HER2 Overexpression Research Articles

Hedgehog Pathway Is a Regulator of Stemness in HER2-Positive Trastuzumab-Resistant Breast Cancer

HER2 overexpression occurs in 20–30% of breast cancers and is associated with poor prognosis. Trastuzumab is a standard treatment for HER2-positive breast cancer; however, resistance develops in approximately 50% of patients within a year. The Hedgehog (Hh) signalling pathway, known for its role in maintaining stemness in various cancers, may contribute to trastuzumab resistance in HER2-positive breast cancer. This study aimed to investigate the role of Hedgehog signalling in maintaining stemness and contributing to trastuzumab resistance in HER2-positive breast cancer cell lines. Trastuzumab-resistant HER2-positive breast cancer cell lines, SKBR3 and HCC1954, were developed through continuous trastuzumab exposure. Cells were treated with GANT61 (Hh inhibitor, IC50:10 µM) or SAG21K (Hh activator, IC50:100 nM) for 24 h to evaluate the Hedgehog signalling response. Stemness marker expression (Nanog, Sox2, Bmi1, Oct4) was measured using qRT-PCR. The combination index (CI) of GANT61 with trastuzumab was calculated using CompuSyn software(version 1.0) to identify synergistic doses (CI < 1). The synergistic concentrations’ impact on stemness markers was assessed. Data were analysed using two-way ANOVA and Tukey’s post hoc test (p < 0.05). Trastuzumab-resistant cells exhibited increased Hedgehog signalling activity. Treatment with GANT61 significantly downregulated stemness marker expression, while SAG21K treatment led to their upregulation in both SKBR3-R and HCC1954-R cells. The combination of GANT61 and trastuzumab demonstrated a synergistic effect, markedly reducing the expression of stemness markers. These findings indicate that Hedgehog signalling plays a pivotal role in maintaining stemness in trastuzumab-resistant cells, and that the inhibition of this pathway may prevent tumour progression. Hedgehog signalling is crucial in regulating stemness in trastuzumab-resistant HER2-positive breast cancer. Targeting this pathway could overcome resistance and enhance trastuzumab efficacy. Further studies should explore the clinical potential of Hedgehog inhibitors in combination therapies.

Evidence for Unified Assessment Criteria of HER2 IHC in Colorectal Carcinoma

HER2 expression is an important biomarker for the management of RAS wild-type metastatic colorectal carcinoma (CRC). Immunohistochemistry (IHC) with reflex in situ hybridization (ISH) is accepted as a standard method of assessment, yet there are currently two sets of criteria used to interpret results: the HERACLES criteria, and the My Pathway criteria. The HERACLES criteria require ISH confirmation when IHC staining is 3+ in 10-49% of cells, while the My Pathway criteria mirror those for gastric HER2 assessment and do not recommend ISH confirmation in the previously referenced scenario. We aimed to assess the prevalence of HER2 3+ heterogeneity and its association with ERBB2 copy number amplification (CNA) to evaluate the necessity of ISH testing when IHC staining is 3+ in <50% of cells.Next-generation sequencing (NGS) of DNA (592-gene panel or whole exome sequencing; WES) was performed for 13 208 colorectal carcinoma (CRC) tumors submitted to Caris Life Sciences (Phoenix, AZ). HER2 (4B5) expression was tested by IHC. A subset of tumors was tested for ERBB2 amplification via chromogenic ISH and/or via NGS (copy number amplification [CNA]). X2/Fisher-Exact tests were applied where appropriate, with p-values adjusted for multiple comparisons (p< 0.05).Of 13 208 CRCs with HER2 IHC, 87.4% (11 541/13 208) were negative for HER2 expression (intensity ≤3+ and < 10% tumor-cell staining) and 11.2% (1 473/13 208) demonstrated at least low HER2 expression (1-2+ and ≥10%). Only 1.5% (194/13 208) of all tested tumors were either positive or heterogeneously positive for HER2 overexpression (3+, ≥10%). Of these, 14% (28/194) had heterogenous HER2 overexpression (3+ staining of 10-49% of cells). Among 22 HER2-positive/heterogenous cases with successful ISH testing, 100% (22/22) demonstrated amplification via ISH.Because the classification of tumors as HER2-positive/heterogenous by IHC correlated very closely with ISH positivity, our results suggest that ISH is likely unnecessary for CRCs with 3+ HER2 overexpression in 10-49% of neoplastic cells.

Metabolic syndrome and risks of breast cancer outcomes for luminal, triple-negative, and HER2-overexpressing subtypes.

