.001) but not with ER/PR status of the primary tumor. HER2ECD baseline levels were positively associated with the presence of visceral disease (P = 0.05) and poor patients’ outcome (Cox-regression: P = 0.009). Patients with high baseline levels (> 35 ng/ml) had the worst overall survival (P = 0.03) if treated with upfront combination therapy. Conversely, patients with low HER2ECD baseline values (< 15 ng/ml) had longer time to progression on combined trastuzumab-chemotherapy when first treated with trastuzumab monotherapy (P = 0.02). Monitoring HER2ECD levels during the course of the trial revealed significant time (P = 0.001) and time-treatment arm interactions (P = 0.0007). Under upfront trastuzumab alone, the HER2ECD levels remained stable until just before disease progression. In patients responding to combination treatment HER2ECD levels decreased to > 20%.ConclusionsPlasma HER2ECD levels in patients with metastatic breast cancer reflect HER2 disease status. This robust biomarker might help identifying patients without visceral disease profiting from a sequential treatment’s modality. Monitoring HER2ECD levels during trastuzumab monotherapy could help defining the optimal time to introduce chemotherapy.Trial registrationRegistration Number by ClinicalTrials.gov: NCT00004935, Trial number: SAKK22/99. Registered on 27 January 2003.

The updated 2018 American Society of Clinical Oncology/College of American Pathologists guideline on human epidermal growth factor receptor 2 interpretation in breast cancer: comparison with previous guidelines and clinical significance of the proposed in situ hybridization groups

The aim of the study was to evaluate the impact of the updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline on human epidermal growth factor receptor 2 (HER2) interpretation in breast cancer compared with that of the previous guidelines and also the significance of in situ hybridization (ISH) groups proposed by the updated guideline. HER2 ISH reports and immunohistochemistry (IHC) data from 1,348 invasive breast cancers diagnosed at a single institution were included in this study. HER2 IHC was reassessed using the 2018 guideline, and HER2 ISH status was determined by the 2007, 2013, and 2018 guidelines. When applying the updated guideline, most of the HER2 ISH-equivocal cases as per the previous guidelines were reclassified as ISH negative, and 0.8% of HER2 ISH-positive tumors as per the 2007 guideline and 2.5% of those as per the 2013 guideline were changed to ISH negative. Accordingly, the negative HER2 ISH results significantly increased in the 2018 guideline compared with the 2013 guideline. HER2 ISH-positive tumors in ISH group 3 (HER2/chromosome enumeration probe 17 [CEP17] ratio <2.0 and average HER2 copy number ≥6.0 per cell) were characterized by equivocal HER2 protein expression, CEP17 copy number gain, and low HER2 copy numbers compared with classic HER2 ISH-positive tumors in ISH group 1 (HER2/CEP17 ratio ≥2.0 and average HER2 copy number ≥4.0 per cell). HER2 ISH-negative tumors in ISH group 4 (HER2/CEP17 ratio <2.0 with average HER2 copy number ≥4.0 and<6.0 per cell) revealed more aggressive clinicopathologic features and poorer clinical outcomes than those in ISH group 5 (HER2/CEP17 ratio <2.0 and average HER2 copy number <4.0 per cell), especially in the hormone receptor-positive subgroup. In conclusion, implementation of the updated 2018 ASCO/CAP guideline leads to a significant increase in HER2 ISH-negative results compared with the 2013 guideline, mainly via reclassification of the ISH-equivocal cases to ISH-negative ones. ISH groups proposed by the updated guideline provide additional information on the clinicopathologic characteristics of the tumors.

The assessment of HER2 status and its clinical implication in breast cancer

Amplification and overexpression of human epidermal growth factor receptor 2 (HER2) in breast cancer is associated with an adverse prognosis. The introduction of trastuzumab and lapatinib has substantially improved the clinical outcomes of patients with HER2-positive breast cancer. The key element of the successful application of anti-HER2 therapies in real-world has been the selection of candidates for treatment based on the level of HER2 positivity of the tumor. HER2 status of breast cancer is clinically assessed by HER2 protein expression with immunohistochemistry (IHC) or HER2 gene amplification with in situ hybridization (ISH). The 2018 American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) HER2 guideline focused update revised the HER2 scoring criteria. Digital image analysis (DIA) has emerged as an objective and reproducible IHC scoring method and the ASCO/CAP HER2 guideline has acknowledged DIA as a diagnostic modality. In this article, we aim to review the assessment of HER2 status and its clinical application in breast cancer.

