Human Epidermal Growth Factor 2 Status Research Articles

Abstract PO1-05-10: Clinical effectiveness of CDK4/6 inhibitors in HER2-low metastatic breast cancer

Abstract Introduction: There is growing evidence indicating that human epidermal growth factor 2 (HER2)-low is a unique subtype of breast cancer that comprises a substantial share of patients historically classified as HER2 negative. Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) are important in the treatment of hormone receptor-positive (HR+)/HER2-negative metastatic breast cancer (MBC). Whether HER2-low status or the level of HER2 gene amplification have prognostic significance for HR+/HER2-negative MBC patients treated with ET and CDK4/6i remains an area of active investigation. Methods: Patients diagnosed with HR+/HER2-negative MBC and who were treated with palbociclib, ribociclib, or abemaciclib from 6/10/2015 to 12/28/2022 were selected from the Montefiore Health system database and followed until 3/24/2023. HER2-0 was defined as immunohistochemistry (IHC) 0, and HER2-low was defined as IHC 1+ or IHC 2+/in situ hybridization negative by 2018 ASCO/CAP guidelines. Median values were used to establish cutoffs for HER2/CEP17 ratio and HER2 gene copy number (GCN). Characteristics of the patients and tumors in the subgroups were compared using chi-squared/Fisher’s exact test for categorical data and Kruskal-Wallis/Wilcox signed rank tests for continuous data. Kaplan-Meier and Cox proportional hazards analysis were used to compare overall survival (OS) and progression free survival (PFS). Results: 239 patients received CDK4/6i, with 46 HER2-0 and 193 HER2-low patients. There was no statistically significant difference in clinicopathological characteristics between both cohorts. No significant differences were observed in median OS (36 vs 34 months, P > 0.9) and median PFS (44 vs 35 months, P = 0.4) between HER2-0 and HER2-low patients. Adjusting for HER2 status, multivariable analysis showed no statistically significant association between HER2-low status and worse OS (HR: 1.03, P = 0.9) or worse PFS (HR: 1.37, P = 0.4). The median HER2/CEP17 ratio was 1.25 (Interquartile range (IQR): 1.18-1.39), and the median HER2 GCN was 2.58 (IQR: 2.10-3.18). Median OS (25 vs 37, P = 0.15) and median PFS (35 vs 37, P = 0.15) showed no significant differences between ratio-below vs above-median patients. However, patients with GCN-below-median had significantly worse OS (25 vs 37 months, P = 0.026), with no significant difference in median PFS (38 vs 35 months, P = 0.3). Multivariate analysis revealed a significant effect of GCN-below-median on OS (HR: 0.50, P = 0.022) but not on PFS. Conclusion: The clinical effectiveness of CDK4/6i is not influenced by HER2-low status; however, the extent of HER2 gene amplification may have a substantial impact on therapy responsiveness in MBC patients undergoing CDK4/6i treatment. Table 1. Baseline characteristics of patients with MBC comparing HER2-0 vs HER2-low, above/below median HER2/CEP17 ratio, and above/below median HER2 GCN. Table 2. Median OS and PFS in patients with MBC comparing HER2-0 vs HER2-low, above/below median HER2/CEP17 ratio, and above/below median HER2 GCN. Table 3. Multivariable analysis of OS and PFS for patients with MBC comparing HER2-0 vs HER2-low, above/below median HER2/CEP17 ratio, and above/below median HER2 GCN. Citation Format: Frank Zhang, Jesus Anampa Mesias. Clinical effectiveness of CDK4/6 inhibitors in HER2-low metastatic breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-05-10.

Prediction of human epidermal growth factor receptor 2 (HER2) status in breast cancer by mammographic radiomics features and clinical characteristics: a multicenter study.

To preoperatively evaluate the human epidermal growth factor 2 (HER2) status in breast cancer using mammographic radiomics features and clinical characteristics on a multi-vendor and multi-center basis. This multi-center study included a cohort of 1512 Chinese female with invasive ductal carcinoma of no special type (IDC-NST) from two different hospitals and five devices (1332 from Institution A, used for training and testing the models, and 180 women from Institution B, as the external validation cohort). The Gradient Boosting Machine (GBM) was employed to establish radiomics and multiomics models. Model efficacy was evaluated by the area under the curve (AUC). The number of HER2-positive patients in the training, testing, and external validation cohort were 245(26.3%), 105 (26.3.8%), and 51(28.3%), respectively, with no statistical differences among the three cohorts (p = 0.842, chi-square test). The radiomics model, based solely on the radiomics features, achieved an AUC of 0.814 (95% CI, 0.784-0.844) in the training cohort, 0.776 (95% CI, 0.727-0.825) in the testing cohort, and 0.702 (95% CI, 0.614-0.790) in the external validation cohort. The multiomics model, incorporated radiomics features with clinical characteristics, consistently outperformed the radiomics model with AUC values of 0.838 (95% CI, 0.810-0.866) in the training cohort, 0.788 (95% CI, 0.741-0.835) in the testing cohort, and 0.722 (95% CI, 0.637-0.811) in the external validation cohort. Our study demonstrates that a model based on radiomics features and clinical characteristics has the potential to accurately predict HER2 status of breast cancer patients across multiple devices and centers. By predicting the HER2 status of breast cancer reliably, the presented model built upon radiomics features and clinical characteristics on a multi-vendor and multi-center basis can help in bolstering the model's applicability and generalizability in real-world clinical scenarios. • The mammographic presentation of breast cancer is closely associated with the status of human epidermal growth factor receptor 2 (HER2). • The radiomics model, based solely on radiomics features, exhibits sub-optimal performance in the external validation cohort. • By combining radiomics features and clinical characteristics, the multiomics model can improve the prediction ability in external data.

