HER2 Testing Research Articles

Real-world biomarker testing and first-line treatment patterns among locally advanced, unresectable or metastatic gastric and gastroesophageal junction adenocarcinoma patients in the US.

348 Background: Advanced-stage gastric cancer and gastroesophageal junction adenocarcinoma (advG/GEJC) are leading causes of cancer-related morbidity and mortality. Chemotherapy is the traditional first-line (1L) therapy for patients in the advanced setting, with targeted and immunotherapy considered based on biomarker expression. This study aimed to describe real-world HER2 and PD-L1 testing practices and 1L treatment patterns among advG/GEJC patients. Methods: A retrospective cohort study was conducted among adult patients diagnosed with advG/GEJC between 01 Jan 2017 and 30 Jun 2023 usingthe US-based Flatiron Health electronic health record-derived de-identified database. HER2 and PD-L1 testing practices were evaluated prior to and up to 1-month post-1L treatment initiation or 6 months post-advG/GEJC diagnosis date in untreated patients. 1L treatment regimens were described overall and stratified by HER2 and PD-L1 expression. Results: Among 4,256 advG/GEJC patients, the average age was 67 years with the majority male (68%), non-Hispanic white (44%), and with metastatic disease (64%). Nearly three quarters (72%) of patients included received a HER2 test and 55% had a HER2 test with a valid result within the timeframe mentioned above. More than a quarter of patients (27%) received a PD-L1 test and 25% had a PD-L1 test with a valid result. PD-L1 testing before the approval of nivolumab in 1L (i.e. before 2021) showed testing at 19% (490/2,629; 17% with a valid result) and from 2021 onward at 40% (643/1,627; 37% with a valid result). Across the full cohort, half of the patients received chemotherapy alone (52%) and one quarter received no treatment (25%). Similar treatment patterns were observed in the subset of 1,117 patients who did not receive a HER2 or PD-L1 test; 54% received chemotherapy alone and 36% no treatment. Of the 340 patients who were tested for HER2 and were HER2 positive, half (52%) received trastuzumab combination therapy, 23% received chemotherapy alone, and 18% had no treatment. Of the 301 patients who received a PD-L1 test with a combined positive score (CPS) ≥5 from 2021 onward, 41% received immunotherapy, 34% received chemotherapy alone and 18% had no treatment. Prior to 2021, most patients with a PD-L1 test and CPS >5 used chemotherapy alone (57%; 132/233), 13% (31/233) received PD-L1 targeted therapies and 19% (43/233) received no treatment. Conclusions: This study describes a potential subset of US advG/GEJC patients who do not receive a HER2 or PD-L1 test and/or do not receive eligible targeted or immunotherapy as part of routine clinical practice. As precision medicine options continue to evolve, these data suggest an opportunity to further understand the drivers for biomarker testing as well as the factors impacting the use of biomarker-informed treatment options.

Impact of education on clinical confidence utilizing HER2-targeted therapies in colorectal cancer.

225 Background: Novel targeted therapies entered the treatment landscape in patients with HER2-positive metastatic colorectal cancer (mCRC). To ensure that these therapies are used effectively, clinicians must assess tumor HER2 status and recognize how HER2-directed treatment modalities fit into the current paradigm. To further enable clinicians to integrate HER2-targeted therapies, an educational program was designed in 2023. Methods: A one-hour online, video-based program was designed for clinicians and their teams and hosted on MedLive from February 2023 for one year. Knowledge and competence questions were administered pre-, and immediate post-activity. Additional questions assessed attitudes, barriers, and intended practice changes related to HER-positive mCRC. Results: Over 4,000 participants engaged in the educational activity, 67% of whom were physicians, and 63% noting their specialty as oncology. Approximately 68% identified as treaters seeing 14 patients with CRC per week with 78% of those patients have HER2-positive CRC. All pre-post questions showed significant improvements in knowledge and competence related to HER2 amplification testing methodologies, trial eligibility criteria, identification of patients who would benefit from anti-HER2 targeted regimens, and adverse events associated with anti-HER2 agents. Following the activity, 51% were more likely to incorporate testing for HER2 expression level or amplification prior to the selection of targeted therapy for their patients. The greatest challenges faced when managing patients with HER2-positive mCRC were affordability of therapy for patients (50%), adherence to treatment schedules (25%) and patient anxiety about treatment efficacy (24%). The most common barriers to patient enrollment in clinical trials identified by clinicians were lack of trials at their institutions (35%), lack of trials in their geographic region (21%), and patient lack of interest (20%). Qualitative insights on intended practice changes were shared by learners post-activity. Conclusions: The outcomes of this educational activity demonstrate the effectiveness of education in improving knowledge and confidence from testing to adverse event management to better integrate new regimens into practice. Encouraging practice changes were also seen from the write-in responses from learners. Additional needs were also identified to further solidify HER2 testing as a prerequisite for anti-HER2 targeted therapies, selecting eligible patients, and timely management of adverse events.

