Characteristics of HER2-negative breast cancers with FISH-equivocal status according to 2018 ASCO/CAP guideline

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.

Clinicopathological features, treatment patterns, and survival outcomes among Syrian patients with advanced breast cancer

Background

Advanced breast cancer (ABC) is a heterogeneous disease with varied prognoses, that is affected by many clinicopathological features. This study aimed to investigate the clinicopathological characteristics, first-line treatment (FLx), and prognostic impact of these features on survival among Syrian patients with ABC.

Materials and methods

This retrospective cohort study included patients with ABC. The association of clinicopathological factors with survival was assessed using Kaplan-Meier curves and the log-rank test, as well as the Cox proportional hazards regression model to calculate the hazard ratio (HaR).

Results

A total of 423 patients with ABC were included in the study, with a median age (range) of 47 years (23-82). 83% of metastases were metachronous. Most patients (91.8%) received chemotherapy as the FLx. The median progression-free survival (PFS) and overall survival (OS) of all the patients were 7 and 16 months, respectively. The median PFS was associated with four factors, which were time of metastasis (adjusted HaR=1.861, 95% CI 1.420-2.438, P<0.0001), performance status (PS) (adjusted HaR=1.456, 95% CI 1.049-2.021, P=0.025), ovarian metastasis (adjusted HaR=7.907, 95% CI 1.049-59.576, P=0.045), and FLx (adjusted HaR=2.536, 95% CI 1.581-4.068, P<0.0001). Similarly, the OS was associated with three factors, including hormone receptors (HRs) status (adjusted HaR=1.124, 95% CI 1.009-1.252, P=0.034), time of metastasis (adjusted HaR=2.099, 95% CI 1.588-2.775, P<0.0001), and PS (adjusted HaR=1.787, 95% CI 1.429-2.233, P<0.0001). In the HR-positive/human epidermal growth receptor 2 (HER2)-negative group, endocrine therapy was significantly associated with longer PFS compared with chemotherapy (15 vs 7 months, adjusted HaR=2.699, 95% CI 1.417-5.143, P=0.003). Furthermore, there was no difference in OS between the two treatment modalities (P=0.855).

Conclusions

ABC survival varies depending on the location of metastases. Good PS and synchronous stage 4 disease were independent prognostic factors for longer PFS and OS. In the HR-positive/HER2-negative group, PFS for endocrine therapy was significantly longer than chemotherapy, with no differences in OS. This study confirms that endocrine therapy is preferred as an FLx for ABC in the HR-positive/HER2-negative group.

Complete response and long-term survival to endocrine monotherapy in a patient with metastatic breast cancer in a low-income country: a case report

BACKGROUND

Breast cancer is the most common cancer in women. Progression-free survival for hormone receptor-positive/human epidermal growth factor receptor-2-negative metastatic breast cancer treated with endocrine therapy in combination with cyclin4/6-dependent kinase is approximately 25 months. This case represents metastatic breast cancer treated with endocrine therapy, leading to long-term survival.

CASE PRESENTATION

A 40-year-old Syrian woman diagnosed with hormone receptor-negative breast cancer was treated surgically with adjuvant chemotherapy and radiotherapy. She developed local and nodal recurrences that were hormone receptor-positive, followed by a recurrence of malignant pleural effusion. She was initially treated with chemotherapy and then placed on endocrine therapy with a complete response from 2014 until now. The patient also suffered from adverse events of medications, such as heart failure and osteoporosis, which were treated appropriately.

CONCLUSION

This case demonstrates a long-lasting complete response to metastatic breast cancer with malignant pleural effusion. This shows the validity of endocrine therapy in recurrent hormone receptor-positive breast cancer, especially in countries that cannot afford targeted therapies or genetic tests. It also highlights the necessity for a better understanding of the prognostic and predictive factors.

The unique monoclonal antibodies and immunochemical assay for comprehensive determination of the cell-bound and soluble HER2 in different biological samples