Quantitative digital imaging analysis of HER2 immunohistochemistry predicts the response to anti-HER2 neoadjuvant chemotherapy in HER2-positive breast carcinoma.

Patients with HER2-positive breast cancer commonly receive anti-HER2 neoadjuvant chemotherapy and pathologic complete response (pCR) can be achieved in up to half of the patients. HER2 protein expression detected by immunohistochemistry (IHC) can be quantified using digital imaging analysis (DIA) as a value of membranous connectivity. We aimed to investigate the association HER2 IHC DIA quantitative results with response to anti-HER2 neoadjuvant chemotherapy. Digitized HER2 IHC whole slide images were analyzed using Visiopharm HER2-CONNECT to obtain quantitative HER2 membranous connectivity from a cohort of 153 HER2+ invasive breast carcinoma cases treated with anti-HER2 neoadjuvant chemotherapy (NAC). HER2 connectivity and other factors including age, histologic grade, ER, PR, and HER2 fluorescence in situ hybridization (FISH) were analyzed for association with the response to anti-HER2 NAC. Eighty-three cases (54.2%) had pCR, while 70 (45.8%) showed residual tumor. Younger age, negative ER/PR, higher HER2 DIA connectivity, higher HER2 FISH ratio and copy number were significantly associated with pCR in univariate analysis. Multivariate analysis demonstrated only age, HER2 DIA connectivity, PR negativity, and HER2 copy number was significantly associated with pCR, whereas HER2 DIA connectivity had the strongest association. HER2 IHC DIA connectivity is the most important factor predicting pCR to anti-HER2 neoadjuvant chemotherapy in patients with HER2-positive breast cancer.

Diverse roles of epidermal growth factors receptors in oral and cutaneous canine melanomas

BackgroundThe epidermal growth factor receptors participate in the physiological processes such as regulation of morphogenesis, proliferation and cell migration, but when overexpressed or overactivated they may play an important role in neoplastic progression. Melanoma is the most aggressive skin neoplasm and is characterized by elevated invasion and low survival rates in both humans and dogs. In human melanomas the overexpression of EGFR, HER3 or HER4 is associated with poor prognosis. In canine melanomas the epidermal growth factor receptors expression has not been evaluated. Therefore, this study evaluated the expression of epidermal growth factor receptors by immunohistochemistry and investigated their relationship with morphological characteristics and proliferative indices in cutaneous and oral canine melanoma.ResultsIn cutaneous melanoma an increased proliferative index was associated with increased cytoplasmic HER4 and reduced EGFR and HER3 protein expression. In oral melanomas, membranous HER2 protein expression correlated with occurrence of emboli, but ERBB2 gene amplification wasn’t observed.ConclusionThus, our work evidenced the relationship between HER4 and the stimulus to cell proliferation in cutaneous melanomas, in addition to the relationship between HER2 and the occurrence of emboli in oral melanomas.

Icaritin reduces prostate cancer progression via inhibiting high-fat diet-induced serum adipokine in TRAMP mice model.