Changes in HER2 Amplification Status for Breast Cancer Patients After Immunohistochemistry Directed In Situ Hybridization.

The 2018 ASCO/CAP guidelines for HER2 testing for breast cancer implemented the addition of immunohistochemistry (IHC) directed in situ hybridization (ISH) recount to resolve equivocal results. The implementation of an additional 2+ IHC-directed ISH recount adds additional complexity to the testing workflow for an unclear impact on HER2 results. A retrospective review of all equivocal ISH cases (groups 2, 3, and 4) that underwent 2+ IHC-directed ISH, since the 2018 guidelines, which were finalized as either amplified or not amplified, was performed. HER2 group number and final HER2 amplification status frequently changed after IHC guided ISH assessment, which was due to significant changes in HER2/CEP17 ratio and average HER2 signal number per cell. Equivocal groups 2, 3, and 4 samples with a result of HER2 amplified after 2+ IHC-directed ISH counts were closer to the threshold for amplification on the original ISH count, yet their counts also increased significantly after IHC-directed count in comparison to those samples, which were not amplified. Groups 2 and 4 ISH counts significantly increased after IHC directed ISH for HER2/CEP17 ratio and HER2 signal number per cell. This study represents the most extensive examination of efforts to resolve equivocal HER2 ISH results, highlighting a significant shift in therapeutic options after IHC-guided ISH for a subset of breast cancer patients.

Ultrasonography: an aid in molecular subtyping of breast carcinoma

Introduction: The recognition of molecular subtypes of breast cancer has initiated a new regimen of targeted therapy. Early diagnosis is a key step in improving survival. Therefore, a cost-effective and widely available imaging tool is needed for the timely detection and prediction of the molecular profile of breast cancer. Aim: To study the predictive value of ultrasonographic features in identifying the estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 neu (HER2/neu) expression status, and molecular subtypes of breast cancer. Material and methods: We conducted a study on 51 histopathologically proven invasive breast carcinoma cases over a period of one and a half years. The patients underwent ultrasonography followed by tissue biopsy. Sonographic parameters were assessed based on BI-RADS imaging features. The molecular subtypes of breast cancer were grouped into four subtypes based on the St. Gallen International Expert Consensus Panel. The predictive value of ultrasonographic features was then studied in relation to the hormone receptor status and molecular subtypes of breast cancer. Results: A significant association between posterior acoustic features and molecular subtypes was seen. Posterior acoustic shadowing was associated with progesterone receptor status with an odds ratio (OR) of 36.58, confidence interval (CI) of 5.527–866.1, and p <0.001. The luminal type A molecular subtype was significantly higher in the posterior acoustic shadowing group (10 cases; 52.63%) with an OR of 3.85, CI of 1.12–13.98, and p of 0.02. The proportion of patients with triple-negative molecular subtype (9 cases, 50%) was significantly higher in the posterior acoustic enhancement group, with an OR of 29.42, CI of 4.117–725.4, and p <0.001. Tumors with circumscribed margins were also highly suggestive of the triple-negative molecular subtype [OR of 5.12, CI of 1.16–24.85, and p of 0.03]. The association between the presence or absence of vascularity and its type with molecular subtypes failed to show statistical significance in our study, although vascularity was more frequently observed in triple-negative molecular subtype and luminal type B Her+ve cases. Conclusion: Certain sonographic features are associated with the estrogen/progesterone receptor hormone receptor status and molecular subtypes of breast cancer. With validation of this association, ultrasound may serve as a basic imaging modality for predicting molecular subtypes of breast cancer even in remote areas, where immunohistochemistry hormone receptor and HER2 testing are not available.