The expression of the HER2 (human epidermal growth factor receptor 2) protein in cancer cells is a well-established cancer marker used for diagnostic and therapeutic purposes in modern treatment protocols, especially in breast cancer. The gold-standard immunohistochemical diagnostic methods with the specific anti-HER2 antibodies are utilized in the clinic to measure expression level of the membrane-bound receptor. However, a soluble extracellular domain (ECD) of HER2 is released to the extracellular matrix, thus the blood assays for HER2 measurements present an attractive way for HER2 level determination. There is a need for accurate and validated assays that can be used to correlate the concentration of the circulating HER2 protein with disease clinical manifestations. Here we describe two monoclonal antibodies binding HER2 with a unique sequence of the complementarity-determining regions that recognize HER2 ECD. Development and validation of the sandwich enzyme-linked immunosorbent assay (ELISA) for quantification of the soluble HER2 in a variety of biological samples is also presented. The assay provides HER2 quantitation within a concentrations range from 1.56 to 100 ng/ml with sensitivity at the level of 0.5 ng/ml that meets the expectations for measurements of HER2 in the blood and tumor tissue samples. The method presents satisfactory intra- and inter-assay precision and accuracy for immunochemical quantification of biomarkers in biological samples. The utility of the generated monoclonal anti-HER2 antibodies has been confirmed for use in the precise measurement of HER2 (both cell-bound and soluble) in several types of biological material, including serum, solid tumor tissue, and cell culture medium. Additionally, the developed immunochemical tools have a potential for HER2 detection, not only in a wide range of sample types but also independently of the sample storage/pre-processing, allowing for comprehensive HER2 analysis in tissue (IHC), cultured cells (immunofluorescence) and blood (ELISA).

Targeting MET Amplification: Opportunities and Obstacles in Therapeutic Approaches

The MET gene plays a vital role in cellular proliferation, earning it recognition as a principal oncogene. Therapies that target MET amplification have demonstrated promising results both in preclinical models and in specific clinical cases. A significant obstacle to these therapies is the ability to distinguish between focal amplification and polysomy, a task for which simple MET copy number measurement proves insufficient. To effectively differentiate between the two, it is crucial to utilize comparative measures, including in situ hybridization (ISH) with the centromere or next generation sequencing (NGS) with adjacent genes. Despite the promising potential of MET amplification treatment, the judicious selection of patients is paramount to maximize therapeutic efficacy. The effectiveness of MET inhibitors can fluctuate depending on the extent of MET amplification. Future research must seek to establish the ideal threshold value for MET amplification, identify the most efficacious combination therapies, and innovate new targeted treatments for patients exhibiting MET amplification.

Weakly supervised bilayer convolutional network in segmentation of HER2 related cells to guide HER2 targeted therapies

Overexpression of human epidermal growth factor receptor 2 (HER2/ERBB2) is identified as a prognostic marker in metastatic breast cancer and a predictor to determine the effects of ERBB2-targeted drugs. Accurate ERBB2 testing is essential in determining the optimal treatment for metastatic breast cancer patients. Brightfield dual in situ hybridization (DISH) was recently authorized by the United States Food and Drug Administration for the assessment of ERRB2 overexpression, which however is a challenging task due to a variety of reasons. Firstly, the presence of touching clustered and overlapping cells render it difficult for segmentation of individual HER2 related cells, which must contain both ERBB2 and CEN17 signals. Secondly, the fuzzy cell boundaries make the localization of each HER2 related cell challenging. Thirdly, variation in the appearance of HER2 related cells is large. Fourthly, as manual annotations are usually made on targets with high confidence, causing sparsely labeled data with some unlabeled HER2 related cells defined as background, this will seriously confuse fully supervised AI learning and cause poor model outcomes. To deal with all issues mentioned above, we propose a two-stage weakly supervised deep learning framework for accurate and robust assessment of ERBB2 overexpression. The effectiveness and robustness of the proposed deep learning framework is evaluated on two DISH datasets acquired at two different magnifications. The experimental results demonstrate that the proposed deep learning framework achieves an accuracy of 96.78 ± 1.25, precision of 97.77 ± 3.09, recall of 84.86 ± 5.83 and Dice Index of 90.77 ± 4.1 and an accuracy of 96.43 ± 2.67, precision of 97.82 ± 3.99, recall of 87.14 ± 10.17 and Dice Index of 91.87 ± 6.51 for segmentation of ERBB2 overexpression on the two experimental datasets, respectively. Furthermore, the proposed deep learning framework outperforms 15 state-of-the-art benchmarked methods by a significant margin (P<0.05) with respect to IoU on both datasets.

Invasive Breast Cancer with HER2 ≥4.0 and <6.0: Risk Classification and Molecular Typing by a 21-Gene Expression Assay and MammaPrint Plus BluePrint Testing

PURPOSE

To investigate the HER2 status and clinicopathological features in invasive breast cancer with HER2 ≥4.0 and <6.0, which has always been controversial.

METHODS

Forty breast cancer cases with HER2 ≥4.0 and <6.0 by fluorescence in situ hybridization (FISH) were collected and classified into two groups based on the HRE2/CEP17 ratio (Group A: ≥2.0, n=22; Group B: <2.0, n=18). Clinicopathological characteristics, HER2 status, risk classification, and molecular typing were further analyzed and compared by 21-Gene expression assay and MammaPrint plus BluePrint test.