Real-world data on neoadjuvant chemotherapy with dual-anti HER2 therapy in HER2 positive breast cancer

BackgroundNeoadjuvant chemotherapy with dual-targeted therapy is the standard treatment for human epidermal growth factor 2 (HER2)-positive breast cancer. Although the dual-targeted therapy has significantly improved the pathological complete response (pCR) rate, further investigation is needed to identify biomarkers that predict the response to neoadjuvant therapy.MethodsThis retrospective study analyzed 353 patients with HER2-positive breast invasive ductal carcinoma. The correlation between clinicopathological factors and pCR rate was evaluated. A nomogram was constructed based on the results of the multivariate logistic regression analysis to predict the probability of pCR.ResultsThe breast pCR (b-pCR) rate was 56.1% (198/353) and the total pCR (t-pCR) rate was 52.7% (186/353). Multivariate analysis identified ER status, PR status, HER2 status, Ki-67 index, and neoadjuvant chemotherapy regimens as independent indicators for both b-pCR and t-pCR. The nomogram had an area under the receiver operating characteristic curve (AUC) of 0.73 (95% CI: 0.68–0.78). According to the nomogram, the t- pCR rate was highest in the ER-PR- HER2-positive patients (131/208) and lowest in the ER + PR + HER2-positive patients (19/73). The subgroup analyses showed that there was no significant difference in pCR rate among the neoadjuvant chemotherapy regimens in ER positive, PR positive, HER2 IHC 2 + , Ki67 index < 30% population. However, for ER-PR-HER2-positive patients, the neoadjuvant chemotherapy regimen has a great influence on the pCR rates.ConclusionsPatients with ER-negative, PR-negative, HER2 3 + and high KI-67 index were more likely to achieve pCR. THP may be used as an alternative to AC-THP or TCbHP in selected HER2-positive patients.

HER2-low heterogeneity between primary and paired recurrent/metastatic breast cancer: Implications in treatment and prognosis.

With the largest sample size to date, the authors' objective was to investigate the incidence of primary-to-metastatic human epidermal growth factor 2 (HER2) conversion and the predictors for such conversion. Moreover, no previous studies have evaluated the prognosis of patients who have negative HER2 expression (HER2-0) versus low HER2 expression (HER2-low) when HER2 status was assessed based on all recurrent/metastatic lesions. The authors included 1299 patients who had available HER2 status of primary breast tumors and paired recurrent/metastatic lesions at Fudan University Shanghai Cancer Center and West China Hospital. In total, 370 patients (28.5%) experienced primary-to-metastatic HER2 conversion. Intrapatient intermetastasis spatial heterogeneity and temporal heterogeneity of HER2 were detected. When assessing HER2 based on recurrent/metastatic tumors, patients who had HER2-0 tumors had significantly shorter overall survival than those who had HER2-low tumors in the overall population and in the estrogen receptor (ER)-negative subgroup. However, when assessing HER2 based on primary tumors, there was no difference in overall survival between patients who had HER2-0 versus HER2-low tumors. Moreover, patients who had tumors that converted from HER2-0 to HER2-low had longer overall survival than those who had consistent HER2-0 status in the ER-negative subgroup. By combining four predictors (ER status, Ki67 index, biopsy site, and disease-free interval), the authors established the first prediction tool to estimate the probability of HER2-0 tumors converting to HER2-low/positive tumors. Intrapatient primary-to-metastatic and intermetastatic HER2 heterogeneity were observed in this large-scale cohort study. When evaluating HER2 based on recurrent/metastatic tumors, an overall survival difference was observed between patients who had HER2-0 versus HER2-low, recurrent/metastatic breast tumors. The developed prediction tool might help clinicians screen out patients with primary HER2-0 tumors that have a high probability of HER2 status conversion and recommend them for re-biopsy, thus helping to screen out candidate patients for trastuzumab deruxtecan treatment.

Evaluation of HER2 Gene Amplification using CISH in Patients with HER2 2+ (equivocal) Breast Carcinoma based on Immunohistochemistry in Imam Khomeini Cancer Institute from 2016 to 2018

Background: Human epidermal growth factor 2 (HER2) is known to be an important prognostic factor in breast cancer. Numerous studies have shown HER2+ breast cancers have reduced overall survival and recovery time, as well as the efficacy of anti-HER2 therapies along with chemotherapy in improving disease outcomes. For this reason, it is recommended that all patients with breast cancer should be evaluated for HER2 status. This study aimed to assess the HER2 gene amplification by the CISH method in evaluating the HER2 status in patients with immunohistochemistry (IHC) 2+ (equivocal) results. Methods: This retrospective cross-sectional study examined HER2 status based on the Chromogenic in situ hybridization (CISH) method in 280 breast carcinoma samples with an initial 2+ (equivocal) score in IHC. The relationship between HER2 amplification and hormone receptors (estrogen and progesterone) and Ki67 level was also investigated. Results: In sixty samples (21.4%), the HER2 gene was amplified based on the CISH method. The majority (215, 76.8%) of the samples were negative and 5 (1.8%) samples were indeterminate. No significant relationship was observed between HER2 amplification, estrogen receptor (p=0.143), and ki.67 protein level (p=0.977). There was a significant inverse relationship between HER2 amplification and progesterone receptor positivity (p=0.007). Conclusion: These results demonstrate that CISH is a helpful method to assess HER2 status in equivocal breast cancer and is positive (amplified) in about 21.4% of them.