We evaluated the association between metabolic syndrome (obesity plus two metabolic risk factors) and breast cancer outcomes according to molecular subtype. This population-based prospective cohort consisted of 3,267 women aged 20-69 diagnosed with a first primary invasive breast cancer from 2004-2015 in the Seattle-Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression: luminal (ER+), triple-negative (ER-/PR-/HER2-), and HER2-overexpressing (H2E) (ER-/HER2+). We used time-varying Cox models to assess the association between prevalent and incident metabolic syndrome and risks of recurrence, breast cancer-specific mortality, and all-cause mortality. Metabolic syndrome was associated with a greater risk of recurrence (HR:3.24; 95% CI:1.13-9.33) and breast cancer-specific mortality (HR:5.34; 95% CI:2.32-12.31) only for the H2E subtype, and greater risks of all-cause mortality for luminal (HR:1.92; 95% CI:1.37-2.68), H2E (HR:5.09; 95% CI:2.51-10.32), and all cases combined (HR:1.90; 95% CI:1.42,2.53). We also observed heterogeneity in recurrence and mortality outcomes across specific components of metabolic syndrome and molecular subtypes. Metabolic syndrome is associated with all-cause mortality among women with breast cancer and with breast cancer-specific mortality among women with the H2E subtype. These results highlight the importance of managing comorbidities to decrease the risk for adverse outcomes among breast cancer survivors.

HLA-I and breast cancer prognosis: A systematic review and meta-analysis

BackgroundBreast cancer (BC) is a significant global health issue, accounting for 1 in 8 cancer diagnoses worldwide. HLA class I molecules are typically expressed on the cell surface, but cancer cells can develop mechanisms to evade recognition by CTLs, including the downregulation of HLA class I expression. In this context, we aimed to conduct a systematic review and meta-analysis to clarify the role of HLA class I expression in clinical outcomes for patients with BC. MethodsA comprehensive literature search was conducted across PubMed, Scopus, Web of Science, and the Cochrane databases. Effect sizes, along with I2 and Tau2 statistics, were used to assess heterogeneity through a DerSimonian and Laird random-effects model. Statistical analyses were performed using R statistical software, version 4.2.3. ResultsAmong the 8 included studies, most of the analyzed samples consisted of ductal carcinoma cases (1588, 86.39 %), from the luminal (A or B) intrinsic subtype (1865, 69.07 %), with no lymph node metastasis (2658, 57.24 %), no HER2 overexpression (2594, 67.46 %), negative Ki67 status (1721, 71.26 %), and positive hormone receptor status (4732, 64.05 %). The analysis revealed a significant reduction in disease-free survival (HR 0.57; 95 % CI 0.34 to 0.95; p = 0.034; I2 = 84 %) in the group with low HLA-I expression. However, no significant difference was found between the groups with high and low HLA-I expression regarding overall survival (HR 0.77; 95 % CI 0.28 to 2.14; p = 0.62; I2 = 86 %). ConclusionsThis systematic review and meta-analysis demonstrated that HLA class I expression is associated with a significant improvement in disease-free survival, though no significant effect on overall survival was observed.

Molecular and Clinicopathologic Characterization of HER2-overexpressed Squamous Cell Carcinoma of the Cervix.

HER2 amplification in cervical cancer has been associated with worse clinical prognosis and a potential favorable response to HER2 inhibitors. Immunohistochemistry for the HER2 receptor is a universally accepted surrogate test for HER2 amplification, but no standardized scoring system currently exists for cervical carcinomas. In this study, we investigated HER2 overexpression in cervical squamous cell carcinoma and correlated it with HER2 amplification using fluorescence in situ hybridization (FISH) and molecular methods. Seventy-two cases of human papillomavirus-associated cervical cancer were retrospectively reviewed, and at least 2 representative tumor sections were stained for HER2. HER2 scoring was performed using the 2018 American Society of Clinical Oncology/College of American Pathologist breast cancer criteria, and cases with equivocal (2+) to positive (3+) expression were analyzed for HER2 amplification using FISH and next-generation sequencing. The average patient age was 50yrs (range: 27-85yr), with most patients being African American (73.6%) and diagnosed at FIGO stage I (65.3%). Nineteen (26.4%) had equivocal HER2 expression and 4 (5.5%) showed positive expression. Three of the 4 cases with positive expression had enough tumors for FISH, and all 3 were amplified. Three cases with equivocal expression showed HER2 polysomy on FISH, and none showed HER2 amplification. Late clinical stage, high tumor grade, and regional lymph node metastasis were significantly correlated with HER2 overexpression and HER2 amplification. Next-generation sequencing of the 3 HER2-amplified tumors showed amplification of various genes, including CD274, JAK2, BIRC3, and ERBB2, and a PIK3CA missense mutation. In summary, HER2 immunohistochemistry is a reliable predictive marker of HER2 amplification in cervical cancer.