Deep learning-based prediction of HER2 status and trastuzumab treatment efficacy of gastric adenocarcinoma based on morphological features

BackgroundFirst-line treatment for advanced gastric adenocarcinoma (GAC) with human epidermal growth factor receptor 2 (HER2) is trastuzumab combined with chemotherapy. In clinical practice, HER2 positivity is identified through immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH), whereas deep learning (DL) can predict HER2 status based on tumor histopathological features. However, it remains uncertain whether these deep learning-derived features can predict the efficacy of anti-HER2 therapy.MethodsWe analyzed a cohort of 300 consecutive surgical specimens and 101 biopsy specimens, all undergoing HER2 testing, along with 41 biopsy specimens receiving trastuzumab-based therapy for HER2-positive GAC.ResultsWe developed a convolutional neural network (CNN) model using surgical specimens that achieved an area under the curve (AUC) value of 0.847 in predicting HER2 amplification, and achieved an AUC of 0.903 in predicting HER2 status specifically in patients with HER2 2 + expression. The model also predicted HER2 status in gastric biopsy specimens, achieving an AUC of 0.723. Furthermore, our classifier was trained using 41 HER2-positive gastric biopsy specimens that had undergone trastuzumab treatment, our model demonstrated an AUC of 0.833 for the (CR + PR) / (SD + PD) subgroup.ConclusionThis work explores an algorithm that utilizes hematoxylin and eosin (H&E) staining to accurately predict HER2 status and assess the response to trastuzumab in GAC, potentially facilitating clinical decision-making.

The Role of Predictive and Prognostic Biomarkers in Lower Female Genital Tract Pathology: PD-L1, MMR, HER2, p16, p53, and Beyond.

Biomarkers play a crucial role in the diagnosis, treatment planning, and prognosis of premalignant and malignant lesions and are increasingly used in neoplasia of the lower female genital tract (LFGT) including the cervix, vagina, and vulva. This review will discuss key biomarkers routinely used in LFGT pathology, including programmed cell death ligand 1 (PD-L1), mismatch repair (MMR), and tumor mutational burden (TMB) testing, which are FDA-approved companion diagnostics for anti-PD-1 checkpoint inhibitors. Recent developments in HER2 testing as a marker for anti-HER2 therapies, and prognostic biomarkers such as p53 in HPV-independent vulvar intraepithelial lesions and carcinomas, are also reviewed.

Nationwide survey on HER2 and PD-L1 testing practices in gastric cancer across Japan.

Since HER2 and PD-L1 testing are key to selecting drugs for first-line treatments in advanced gastric cancer, evaluating differences in these tests among institutions is necessary to standardize treatment. A questionnaire survey was conducted targeting institutions certified by the Japanese Gastric Cancer Association. Responses were obtained from 155 institutions. Most institutions performed HER2 testing in-house, while PD-L1 tests were largely outsourced. HER2 scores and PD-L1 CPS rates showed greater variability across institutions than anticipated. In the pre-analytic phase, 10% neutral buffered formalin was commonly used, with fixation practices generally following guidelines. Overall, the impact of fixation-related factors was limited, but in surgical specimens, longer fixation was associated with a higher proportion of score 0/1+ and a lower proportion of score 3+. When examining HER2 scores by institution, if a particular score had a high (or low) frequency in biopsy, the same trend was also seen in surgical specimens. These findings suggest that not only factors related to specimen preparation, but also biases in evaluation criteria among pathologists may contribute to the significant variability among institutions. Standardization of pre- and post-analytic phases, coupled with appropriate training, is essential to achieve consistent gastric cancer therapy.