Abstract P2-03-17: Fluoroestradiol (FES) and Fluorodeoxyglucose (FDG) PET imaging in patients with ER+, HER2+ or HER2- metastatic breast cancer

Abstract Background: 18F-Fluorodeoxyglucose (FDG) has long been used for measuring tumor glycolytic activity in clinical PET imaging. The FDA recently approved 18F-Fluoroestradiol (FES) (Cerianna) as a PET imaging tracer for characterizing disease in patients with estrogen-receptor positive (ER+) breast cancer. As FES PET enters clinical practice it is important to establish its utility in the full population of hormone-receptor positive patients, including for patients with human epidermal growth factor 2 (HER2)-overexpressing tumors. Patients with HER2-positive metastatic breast cancer have historically been treated with combination cytotoxic and HER2-directed therapy, with the understanding that HER2 is the primary driver in this disease state. This retrospective study examined uptake in matched lesions for both FES and FDG PET and compared activity in patients with HER2 positive versus HER2 negative metastatic breast cancer. Methods: Patients were selected from the UW research database who had a history of biopsy-proven primary ER+ breast cancer as well as FES and FDG PET scans within 30 days. We examined FDG and FES scans and recorded SUVmax in up to 16 matched lesions between the two scans. Patients were also divided by HER2 status (+/-). In addition, a subset of patients who underwent at least 2 paired FDG and FES scans were reviewed. Results: 270 matched FDG and FES scans were analyzed in 216 patients with history of ER+, and HER2+ or HER2- breast cancer who were not part of an ongoing clinical trial. 158 (73%) had ductal disease, 38 (18%) had lobular disease. 183 (85%) had HER2- breast cancer. Of the 33 patients who had HER2+ breast cancer, 28 (85%) had ductal carcinoma. 40 patients underwent serial scans, allowing tracking over multiple timepoints. A total of 1323 metastatic sites were recorded (average = 5/scan (range 1,16)), with the majority (71%) representing bony lesions. No difference in quantitative FES or FDG avidity was observed between soft tissue and osseous sites. FES and FDG SUVmax were similar among patients with either HER2- or HER2+ breast cancer (Table 1). Among 40 patients with multiple paired FDG and FES scans, 26 (65%) had 2 scans while the remaining 14 had 3, with FES avidity remaining stable over time. There was no correlation between FES or FDG scans and HER2 status. Conclusion: In a cohort of ER+, HER2+ and HER2- patients undergoing concurrent FDG and FES PET scans, FDG and FES activity was similar regardless of HER2 status. FES uptake in both HER2- and HER2+ patients and stability over time in serial scans suggest that HER2 does not affect ER density. This suggests that in many patients with so-called “triple positive” disease, endocrine therapy may offer a powerful primary rather than ancillary tool in select patients. FES combined with FDG PET may offer utility in predicting and assessing response to therapy in this patient population. Table 1. FES and FDG uptake in patients with HER2- or HER2+ disease Citation Format: Natasha Hunter, Lanell M. Peterson, David A. Mankoff, Mark Muzi, Delphine Chen, William R. Gwin, Shaveta Vinayak, Nancy E Davidson, Jennifer M. Specht, Hannah Linden. Fluoroestradiol (FES) and Fluorodeoxyglucose (FDG) PET imaging in patients with ER+, HER2+ or HER2- metastatic breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-03-17.

Human epidermal growth factor receptor-2 gene expression positivity determined by silver in situ hybridization/immunohistochemistry methods and associated factors in a cohort of Sri Lankan patients with gastric adenocarcinoma: a prospective study.

Positive human epidermal growth factor 2 (HER2) expression and its predictive clinicopathological features remain unclear in Sri Lankan gastric cancer (GC) patients. Here, we aimed to determine GC HER2 status predictors by analyzing associations between clinicopathological features and HER2 expression using immunohistochemistry (IHC) and silver in situ hybridization (SISH). During this 4-year prospective study, clinicopathological data were collected from participants in the National Hospital of Sri Lanka. HER2 IHC and SISH were performed using commercial reagents. Using chi-square tests, associations of HER2-IHC/SISH with clinicopathological features were analyzed. Overall, 145 GC patients were included, 69 had gastrectomies and 76 had biopsies. Positive HER2 expression by IHC was associated with age <60 years, high T stage (assessed pathologically in resections and radiologically in biopsies), high nuclear grade, tumor necrosis, mitosis >5/high-power field, with additional perineural invasion and lymphovascular invasion in resections. These features, excluding lymphovascular invasion but including male sex, were associated with HER2 expression by SISH. Age <60 years, high nuclear grade, tumor necrosis, and perineural invasion are associated factors of HER2 status. These could be used to triage GC patients for HER2 status testing in limited resource settings where IHC/SISH analysis is costly.

Dual-targeted near-infrared photoimmunotherapy for esophageal cancer and cancer-associated fibroblasts in the tumor microenvironment

Cancer-associated fibroblasts (CAFs) play a significant role in tumor progression within the tumor microenvironment. Previously, we used near-infrared photoimmunotherapy (NIR-PIT), a next-generation cancer cell-targeted phototherapy, to establish CAF-targeted NIR-PIT. In this study, we investigated whether dual-targeted NIR-PIT, targeting cancer cells and CAFs, could be a therapeutic strategy. A total of 132 cases of esophageal cancer were analyzed for epidermal growth factor receptor (EGFR), human epidermal growth factor 2 (HER2), and fibroblast activation protein (FAP) expression using immunohistochemistry. Human esophageal cancer cells and CAFs were co-cultured and treated with single- or dual-targeted NIR-PIT in vitro. These cells were co-inoculated into BALB/c-nu/nu mice and the tumors were treated with single-targeted NIR-PIT or dual-targeted NIR-PIT in vivo. Survival analysis showed FAP- or EGFR-high patients had worse survival than patients with low expression of FAP or EGFR (log-rank, P < 0.001 and P = 0.074, respectively), while no difference was observed in HER2 status. In vitro, dual (EGFR/FAP)-targeted NIR-PIT induced specific therapeutic effects in cancer cells and CAFs along with suppressing tumor growth in vivo, whereas single-targeted NIR-PIT did not show any significance. Moreover, these experiments demonstrated that dual-targeted NIR-PIT could treat cancer cells and CAFs simultaneously with a single NIR light irradiation. We demonstrated the relationship between EGFR/FAP expression and prognosis of patients with esophageal cancer and the stronger therapeutic effect of dual-targeted NIR-PIT than single-targeted NIR-PIT in experimental models. Thus, dual-targeted NIR-PIT might be a promising therapeutic strategy for cancer treatment.

