HER2 Expression Research Articles

Efficacy and safety of RC48-ADC in HER2-positive and HER2-low metastatic breast cancer: a multicenter, real-world study

BackgroundA standard treatment recommendation for third-line and subsequent treatments for advanced HER2-positive breast cancer is still missing, especially for low HER2 expression. Nevertheless, there is evidence that these patients might benefits from antibody-drug conjugates (ADCs) treatment. Therefore, this study aimed to evaluate the clinical efficacy, safety, and factors affecting efficacy of Disitamab Vedotin (RC48) for treating HER2-positive and HER2-low metastatic breast cancer (MBC) in the real-world setting.MethodsA retrospective study at five clinical sites was conducted in China, enrolling MBC patients treated with RC48 from July 01, 2021 and May 31, 2023. Patient demographics, treatment patterns, and adverse events (AEs) were recorded and analyzed.ResultsA total of 154 patients were included: 104 (67.53%) patients with HER2-positive and 50 (32.47%) patients with HER2-low MBC. The median progression-free survival (mPFS) was 5.06 months. The objective response rate (ORR) and disease control rate (DCR) were 36.36% and 68.83%, respectively. HER2-positive patients exhibited a mPFS of 5.93 and an ORR of 41.35%. In contrast, patients with low-HER2 had a mPFS of 4.28 months and an ORR of 26.00%. The most common AEs included neutropenia (54.55%), increased AST (53.25%), leukopenia (51.95%), and fatigue (43.51%), mostly graded mild to moderate (grade 1-2).ConclusionsThis extensive study in China demonstrated that RC48 has excellent therapeutic potential for both HER2-positive and HER2-low MBC with a favorable safety profile. The study also suggests that combination therapy significantly boosts efficacy beyond monotherapy, indicating a promising avenue for future ADC development.

Differentiating HER2-low and HER2-zero tumors with 21-gene multigene assay in 2,295h + HER2- breast cancer: a retrospective analysis.

HER2-positivity is an essential marker for therapeutic decisions, while HER2 expression is heterogenous. In recent years, there has been increasing recognition of a subgroup of breast cancer patients who have low levels of HER2 expression, also known as HER2-low because trastuzumab deruxtecan offers clinical benefit for patients with HER2-low metastatic breast cancer. Despite the growing interest in HER2-low breast cancer, there is limited research on how multigene assays can help differentiate between HER2-low and HER2-negative breast cancer. Among HR + HER2- breast cancer, we compared genomic characteristics between HER2-low and HER2-zero using the 21-gene assay. A retrospective review of clinical records was performed in 2,295 patients who underwent Oncotype DX® test in two hospitals between 2013 and 2020. Patients were classified into two groups as the HER2-zero and HER2-low based on HER2 immunohistochemistry. In cases with HER2 2+, no amplification of HER2 gene was confirmed by silver in situ hybridization. High genomic risk was defined as cases with 21-gene recurrence score (RS) > 25. Multivariable binary logistic-regression analysis was performed. Of these, 944 (41.1%) patients were assigned to the HER2-zero group, while 1351 (58.9%) patients were assigned to the HER2-low group. The average Recurrence Score (RS) was found to be 17.802 in the HER2-zero breast cancer group and 18.503 in the HER2-low group, respectively (p-value < 0.005). When comparing the proportion of high RS between the two groups, the HER2-zero group had a high RS rate of 12.4% (117 out of 944), while the HER2-low group had a high RS rate of 17.0% (230 out of 1351) (p = 0.002). The HER2 score identified by qRT-PCR was 8.912 in the HER2-zero group and 9.337 in the HER2-low group (p < 0.005). In multivariable analysis, HER2-low status was found to be an independent factor for high RS, with an odds ratio of 1.517 (1.172-1.964), independent of ER, PR, and Ki67. Within the subgroup of patients with invasive ductal carcinoma, the high RS rates were 19% in the HER2-low group and 14% in the HER2-zero group. However, when considering all patients, there were no significant differences observed in recurrence-free survival and overall survival between the HER2-low and HER2-zero groups. Within HR + HER2- breast cancer, HER2-low tumors are associated with high RS, especially for histologically invasive ductal carcinoma. A prognostic influence of HER2-low expression among HR + HER2- breast cancer remains as an area that requires further study.