Clinical significance of HER2 in urothelial carcinoma and analysis of its correlation with glycolytic metabolic characteristics.

This study aimed to explore the clinical relevance of Human Epidermal Growth Factor Receptor 2 (HER2) in urothelial carcinoma (UC) and its association with glycolytic metabolic markers, insulin resistance, and beta-cell function, shedding light on potential therapies targeting both HER2 pathways and cancer metabolism. In this retrospective analysis, 237 UC patients from the Departments of Urology and Pathology at Shandong Provincial Hospital were examined. From 1 January 2023, to 1 October 2024, patients underwent HER2 testing using immunohistochemistry (IHC). We investigated the relationships between HER2 expression and metabolic indicators such as the Homeostatic Model Assessment for insulin resistance (HOMA-IR), beta-cell function (HOMA-β), the triglyceride-glucose (TyG) index, and lactate dehydrogenase (LDH) levels. HER2 status was determined using a standardized scoring system from the 2021 Clinical Pathological Expert Consensus on HER2 Testing in UC, China. Statistical analysis followed CDC guidelines, using multivariate logistic regression to assess the independent impacts of HER2 on metabolic traits. Of the 237 evaluated UC samples, 87.76% exhibited positive HER2 expression. A significant correlation was found between positive HER2 status, advanced tumor stages, and increased LDH levels, suggesting a link between HER2 expression and heightened glycolytic activity. No significant relationships were observed between HER2 status and TyG levels, HOMA-IR, or HOMA-B. Subgroup analyses confirmed the consistency of the relationship between HER2 expression and LDH levels across different demographics and lifestyle factors. Our findings confirm the significant role of HER2 as a prognostic marker and therapeutic target in UC. The association of HER2 positivity with advanced tumor stages and high LDH levels underscores its complex involvement in disease progression. This study highlights the need to explore HER2's biological mechanisms further and pursue combined therapeutic strategies.

Guideline for HER2 testing in breast cancer (2024 version)

Guideline for HER2 testing in breast cancer (2024 version)

Canadian Consensus Recommendations for Predictive Biomarker Testing in Gastric and Gastroesophageal Junction Adenocarcinoma.

Gastric cancer is common globally and has a generally poor prognosis with a low 5-year survival rate. Targeted therapies and immunotherapies have improved the treatment landscape, providing more options for efficacious treatment. The use of these therapies requires predictive biomarker testing to identify patients who can benefit from their use. New therapies on the horizon, such as CLDN18.2 monoclonal antibody therapy, require laboratories to implement new biomarker tests. A multidisciplinary pan-Canadian expert working group was convened to develop guidance for pathologists and oncologists on the implementation of CLDN18.2 IHC testing for gastric and gastroesophageal junction (G/GEJ) adenocarcinoma in Canada, as well as general recommendations to optimize predictive biomarker testing in G/GEJ adenocarcinoma. The expert working group recommendations highlight the importance of reflex testing for HER2, MMR and/or MSI, CLDN18, and PD-L1 in all patients at first diagnosis of G/GEJ adenocarcinoma. Testing for NTRK fusions may also be included in reflex testing or requested by the treating clinician when third-line therapy is being considered. The expert working group also made recommendations for pre-analytic, analytic, and post-analytic considerations for predictive biomarker testing in G/GEJ adenocarcinoma. Implementation of these recommendations will provide medical oncologists with accurate, timely biomarker results to use for treatment decision-making.

Abstract A046: Development of a scoring system to classify HER2 protein expression in circulating tumor cells through immunofluorescence following isolation using Parsortix® instruments