Association between Radiological and First-Order Statistical Features of the Mammogram, and the Tumor Phenotype in Breast Cancer Patients

Background: Breast cancer is among the most prevalent cancers which can effectively be screened by mammography. The spatial distribution of grey levels of the mammogram known as first-order statistical features (FOSFs) contain higher dimensional data which describe the breast composition. We aim to test these basic measures to differentiate density categories in breast cancer patients, and use them as covariates to investigate the relationship between radiologic and pathologic features of the tumor. Methods: Data from Eighty-five breast cancer subjects, their BI-RADS breast density category (a to d), percentage density (PD), and FOSFs of the mammogram including median, mean, interquartile range, kurtosis, maximum, minimum, standard deviation, skewness, and energy, were extracted. The tumor grade and the percentage of Ki67, ER, PR, and Her2 status were recorded. A linear discriminant analysis, and a support vector machine (SVM) were used to discriminate each density category from others. Then, the relation between variables were investigated using ANCOVA and regression analysis. Results: Density categories a and d were classified by SVM with high accuracy. The key feature of a and d were interquartile range and maximum intensities respectively. Reported tumor margins were related to Her2 overexpression and PR positivity. Spiculated tumor margin predicted percentage of PR expression, with a cumulative odds ratio of 7.85 (CI 2.5- 24.78), when adjusted for age, area of breast, density, and FOSFs, (p=0.0004). Conclusion: The findings of this study suggest that FOSFs can be incorporated in computer-aided systems to adjust for differences in breast composition and to refine risk profiles.

Clinicopathological characteristics of mucinous breast cancer: a retrospective analysis of a 6-years study from national cancer center in Vietnam.

To evaluate clinicopathological features in women with mucinous breast cancer (MBC), distinguishing between pure (PMC) and mixed (MMC) subtype. A retrospective analysis of all 358 women with MBC treated at Vietnam National Cancer hospital from June 2015 to December 2020. PMC was defined by ≥ 90% mucinous components. We identified 358 women with MBC (245 PMC and 113 MMC) representing 2.7% of all 13,254 BC patients. The proportions of stage I, II, III and IV were 34.9%, 50.8%, 10.4% and 3.9% respectively. The rate of HER2 overexpression was 12%, and only 1.4% of patients was treated with anti-HER2. 193 patients (53.9%) had chemotherapy, including 55 patients (15.4%) treated in the neoadjuvant setting. Only 3 patients (5.5%) achieved pCR. PMC patients were older (54.4 ± 13.3 vs 51.1 ± 13.1years), had lower Ki67 expression, lower incidence of nodal metastasis (N +) (p values < 0.05). At a median follow-up of 58months, the 5-year overall survival rate of non-metastatic patients was 86.6%. Multivariate analysis showed N + to be the most significant prognostic factor (HR = 3.3; 95%CI 1.5-7.1), followed by T-stage (HR = 2.9; 95%CI 1.4-6.3), HER2 + (HR = 2.5; 95%CI 1.2-5.3) and MMC subtype (HR = 1.9; 95%CI 1.0-3.9). Poor prognostic factors of MBC include high T-stage, N-positivity, HER2 overexpression and MMC subtype. Given the low response rate to neoadjuvant CT, upfront surgery is appropriate for MBC patients.

Mouse Models of HER2+ Human Breast Cancer: A Literature Review

Introduction: HER2+ breast cancer (BC) makes up 15-20% of BC cases, where HER2 overexpression drives BC progression via proliferative signals. Targeted therapies inhibit HER2's activity but face challenges like resistance and metastasis. Thus, HER2+ BC is a developing research area where many preclinical studies are being conducted, and mice are often used due to their genetic and physiological similarities to humans. This study aims to review and compare existing mouse models to determine the best model of HER2+ BC. Methods: A literature search on PubMed in February 2024 using search terms including HER2, neu, neuNT, MMTV, and mammary tumors identified 16 primary research articles that used Neu-overexpressing mice. The papers were categorized under five models: MMTV-Neu, MMTV-NeuNT, FloxNeo-NeuNT, MMTV-NIC, and MMTV-HER2. Results: Among examined studies, Andrechek et al.'s FloxNeo-NeuNT model had the longest average tumor onset at 447 days, while Kuang et al.'s MMTV-NIC had the shortest at 126 days. Ursini-Segal et al.'s MMTV-NIC mice showed 100% mammary tumor incidence. Most models resulted in mammary adenocarcinomas, with lung metastases commonly observed, especially in papers that used MMTV-NIC. Discussion: Human HER2+ BC is commonly adenocarcinoma and often metastasizes to lungs, bones, liver, and brain. The mouse models were also found to be adenocarcinomas, but they primarily showed lung metastasis, possibly due to insufficient tumor detection methods for brain and bone metastasis. Neu copy numbers in Andrechek et al.’s FloxNeo-NeuNT model also align with findings on HER2 copy number amplification in human HER2+ BC. Conclusion: We have found that MMTV-NIC is the optimal mouse model for HER2+ BC research due to its short latency, 100% tumor incidence, and high rate of lung metastasis.