Clinicopathologic and molecular features associated with response to anti-HER2 therapy in endometrial cancer.

5584 Background: Endometrial cancer (EC) is the most common gynecologic malignancy in the United States. Human epidermal growth factor 2 (HER2) overexpression or gene amplification occurs in 10-60% of EC. The addition of trastuzumab to carboplatin-paclitaxel chemotherapy improves survival in women with HER2-positive serous EC. However, criteria for assessment of HER2 status in EC are not standardized, and furthermore, intratumor heterogeneity may impact therapeutic efficacy. We aimed to identify factors associated with treatment response and survival outcomes in a retrospective cohort of ECs treated with anti-HER2 therapy. Methods: Patients with advanced/recurrent EC treated with trastuzumab or trastuzumab emtansine alone or in combination with chemotherapy from 2013-2021 at our institution were identified. Clinical and treatment information were retrieved from medical records. Central pathology review, HER2 immunohistochemistry (IHC) and fluorescence in-situ hybridization (FISH) were performed. HER2 IHC was scored using modified ASCO/CAP 2007 guidelines for breast cancer. HER2 expression heterogeneity was defined as a 2-degree difference in staining intensity in ≥5% of tumor cells or discordant IHC score on different specimens. HER2 amplification (tumor/normal fold change) was also estimated from targeted next-generation sequencing (NGS). Best response was assessed by RECIST v1.1 as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD), with clinical benefit defined as CR/PR/SD. Results: Among 39 patients included, median age was 69. Histologic subtypes included serous (n = 18, 46%), carcinosarcoma (n = 7, 18%), high-grade EC with ambiguous features (n = 13, 33%) and low-grade endometrioid carcinoma (n = 1, 3%). HER2 IHC results were 0 or 1+ (n = 2, 5%), 2+ (n = 17, 46%), 3+ (n = 18, 49%), with HER2 heterogeneity in 15 cases. By FISH, the HER2/CEP17 ratio was ≥2.0 in 34 (92%) and &lt; 2.0 in 3 (8%); HER2 copy number (CN) was ≥6.0 in 25 (68%) and &lt; 6.0 in 12 (32%). HER2 copy number ≥6.0 was significantly correlated with HER2 amplification by NGS ( p&lt; 0.001). 18 (49%) patients had a co-existing somatic PIK3CA mutation. Amongst parameters assessed, only higher level of HER2 amplification by NGS was significantly associated with clinical benefit ( p= 0.036). None of these features were associated with progression-free survival. Notably, 2 patients with IHC 0/1+ had PD and 1 patient with IHC 3+, but non-amplified by FISH, achieved PR. Conclusions: In our cohort of EC patients treated with anti-HER2 therapy, higher level of HER2 amplification was associated with clinical benefit. Further studies with larger sample sizes are needed to determine whether any additional characteristics are associated with treatment response and survival.

Gene Mutations Associated With Clinical Characteristics in the Tumors of Patients With Breast Cancer.

BackgroundClinical characteristics including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) are important biomarkers in the treatment of breast cancer, but how genomic mutations affect their status is rarely studied. This study aimed at finding genomic mutations associated with these clinical characteristics.MethodsThere were 160 patients with breast cancer enrolled in this study. Samples from those patients were used for next-generation sequencing, targeting a panel of 624 pan-cancer genes. Short nucleotide mutations, copy number variations, and gene fusions were identified for each sample. Fisher’s exact test compared each pair of genes. A similarity score was constructed with the resulting P-values. Genes were clustered with the similarity scores. The identified gene clusters were compared to the status of clinical characteristics including ER, PR, HER2, and a family history of cancer (FH) in terms of the mutations in patients.ResultsGene-by-gene analysis found that CCND1 mutations were positively correlated with ER status while ERBB2 and CDK12 mutations were positively correlated with HER2 status. Mutation-based clustering identified four gene clusters. Gene cluster 1 (ADGRA2, ZNF703, FGFR1, KAT6A, and POLB) was significantly associated with PR status; gene cluster 2 (COL1A1, AXIN2, ZNF217, GNAS, and BRIP1) and gene cluster 3 (FGF3, FGF4, FGF19, and CCND1) were significantly associated with ER status; gene cluster 2 was also negatively associated with a family history of cancer; and gene cluster 4 was significantly negatively associated with age. Patients were classified into four corresponding groups. Patient groups 1, 2, 3, and 4 had 24.1%, 36.5%, 38.7%, and 41.3% of patients with an FDA-recognized biomarker predictive of response to an FDA-approved drug, respectively.ConclusionThis study identified genomic mutations positively associated with ER and PR status. These findings not only revealed candidate genes in ER and PR status maintenance but also provided potential treatment targets for patients with endocrine therapy resistance.