Objective: Obesity resulting from high-fat diets has a close relationship with the morbidity and mortality associated with Prostate cancer (PCa) in males. The anti-cancer role of Icaritin (ICT, a traditional Chinese herbal medicine) has been reported in several types of cancer including PCa. Adipokines are novel adipocyte-specific secretory protein, which plays a key role in the development of various diseases including obesity, diabetes, atherosclerosis, and cancer. However, the function of ICT and the molecular mechanisms underlying its role in PCa regression through modulation of adipokines have not been studied. Here, we assessed the anti-cancer properties of ICT under the influence of human epidermal growth factor receptor type 2 (HER2) pathway modulating adipokines in obese PCa models.Materials and Methods: In this study, we used transgenic adenocarcinoma of mouse prostate (TRAMP), a well-established animal model for the study of PCa pathogenesis. All the animals were fed on a high-fat diet (HFD with 40% fat) and divided into two groups, one received ICT solution of 30 mg/kg body bwt (i.p) while the other group served as control without any ICT treatment. The mortality rate, tumor formation and fat ratio were assessed by histopathological and magnetic resonance analysis at different time points of 20th, 24th and 28th weeks. The protein expression of HER2 and serum levels of adipokines were measured using western blotting, IHC and multiplex immunoassays. The PCa grade in 12 TRAMP mice were longitudinally evaluated to visualize PCa development and progression upon post-surgery using PET/CT scanning.Results: We observed that ICT treatment significantly reduces the total mortality rate of TRAMP mice (p = 0.045) and the percentage of prostate intraepithelial neoplasia (PIN) or PCa (p = 0.029). Interestingly, significantly decreased levels of leptin (p = 0.006 @20th wk) and the elevated levels of adiponectin (p = 0.030 @20th wk) were observed in different subgroups upon ICT treatment in a time-dependent manner. In addition, a decrease level of HER2 (p = 0.032 @28th wk) and an elevated level of PEA3 (p = 0.014 @28th wk) were also detected in ICT treated group. The PET/CT-based imaging showed that ICT vs non-ICT treated mice had different standard uptake value and metastasis.Discussion and Conclusion: Our results showed potent anti-cancer properties of ICT through the modulation of adipokine secretion may alter the expression and activation of HER2 pathway as an alternative mechanism to prevent PCa progression. Altogether, our findings indicate that ICT could be a promising cancer preventive agent with the potential to target and eradicate tumor cells in obese PCa patients.

A Validation Study of Human Epidermal Growth Factor Receptor 2 Immunohistochemistry Digital Imaging Analysis and its Correlation with Human Epidermal Growth Factor Receptor 2 Fluorescence In situ Hybridization Results in Breast Carcinoma

Background: The Visiopharm human epidermal growth factor receptor 2 (HER2) digital imaging analysis (DIA) algorithm assesses digitized HER2 immunohistochemistry (IHC) by measuring cell membrane connectivity. We aimed to validate this algorithm for clinical use by comparing with pathologists’ scoring and correlating with HER2 fluorescence in situ hybridization (FISH) results. Materials and Methods: The study cohort consisted of 612 consecutive invasive breast carcinoma specimens including 395 biopsies and 217 resections. HER2 IHC slides were scanned using Philips IntelliSite Scanners, and the digital images were analyzed using Visiopharm HER2-CONNECT App to obtain the connectivity values (0–1) and scores (0, 1+, 2+, and 3+). HER2 DIA scores were compared with Pathologists’ manual scores, and HER2 connectivity values were correlated with HER2 FISH results. Results: The concordance between HER2 DIA scores and pathologists’ scores was 87.3% (534/612). All discordant cases (n = 78) were only one-step discordant (negative to equivocal, equivocal to positive, or vice versa). Five cases (0.8%) showed discordant HER2 IHC DIA and HER2 FISH results, but all these cases had relatively low HER2 copy numbers (between 4 and 6). HER2 IHC connectivity showed significantly better correlation with HER2 copy number than HER2/CEP17 ratio. Conclusions: HER2 IHC DIA demonstrates excellent concordance with pathologists’ scores and accurately discriminates between HER2 FISH positive and negative cases. HER2 IHC connectivity has better correlation with HER2 copy number than HER2/CEP17 ratio, suggesting HER2 copy number may be more important in predicting HER2 protein expression, and response to anti-HER2-targeted therapy.

Triple negative breast cancer: A thorough review of biomarkers.

Triple-negative breast cancer (TNBC) is defined as a type of breast cancer with lack of expression of estrogen receptor (ER), progesterone receptor (PR) and HER2 protein. The tumorigenesis is not likely to be driven by hormonal or HER2 pathway. In comparison to other types of breast cancer, TNBC stands out for its aggressive behavior, more prone to early recurrence. Historically, TNBC has been considered a disease with poor response to molecular target therapy, requiring better validation of biomarkers. Recent issues related to tumor heterogeneity have been widely discussed suggesting the subdivision of TNBC into different molecular subtypes. Through a complete research on the main published trials databases and platforms of ongoing clinical studies, the current manuscript was carried out in order to present a critical view of the role of immunohistochemical and molecular biomarkers for the prognosis and response prediction of TNBC to traditional therapy and new molecular target agents.

