Human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor-positive breast cancer: new insights into molecular interactions and clinical implications

Role of artificial intelligence -based machine learning model in predicting HER2/neu gene status in breast cancer

Our study investigated the predictive efficacy of AI-based Machine Learning (ML) model for determining HER2 status in a population of 3424 breast cancer patients. Multivariate logistic regression analysis identified several independent variables that were predictive of HER2 positivity, namely age ≤ 40 years, tumor multicentricity, high tumor grade, high-grade DCIS, N3 stage disease, and negative ER status (p < 0.05). These findings suggest that patients presenting with these factors may benefit from more aggressive and targeted therapies. Furthermore, XGBoost ML model was trained using the dataset of 3324 patients, which was divided into an 80 % training set and a 20 % test set. The model achieved an impressive accuracy of 95 % on both training and test sets, as evidenced by the area under the curve (AUC) values of 0.95. The model ranked the presence of DCIS, DCIS component (major versus minor), DCIS grade, multiplicity of the tumor, and ER status as the top four variables for predicting HER2/neu status. To validate the performance of the proposed model, blind HER2 status data from an external validation cohort of 100 cases were utilized. Notably, the model demonstrated a sensitivity of 90.5 %, indicating its ability to accurately identify HER2-positive cases, and a specificity of 84.4 %, suggesting its capability to correctly classify HER2-negative cases. These results highlight the promising predictive efficacy of AI-based ML in determining HER2 status in breast cancer patients. The model's ability to accurately identify HER2-positive cases can assist in guiding treatment decisions, ensuring that patients receive appropriate and targeted therapies. However, further research with larger datasets is necessary to validate and generalize these findings.

Molecular shifts in breast cancer following neoadjuvant chemotherapy: a prospective study and review of literature

BACKGROUND

Standard clinical guidelines recommend evaluating Estrogen & progesterone Receptor (ER, PR), Human epidermal growth factor receptor-2 (HER-2), and Ki-67 in breast cancer biopsy samples. This study investigates the changes in molecular subtype following neoadjuvant chemotherapy (NACT) in breast cancer patients.

METHODS

Patients aged 18 to 65 years who underwent core needle biopsy before NACT and received at least four chemotherapy cycles were included in the study. Patients with inflammatory breast cancer, de novo metastatic or bilateral breast cancer, pregnancy, lactation, prior endocrine/radiation therapy, or achieved pathological complete response (pCR) were excluded. Molecular profiles (ER, PR, HER-2, Ki-67) were analyzed pre- and post-NACT.

RESULTS

The study involved 100 breast cancer patients with a median age of 51.78 years. 47% of patients underwent breast-conserving surgery (BCS), while 53% underwent modified radical mastectomy (MRM). Seventy-six percent of patients had tumors larger than 5 cm, and 72% presented with axillary lymph node metastasis. Initially, 90% and 89% of patients were ER, and PR positive, respectively, which decreased to 81% and 75% post-surgery. Ki67 expression showed a significant reduction following chemotherapy. Larger tumors and lymph node-positivity had significant changes in molecular subtypes.

CONCLUSION

The study revealed significant alterations in ER, PR, HER-2, and Ki-67 levels post-NACT, prompting reassessment for tailored therapy.

Characterisation of HER2-Driven Morphometric Signature in Breast Cancer and Prediction of Risk of Recurrence

INTRODUCTION

Human epidermal growth factor receptor 2-positive (HER2-positive) breast cancer (BC) is a heterogeneous disease. In this study, we hypothesised that the degree of HER2 oncogenic activity, and hence response to anti-HER2 therapy is translated into a morphological signature that can be of prognostic/predictive value.

METHODS

We developed a HER2-driven signature based on a set of morphometric features identified through digital image analysis and visual assessment in a sizable cohort of BC patients. HER2-enriched molecular sub-type (HER2-E) was used for validation, and pathway enrichment analysis was performed to assess HER2 pathway activity in the signature-positive cases. The predictive utility of this signature was evaluated in post-adjuvant HER2-positive BC patients.