Single-cell sequencing unveils mitophagy-related prognostic model for triple-negative breast cancer

BackgroundTriple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer lacking hormone receptors and HER2 expression, leading to limited treatment options and poor prognosis. Mitophagy, a selective autophagy process targeting damaged mitochondria, plays a complex role in cancer progression, yet its prognostic significance in TNBC is not well understood.MethodsThis study utilized single-cell RNA sequencing data from the TCGA and GEO databases to identify mitophagy-related genes (MRGs) associated with TNBC. A prognostic model was developed using univariate Cox analysis and LASSO regression. The model was validated across multiple independent cohorts, and correlations between MRG expression, immune infiltration, and drug sensitivity were explored.ResultsNine key MRGs were identified and used to stratify TNBC patients into high-risk and low-risk groups, with the high-risk group showing significantly worse survival outcomes. The model demonstrated strong predictive accuracy across various datasets. Additionally, the study revealed a correlation between higher MRG expression levels and increased immune cell infiltration, as well as potential responsiveness to specific chemotherapeutic agents.ConclusionThe mitophagy-related prognostic model offers a novel method for predicting outcomes in TNBC patients and highlights the role of mitophagy in influencing the tumor microenvironment, with potential applications in personalized treatment strategies.

Current status and challenges in HER2 IHC assessment: scoring survey results in Japan.

This study aimed to assess the concordance of human epidermal growth factor receptor 2 (HER2) expression scoring by immunohistochemistry (IHC) among practicing pathologists in Japan, given the challenging nature of scoring and the critical role of HER2 status in breast cancer management. Whole slide images (WSI) from 20 invasive breast cancer cases (1 representative WSI per case) selected to represent a diverse IHC scores and staining patterns were used in an online survey involving seven reference pathologists who established consensus HER2 IHC scores (0 to 3 +) decided by majority interpretation. Participating pathologists nationwide scored the same 20 WSI cases online using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guidelines. Deidentified case metadata were registered in the uPath system. A total of 144 participating pathologists responded. The scoring results of the participating pathologists most commonly agreed with the consensus IHC score, followed by a ± 1 point deviation and no survey responses with > 1 point deviation. The mean percentage of agreement with the consensus score for all 20 cases was 63.4%. In cases where the reference pathologists' scores were discordant, the participating pathologists also showed a lower concordance rate. This study highlighted the current status of HER2 expression scoring by IHC for breast cancer among pathologists in Japan. These findings underscore the challenges in HER2 IHC scoring cases and emphasize the need for improved standardization and training, especially in the evolving landscape of HER2-targeted 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.

HER2 expression by next-generation sequencing versus immunohistochemistry in uterine serous carcinoma at a major gynecologic oncology referral center in the Southeast

HER2 expression by next-generation sequencing versus immunohistochemistry in uterine serous carcinoma at a major gynecologic oncology referral center in the Southeast

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.

A Comparison Between Immunohistochemistry and mRNA Expression to Identify Human Epidermal Growth Factor Receptor 2–Low Breast Cancer