The prognostic impact of GSTM1/GSTP1 genetic variants in bladder Cancer

BackgroundThe glutathione S-transferases (GSTs) are a superfamily of phase II detoxifying enzymes that inactivates a wide variety of potential carcinogens through glutathione conjugation. Polymorphic changes in the GST genes have been reported to be associated with increased susceptibility to cancer development and anticancer drug resistance. In this study, we investigated the association between genetic variants in GSTM1 and GSTP1 and patients’ clinicopathological parameters. The prognostic values of such associations were evaluated among bladder cancer patients.MethodsGenotyping of GSTM1 and GSTP1 in bladder cancer patients was assessed using polymerase chain reaction followed by DNA sequencing. Overall survival was estimated using the Kaplan-Meier method and multiple logistic regression and correlation analysis were performed.ResultsThe GSTM1 null genotype was significantly associated with poor overall survival compared with the wild-type GSTM1 genotype. There was a trend towards better overall survival in patients with wild-type GSTP1 allele (AA) compared with GSTP1 (AG/GG) genotype. Interestingly, Kaplan-meier survival curve for GSTM1 null patients adjusted for sub-cohort with amplified HER2 gene showed poor survival compared with the GSTM1 null/ non-amplified HER2 gene. Also the same population when adjusted with HER2 protein expression, data showed poor survival for patients harboring GSTM1 null/high HER2 protein expression compared with low protein expression.ConclusionThis study focuses on the impact of GSTM1 null genotype on bladder cancer patients’ outcome. Further investigations are required to delineate the underlying mechanisms of combined GSTM−/− and HER2 status in bladder cancer.

Clinical significance of evaluating hormone receptor and HER2 protein using cell block against metastatic breast cancer: a multi-institutional study.

Hormone receptor and human epidermal growth factor receptor 2 (HER2) protein tests in metastatic breast cancer tissue are recommended in the guidelines of the American Society of Clinical Oncology/American Pathology Association. As part of a multi-institutional study by the National Hospital Organization, we conducted an investigation to examine these molecular markers, using cytological specimens as a substitute for tissue specimens from breast cancer metastasis. To confirm the usefulness of receptors tested in metastatic lesions, the treatment course of registered metastatic breast cancer patients was analyzed. During the April 2015 to March 2016 registration period, there were 62 registrations. Types of metastatic lesions include pleural fluid (44 samples), ascites (14 samples), lymph nodes (2 samples), pericardial fluid (1 sample), and dorsal subcutaneous mass (1 sample). A stable test result was obtained by adopting the receptor examination method, using cell block for immunostaining cytological specimens. The discordance rates of estrogen receptor (ER), progesterone receptor (PR), and HER2 protein expression were 18.2% (95% confidence interval (CI): 7.9–28.8%), 36.4% (95% CI: 23.7–49.1%), and 8.2% (95% CI: 0.1–16.3%), respectively, between the primary tumor and metastatic lesion. Patients who changed from primary negative to metastatic positive ER status had taken a significantly longer time for metastatic foci to appear. Patients with positive ER status in metastatic lesions had significantly better prognosis than ER-negative cases (P = 0.030) by the Log-Rank test. The ER status of the metastatic lesion and the metastatic site were independent prognostic factors by Cox multivariate analysis. Receptor examination with cytological specimens in metastatic lesions has been useful as it provides guidance for the treatment of metastatic breast cancer.

775P - Trastuzumab and pertuzumab added to neoadjuvant chemoradiotherapy in resectable HER2+ esophageal adenocarcinoma patients: An update on survival and predictive biomarkers in the TRAP study