Targeted PHA Microsphere-Loaded Triple-Drug System with Sustained Drug Release for Synergistic Chemotherapy and Gene Therapy.

The combination of paclitaxel (PTX) with other chemotherapy drugs (e.g., gemcitabine, GEM) or genetic drugs (e.g., siRNA) has been shown to enhance therapeutic efficacy against tumors, reduce individual drug dosages, and prevent drug resistance associated with single-drug treatments. However, the varying solubility of chemotherapy drugs and genetic drugs presents a challenge in co-delivering these agents. In this study, nanoparticles loaded with PTX were prepared using the biodegradable polymer material poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx). These nanoparticles were surface-modified with target proteins (Affibody molecules) and RALA cationic peptides to create core-shell structured microspheres with targeted and cationic functionalization. A three-drug co-delivery system (PTX@PHBHHx-ARP/siRNAGEM) were developed by electrostatically adsorbing siRNA chains containing GEM onto the microsphere surface. The encapsulation efficiency of PTX in the nanodrug was found to be 81.02%, with a drug loading of 5.09%. The chemogene adsorption capacity of siRNAGEM was determined to be 97.3%. Morphological and size characterization of the nanodrug revealed that PTX@PHBHHx-ARP/siRNAGEM is a rough-surfaced microsphere with a particle size of approximately 150 nm. This nanodrug exhibited targeting capabilities toward BT474 cells with HER2 overexpression while showing limited targeting ability toward MCF-7 cells with low HER2 expression. Results from the MTT assay demonstrated that PTX@PHBHHx-ARP/siRNAGEM exhibits high cytotoxicity and excellent combination therapy efficacy compared to physically mixed PTX/GEM/siRNA. Additionally, Western blot analysis confirmed that siRNA-mediated reduction of Bcl-2 expression significantly enhanced cell apoptosis mediated by PTX or GEM in tumor cells, thereby increasing cell sensitivity to PTX and GEM. This study presents a novel targeted nanosystem for the co-delivery of chemotherapy drugs and genetic drugs.

HER2-low non-metastatic breast cancer in Qatar-a nationwide retrospective cohort study to evaluate the response to neoadjuvant chemotherapy: a real-world analysis.

Globally, breast cancer is the most prevalent cancer and one of the leading causes of cancer-related death among women. HER2-low breast cancer represents a recently identified molecular category within breast cancer characterized by tumors displaying only slight overexpression of HER2 or lacking gene amplification. To illustrate, HER2-low tumors typically have an IHC (immune histochemistry) score of 1+ or 2+ with negative amplification. Nonetheless, recent findings indicate that even a slight amplification of HER2 could notably influence both therapeutic responses and prognostic outcomes. Our study aims to unveil the impact of HER2-low expression on the response to anthracycline and taxane-based neoadjuvant chemotherapy (NACT) in comparison to the HER2-negative group in non-metastatic breast cancer. This is a retrospective cohort study. All patients' profiles with non-metastatic, HER2-low, and HER2-negative breast cancers who were administered neo-adjuvant chemotherapy and had surgery performed within the period spanning from 1 January 2018 to 30 August 2022 were enrolled. HER2-positive breast cancer patients were excluded. The evaluation of patients' responses was conducted through the examination of surgical pathology reports to compare the two study groups (HER2-low and HER2-negative). The primary objective was evaluating the response to NACT comparing the objective response rate (ORR) in each of the two groups of HER2-low and HER2-negative patients. The total number of patients included was 262 patients; the majority were HER2-low 89% (233/262) vs. 11% (29/262) HER2-negative. An ORR (complete and partial response) to NACT was shown in 71% (185/262) of all patients. The ORR was similar in both groups, 70% (164/233) in the HER2-low group vs. 73% (21/29) in the HER2-negative group, with a statistical difference, OR: 1 (95% CI: 0.8-1), p-value 0.8. Similarly, the pathological complete response (pCR) rate was the same in both study groups at 14%, OR: 0.7 (95% CI: 0.2-3), p-value: 0.6. Interestingly, patients with hormone-positive tumors across both study groups had a higher response rate compared to hormone-negative patients. In the HER2-low cohort, the ORR was higher in patients with hormone-positive tumors in comparison with those with hormone-negative tumors [73% vs. 27%, OR: 0.8 (95% CI:0.8-1), p-value: 0.001]. Comparatively, in the HER2-negative cohort, ORR was also higher in patients with hormone-positive tumors compared to hormone-negative tumors [52% vs. 48%, OR: 2 (95% CI: 1-5), p-value: 0.05]. Subsequently, the ORR of all hormone-positive tumors with a positive outcome (CR or PR) was assessed categorizing the patients based on their HER2 expression. Concerning patients who expressed partial response (N = 115), a statistically significant difference was observed in HER2- low hormone-positive tumors as opposed to HER2-negative hormone-positive tumors [90% vs. 10%, OR: 0.7 (95% CI: 0.5-0.9), p-value: 0.001]. Remarkably, all patients with complete responses were from the HER2-low cohort. Our findings demonstrated a significant influence of HER2-low expression on the response to neoadjuvant chemotherapy among patients with hormone-positive HER2-low breast cancer within the studied cohort. Further studies are needed to evaluate the influence of hormonal expression on the response rate to NACT in the HER2-low patients in our population.