Context.— Breast cancers (BCs) with low levels of human epidermal growth factor receptor 2 (HER2) expression (HER2-low) have become a targetable subset because of novel antibody-drug conjugates. HER2 immunohistochemistry (IHC) is the recommended assay for HER2 classification but is associated with limited interobserver agreement concerning HER2-low identification. Objective.— To investigate whether mRNA expression quantified via quantitative reverse transcription–polymerase chain reaction (RT-qPCR) could serve as a valuable complementary and more objective method to identify HER2-low BCs. Design.— We selected all cases from a previously published interobserver study, which included 105 needle biopsies from HER2 nonamplified BC cases. HER2 IHC was evaluated by 16 pathologists. For the current study, mRNA was extracted from microdissected invasive tumor cells. RT-qPCR was performed for quantitative evaluation of HER2, using the cutoff values of the MammaTyper assay. We compared the mRNA expression levels with the IHC scores of the majority agreement (IHC 0, IHC &amp;gt;0, &amp;lt;1+ [ultralow], 1+, 2+) and the following HER2 subcategories: HER2 0/ultralow and HER2-low (IHC 1+ and 2+/fluorescence in situ hybridization negative). Results.— In total, 88 nonamplified HER2 cases could be analyzed. Based on IHC, 17 cases were HER2 0/ultralow and 71 were HER2-low. The mean rank HER2 mRNA level was significantly higher in HER2-low cases than in the HER2 0/ultralow group (P &amp;lt; .001). However, 10 of 17 HER2 0/ultralow cases by IHC (58.8%) were classified as HER2-low by MammaTyper, 2 of 71 cases (2.8%) were HER2-low by IHC and HER2 0/ultralow by MammaTyper, and 2 (2.8%) were HER2-low by IHC and HER2-positive by RP-qPCR. Conclusions.— Our findings indicate a strong agreement between mRNA expression quantified by RT-qPCR and HER2 IHC scores, although there was a substantial proportion of discordant HER2 results between both methods owing to overestimation of HER2 expression by MammaTyper compared to IHC. Future large-scale trials should determine which technique is best associated with clinical outcome.

64Cu]Cu-NOTA-Trastuzumab and [89Zr]Zr-DFO-Trastuzumab in Xenografts with Varied HER2 Expression.

Positron emission tomography (PET) has potential as a complementary technique to biomarker analysis, especially for human epidermal growth factor receptor 2 (HER2)-expressing tumors characterized by high heterogeneity. In this study, zirconium-89 (89Zr) and copper-64 (64Cu) labeled trastuzumab were employed to monitor varying levels of tumoral HER2 expression. Additionally, we studied the use of the cholesterol-depleting lovastatin as a pharmacological approach to enhance cell-surface HER2 expression in tumors with moderate to low HER2 levels, aiming to increase antibody accumulation in these tumor types. Both 89Zr- and 64Cu-labeled trastuzumab effectively monitor HER2 expression levels in xenografts exhibiting varying HER2 expression. No significant difference in tumor uptake was observed between 89Zr- or 64Cu-labeled trastuzumab, and tumor uptake for both radioimmunoconjugates positively correlated with HER2 protein levels. These findings underscore the potential of PET to monitor HER2 protein levels across heterogeneous tumors. Furthermore, our results suggest that further optimization of statin dosing and timing could offer a promising strategy to enhance trastuzumab accumulation in HER2-high, HER2-moderate, and HER2-low tumors.

A Rare Case of Triple-Negative Breast Cancer with RAD51D Gene Mutation

Background: The heterogeneity of breast cancer (BC) subtypes poses a significant challenge, with carcinogenesis involving multiple stages and genes, including proto-oncogenes, tumor suppressor genes, and DNA repair genes. Next-generation sequencing has expanded access to multigene panels, such as RAD51 paralogs, which increase the risk of ovarian cancer and possibly triple-negative (TN) BC. Case presentation: We present a rare case of a 45-year-old woman with TNBC and a RAD51D gene mutation. Mammography and breast ultrasonography revealed an irregular, 30 mm hypoechoic area and dystrophic calcifications in the right breast. Immunohistochemistry showed a lack of expression of ER, RP, HER-2, and P53, with 50% of neoplastic cell nuclei positive for Ki-67. Next-generation sequencing revealed a mutation in RAD51D and MUYTH genes. The patient underwent partial mastectomy, chemotherapy, and prophylactic mastectomy. Conclusion: Genetic analysis is crucial for identifying specific mutations contributing to TNBC development. Current preventive interventions primarily address BRCA1 and BRCA2 mutations, following established guidelines.

Comparing the Sensitivity of HER2 Epitope Detection of HercepTest mAb pharmDx (Dako Omnis, GE001) and Ventana PATHWAY Anti-HER-2/neu (4B5) Using IHC Calibrators.