BackgroundPreliminary data from the TRAP study demonstrated feasibility of neoadjuvant chemoradiation (nCRT) with trastuzumab and pertuzumab. Here, we present updated survival results with propensity score matching, including potential predictive biomarkers for response to this treatment. MethodsPatients (pts) with HER2+ resectable esophageal adenocarcinoma (EAC) received nCRT with trastuzumab and pertuzumab (Schokker et al, JCO 2018 suppl. 4057). Survival data was compared with patients not receiving study medication in the Dutch Cancer Registry, using propensity score matching (1:4) based on a logistical regression model, matching for baseline demographic and clinical characteristics. HER2 status was not included as a matching variable, since it was unknown in the majority of pts in the matched cohort. Associations between baseline F-FDG uptake on PET scans, measured by the maximum standardized uptake value (SUVmax), or ΔSUVmax and pathological complete response (pCR) were assessed. Furthermore, expression of HER2 and growth factor receptor-bound protein (Grb)7 was assessed by immunohistochemistry on baseline biopsies. Results were correlated with pCR and survival. Results40 pts were enrolled and pCR was seen in 34%. Progression-free survival (PFS) rates at 1 and 3 years were 83% and 72%, respectively, with 1- and 3-year overall survival (OS) rates of 90% and 71% (median follow-up 32.1 months). A statistically significant difference in OS was observed for nCRT with trastuzumab and pertuzumab compared to nCRT (3-year OS rate 71% vs 54%, p=0.039). Baseline and post-treatment PET scans were available for 40 and 34 pts, respectively. Baseline SUVmax was not predictive for recurrence or death, neither did ΔSUVmax correlate with pCR (p>0.05). HER2 3+ pts and pts with Grb7+ tumours at baseline demonstrated a significantly better response to treatment (p=0.016 respectively p=0.007). ConclusionsCompared to a propensity score matched cohort receiving nCRT, OS of pts with resectable HER2+ EAC receiving nCRT with trastuzumab and pertuzumab is statistically better. Grb7 and HER2 3+ are potential predictive biomarkers for response to this treatment. Clinical trial identificationNCT02120911 April 23, 2014. Legal entity responsible for the studyThe authors. FundingRoche. DisclosureR.H.A. Verhoeven: Research grant / Funding (self): Roche; Research grant / Funding (self): Bristol-Myers Squibb. M. van Oijen: Research grant / Funding (institution): Roche; Research grant / Funding (institution): Servier; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Nordic. G.A.P. Hospers: Advisory / Consultancy, Payment to institution: Amgen; Advisory / Consultancy, Payment to institution: Roche; Advisory / Consultancy, Payment to institution: MSD; Advisory / Consultancy, Research grant / Funding (institution), Payment to institution: BMS; Advisory / Consultancy, Payment to institution: Pfizer; Advisory / Consultancy, Payment to institution: Novartis; Research grant / Funding (institution), Payment to institution: Seerave. M. Bijlsma: Research grant / Funding (institution): Celgene; Advisory / Consultancy: Servier. M.I. van Berge Henegouwen: Honoraria (institution), Research grant / Funding (institution): Stryker; Honoraria (institution), Research grant / Funding (institution): Olympus; Honoraria (institution), Advisory / Consultancy: Medtronic; Honoraria (institution), Research grant / Funding (institution): Mylan. H.W.M. van Laarhoven: Honoraria (self), Advisory / Consultancy: Lilly/ImClone; Advisory / Consultancy, Research grant / Funding (institution): Nordic Group; Advisory / Consultancy, Research grant / Funding (institution): Bristol-Myers Squibb; Travel / Accommodation / Expenses: AstraZeneca; Research grant / Funding (institution): Bayer Schering Pharma; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): Janssen-Cilag; Research grant / Funding (institution): Lilly; Research grant / Funding (institution): Philips Healthcare; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Merck Sharp & Dohme. All other authors have declared no conflicts of interest.

HER2 testing of gynecologic carcinosarcomas: tumor stratification for potential targeted therapy.

A recent phase II clinical trial showed increased progression-free survival in patients with HER2-positive endometrial serous carcinoma receiving trastuzumab in addition to carboplatin-paclitaxel chemotherapy. Similar to endometrial serous carcinomas, carcinosarcomas of the female genital tract have a dismal prognosis and could potentially benefit from new targeted therapeutic approaches. We aimed to systematically evaluate the characteristics of HER2 expression/amplification in gynecologic carcinosarcomas using standardized staining methods and scoring criteria. Tumors from 80 patients (65 uterine, 15 tubo-ovarian) were included, containing a serous (60%), endometrioid (10%), clear cell (3%), undifferentiated (3%), neuroendocrine (1%), or mixed (24%) carcinoma, and either a homologous (46%), or a heterologous (54%) sarcoma component. HER2 scores were assigned to both components per the 2007 and 2013 ASCO/CAP breast scoring criteria. A total of 13 cases (12 uterine, 1 ovarian, 16%) were HER2 positive (either by immunohistochemistry or FISH) using the 2013 criteria, while only 10 cases (9 uterine, 1 ovarian, 13%) were HER2 positive per the 2007 criteria. Nine cases showed a change in their HER2 immunohistochemical score between the two scoring systems, including two cases with a change in the overall HER2 status from negative (2007) to positive (2013). Heterogeneity of HER2 protein expression was observed in 38% of HER2-positive tumors, and a lateral/basolateral membranous staining pattern was common. The sarcoma component showed 2+, equivocal HER2 expression in five cases, one of which also demonstrated HER2 amplification by FISH. All HER2-positive carcinosarcomas had either a serous or a mixed carcinoma component, and all but one HER2-positive tumors were of uterine primaries. Our study demonstrates that gynecologic carcinosarcomas share similarities in their HER2 expression/amplification profiles to endometrial serous carcinomas, which should be taken into account when assessing their HER2 status to ensure appropriate patient selection for potential targeted HER2-based therapies in the future.