RESULTS

A total of 57 morphometric features were evaluated; of them, 22 features were significantly associated with HER2 positivity. HER2 IHC score 3+/oestrogen receptor-negative tumours were significantly associated with HER2-related morphometric features compared to other HER2 classes including HER2 IHC 2+ with gene amplification, and they showed the least intra-tumour morphological heterogeneity. Tumours displaying HER2-driven morphometric signature showed the strongest association with PAM50 HER2-E sub-type and were enriched with ERBB signalling pathway compared to signature-negative cases. BC patients with positive HER2 morphometric signature showed prolonged distant metastasis-free survival post-adjuvant anti-HER2 therapy (p = 0.007). The clinico-morphometric prognostic index demonstrated an 87% accuracy in predicting recurrence risk.

CONCLUSION

Our findings underscore the strong prognostic and predictive correlation between HER2 histo-morphometric features and response to targeted anti-HER2 therapy.

Synthesis, characterization and bioactivity of new pyridine-2(H)-one, nicotinonitrile, and furo[2,3-b]pyridine derivatives

Pyridone heterocycles, such as furo[2,3-b]pyridines, have emerged as prominent scaffolds in medicinal chemistry due to their versatile pharmacological properties, including significant anticancer activity. In this study, we successfully synthesized new pyridine-2(H)-one, nicotinonitrile, and furo[2,3-b]pyridine derivatives from chalcones bearing 4-(benzyloxy)phenyl and dichlorothiophenyl subunits to explore their therapeutic potential against breast cancer. By employing a synthetic strategy involving Claisen-Schmidt condensation followed by sequential cyclizations and functional modifications, we synthesized and characterized four compounds (MI-S0, MI-S1, MI-S2, and MI-S3) using various spectroscopic methods, including FT-IR, 1H-NMR, 13C-NMR, DEPT, H,H- and C,H-COSY, and HRMS. The in vitro cytotoxic activity of these compounds was evaluated against two breast cancer cell lines, MCF-7 and MDA-MB-231, and compared with a noncancerous breast cell line, MCF-10A. All compounds exhibited potent cytotoxic activities with minimal selectivity toward normal cells. Molecular docking studies targeting the serine/threonine kinase AKT1, estrogen receptor alpha (ERα), and human epidermal growth factor receptor 2 (HER2) revealed strong binding affinities, suggesting a mechanism involving the disruption of key cellular signaling pathways. These findings underscore the potential of furo[2,3-b]pyridine derivatives as promising candidates for further development into anticancer agents, laying the groundwork for future investigations into their selective therapeutic efficacy and molecular mechanisms of action.

Clinicopathologic Features of Breast Tumors in Germline TP53 Variant-Associated Li-Fraumeni Syndrome

We present one of the largest cohorts of TP53 -pathogenic germline variants (PGVs) associated with patients with Li-Fraumeni syndrome (n = 82) with breast tumors (19 to 76 y; median age: 35). Most had missense variants (77%), followed by large gene rearrangements (LGRs; 12%), truncating (6%), and splice-site (5%) variants. Twenty-one unique germline missense variants were found, with hotspots at codons 175, 181, 245, 248, 273, 334, and 337. Of 100 total breast tumors, 63% were invasive (mostly ductal), 30% pure ductal carcinoma in situ, 4% fibroepithelial lesions, and 3% with unknown histology. Unlike BRCA -associated tumors, approximately half of the breast cancers exhibited HER2 -positivity, of which ~50% showed estrogen receptor coexpression. Pathology slides were available for review for 61 tumors (44 patients), and no significant correlation between the type of TP53 PGVs and histologic features was noted. High p53 immunohistochemistry expression (>50%) was seen in 67% of tumors tested (mostly missense variant). Null pattern (<1% cells) was seen in 2 (LGR and splicing variants carriers). Surprisingly, 2 tumors from patients with an LGR and 1 tumor from a patient with a truncating variant showed p53 overexpression (>50%). The subset of patients with the Brazilian p.R337H variant presented at a higher age than those with non-p.R337H variant (46 vs 35 y) though statistically insignificant ( P = 0.071) due to an imbalance in the sample size, and were uniquely negative for HER2 -overexpressing tumors. To conclude, breast cancer in carriers of TP53 PGVs has some unique clinicopathological features that suggest differential mechanisms of tumor formation. p53 immunohistochemistry cannot be used as a surrogate marker to identify germline TP53 -mutated breast cancers.