Accurate assessment of HER2 expression levels is paramount for determining eligibility for targeted therapies. HER2 immunohistochemistry provides a semiquantitative measurement of HER2 protein overexpression. Historically, little focus has been on the lower end of the HER2 expression range. The advent of novel therapeutic molecules that require fewer membrane epitopes to be effective has prompted a reevaluation of the current immunohistochemistry testing protocols, with special emphasis on the detection limit. Here, we have used Boston Cell Standards technology to determine the sensitivity of 2 commercially available HER2 immunohistochemistry assays, including a lower limit of detection.

Immunomodulatory effects of trastuzumab deruxtecan through the cGAS-STING pathway in gastric cancer cells

Although the efficacy of trastuzumab deruxtecan (T-DXd) against HER2-positive gastric cancers (GCs) has driven its clinical application, the precise mechanisms governing its immunomodulatory role remain unclear. In this study, we examined the immune-related mechanisms of action of T-DXd in GC cells. T-DXd exhibited potent antitumor effects in GC cells across diverse HER2 expression levels by inducing DNA damage and apoptosis. Activation of the DNA damage response by T-DXd led to increased PD-L1 expression. RNA-Seq analysis revealed that T-DXd modulated immune-related pathways, resulting in the upregulation of genes associated with inflammation and IFN signaling. Importantly, T-DXd activated the cGAS-STING pathway, inducing an IFN-I response in HER2-positive GC cells. Furthermore, T-DXd activated dendritic cells via the cancer cell-intrinsic cGAS-STING-IFN axis and enhanced PBMC-mediated tumor cell killing by activating CD8+ T cells. These findings provide valuable insights into the role of the cytosolic DNA sensing pathway in the action of T-DXd and offer a compelling rationale for combining T-DXd with immune checkpoint blockade therapies in GC treatment.

Trastuzumab Duocarmazine in Pretreated Human Epidermal Growth Factor Receptor 2-Positive Advanced or Metastatic Breast Cancer: An Open-Label, Randomized, Phase III Trial (TULIP).

Human epidermal growth factor receptor 2 (HER2)-targeted therapy is standard of care for HER2-positive (HER2+) breast cancer, but most patients develop progressive disease with persistent HER2 expression. No definitive treatment guidance currently exists beyond second line. Trastuzumab duocarmazine (T-Duo) is a third-generation, HER2-targeted antibody-drug conjugate that demonstrated efficacy and acceptable safety in phase I studies of heavily pretreated patients with HER2+/HER2-low breast cancer. In this open-label, randomized, phase III trial, T-Duo was compared with physician's choice (PC) in patients with unresectable locally advanced/metastatic HER2+ breast cancer with progression during/after ≥2 HER2-targeted therapies or after trastuzumab emtansine (T-DM1). The primary endpoint was progression-free survival (PFS) by blinded independent central review. In total, 437 patients were randomly assigned 2:1 to T-Duo (n = 291) or PC (n = 146). The median age was 56.0 years (range, 24-86); most patients (93.6%) had metastatic disease. The median time from diagnosis of metastatic disease to trial entry was 3.5 years; the median number of prior HER2-targeted therapies in metastatic setting was three. The median PFS was 7.0 months (95% CI, 5.4 to 7.2) with T-Duo versus 4.9 months (95% CI, 4.0 to 5.5; hazard ratio [HR], 0.64 [95% CI, 0.49 to 0.84]; P = .002) with PC. PFS benefit was maintained across most predefined subgroups. The median overall survival (first analysis) was 20.4 (T-Duo) versus 16.3 months (PC; HR, 0.83 [95% CI, 0.62 to 1.09]; P = .153). Objective response rate was 27.8% (T-Duo) versus 29.5% (PC); other efficacy end points-clinical benefit rate, duration of response, and reduction in target lesion measurement-tended to favor T-Duo. Grade ≥3 treatment-emergent adverse events occurred in 52.8% (T-Duo) versus 48.2% (PC). Treatment with T-Duo was manageable, but tolerability was affected by prevalent ocular toxicity, leading to a higher discontinuation rate in the T-Duo arm. T-Duo significantly reduced the risk of progression in patients with advanced HER2+ breast cancer who have progressed during/after ≥2 HER2-targeted therapies or after T-DM1.