Abstract Background. HER2 testing through immunohistochemistry (IHC) is routinely performed on tissue biopsy samples from metastatic breast cancer (MBC) patients, resulting in a HER2 score that is used in patient stratification and treatment decisions. However, tissue biopsy is invasive, with little opportunity for re-examination while liquid biopsy is minimally invasive and allows monitoring of disease progression through recurrent sample collection. This study aimed to establish an assay (Research Use Only) allowing scoring of HER2 protein expression in circulating tumor cells (CTCs), by immunofluorescence (IF) staining, using cancer cell lines of known HER2 expression. Method. Cultured cancer cell lines with HER2 expression comparable to tissue samples (i.e. HER2 0, 1+, 2+ and 3+ by IHC score) were used in this study (SKBR3 [3+], HCC1954 [3+], SKOV-3 [2+/3+], ZR-75-1 [2+], MCF-7 [0 – 1+] and Hs 578T [0]). Cultured cancer cells were spun onto CellKeep™ slides and stained with ANGLE’s Portrait HER2 IF panel, comprising a nuclear dye, an anti-HER2 antibody, epithelial, mesenchymal and leukocyte markers. Slides were imaged on a BioView Allegro Plus, a platform equipped with artificial intelligence for automated imaging, CTC candidate identification and reporting. The workflow was implemented using samples from 5 MBC patients with known HER2 IHC scores, whose blood was drawn into Streck Cell-Free DNA tubes and processed on ANGLE's Parsortix® instrument, a marker-independent microfluidic device which isolates CTCs based on size and deformability, before being stained with the Portrait HER2 assay. The cohort is being expanded and currently includes three HER2 0 and two HER2 3+ patients as diagnosed by tissue IHC. Results. By observing mean fluorescence intensity (MFI) of each cancer cell line reported to be reflective of each IHC score, thresholds were set to establish a protein scoring system. 95%, 95% and 91% of SKBR3, HCC1954 and SKOV-3, respectively, fell in the 3+ class, 83% of ZR-75-1 fell in the 2+ class, 69% of MCF-7 fell in the 1+ class and 25% and 89% of MCF-7 and Hs 578T, respectively, fell in the 0 class. ≥1 CTC were found in all 5 subjects (mean=405, median=146), with 60% donors presenting mesenchymal CTCs, 20% epithelial CTCs and 20% epithelial and mesenchymal CTCs. HER2+ CTCs were found in both HER2 3+ donors, but not in the HER2 0 donors. HER2+ CTCs from both donors fell in the 3+ class based on MFI, despite one donor receiving Herceptin treatment (1 CTC) and the other being treatment naïve (435 CTCs). Conclusion. This study showed it is possible to establish a HER2 protein scoring system using cultured cancer cell lines stained with the Portrait HER2 assay and demonstrates the potential utility of liquid biopsy in tracking HER2 status. This scoring system will be applied to CTCs isolated from an extended cohort of MBC patients with known tissue biopsy HER2 IHC results to test the robustness of the system and assess concordance of CTC and tissue biopsy scores. FISH will be performed on the samples from MBC patients to confirm results. Citation Format: Alex Young, Laila Vlietinck, Bethan Edwards, Liam Cook, Chassidy Johnson, Mariacristina Ciccioli, Anne-Sophie Pailhes-Jimenez. Development of a scoring system to classify HER2 protein expression in circulating tumor cells through immunofluorescence following isolation using Parsortix® instruments [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A046.

Trastuzumab Deruxtecan in Advanced Solid Tumors With Human Epidermal Growth Factor Receptor 2 Amplification Identified by Plasma Cell-Free DNA Testing: A Multicenter, Single-Arm, Phase II Basket Trial.

HERALD/EPOC1806 was conducted as a multicenter phase II trial assessing trastuzumab deruxtecan (T-DXd) therapy for patients with human epidermal growth factor receptor 2 (HER2)-amplified progressive stage solid tumors detected by cell-free DNA (cfDNA) testing. Patients exhibited advanced solid tumors with HER2 amplification that was identified via next-generation sequencing of cfDNA testing, without the requirement for immunohistochemical HER2 testing. The studied group was administered T-DXd at 5.4 mg/kg once every 3 weeks until onset of disease progression or intolerable toxicity. Overall, 4,734 patients underwent cfDNA testing from December 2019 to January 2022, and 252 demonstrated HER2 amplification. Finally, the study included 62 patients with 16 cancer types with a median baseline plasma HER2 copy number (CN) of 8.55 (range, 2.4-73.9). Confirmed overall response rate (ORR) by investigator assessment was 56.5% (95% CI, 43.3 to 69.0), thus showing a value beyond the 5% threshold. Responses were evaluated for 13 cancer types, including KRAS-mutant colorectal (1/3), PIK3CA-mutant endometrial (5/6), and tissue HER2-negative gastric (1/2) cancers. Plasma HER2 CN above versus below the baseline median value did not differ for impact response; however, clearance of HER2 amplification in cfDNA on cycle 2 day 1 had higher response values compared with persistence. Median progression-free survival and response duration were 7.0 (95% CI, 4.9 to 9.7) and 8.8 (95% CI, 5.8 to 11.2) months, respectively, with the majority of complications being mild to moderate. Interstitial lung diseases were identified in 16 (26%) patients, including 14 patients with grade 1 disease, one patient with grade 2 disease, and one patient with grade 3 disease. T-DXd treatment demonstrated high ORR with durable response in patients with advanced HER2-amplified solid tumors determined with cfDNA testing.