RESULTS

The majority of cases in both groups were invasive carcinoma (NOS), with histological grade II, HR+, Ki-67 ≥20%, HER2 2+, and a high risk of recurrence, although younger patients and lymph node metastases were more common in Group A. Surprisingly, all HR+ breast cancers in both groups were classified as luminal-type, HR- cases were all basal-type or unknown, and the index of HER2 in all cases was <0.000 using the BluePrint test, which indicated that HER2 status should be negative. Furthermore, the level of HER2 mRNA expression in all cases of both groups was <10.7, which was defined as HER2 negative by the 21-Gene expression assay. In addition, 10 patients of Group A received anti-HER2 neoadjuvant therapy; only one patient with HR- achieved Grade 5 based on the Miller-Payne system, whereas none of the patients achieved pathological complete response (pCR) based on the Residual Cancer Burden system.

CONCLUSION

Group A breast cancer, which has always been unquestionably diagnosed as HER2 amplification, was more likely to be HER2 negative and derived less benefit from anti-HER2 neoadjuvant chemotherapy. Group A breast cancer should be distinguished from classical HER2-positive breast cancers when assessing HER2 FISH, and a larger cohort of Group A patients should be included in further studies.

Indian Data on HER2 Fluorescence In Situ Hybridization in Invasive Breast Cancer with Immunohistochemically Equivocal Results As Per 2018 ASCO/CAP Guidelines

Biren ParikhIntroduction  Hormonal status and HER2 expression are valuable biomarkers and dictate the management of the patients diagnosed with invasive breast cancer (IBC). It is crucial to identify the patients who truly respond to anti-HER2 targeted therapy. Updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines has recommended certain modifications in HER2 interpretation by fluorescence in situ hybridization (FISH) with concomitant immunohistochemistry (IHC). Objectives  We aimed to evaluate HER2 FISH interpretation in IBC with equivocal IHC results as per 2018 ASCO/CAP recommendations and compare FISH results with hormonal receptor status. Materials and Methods  FISH results of 502 cases of IBC with equivocal IHC report between January 2016 to January 2022 were reviewed retrospectively. FISH results were categorized according to ASCO/CAP guidelines 2018 into five respective groups. Results  FISH testing in IHC equivocal cases showed 219 (43.6%) cases were classic amplified (positive) belonged to group 1, 217(43.2%) cases were classic nonamplified (negative) fell into group 5, 39 (7.8%) and 02 (0.4%) patients were in group 2 (negative) and group 3 (positive), and 25 (5.0%) cases were in group 4 (negative). About 52.1 and 49.3% of cases with estrogen receptor and progesterone receptor positivity were reported as HER2 positive. Among 502 cases, 25 equivocal cases according to the 2013 guidelines were redefined as HER2 negative and 02 (0.4%) cases reported positive were classified negative as per updated 2018 guidelines. Conclusion  Revised 2018 guidelines is helpful in accurate identification of HER2 status and in avoiding targeted therapy in unwarranted cases. Updated 2018 guidelines has removed equivocal HER2-FISH category that has eliminated management dilemma in these cases. Only long-term clinical follow-up will establish the validity of the updated guidelines.

Immunohistochemical Marker Patterns in Female Breast Cancer

BACKGROUND: Breast cancer (BC) represents the most common cancer in women worldwide and in Bulgaria. Its great medico-social importance determines the intensive complex research devoted to BC prevention, early diagnosis and management. AIM: The objective of the present investigation is to reveal some essential peculiarities of four main immunohistochemical markers used in the diagnosis of molecular subtypes of female BC. MATERIALS AND METHODS: During the period between December 1, 2017 and November 30, 2020, we examined a total of 128 randomly selected female BC patients operated on in Marko Markov Specialized Hospital for Active Treatment of Oncological Diseases of Varna, Bulgaria. We analyze BC molecular types and four immunohistochemical markers in BC patients. The expression of estrogen (ER) and progesterone (PR) receptors is assessed in mammary gland biopsies and surgical specimens by using the indirect immunoperoxidase method with EnVision™ FLEX MiniKit, that of HER2 with HercepTest™ and that of Ki-67 proliferation index with Leica Aperio Scan Scope AT2 device. The positivity and negativity of these receptors in single molecular subtypes is evaluated. RESULTS: The luminal B HER2-positive and the luminal B HER2-negative subtypes are most common - in 36.72% and 35.16% of the cases, respectively. TNBC subtype is established in 11.72%) the luminal A - in 8.59% and the non-luminal HER2-positive subtype - in 7.81% of the cases. The positive expression is statistically significantly more common in ER (t=8.972; p<0.0001) and PR (t=2.828; p<0.01), while the negative expression insignificantly prevails in HER2. CONCLUSION: Our immunohistochemical results in female BC patients prove the role of single receptor expression for the proper and timely decision making about the necessity and benefit of additional chemotherapy in selected surgically treated cases.