Factors associated with first-to-second-line attrition among patients with metastatic breast cancer in the real world

BACKGROUND

Estimating patient attrition across lines of treatment (i.e. the probability that upon treatment failure the patient will not be able to receive a subsequent treatment) may be a valuable tool for optimizing treatment sequencing. We sought to describe the first-to-second-line attrition rate and factors associated with attrition in a real-world cohort of patients with metastatic breast cancer.

METHODS

The Gruppo Italiano Mammella (GIM)14/BIO-META (NCT02284581) is an ongoing, ambispective observational multicenter study enrolling patients with metastatic breast cancer receiving first-line therapy. In patients experiencing disease progression, attrition was defined as no further anticancer treatment and death within 6 months from the end of first-line therapy. The attrition rate from the first-to-second line was studied by descriptive analyses and univariate and multivariable logistic models were used to explore potentially predictive factors.

RESULTS

From January 2000 to December 2021, 3109 patients with metastatic breast cancer were enrolled in the GIM14/BIO-META study. Among them, 2498 patients experienced first-line treatment failure. Overall, first-to-second line attrition was 9.0% (95% confidence interval 7.9% to 10.1%), with similar attrition for patients with hormone receptor-positive/HER2-negative (8.5%) and HER2-positive (7.1%) breast cancer. Patients with triple-negative disease experienced the highest attrition (13.0%). Age, menopausal status, disease-free interval from primary tumor diagnosis, type of metastatic spread, and tumor subtype independently predicted first-to-second-line attrition.

CONCLUSIONS

These findings could inform treatment decisions and guide clinical research on treatment sequencing. For instance, patients with the lowest risk of attrition may be the ideal candidates for trials exploring de-escalated first-line regimens, followed by more aggressive treatments upon progression.

Targeting LINC00665/miR-199b-5p/SERPINE1 axis to inhibit trastuzumab resistance and tumorigenesis of gastric cancer via PI3K/AKt pathway

Long noncoding RNAs (lncRNAs) serve as critical mediators of tumor progression and drug resistance in cancer. Herein, we identified a lncRNA, LINC00665, associated with trastuzumab resistance and development in gastric cancer (GC). LINC00665 was highly expressed in GC tissues and high expression of LINC00665 was correlated with poor prognosis. LINC00665 knockdown was verified to suppress migration, invasion, and resistance to trastuzumab in GC. Furthermore, we found that LINC00665 participates in the infiltration of naive B cells, mast cells, and T follicular helper (Tfh) cells. Mechanistically, LINC00665 was confirmed to regulate tumorigenesis and trastuzumab resistance by activating PI3K/AKt pathway. LINC00665 sponged miR-199b-5p to interact with SERPINE1 expression, resulting in the increase of phosphorylation of AKt, thus participating in the PI3K/AKt pathway. To summarize, LINC00665 facilitated the tumorigenesis and trastuzumab resistance of GC by sponging miR-199b-5p and promoting SERPINE1 expression, which further activated PI3K/AKt signaling; this finding reveals a new mechanism by which LINC00665 modulates tumor development and drug resistance in GC.

ERBB2/HOXB13 co-amplification with interstitial loss of BRCA1 defines a unique subset of breast cancers

BACKGROUND

The HOXB13/IL17RB gene expression biomarker has been shown to predict response to adjuvant and extended endocrine therapy in patients with early-stage ER+ HER2- breast tumors. HOXB13 gene expression is the primary determinant driving the prognostic and endocrine treatment-predictive performance of the biomarker. Currently, there is limited data on HOXB13 expression in HER2+ and ER- breast cancers. Herein, we studied the expression of HOXB13 in large cohorts of HER2+ and ER- breast cancers.

METHODS

We investigated gene expression, genomic copy number, mutational signatures, and clinical outcome data in the TGGA and METABRIC breast cancer cohorts. Genomic-based gene amplification data was validated with tri-colored fluorescence in situ hybridization.