HER2-Low Breast Cancer: Prognosis and Future Treatment Prospective

The human epidermal growth factor 2 (HER2) is a tyrosine kinase belonging to the Human Epidermal Receptor family [1]. HER2 is amplified leading to HER2 overexpression in 15% of breast cancers (BC) [2]. HER2 overexpression leads to poor prognosis, but offers the unique possibility to use a targeted therapy with monoclonal antibodies. This therapeutic option has radically changed the history of HER2 BC [3]. HER2 overexpression represents at present the most powerful predictive factor for likeliness of response to anti-HER2 agents [5]. The HER2 status is routinely assessed either using immunohistochemistry (HER2 protein expression level) or in situ hybridization (HER2 gene status) [2,5,6]. For the purpose of HER2 assessment, international guidelines have been developed by experts in the field, and have changed over the years according to new data. HER2 heterogeneity is linked to the complexity of equivocal results, HER2 mutations and the upcoming category of HER2-low BC [7]. Intratumor genetic heterogeneity interests various types of human cancers, including BC and HER2 overexpression and amplification, and it is demonstrated to be significantly more common in cases with HER2 equivocal status [8]. Equivocal cases frequently feature low levels of HER2 amplification. Several studies showed that HER2 heterogeneity is related to poor outcome, shorter disease-free survival and overall survival. Patients with HER2 heterogeneity are less responsive to target therapies as confirmed by a lower achievement of pathologic complete response following neoadjuvant treatment [9]. In spite of the scarcity of data still available on HER2-low BC, different intrinsic subtypes seem to influence different clinical behavior and response to treatment, as this has already been proved for other BC subtypes. HER2-low/HR- BC showed a higher frequency of HER2-enriched instrinsic subtype than HER2-/HR- BC. This might mean that, despite in clinical practice HER2-low/HR- BC is considered as HER2-/HR, these subtypes of BCs might reflect a different clinical behavior and a different response to targeted therapy [10]. Recent studies underlined that HER2-enriched instrinsic subtype are the most beneficial in reduction of risk of progression and death after CDK6/6-inhibitors treatment, compared to the other subtypes [11]. Traditionally HER2-positive BCs were separated from HER2-negative BCs, based on solid clinical data stating that only tumors driven by HER2 oncogene addition benefit from targeted therapies [12]. However in recent years new therapies have been developed, in particular the antibody drug conjugates which deliver chemotherapy inside the BC. Some of these agents - such as trastuzumab duocarmazine and trastuzumab deruxtecan showed encouraging response rates also in the so called HER2-low BC. For example, the phase 1 study of DS-8201 showed an overall response rate of 37% in pretreated HER2-low metastatic cancer patients, with a median duration of response of 10.4 months [13]. These data suggests a paradigm shift in the definition of HER2 status, which may be based on 3 groups: 1.HER2-positive, 2.HER2- negative, 3.HER2-low BCs, that may potentially benefit from a targeted therapy, even in absence of the addition of the tumor cells to the HER2 oncogene [7]. At present there are no formal definitions of HER2-low BC, but it seems reasonable to define as HER2-low all BCs displaying a score of 1+ or 2+ HER2 expression and no HER2 amplification. This assumption would categorize up to 55% of BCs as HER2-low. For this subtype there are no targeted therapies approved [7]. The majority of HER2 somatic mutations found in BCs have not been associated with HER2 gene amplification. However preclinical data suggest that functionally active HER2 mutations may lead to HER2 targeted therapies sensitivity [14]. Other preclinical models suggest that pertuzumab inhibits tumor proliferation even in absence of HER2 overexpression [15].So, HER2 mutation-positive but HER2-negative BC may benefit from targeted drugs, but further studies are needed. For example, trastuzumab, deruxtecan, a novel enzyme-cleavable linker, showed significant objective response and disease control in a group of patients including 25% HER2-low BCs, and therefore is worthy of further studies in this subgroup of patients [16]. The new agents being tested for HER2-low BC patients are antibody drug conjugates deploying anti-HER2 epitopes in their antibody component, but with different cytotoxic warheads and a bi-specific antibody targeting both HER2 and HER3 [17]. In conclusion, the concept of HER2-positive versus HER2-negative disease is changing, including the definition of “HER2-low” BC, against which new therapies such as antibody drug conjugates may be extremely effective.

Correlation of B-cell lymphoma 2 immunoexpression in invasive carcinoma of breast, no special type with hormone receptor status, proliferation index, and molecular subtypes.

B-cell lymphoma 2 is involved in various cancers including breast carcinoma. Its expression in breast cancer has been associated with good prognostic factors such as hormone receptor expression, low Ki-67, low grade, and earlier stage. It is also considered to be an independent prognostic factor for luminal and triple-negative tumors. We aimed to determine the expression of B-cell lymphoma 2 (BCL2) in different molecular subtypes of invasive ductal carcinoma of breast and its association with prognostic indicators. Fifty samples of invasive carcinoma of breast, no special type (NST), were categorized into molecular subtypes according to immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), and Ki-67 and then evaluated for BCL2 expression. The expression of BCL2 was correlated with ER, PR, HER2, and Ki-67 and compared between luminal and nonluminal subtypes. The BCL2 expression was seen in 68% of the cases with a significant association with ER, PR, and luminal subtypes. No significant association of BCL2 expression was seen with grade, HER2 and Ki-67 status of the tumor, or age group of the patients. BCL2 expression is significantly associated with ER, PR, and luminal subtypes in breast cancer. BCL2 is a marker of good prognosis in invasive carcinoma of breast, NST.

Machine Learning Frameworks to Predict Neoadjuvant Chemotherapy Response in Breast Cancer Using Clinical and Pathological Features.