Should a borderline negative HER2 result in a core biopsy of invasive carcinoma of the breast have HER2 assessment repeated in the excision specimen?

AimThe 2015 UK guidelines for HER2 assessment in breast cancer recommended repeat assessment if the core biopsy was scored as 2+ on HER2 immunohistochemistry (IHC) with borderline negative in situ...

Performance of a HER2 testing algorithm tailored for urothelial bladder cancer: A Bi-centre study

AimsThis study aimed to develop an AI algorithm for automated HER2 scoring in urothelial bladder cancer (UBCa) and assess the interobserver agreement using both manual and AI-assisted methods based on breast cancer criteria. Methods and ResultsWe utilized 330 slides from two institutions for initial AI development and selected 200 slides for the ring study, involving six pathologists (3 senior, 3 junior). Our AI algorithm achieved high accuracy in two independent tests, with accuracies of 0.94 and 0.92. In the ring study, the AI-assisted method improved both accuracy (0.66 vs 0.94) and consistency (kappa=0.48; 95 % CI, 0.443–0.526 vs kappa=0.87; 95 % CI, 0.852–0.885) compared to manual scoring, especially in HER2-low cases (F1-scores: 0.63 vs 0.92). Additionally, in 62.3 % of heterogeneous HER2-positive cases, the interpretation accuracy significantly improved (0.49 vs 0.93). Pathologists, particularly junior ones, experienced enhanced accuracy and consistency with AI assistance. ConclusionsThis is the first study to provide a quantification algorithm for HER2 scoring in UBCa to assist pathologists in diagnosis. The ring study demonstrated that HER2 scoring based on breast cancer criteria can be effectively applied to UBCa. Furthermore, AI assistance significantly improves the accuracy and consistency of interpretations among pathologists with varying levels of experience, even in heterogeneous cases.

MO19-3 Comparison of HER2 expression status between conventional HER2 test and VENTANA HER2 (4B5) of metastatic breast cancer

MO19-3 Comparison of HER2 expression status between conventional HER2 test and VENTANA HER2 (4B5) of metastatic breast cancer

Analysis of HER2-Low Breast Cancer in Aotearoa New Zealand: A Nationwide Retrospective Cohort Study.

To perform the first national analysis of demographic and clinicopathological features associated with the HER2 positive, HER2-low, and HER2-zero invasive breast cancers in New Zealand. The study will reveal the proportion of women who may benefit from new HER2-targeted antibody drug conjugate (ADC) therapies. Utilising data from Te Rēhita Mate Ūtaetae (Breast Cancer Foundation NZ National Register), the study analysed data from women diagnosed with invasive breast cancer over a 21-year period. The HER2 status of tumours was classified into three categories-HER2-zero, HER2-low, HER2-positive. From 2009-2021, 94% of women underwent HER2 testing, with 14% diagnosed with HER2-positive breast cancer. For advanced-stage disease, 38% of those formerly classified as HER2-negative were reclassified as HER2-low. Including HER2-positive breast cancers, this indicates that 60% of women with advanced breast cancer may potentially benefit from the new HER2-directed ADCs (approximately 120 women per year). The findings suggest a significant proportion of women with invasive breast cancer in New Zealand could benefit from new HER2-targeted treatments. There is a need to standardise HER2 testing to enhance personalised treatment and improve outcomes.