Efficacy and safety of dual blockade of HER2 and PD-1 in patients with HER2-positive gastric cancer: a retrospective, multicentre study

Human epidermal growth factor receptor 2 (HER2) expression is one of the most important pathological characteristics of gastric cancer. The positive rate of HER2 expression in patients with gastric cancer is approximately 20%. The phase III Keynote-811 study revealed that anti-HER2 and anti-PD-1 therapy combined with chemotherapy could significantly improve the objective response rate as first-line treatment in patients with HER2-positive advanced gastric cancer. In the present study, we aimed to evaluate the efficacy of combination therapy with trastuzumab and PD-1 inhibitors in patients with advanced HER2-positive gastric cancer in a real-world setting. Seventy-two HER2-positive gastric cancer patients from three hospitals in China were retrospectively reviewed. These patients were treated with trastuzumab plus one anti-PD-1 agent with or without chemotherapy. The overall response rate, progression-free survival and overall survival were assessed according to the Response Evaluation Criteria in Solid Tumours (RECIST 1.1). From January 2018 to October 2021, 72 patients with HER2-positive gastric cancer received trastuzumab and a PD-1 inhibitor with or without chemotherapy as neoadjuvant chemotherapy, first-line therapy, second-line therapy or salvage therapy. The ORR was 54.2% for all patients and 79.4% for previously untreated patients. The median PFS and median OS were 10 months (95% CI: 8–13 months) and 26.1 months (95% CI: 18.5-NA months), respectively, for all patients. Grade 3 adverse effects occurred in approximately 25% of patients. Immune-related adverse effects occurred in approximately 12.5% of patients. Trastuzumab and PD-1 inhibitor combination therapy with or without chemotherapy achieved satisfactory survival outcomes in patients with HER2-positive gastric cancer with acceptable safety.

Immune marker expression and prognosis of early breast cancer expressing HER3

IntroductionThere is a strong rationale for targeting HER3, as HER3 contributes to tumorigenesis and treatment resistance. However, the prognostic role of HER3 and their association with immunoregulatory protein expression has not been established. MethodsThe main objective of this study was to investigate the prognostic role of HER3 expression and identify immunoregulatory marker expression according to HER3 status. HER3 expression and 10 immunoregulatory protein (PD-1/PD-L1/PD-L2/IDO/TIM-3/OX40/OX40L/B7-H2/B7-H3/B7-H4) expression was identified in 320 stage I-III breast cancer patients who received curative surgery at Seoul National University Hospital in 2008. The median follow-up duration was 88.8 months. Criteria for HER3 IHC was adopted from HER2 IHC score and only those with 3 + was considered positive. ResultsAmong 320 patients, 213 (67.2 %) had luminal A disease, 30 (9.5 %) had luminal B disease, 28 (8.8 %) had HER2-positive disease, and 46 (14.5 %) had triple negative disease. HER3 expression was shown in 153 patients (47.8 %). Tumors with HER3-expression had more immunogenic tumor microenvironment compared to HER3-negative tumor. In addition, patients with HER3 expression had favorable 5-year relapse free survival compared to HER3-negative patients (5-year RFS 92.5 % vs. 85.2 %, p = 0.038). However, in the multivariate analysis, HER3 expression was not a prognostic factor, but expression of immunoregulatory protein was a prognostic factor. ConclusionsThis study identified immunoregulatory protein expression according to HER3 status in breast cancer patients. As tumor with HER3 expression have more immunogenic microenvironment, investigating combination treatment of HER3 targeting agent and immunotherapy in HER3 expressing breast cancer may be promising.

Multiparametric MRI Radiomics With Machine Learning for Differentiating HER2-Zero, -Low, and -Positive Breast Cancer: Model Development, Testing, and Interpretability Analysis.