Expression of human epidermal growth factor receptor 2 (HER2) in colorectal cancer and its correlation with clinicopathological characteristic among Jordanian patients

Abstract Introduction/Objective Human epidermal growth factor receptor 2 (HER2/neu) is a well-established therapeutic target in breast and gastric cancers. Currently HER2 expression is being considered in other solid tumors including colorectal cancer (CRC). We aimed to investigate HER2 expression in CRC among Jordanians and its association with clinicopathological variables. Methods/Case Report Formalin-fixed, paraffin-embedded tissue blocks of 69 CRC cases were retrieved with their clinicopathological data. Tissue microarray (TMA) were constructed and immunostained using anti-HER2/neu 4B5 monoclonal antibody (Ventana, Tucson, AZ). HER2 scoring was performed by two experienced pathologists using the HERACLES criteria (HER2 positivity: cases of (3+) in ≥10% of cells and FISH-positive equivocal cases). Fisher’s exact/Chi-square test was used to investigate the association between HER2 s and clinicopathological data such as age, gender, histological differentiation, node and metastasis (NM) stage, and tumor site. Survival analysis was evaluated using Kaplan–Meier curves. Results (if a Case Study enter NA) Any degree (score) of HER2/neu expression was seen in 43.5 % of the cases. In 25 (36.2%), 4 (5.8%) and 1 (1.5%) the HER2 score was 1+, 2+ and 3+ respectively. The rest of the cases, 39 (56.5%) were scored as 0. Two of the four cases with a score (2+) required ISH testing to confirm amplification which was not performed. No significant association was found between HER2/neu expression and clinicopathological parameters or with survival. However, survival analysis showed that combined 2+/ 3+ group tend to have worse overall (OS) and event -free survival than the (0/1+) group. Conclusion The prevalence of HER2 overexpression in CRC is low among Jordanian patients, with only 1.5% of the study sample exhibiting definite HER2 overexpression. This rate is lower than the 3-5% rate reported in general, however the small sample size and lack of FISH confirmation might have contributed to this low rate. There was a trend towards worse OS and EFS in HER2 positive cases

Beamion LUNG-1, a Phase Ia/Ib trial of the HER2-specific tyrosine kinase inhibitor, zongertinib (BI 1810631), in patients with HER2-driven tumors: outcomes according to HER2 aberration type