Neoadjuvant chemotherapy (NAC) is used to treat locally advanced breast cancer (LABC) and high-risk early breast cancer (BC). Pathological complete response (pCR) has prognostic value depending on BC subtype. Rates of pCR, however, can be variable. Predictive modeling is desirable to help identify patients early who may have suboptimal NAC response. Here, we test and compare the predictive performances of machine learning (ML) prediction models to a standard statistical model, using clinical and pathological data. Clinical and pathological variables were collected in 431 patients, including tumor size, patient demographics, histological characteristics, molecular status, and staging information. A standard multivariable logistic regression (MLR) was developed and compared with five ML models: k-nearest neighbor classifier, random forest (RF) classifier, naive Bayes algorithm, support vector machine, and multilayer perceptron model. Model performances were measured using a receiver operating characteristic (ROC) analysis and statistically compared. MLR predictors of NAC response included: estrogen receptor (ER) status, human epidermal growth factor-2 (HER2) status, tumor size, and Nottingham grade. The strongest MLR predictors of pCR included HER2+ versus HER2- BC (odds ratio [OR], 0.13; 95% CI, 0.07 to 0.23; P < .001) and Nottingham grade G3 versus G1-2 (G1-2: OR, 0.36; 95% CI, 0.20 to 0.65; P < .001). The area under the curve (AUC) for the MLR was AUC = 0.64. Among the various ML models, an RF classifier performed best, with an AUC = 0.88, sensitivity of 70.7%, and specificity of 84.6%, and included the following variables: menopausal status, ER status, HER2 status, Nottingham grade, tumor size, nodal status, and presence of inflammatory BC. Modeling performances varied between standard versus ML classification methods. RF ML classifiers demonstrated the best predictive performance among all models.

Computer-Aided Diagnosis Parameters of Invasive Carcinoma of No Special Type on 3T MRI: Correlation with Pathologic Immunohistochemical Markers.

PurposeTo investigate the correlation between computer-aided diagnosis (CAD) parameters in 3-tesla (T) MRI and pathologic immunohistochemical (IHC) markers in invasive carcinoma of no special type (NST).Materials and MethodsA total of 94 female who were diagnosed with NST carcinoma and underwent 3T MRI using CAD, from January 2018 to April 2019, were included. The relationship between angiovolume, curve peak, and early and late profiles of dynamic enhancement from CAD with pathologic IHC markers and molecular subtypes were retrospectively investigated using Dwass, Steel, Critchlow-Fligner multiple comparison analysis, and univariate binary logistic regression analysis.ResultsIn NST carcinoma, a higher angiovolume was observed in tumors of higher nuclear and histologic grades and in lymph node (LN) (+), estrogen receptor (ER) (−), progesterone receptor (PR) (−), human epidermal growth factor 2 (HER2) (+), and Ki−67 (+) tumors. A high rate of delayed washout and a low rate of delayed persistence were observed in Ki−67 (+) tumors. In the binary logistic regression analysis of NST carcinoma, a high angiovolume was significantly associated with a high nuclear and histologic grade, LN (+), ER (−), PR (−), HER2 (+) status, and non-luminal subtypes. A high rate of washout and a low rate of persistence were also significantly correlated with the Ki-67 (+) status.ConclusionAngiovolume and delayed washout/persistent rate from CAD parameters in contrast enhanced breast MRI correlated with predictive IHC markers. These results suggest that CAD parameters could be used as clinical prognostic, predictive factors.

Influence of Age, Estrogen receptor (ER),Progesterone receptor (PR) and Epidermal growth factor -2 (HER-2) in Breast Carcinoma Patient in correlation with Radionuclide Bone Scan – Single Institute Based Experience

Background: Breast carcinoma is a common type of malignancy in women worldwide. Radionuclide bone scintigraphy is recognized choice of investigation for the detection of bone metastases both in asymptomatic and symptomatic patients. Biomarkers like Estrogen Receptor (ER), Progesterone Receptor (PR), Human Epidermal growth factor -2 (HER-2) also play important role in the management and prognosis of breast cancer. The study was aimed to find out the relationship between the MDP bone scan findingsand hormone receptor and HER-2 status of breast carcinoma patients referred to the Institute of Nuclear Medicine and Allied Sciences (INMAS), Mitford, Dhaka.&#x0D; Patients and Methods: This cross sectional study was conducted among 301 breast carcinoma patients between January 2018 and December 2019. Planar bone scan and SPECT (if needed) was done to all the patients after intravenous injection of 99mTc-MDP. Receptor status (ER, PR and HER-2) were documented from the patient’s medical records. Breast tumors were classified as (a) Triple positive- HER2-, ER-, and PR-positive) (b) Triple negative- HER2-, ER-, and PR-negative (c) Hormonereceptor (HR) positive (ER+/PR+) with HER-2 negative and d) HR negative (ER-/PR-) with HER-2 positive.Patients were broadly grouped according to age as A. less than 50 years (n = 59) and B. more than 50 (n = 260 ) years.&#x0D; Results: The mean age of the patients enrolled for this study was 59.02±9.3 with range of 32 to 81 years. Out of the 301 patients, positive bone scans were found in 105 (34.8%) and negative bone scan were found 196 (66.2%). Patients of group A (&lt;50years) with triple negative and HR+/HER-status had no bone or bone with visceral metastases. Triple positive subtype had 2 bone metastases, and HR-/HER-2+ subtype had 2 bone metastases and 1 had bone with visceral metastases. Group B (&gt; 50years) patients having HR+/HER2- receptor status showed 16% solitary metastases, 53.2% multiple metastases, 33.3% extensive bony metastases, 13.6% bone with visceral metastases. Triple negative subtype showed 36.0 % solitary metastases, 19.1% bone with visceral metastases. Triple positive subtype group had 40.0% solitary metastases, 34.0 % multiple metastases, 66.7% extensive bony metastases, and 13.6% bone with visceral metastases. HR-/HER-2+ subtype group had 8% solitary metastases, 12.8% multiple metastases, and 18.2 % bone metastases with visceral involvement Overall relationship between bone scan and hormone receptor subtype, showed that most of the patients had HR+/ HER-2-(35.2%) subtype and 25.6% patient had triple positive, 23.3% patient had triple negative and 15.9% patient had HR-/HER-2 – receptor subtype. This study showed the visceral involvement with bone metastases (13 % in HR+/HER-2- 52.2 % in triple negative, 13 % in triple positive, 21.7 % in HR-/HER-2+subtype). Highest bone only metastases (35) in triple positive and HR+/HER-2-(31) subtype. Most of the patiens who had bone metastases with visceral involvement belong to triple negative (52.2%) and HER-2 subtypes -HR-/HER-2+ (21.7%). The result was significant (P&lt;0.001).&#x0D; Conclusion: It is observed from this study that triple positive and HR+/HER-2- were more likely to develop bone metastases than triple negative and HR-/HER-2-. Patients with bone scan negative and HR-/HER-2- or triple negative receptor status most likely develop visceral metastases&#x0D; Bangladesh J. Nuclear Med. 22(2): 114-118, Jul 2019