Estrogen Receptor-positive Ductal Carcinoma In Situ Frequently Overexpresses HER2 Protein Without Gene Amplification

Overexpression of human epidermal growth factor receptor 2 (HER2) protein is well known to be more frequent in ductal carcinoma in situ (DCIS) than in invasive ductal carcinoma (IDC). However, the reasons for this difference are poorly understood. On the basis of the high frequency of estrogen receptor-positive (ER+) and HER2-positive (HER2+) DCIS, we hypothesized that this tumor type overexpresses HER2 protein without gene amplification and retrospectively investigated the HER2/neu gene status of 71 ER(+)HER2(+) DCIS, surgically removed during the 2007 to 2017 period, employing fluorescence in situ hybridization (FISH). To compare HER2 protein expressions between in situ and invasive components of individual tumors, 86 pT1mi/1a IDC with predominantly in situ disease were also examined. Furthermore, for comparison of FISH status between in situ and coexisting invasive components, another patient cohort, 78 FISH-positive IDC cases, were employed. To elucidate biological differences among DCIS with various combinations of ER and HER2 protein expressions, we also analyzed public microarray data of mRNA. HER2 gene amplification was observed in 35% of ER(+) and HER2 protein-overexpressing specimens, significantly lower than the 94% in ER-negative (ER-) and HER2 protein-overexpressing specimens (P<0.001). HER2 protein expression was decreased in the invasive component as compared with coexisting in situ portions in 40% of individual tumors, whereas the FISH status of these 2 components was well preserved. Moreover, ER(+) and HER2 protein-overexpressing DCIS showed significantly higher hypoxia-inducible factor-1α protein expression than the ER(+) and HER2 protein-nonoverexpressing tumors (P=0.016). We revealed that ER(+) and HER2 protein-overexpressing DCIS, especially ER-high tumors, frequently overexpress HER2 protein without gene amplification. Our data may provide novel insights for understanding the biology of DCIS.

In situ analysis of Her2 DNA and RNA in retinoblastoma and adjacent retina.

Retinoblastoma (RB) is an ocular tumor of early childhood. Current treatments attempt to preserve visual function, but may spare chemoresistant tumor cells. One potential therapeutic target for RB is HER2, (ERBB2), expressed in RB in truncated form. In this study, we tested the hypothesis that Her2 DNA and RNA are expressed in RB tumors and adjacent retina. We examined 24 human RB tumors as well as normal-appearing adjacent retinal tissues for Her2 DNA and RNA expression by in situ hybridization. We also examined 28 RB tumors for HER2 protein immunoreactivity. 21/22 RB tumors expressed Her2 DNA and 14/19 tumors expressed Her2 RNA. In 17 paired cases, there were three cases in which Her2 DNA was detected, but not RNA. We also saw Her2 RNA signal in six instances of “normal” adjacent retinal tissue. Heterogeneous HER2 protein expression in specific tumor regions also was confirmed by quantitative HER2 immunohistochemistry. In summary, Her2 DNA and RNA are expressed in many RB tumors, and in some adjacent ocular tissues, with hetereogenous protein expression throughout. These results may provide important insights regarding RB tumor progression, and drug targeting approaches designed to spare the eye, preserve vision and improve quality of life for RB patients.