Abstract Introduction/Objective Beamion LUNG-1 (NCT04886804) is an ongoing, Phase Ia/Ib trial evaluating the novel HER2- specific tyrosine kinase inhibitor, zongertinib, in patients with HER2 aberration-positive solid tumors (Phase Ia) and HER2 mutation-positive NSCLC (Phase Ib). Here, we report data from Phase Ia according to HER2 aberration type. Methods/Case Report Phase Ia enrolled patients with HER2 aberration-positive (by local assessment: gene mutations, rearrangements, amplification, or overexpression) advanced/metastatic solid tumors. Patients received escalating doses of zongertinib BID (≥15 mg) or QD (≥60 mg), guided by a Bayesian model with overdose control. The primary endpoint of Phase Ia was maximum tolerated dose (MTD) based on dose-limiting toxicities (DLTs). Results (if a Case Study enter NA) At data cut-off (January 29, 2024), 83 patients received zongertinib (BID n=17; QD n=66). Three patients had DLTs during the MTD evaluation period (G3 decreased platelets, G3 diarrhea, G4 neutropenia); the MTD was not reached. Treatment-related adverse events (TRAEs; all/G3/G4/G5) were reported in 76%/8%/1%/0% of patients. Confirmed investigator-assessed ORR/DCR rates in evaluable patients/patients with NSCLC (n=74/n=41) were 35%/85% and 44%/93%; median duration of response was 12.7/15.8 months, respectively. Based on preliminary data, 43 patients were HER2 mutation-positive (TKD/non-TKD/unknown n=36/n=6/n=1; A775_G776insYVMA n=16; G778dupGSP insertions n=3; S310F n=2); 23 patients overexpressed HER2 (2+/3+); 17 had HER2 amplification; 3 patients had NRG1 fusions. ORR/DCR rates (regardless of confirmation) in patients with TKD mutation-positive, A775_G776insYVMA-positive, non-TKD mutation-positive, G778dupGSP-positive and S310F- positive tumors were 64%/97%, 69%/94%, 20%/100%, 33%/100% and 50%/100%, respectively. ORR/DCR rates (regardless of confirmation) in patients with HER2 overexpressing tumors (+/- amplification) were 39%/83%. Of the 3 patients with NRG1 fusions, one had a partial response and two had stable disease. Conclusion In this preliminary analysis, zongertinib showed promising activity across a broad range of tumor types with different HER2 aberrations, including aberrations that have historically been difficult to treat. Updated data will be presented.

Affibody-Drug Conjugates Targeting the Human Epidermal Growth Factor Receptor-3 Demonstrate Therapeutic Efficacy in Mice Bearing Low Expressing Xenografts.

The outcome of clinical trials evaluating drugs targeting the human epidermal growth factor receptor 3 (HER3) has been poor, with primary concerns related to lack of efficacy. HER3 is considered a difficult target since its overexpression on tumors is relatively low and there is normal expression in many different organs. However, a significant number of patients across different cancer indications have overexpression of HER3 and the development of novel modalities targeting HER3 is therefore warranted. Here, we have investigated the properties of affibody-based drug conjugates targeting HER3. The HER3-targeting affibody molecule ZHER3 was fused in a mono- and bivalent format to an engineered albumin-binding domain (ABD) for in vivo half-life extension and was coupled to the cytotoxic drug DM1 via a non-cleavable maleimidocaproyl (mc) linker. In vivo, a moderate uptake was observed for [99mTc]Tc-labeled ZHER3-ABD-ZHER3-mcDM1 in HER3 expressing BxPC3 tumors (3.5 ± 0.3%IA/g) at 24 h after injection, and clearance was predominately renal-mediated. Treatment of mice with BxPC3 human pancreatic cancer xenografts showed that a combination of ZHER3-ABD-ZHER3-mcDM1 and its cytostatic analog ZHER3-ABD-ZHER3 was efficacious and superior to treatment with only ZHER3-ABD-ZHER3, providing tumor growth inhibition and longer median survival (90 d) in comparison to monotherapy (68 d) and vehicle control (49 d). ZHER3-ABD-ZHER3-mcDM1 was found to be a potent drug conjugate for the treatment of HER3-expressing tumors in mice.

Clinical and Molecular Characteristics of High-Risk, Recurrent, or Metastatic Endometrial Cancer That Is Human Epidermal Growth Factor Receptor 2-Low.

Recent success of human epidermal growth factor receptor 2 (HER2)-targeted antibody-drug-conjugate trastuzumab-deruxtecan in HER2-low and HER2-positive tumors has sparked interest in examining the HER2 status of tumors not traditionally associated with HER2 amplification. Despite the increasing number of systemic treatment options, patients with advanced endometrial cancer (EC) still face a poor prognosis. This study evaluates HER2-low status in over 800 EC, correlating HER2 with both molecular and clinical features. HER2 status was determined by immunohistochemistry (IHC) and dual in situ hybridization (DISH) on four studies of previously classified high-risk EC (PORTEC-3 and Medical Spectrum Twente cohort), recurrent or metastatic EC (DOMEC), and a primary stage IV cohort. EC was classified as HER2-negative (IHC 0), HER2-low (IHC 1+/2+ without amplification), or HER2-positive (IHC 3+ or DISH-confirmed amplification). Survival analysis was performed using the Kaplan-Meier method. Cox proportional hazards models assessed the independence of any prognostic impact of HER2 status. HER2 status was determined in 806 EC: 74.8% were HER2-negative, 17.2% HER2-low, and 7.9% HER2-positive. HER2-low was found across all molecular classes and histotypes. The highest rates of HER2-low and HER2-positive tumors were in recurrent or metastatic EC (35.6% and 15.6%), followed by primary stage IV EC (29.9% and 12.4%) and high-risk EC (14.2% and 6.8%). HER2 status had no independent prognostic value. A quarter of high-risk, metastatic, or recurrent EC exhibited HER2 overexpression. The presence of HER2 overexpression in all clinical and molecular categories highlights the need for broad testing and offers treatment options for a wide range of patients.