BACKGROUND: MRI radiomics has been explored for three-tiered classification of breast cancer HER2 expression (i.e., HER2-zero, HER2-low, or HER2-positive), although understanding of how such models reach their predictions is lacking. OBJECTIVE: To develop and test multiparametric MRI radiomics machine-learning models for differentiating three-tiered HER2 expression levels in patients with breast cancer, and to explain the contributions of model features through local and global interpretations using SHapley Additive exPlanation (SHAP) analysis. METHODS: This retrospective study included 737 patients (mean age, 54.1±10.6 years) with breast cancer from two centers (center 1: n=578; center 2: n=159), who underwent breast MRI and had HER2 expression determined after excisional biopsy. Analysis entailed two tasks: differentiating HER2-negative (i.e., HER2-zero or HER2-low) from HER2-positive tumors (task 1), and differentiating HER2-zero from HER2-low tumors (task 2). For each task, patients from center 1 were randomly assigned in 7:3 ratio to training (task 1: n=405; task 2: n=284) or internal test (task 1: n=173; task 2: n=122) sets; those from center 2 formed an external test set (task 1: n=159; task 2: n=105). Radiomics features were extracted from early-phase dynamic contrast-enhanced images (DCE), T2-weighted images (T2WI), and DWI. For each task, a support vector machine (SVM) was used for feature selection; a multiparametric radiomics score (radscore) was computed using feature weights from SVM correlation coefficients; conventional MRI and combined models were constructed; and model performances were evaluated. SHAP analysis was used to provide local and global interpretations for model outputs. RESULTS: In the external test set, for task 1, AUCs for the conventional MRI model, radscore, and combined model were 0.624, 0.757, and 0.762, respectively; for task 2, AUC for radscore was 0.754, and no conventional MRI model or combined model could be constructed. SHAP analysis identified early-phase DCE features as having the strongest influence for both tasks; T2WI features also had a prominent role for task 2. CONCLUSION: The findings indicate suboptimal performance of MRI radiomics models for noninvasive characterization of HER2 expression. CLINICAL IMPACT: The study provides an example of the use of SHAP interpretation analysis to better understand predictions of imaging-based machine learning models.

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.

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.

Solid-basaloid Variant of Mammary Adenoid Cystic Carcinoma – Report of an Unusual Case with Literature Review

Abstract Introduction/Objective Adenoid cystic carcinoma (AdCC) of breast is a rare subtype of malignancy, constituting approximately 0.1% of all breast carcinomas. The solid-basaloid variant (SB-AdCC) is exceedingly uncommon. Here, we present such an unusual case of SB-AdCC. Methods/Case Report A 64-year-old woman who underwent screening mammography presented with abnormal findings, revealing a hypoechoic ovoid, lobulated nodule at 7:00 of the left breast, which prompted an ultrasound- guided biopsy. Histologically, the biopsy cores demonstrated a 9 mm infiltrative round, solid nests with focal “cribriforming” areas. It was composed of monomorphic basaloid epithelial cells with marked nuclear atypia and high mitotic count. High-grade ductal carcinoma in situ, solid papillary carcinoma, and nonspecific invasive carcinoma were in differentials. Immunohistochemical (IHC) staining expressed positivity for CD117 and CK 5/6, while p63, SMMHC, and synaptophysin were negative. MYB gene rearrangement confirmed by fluorescence in situ hybridization. As expected, the tumor lacked ER, PR, and HER2 expression by IHC. Left breast mastectomy and axillary lymph node dissection have been scheduled. Results (if a Case Study enter NA) NA Conclusion Per literature review, the mean age of SB-AdCC at diagnosis was 68 years (33-84 years) with an average tumor size of 25 mm (12-70 mm). It had more aggressive behavior, with a higher propensity for lymph node metastasis, locally recurrence, and distant metastasis. The median disease-free survival was 46.5 months versus 151.8 months in those with class AdCC. Notably, neovascularization has emerged as a strong independent predictor of outcome in SB-AdCC. Most patients were treated with surgical excision, axillary lymph node dissection, and/or adjuvant chemotherapy. Limited studies demonstrated that neoadjuvant chemotherapy may induce an excellent response. Furthermore, a distinct molecular mutation enriched in NOTCH and CREBBP genes has been identified, which could be novel potential therapeutic target. Thus, awareness of this extremely rare breast cancer subtype and accurate differentiation from other entities are paramount for appropriate management strategies.

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