HER2 double-equivocal breast cancer in Chinese patients: a high concordance of HER2 status between different blocks from the same tumor

PurposeHuman epidermal growth factor receptor 2 (HER2) status is both an independent prognostic factor and a predictive factor for the efficacy of targeted therapy for breast cancer, so it is critical to accurately detect HER2 protein expression and/or gene amplification. According to the recommendations of the 2013 American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) guidelines for HER2 breast cancer testing, an additional test should be pursued on a different block from the same tumor as one of the options for patients with immunohistochemistry (IHC) 2+ and a HER2/CEP17 ratio of < 2.0 with an average HER2 signals per tumor cell of ≥ 4.0 and < 6.0 by reflex test using dual-probe fluorescence in situ hybridization (FISH) (double-equivocal HER2). Our aim in this study is to explore the consistency of HER2 status between the two blocks.MethodsWe retrospectively analyzed 5685 primary invasive breast cancers between April 2015 and January 2019 from Peking Union Medical College Hospital. For cases with double-equivocal HER2 revealed in initial blocks, HER2 gene status was evaluated by FISH in a different block from the same tumor. The FISH score was interpreted according to the 2013 ASCO/CAP guidelines for HER2 testing.ResultsIn our cohort of 5685 specimens, the overall HER2 IHC3+, 2+, 1+ and 0 cases were 20.5%, 31.8%, 28.3%, and 19.5%, respectively. Then, 13.7%, 66.3%, and 20.0% of HER2 amplification, non-amplification, and equivocation rates were found, respectively, in IHC2+ patients (n = 1777) by reflex FISH assay. For specimens with double-equivocal HER2 (n = 333), HER2 status was assessed in another block from the same tumor by FISH and then the frequency of HER2 positive, negative, and equivocation was estimated at 5.7%, 22.5%, and 71.8%, respectively. Because double-equivocal HER2 cases are classified in the HER2 negative category by the 2018 ASCO/CAP HER2 testing guidelines, only 1.3% (19/1511) of HER2 positive patients were determined through additional HER2 testing in another block from the HER2 negative population.ConclusionsHER2 status in different blocks from the same tumor in primary invasive breast cancer was highly concordant. Our data supported the recommendation of the 2018 ASCO/CAP HER2 testing guidelines in breast cancer to remove the suggestion for additional HER2 testing using another block contained in the previous version.

A phase Ib/II study of HER3-targeting lumretuzumab in combination with carboplatin and paclitaxel as first-line treatment in patients with advanced or metastatic squamous non-small cell lung cancer

PurposeThis study investigated the safety and clinical activity of lumretuzumab, a humanised antihuman epidermal growth factor receptor 3 (HER3) monoclonal antibody, in combination with carboplatin and paclitaxel in first-line treatment of patients with squamous non-small cell lung cancer (sqNSCLC). HER3 ligand heregulin and HER3 protein expression were evaluated as potential biomarkers of clinical activity.Patients and methodsThis open-label, phase Ib/II study enrolled patients receiving lumretuzumab at 800 mg (flat) in combination with carboplatin (area under the curve (AUC) 6 mg/mL×min) and paclitaxel (200 mg/m2) administered intravenously on a every 3-week schedule. Adverse event (AE) rates and tumour responses were determined. Heregulin messenger RNA (mRNA) and HER3 protein expression were investigated in archival tumour biopsies.ResultsAltogether, 12 patients received lumretuzumab in combination with carboplatin and paclitaxel. The most frequent AEs were gastrointestinal, haematological and nervous system toxicities, which were generally mild and manageable. Partial responses were observed in 3 of 12 patients lasting 81, 177 and 207 days. All responses were achieved in tumours expressing higher heregulin mRNA levels.ConclusionLumretuzumab in combination with carboplatin and paclitaxel was well tolerated. Objective responses were enriched in tumours expressing higher heregulin mRNA levels.

Association of family history of tumors with clinicopathological characteristics and prognosis of colorectal cancer.

To investigate the association of family history of malignant tumors with clinicopathological characteristics of colorectal cancer, and its effects on prognosis. We conducted a retrospective review of pathological and follow-up data of patients with colorectal cancer treated in our hospital from January 2010 to December 2015. Of 870 patients undergoing surgery, 737 received follow-up (84.7%). Among them, 192 (26.1%) were family history of malignant neoplasm-positive [MN-FH (+)] and 545 (73.9%) were family history of malignant neoplasm-negative [MN-FH (-)]. MN-FH (+) patients had earlier disease onset, smaller tumor diameter, lower rate of lymph node metastasis, and lower depth of invasion. There were significant differences in BMI between the groups (P<0.05) but no differences in sex or tumor differentiation grade (P>0.05). Rates of Her-2 and p53 protein expression in MN-FH (+) patients were 34.3 and 40.5%, respectively, compared with 22.2 and 26.3% in MN-FH (-) patients. In stage 3, significantly higher Her-2 and p53 protein expression rates were observed in MN-FH (+) than in MN-FH (-) patients. Fluorescence in-situ hybridization showed significantly higher Her-2 expression in MN-FH (+) than in MN-FH (-) patients. The 3 and 5-year overall survival, disease-free survival, and progression-free survival were significantly lower in MN-FH (+) than in MN-FH (-) patients (P<0.05). MN-FH (+) patients with colorectal cancer had earlier disease onset and smaller tumor area, lower invasion depth, a lower rate of lymph node metastasis, and earlier TNM tumor stage at diagnosis than MN-FH (-) patients. BMI value distribution significantly differed between groups. However, long-term prognosis was worse for MN-FH (+) than MN-FH (-) patients, suggesting that internal pathogenic genes play a more crucial role than external environmental factors in prognosis. Family history of tumors could be an independent prognostic factor for colon cancer.