Brain Metastases from Esophageal Cancer: A Retrospective Review from a Single Institution

Patients with brain metastases (BrM) from esophageal cancer have poor prognosis, the incidence of which is expected to rise due to improved survival from the primary tumor and increased neuroimaging. We aimed to identify patient and esophageal cancer characteristics associated with shorter survival in patients with BrM and, secondly, to compare the prognosis of patients with HER2 overexpression. We retrospectively reviewed patients with BrM from esophageal cancer at a single institution from 2008-2021. We collected patient demographics, primary tumor and BrM characteristics, and treatment. Our primary outcome was median survival from the time of BrM. The median age at primary diagnosis was 66.5 years and 86% were male. Of the 49 patients, 71% had adenocarcinoma, 20% squamous cell carcinoma and 8% other. 71% of patients presented with stage III or IV disease, including 16% with synchronous primary and BrM. The median time to BrM was 10.1 months (IQR 1.7-22.8) and the median survival from BrM was 8.4 months (95%CI 4.8-16.8). On multivariable analysis, treatment with stereotactic radiosurgery (HR=0.19;p=0.04), surgical resection (HR 0.24;p=0.03) and immunotherapy (HR 0.19;p=0.04) were associated with increased survival while KPS ≤70 (HR=13.2;p<0.001) was associated with decreased survival. HER2 overexpression was found in 22% of patients, but we noted no survival difference (5.2 months HER2+ versus 9.8 months HER2neg;p=0.95). The median survival from esophageal-to-brain metastasis was 8.4 months. Patients with a single lesion, KPS score >70, and treatment with surgical resection was correlated with improved survival. Further, HER2+ patients had distinct patient and BrM characteristics.

318 (PB306): HER2 overexpression initiates breast tumorigenesis non-cellautonomously by inducing oxidative stress in the tissue microenvironment

318 (PB306): HER2 overexpression initiates breast tumorigenesis non-cellautonomously by inducing oxidative stress in the tissue microenvironment

Concordance of HER2 Expression in Paired Primary and Metastatic Sites of Endometrial Serous Carcinoma and the Effect of Intratumoral Heterogeneity

Primary endometrial serous carcinoma, known for its aggressive nature and poor prognosis, shares similarities with breast and gastric cancers in terms of potential HER2 overexpression as a therapeutic target. Assessing HER expression is complicated by tumor heterogeneity and discrepancies between primary and metastatic sites. In this study, we retrospectively analyzed HER amplification and expression in 16 pairs of primary endometrial serous carcinoma resections and corresponding metastases. HER2 status was determined using immunohistochemistry (IHC), with criteria based on the percentage and intensity of tumor cell staining. Confirmatory techniques, such as dual in situ hybridization (DISH) and fluorescence in situ hybridization (FISH), were also employed. This study reports on the concordance rates and the presence and pattern of HER2 heterogeneity. Our results showed an 87.5% concordance rate in HER2 amplification status between primary and metastatic sites, with 33% of cases scored as 2+ being amplified. Heterogeneity was observed in 100% of amplified cases and 95% of non-amplified cases on in situ testing, with variations in heterogeneity patterns between techniques. In conclusion, our findings emphasize the importance of testing both primary and metastatic sites or recurrences, with a concordance rate of 87.5%. In addition, a review of the literature and combining the results showed a concordance rate of up to 68%. The presence and pattern of heterogeneity, particularly in cases of mosaic or clustered heterogeneity in the primary tumor, may serve as reliable indicators of concordance, predicting a non-amplified HER2 status in corresponding metastases.

HER2 expression in upper tract urothelial carcinoma and the relationship with clinicopathological characteristics-an analysis of 155 patients in Southwest China.