RESULTS

In the TCGA breast cancer cohort, HOXB13 gene expression was significantly higher in HER2+ versus HER2- breast cancers, and its expression was also significantly higher in the ER- versus ER+ breast cancers. HOXB13 is frequently co-gained or co-amplified with ERBB2. Joint copy gains of HOXB13 and ERBB2 occurred with low-level co-gains or high-level co-amplifications (co-amp), the latter of which is associated with an interstitial loss that includes the tumor suppressor BRCA1. ERBB2/HOXB13 co-amp tumors with interstitial BRCA1 loss exhibit a mutational signature associated with APOBEC deaminase activity and copy number signatures associated with chromothripsis and genomic instability. Among ERBB2-amplified tumors of different tissue origins, ERBB2/HOXB13 co-amp with a BRCA1 loss appeared to be enriched in breast cancer compared to other tumor types. Lastly, patients with ERBB2/HOXB13 co-amplified and BRCA1 lost tumors displayed a significantly shorter progression-free survival (PFS) than those with ERBB2-only amplifications. The difference in PFS was restricted to the ER- subset patients and this difference in PFS was not solely driven by HOXB13 gene expression.

CONCLUSIONS

HOXB13 is frequently co-gained with ERBB2 at both low-copy number level or as complex high-level amplification with relative BRCA1 loss. ERBB2/HOXB13 amplified, BRCA1-lost tumors are strongly enriched in breast cancer, and patients with such breast tumors experience a shortened PFS.

Investigating the Correlation Between Long-Term Response in Patients with Metastatic HER2+ Breast Cancer and the Activity of Regulatory T Cells: A Retrospective Study

Background

Trastuzumab is commonly utilized in the management of metastatic HER2-positive breast cancer. Our main goal was to examine the clinical outcomes and immune markers of patients who received trastuzumab and chemotherapy treatment.

Methods

Between 1995 and 2012, a total of 98 patients diagnosed with metastatic HER2-positive breast cancer were retrospectively analyzed at Ege University Hospital and Tepecik Training and Research Hospital. The clinicopathological characteristics and clinical outcomes of the patients were assessed, and the associations between response rates, survival and the immune profiles of tumor infiltrating lymphocytes were statistically evaluated.

Results

The average age of patients at the time of diagnosis was 50.1±10.3 (ranging from 30 to 79) years. The mean follow-up period for all patients was 97.9±53.8 months. Among the patients, complete response was observed in 24.5%, partial response in 61.2%, and stable disease in 8.2% of cases. The average progression-free survival was 50.3±26.9 months (ranging from 1 to 163 months), and the average overall survival was 88.8±59.4 months (ranging from 12 to 272 months). After analyzing all cases, it was found that patients who were younger (p=0.006), exhibited higher CD3-positivity (p=0.041), presented with higher FOXP3-positivity (p=0.025), showed complete or at least partial response to treatment (p=0.008), and experienced a long-term response to trastuzumab (and chemotherapy) treatment had longer survival (p=0.001).

Conclusion

Patients with HER2-positive breast cancer, who initially respond positively to palliative trastuzumab and chemotherapy treatment, can achieve long-term tumor remission lasting for several years.

Distinct ER and PR expression patterns significantly affect the clinical outcomes of early HER2-positive breast cancer: A real-world analysis of 871 patients treated with neoadjuvant therapy

INTRODUCTION

The impact of distinct estrogen receptor (ER) and progesterone receptor (PR) expression patterns on tumor behavior and treatment outcomes within HER2-positive breast cancer is not fully explored. This study aimed to comprehensively examine the clinical differences among patients with HER2-positive breast cancer harboring distinct ER and PR expression patterns in the neoadjuvant setting.

METHODS

This retrospective analysis included 871 HER2-positive breast patients treated with neoadjuvant therapy at our hospital between 2011 and 2022. Comparisons were performed across the three hormone receptor (HR)-specific subtypes, namely the ER-negative/PR-negative/HER2-positive (ER-/PR-/HER2+), the single HR-positive (HR+)/HER2+, and the triple-positive breast cancer (TPBC) subtypes.