177P HER2 testing in multiple solid tumors: Concordance between 3 scoring algorithms

177P HER2 testing in multiple solid tumors: Concordance between 3 scoring algorithms

394P Quantitative standardized high sensitivity (HS)-HER2 testing predicts outcomes with trastuzumab deruxtecan (T-DXd) for metastatic breast cancer (MBC)

394P Quantitative standardized high sensitivity (HS)-HER2 testing predicts outcomes with trastuzumab deruxtecan (T-DXd) for metastatic breast cancer (MBC)

Human Epidermal Growth Factor 2 (Her-2) Expression in Gastric and Gastroesophageal Carcinomas: A Clinicopathological Evaluation in a Tertiary Care Institute.

Introduction Gastric carcinoma is a significant global health concern, known for its high mortality rate. HER-2 overexpression is observed in a notable proportion of gastric carcinoma and is associated with a worse prognosis. However, HER-2 expression enables targeting the protein by monoclonal antibodies that improve overall survival in HER-2-positive gastric cancers. This study aims to evaluate the HER-2 expression in gastric and gastroesophageal carcinomas. Materials and methods This observational study was conducted in the Department of Pathology, involving 60 endoscopic biopsy and resection specimens of gastric and gastroesophageal carcinomas. HER-2 expression was assessed by immunohistochemistry (IHC) based on the Trastuzumab for GAstric Cancer (ToGA) trial's scoring system. The primary outcome was HER-2 status, with statistical analysis performed to evaluate associations with various clinicopathological parameters. Results Among 60 cases, 26 (43.3%) showed HER-2 positivity. HER-2 positivity was significantly (p=0.004) associated with age, being higher in 20-39 years and ≥80 years age groups. Gender and tumor location were not significantly associated with HER-2 positivity. Moderate and poorly differentiated carcinomas exhibited higher HER-2 positivity. Histological types, tubular adenocarcinoma, and papillary adenocarcinoma showed significant (p=0.01) association with HER-2 positivity compared to other types. Conclusion HER-2 status assessment is crucial in managing gastric and gastroesophageal carcinomas. HER-2 positivity is notably higher in certain age groups and histological types particularly tubular and papillary adenocarcinoma, and in moderately to poorly differentiated carcinomas. These insights can aid in selecting appropriate gastric and gastroesophageal carcinomas that warrant HER-2 testing on IHC. Identifying gastric and gastroesophageal carcinomas that show HER2 expression may highlight potential candidates for targeted therapy.

Availability and geographic access to breast cancer pathology services in Ghana.

Breast cancer poses a significant health challenge in Sub-Saharan Africa, particularly in Ghana, where late-stage diagnoses and limited healthcare access contribute to elevated mortality rates. This study focuses on the crucial role of pathology and laboratory medical (PALM) services in the timely diagnosis of breast cancer within Ghana. A cross-sectional survey of hospitals was completed from November 2020 to October 2021, with 94.8% of identified in-country hospitals participating. Pathology service-related parameters assessed included whether pathology was available for the diagnosis of breast cancer on-site or via external referral, the number of pathology personnel, additional breast cancer diagnostic capabilities including estrogen and progesterone and/or HER2 testing, and the time from biopsy to patients receiving their results. Geospatial mapping was used to identify areas of limited access. Of the 328 participating hospitals, 136 (41%) reported breast cancer pathology services, with only 6 having on-site capabilities. Pathology personnel, comprising 15 consultants and 15 specialists, were concentrated in major referral centers, particularly in Greater Accra and Kumasi. An assessment of referral patterns suggested that 75% of the population reside within an hour of breast cancer pathology services. Among the 136 hospitals with access to breast cancer pathology, only a limited number reported that results included ER/PR (38%) and HER2 testing (33%). Ghana has been able to ensure significant pathology service availability through robust referral pathways with centralized labs. Despite this, difficulties persist with the majority of pathology results not including hormone receptor testing which is important in providing tumor specific treatment.