We aimed to evaluate the expression of HER2 in patients with upper tract urothelial carcinoma (UTUC) in Southwest China by using a relatively large cohort, and to determine the relationship between HER2 expression and clinicopathological characters. We retrospectively enrolled the clinical data of 155 UTUC patients who have undergone radical nephroureterectomy (RNU) from March 2019 to September 2022. HER2 expression was assessed using immunohistochemistry and scored according to the HercepTest (Scores of 0 or 1 + were considered as negative and 2 + or 3 + as positive). Tumor molecular phenotype was classified by the panel of CK20, CK5/6, and CD44. HER2 was overexpressed in 55 (35.5%) patients. It was associated with pathologic characteristics such as grade (p = 0.017), tumor molecular phenotype (p < 0.001) and Ki-67 expression (p = 0.017). On univariate and multivariable logistic regression analysis, HER2 overexpression remained associated with higher grade (HR, 10.6; 95% CI 1.0-112.6; p = 0.050) and luminal molecular phenotype (HR, 8.0; 95% CI 1,6-38.4; p = 0.010). During disease progression after nephroureterectomy, the phenotype of the tumor might change and a switch phenomenon in phenotype after recurrence in the bladder was reported. According to our study, in Southwest China, one-third of UTUC patients overexpressed HER2. Tumors with high grade or luminal phenotype tended to be HER2 positive. HER2 may represent a promising target for therapy in UTUC.

Potential Advantages of Idarubicin-Loaded Trastuzumab-Coated Liposomes for Combating Head and Neck Squamous Cancer Cells.

Head and neck squamous cell carcinoma (HNSCC) with a high mortality rate is among the most common types of cancer in the world. Human epidermal growth factor receptor 2 (HER2) is expressed higher than normal level in the most HNSCC tumors, making them resistant to chemotherapy and radiotherapy. Therefore, HER2 has been introduced as a suitable target for anticancer drugs. The aim of this study is to examine the efficacy of a treatment protocol involving targeted delivery of idarubicin encapsulated in trastuzumab-decorated liposomes to HNSCC cells. In the current experimental study, efficacies of idarubicin, prepared liposomal idarubicin, and constructed immunoliposomal idarubicin (trastuzumab-decorated) were investigated in killing HN5 cells, a HER2- overexpressing HNSCC-originating cell line. Liposomal content of idarubicin and trastuzumab were qualified by UVVisible spectroscopy and preparations were characterized for shape and size by atomic force microscopy (AFM) and dynamic light scattering (DLS). To clarify role of the missing parts of the available crystal structure (PDB ID: 1n8z) within trastuzumab-HER2 interactions, we used a 40 ns molecular dynamic simulation approach. Based on the obtained results, liposomal idarubicin showed higher toxicity of the encapsulated drug on HN5 cells compared to the traditional free drug formulations. The immunoliposomal form of idarubicin was more effective than the liposomal formulation, in killing of HN5 cells. In addition, simulation of interactions between trastuzumab and HER2 revealed that the missing parts (in the crystal structure) of HER2 have critical interaction with trastuzumab, through salt-bridges and hydrogen bonds. It seems that the prepared immunoliposomes could attach more efficiently to HER2 overexpressing cells, which consequently leads to increasing cellular uptake of idarubicin through a receptor-mediated endocytosis mechanism. Moreover, simulation of the interaction between HER2 and trastuzumab suggested considerable possibilities for increasing trastuzumab affinity to HER2.

Prognostic Impact of Surgical Margin Status on Overall Survival of Patients with Early Breast Cancer: A Retrospective Analysis from the Department for Women's Medicine at Charité - University Hospital Berlin.

The impact of surgical margins on the prognosis of early breast cancer remains uncertain, particularly in the context of modern treatment approaches. This study aimed to investigate whether involved margins after surgery for early breast cancer affect overall survival. We conducted a retrospective analysis of 3767 patients who underwent surgery for primary breast cancer or carcinoma in situ between 2006 and 2022 at Charité - University Hospital Berlin. Survival analysis based on margin status and a subsequent multivariate Cox regression analysis were conducted. With a median follow-up of 72.2 months, clear margins were achieved in 81.4% of patients (n=3068) after primary surgery, while 16.2% (n=610) required re-excision. Only 2.4% of patients (n=89) had definitively involved margins. Margin involvement was more common in hormone receptor-positive disease, lobular subtype, carcinoma in situ, or locally advanced tumors, but less frequent in patients with previous neoadjuvant chemotherapy or triple-negative breast cancer. The Kaplan-Meier survival curves showed a significant separation with worse outcomes for patients with definitive R1 resections. However, the multivariate Cox regression analysis detected no statistically significant difference in overall survival based on margin status. Breast conserving surgery (HR 0.66; 95% CI 0.54-0.81) and HER2 overexpression (HR 0.65; 95% CI 0.48-0.89) were associated with improved survival. Patients who underwent breast-conserving surgery in our study demonstrated favorable outcomes compared to patients after mastectomy. Although margin status did not significantly affect overall survival, larger multicenter studies are needed to evaluate the prognostic implications of margin involvement in breast cancer treatment in different tumor stages, tumor subtypes and local and systemic treatments.