Abstract 29: Activity of trastuzumab emtansine (T-DM1) in 3D cell culture

Abstract Introduction: Cell spheroids/aggregates generated from three dimensional (3D) cell culture methods are similar to real tumors in terms of tissue morphology, biology, and gene expression. We performed a unique 3D cell culture drug efficacy study with Trastuzumab emtansine (T-DM1) across a number of breast cancer cell lines that were previously investigated in 2D cell culture (Lewis Phillips, et al, 2008). We obtained significantly different results for some cell lines grown as 3D spheroids/aggregates when compared to those grown as 2D cultures. Methodology: We performed 3D cell culture and produced FFPE blocks (using novel methods) from 3D spheroids/aggregates to determine HER2 (IHC) protein expression levels for five cell lines: SK-BR-3; BT-474; MDA-MB-361; MDA-MB-175 and MCF-7. We also performed HER2 gene-protein assay (HER2 GPA) to determine HER2 gene amplification along with IHC protein expression status in four cell lines: SK-BR-3; BT-474; MDA-MB-361 and MDA-MB-175. Drug (T-DM1) activity testing using CellTiterTM-Glo 3D cell viability assay was performed on 3D cell spheroids/aggregates for comparison with 2D cells. Images were obtained of T-DM1 internalization in BT-474 cells and spheroids using pHrodo™ iFL Human IgG Labeling Reagent. Results: In 3D spheroids/aggregates, HER2 IHC staining and GPA assay showed for SK-BR-3 and BT-474 HER2 3+ expression and HER2/CEP17 of ≥ 2; MDA-MB-361 cells with HER2 2+ expression and HER2/CEP17 of ≥ 2.0; MDA-MB-175 cells with HER2 1+ expression and HER2/CEP17 &amp;lt; 2.0 and MCF-7 cells with HER2 0+(IHC staining only without HER2 GPA data). Some of the 3D spheroids/aggregates in MDA-MB-361 cells showed heterogeneous expression of HER2 protein. The IC50 values of 3D spheroids/aggregates for some cell lines were significantly higher than were demonstrated for cell lines grown in 2D cell cultures. The fold changes between 3D spheroids and 2D cells (72h T-DM1 treatment time) are: 4.2 for SK-BR-3; ≳ 10 for BT-474 and 22 for MDA-MB-361. Additionally, the fluorescent images showed that a longer incubation time was required for the T-DM1 drug (3 µg/ml) to be internalized effectively into BT-474 3D spheroids; for example, about 120h for 3D spheroids in comparison to about 36h in 2D cells. Interestingly, the 3D spheroids incubated for 120h with T-DM1 (470 µm) are smaller in size than 3D spheroids in the control group (600 µm) incubated for 120h without T-DM1 treatment. Conclusions: Drug efficacy studies performed on 3D cultured spheroids/aggregates are expected to be very important and biologically relevant for determining drug activity in tumor tissue. Our drug efficacy study using 3D cell culture demonstrated greater concentrations of T-DM1 and longer incubation times were required than for cells grown as 2D in some cell lines, likely due to less efficient internalization. Citation Format: Jean Z. Boyer, Gail Lewis Phillips, Hiro Nitta, Karl Garsha, Eric May, Brittany Admire, Robert Kraft, Megan Peccarelli, Andre Zamorano, Scott Gill, Eslie Dennis, Liz Vela, Penny Towne. Activity of trastuzumab emtansine (T-DM1) in 3D cell culture [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 29.