CT Radiomics for Distinction of Human Epidermal Growth Factor Receptor 2 Negative Gastric Cancer

The purpose of this study was to investigate the role of computed tomography (CT) radiomics for the prediction of the human epidermal growth factor 2 (HER2) status in patients with gastric cancer. One hundred and thirty two consecutive patients with advanced gastric cancer undergoing radical gastrectomy were retrospectively reviewed. All patients received preoperative contrast CT examination, and immunohistochemistry results of their HER2 status were available. All the subjects were randomly divided into a training cohort (n = 90) and a test cohort (n = 42). Arterial phase (AP) and portal phase (PP) contrast CT images were retrieved for tumor segmentation and feature extraction. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate the performance of the radiomics classifiers. Among the 132 patients, a total of 99 patients were HER2 negative, and the remaining 33 patients were border line or positive. The AP radiomics model could distinguish HER2-negative cases with an AUC of 0.756 (95% confidence interval [CI]: 0.656-0.840) in the training cohort, which was confirmed in the test cohort with AUC of 0.830 (95% CI: 0.678-0.930). The PP radiomics model showed AUCs of 0.715 (95% CI: 0.612-0.804) and 0.718 (95% CI: 0.554-0.849) in the training and test cohort for distinction of negative HER2 cases, respectively. Radiomics models based on standard-of-care CT images hold promise for distinguishing HER2-negative gastric cancer.

Abstract P3-08-41: Central nervous system metastases in breast cancer: The impact of age on patterns of development and outcome

Abstract Background: Breast cancer is the second most common cause of central nervous system (CNS) metastasis, leading to a significant decrease in survival rate. High risk groups for CNS involvement include younger age, human epidermal growth factor 2 (HER2) over-expression, estrogen receptor (ER) and progesterone receptor (PR) negativity, high histologic grade, and presence of systemic metastases. Young age at diagnosis of breast cancer is associated with more aggressive biological behavior and worse prognosis than in the elderly. However, data are limited regarding CNS involvement in this group of patients. Although it could be expected that younger patients would also have a poor prognosis after the diagnosis of CNS metastases, earlier studies have demonstrated conflicting results, some with favorable outcomes for this unique group. In this study we aimed to explore the differences in the patterns and outcome of CNS involvement according to age at diagnosis of breast cancer (≤45 years vs. &amp;gt;45 years). Methods: A retrospective database of consecutive breast cancer patients who were treated in our institute and were diagnosed with CNS metastases during 2006-2019 was generated. Data analyzed included age at diagnosis of breast cancer, age at diagnosis of CNS involvement, histopathological factors (histology, grade, hormone receptor and HER2 status), treatments given before and after CNS involvement, characteristics of CNS involvement (location, number of brain deposits, clinical manifestations), overall survival, time to CNS progression, and survival after diagnosis of CNS disease. Results: Study cohort was comprised of 174 patients: 65 patients were age≤45 and 109 patients were older than 45 at breast cancer diagnosis. The percentage of patients with triple-negative breast cancer was higher among the younger age group (24.6% vs. 14.7%). Median overall survival from breast cancer diagnosis was significantly longer for younger patients [117.1 months (95% CI 67.2-167) vs. 88 months (95% CI 65.6-110.4), p=0.017]. Median time from breast cancer diagnosis to development of CNS metastases was also significantly longer in the younger age group [58.1 months (95% CI 46.5-69.6) vs. 37.5 months (95% CI 22.9-52.2), p=0.021]. Median survival as measured from time of CNS involvement was 18.7 months (95% CI 10.8-26.6) in the younger group vs. 11.1 months (95% CI 7.8-14.5) in the older patients (p=0.341). Survival of patients with triple-negative breast cancer from time of CNS metastases diagnosis was significantly longer for the younger age group [22.5 months (95% CI 1.2-43.8) vs. 7.9 months (95% CI .77-15.1), p=0.033]. The number, location and clinical presentation of CNS metastases were not statistically different between the two groups. Systemic and CNS-directed treatment approaches were also similar. Conclusion: While the presentation of CNS metastasis was similar between the different age groups, younger patients had significantly longer CNS-free interval and longer overall survival. Numerically, after diagnosis of CNS involvement younger patients had longer survival, but the difference was statistically significant only for patients with triple-negative disease. Citation Format: Matan Ben-Zion Berliner, Shlomit Yust-Katz, Inbar Lavie, Alexandra Amiel, Dalia Zoref, Daniel Hendler, Hadar Goldvaser, Michal Sarfaty, Ofer Rotem, Olga Ulitsky, Tali Siegal, Victoria Neiman, Rinat Yerushalmi. Central nervous system metastases in breast cancer: The impact of age on patterns of development and outcome [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-41.

Prognostic significance of epidermal growth factor receptor gene mutations and human epidermal growth factor 2 expression in breast carcinoma metastatic to the liver

Background: Breast cancer is the most prevalent cancer among females, and metastatic disease is not curable and is treated palliatively. Members of the ErbB family have an important role in the development and progression of breast cancer. The aim of this study was to determine the relationship between epidermal growth factor receptor (EGFR) gene mutation, human epidermal growth factor 2 (HER2) expression, hormone receptor statuses, and clinicopathological parameters in liver metastases from breast cancer. Materials and Methods: This study included 41 patients diagnosed with liver metastasis from breast carcinoma, based on morphological and immunohistochemical findings, in our pathology laboratory between 2011 and 2018. EGFR gene mutations were analyzed by polymerase chain reaction (PCR) in these cases. Results: EGFR gene mutation analysis was performed by PCR, and no mutations were detected. HER2 and ER statuses of the primary breast tumor were available in 23 cases. HER2 status conversions were present in 9 cases (39.1%); however, this was not statistically significant (P = 0.197). Estrogen receptor (ER) conversions were present in 4 cases (17.4%); however, this was not statistically significant (P = 1.000). Progesterone receptor (PR) conversions were detected in 10 cases (45.5%). There were 10 (45.5%) cases with PR-positive primary tumors and PR-negative liver metastases. No cases with a PR-negative primary tumor developed a PR-positive liver metastasis (P = 0.02). Conclusions: No EGFR gene mutations were detected in any of our cases by PCR. There was no statistically significant relationship between clinicopathological parameters and EGFR mutation. The comparison of ER, PR, and HER2 expression between the primary tumor and metastases revealed status conversions in some cases. However, only PR conversion was statistically significant. Studies on EGFR gene mutations that include larger series are warranted to identify the candidates who can benefit from targeted therapies.

HER2 gene status and mRNA expression in immunohistochemistry 1+ breast cancer

Objective: To investigate human epidermal growth factor 2 (HER2) gene status and in situ mRNA expression in breast cancers with immunohistochemistry(IHC) 1+ , and to reveal HER2 positive rate in these patients to provide reference data for obtaining precise HER2 results and modifying relevant clinical strategy to breast cancer. Methods: Sixty-five IHC 1+ formalin-fixed and paraffin-embedded samples of invasive breast carcinoma of no special type (IBC-NST) were collected by surgical operation at Peking Union Medical College Hospital during 2011 to 2013. HER2 status and in situ mRNA expression were tested by fluorescence in situ hybridization (FISH) and RNAscope, respectively, by using tissue microarray. Metastatic lymph node was re-tested by FISH if HER2 status was equivocal or negative and with high expression of mRNA in the primary lesion. Results: Four of 65 samples (6.2%) were FISH positive, which included 2 cases of HER2/CEP17>2 and average HER2 copy number>4 and 2 cases of HER2/CEP17<2 and average HER2 copy number>6. In the 4 samples of HER2 positive, 2 patients showed high in situ mRNA expression (3 scores by RNAscope), 2 patients showed moderate in situ mRNA expression (2 scores by RNAscope). In addition, 3 specimens with HER2/CEP17>2 and average HER2 copy number<4 were found in all patients, which included 2 cases of high in situ mRNA expression (3 and 4 scores by RNAscope) and 1 cases of moderate in situ mRNA expression (2 scores by RNAscope). There was no significant association between HER2 status or mRNA expression and clinicopathological characteristics, including tumor size, histopathological differentiation, lymph node metastasis and lymphovascular invasion (P>0.05). Conclusions: A small number of HER2 IHC 1+ patients exist mRNA expression by using FISH method, which suggested that these patients might benefit from anti-HER2 therapy potentially. Since the importance for patients with breast cancers to develop diagnostic and therapeutic strategies from accurate molecular typing, further studies based on a larger cohort are needed to validate our findings.

Rapid micro fluorescence in situ hybridization in tissue sections.

This paper describes a micro fluorescence in situ hybridization (μFISH)-based rapid detection of cytogenetic biomarkers on formalin-fixed paraffin embedded (FFPE) tissue sections. We demonstrated this method in the context of detecting human epidermal growth factor 2 (HER2) in breast tissue sections. This method uses a non-contact microfluidic scanning probe (MFP), which localizes FISH probes at the micrometer length-scale to selected cells of the tissue section. The scanning ability of the MFP allows for a versatile implementation of FISH on tissue sections. We demonstrated the use of oligonucleotide FISH probes in ethylene carbonate-based buffer enabling rapid hybridization within <1 min for chromosome enumeration and 10–15 min for assessment of the HER2 status in FFPE sections. We further demonstrated recycling of FISH probes for multiple sequential tests using a defined volume of probes by forming hierarchical hydrodynamic flow confinements. This microscale method is compatible with the standard FISH protocols and with the Instant Quality FISH assay and reduces the FISH probe consumption ∼100-fold and the hybridization time 4-fold, resulting in an assay turnaround time of <3 h. We believe that rapid μFISH has the potential of being used in pathology workflows as a standalone method or in combination with other molecular methods for diagnostic and prognostic analysis of FFPE sections.