RESULTS

Of 871 patients, 21.0% had ER-/PR-/HER2+ tumors, 33.6% had single HR+/HER2+ disease, and 45.4% had TPBC. Individuals with single HR+/HER2+ tumors and TPBC cases demonstrated significantly lower pathological complete response (pCR) rates compared to those with ER-/PR-/HER2+ tumors (36.9% vs. 24.3% vs. 49.2%, p < 0.001). Multivariate analysis confirmed TPBC as significantly associated with decreased pCR likelihood (OR = 0.42, 95%CI 0.28-0.63, p < 0.001). Survival outcomes, including disease-free survival (DFS) and overall survival (OS), showed no significant differences across HR-specific subtypes in the overall patient population. However, within patients without anti-HER2 therapy, TPBC was linked to improved DFS and a trend towards better OS.

CONCLUSIONS

HER2-positive breast cancer exhibited three distinct HR-specific subtypes with varying clinical manifestations and treatment responses. These findings suggest personalized treatment strategies considering ER and PR expression patterns, emphasizing the need for further investigations to unravel molecular traits underlying HER2-positive breast cancer with distinct HR expression patterns.

Three-Dimensional Cultivation a Valuable Tool for Modelling Canine Mammary Gland Tumour Behaviour In Vitro

Cell cultivation has been one of the most popular methods in research for decades. Currently, scientists routinely use two-dimensional (2D) and three-dimensional (3D) cell cultures of commercially available cell lines and primary cultures to study cellular behaviour, responses to stimuli, and interactions with their environment in a controlled laboratory setting. In recent years, 3D cultivation has gained more attention in modern biomedical research, mainly due to its numerous advantages compared to 2D cultures. One of the main goals where 3D culture models are used is the investigation of tumour diseases, in both animals and humans. The ability to simulate the tumour microenvironment and design 3D masses allows us to monitor all the processes that take place in tumour tissue created not only from cell lines but directly from the patient's tumour cells. One of the tumour types for which 3D culture methods are often used in research is the canine mammary gland tumour (CMT). The clinically similar profile of the CMT and breast tumours in humans makes the CMT a suitable model for studying the issue not only in animals but also in women.

Clinicopathological differences and survival benefit in ER+/PR+/HER2+ vs ER+/PR-/HER2+ breast cancer subtypes

INTRODUCTION

Breast cancer subtypes based on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression have significant implications for prognosis. HER2-positive tumors historically demonstrated poorer survival, but anti-HER2 targeted therapy improved outcomes. However, hormone receptor (HR)-positive patients may experience reduced benefit due to HER2-HR signaling crosstalk.

METHODS

Data from two databases, the Shanghai Jiao Tong University Breast Cancer Data Base (SJTUBCDB) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, were analyzed. Propensity score adjustments were used to balance patient characteristics between ER+/PR+/HER2+ and ER+/PR-/HER2+ subtypes. Kaplan-Meier survival curves estimated disease-free survival (DFS), breast cancer-specific survival (BCSS), overall survival (OS) for these subtypes in the SJTUBCDB, while subgroup analyses using multivariable models were performed based on menstruation, pN stage, HER2-targeted therapy, and endocrinotherapy.

RESULTS

The ER+/PR+/HER2+ group showed significantly better DFS and BCSS than the ER+/PR-/HER2+ group, particularly in postmenopausal and pN0 stage patients. Survival outcomes were similar after anti-HER2 therapy or endocrine aromatase inhibitor (AI) therapy in both groups. However, among patients receiving selective estrogen receptor modulator (SERM) treatment, those in the ER+/PR-/HER2+ group had a significantly worse prognosis compared to ER+/PR+/HER2+ patients.

CONCLUSIONS

HER2-positive breast cancers with different HR statuses exhibit distinct clinicopathological features and survival outcomes. Patients in the ER+/PR+/HER2+ group generally experience better survival, particularly in postmenopausal and pN0 stage patients. Treatment strategies should consider HR status and specific modalities for better personalized management.

New insights into HER2-low breast cancer brain metastasis: A retrospective analysis

BACKGROUND

A considerable number of patients with breast cancer will suffer from brain metastasis in the advanced setting. The HER2 status serves as a significant prognostic factor and the reference of applying treatment for patients with breast cancer brain metastasis (BCBM).

METHODS

Between January 2010 and July 2021, patients with BCBM who had available HER2 status were identified. The patients with HER2 1+ in immunohistochemistry (IHC) or IHC 2+ and fluorescence in situ hybridization (FISH) negative were categorized as HER2-low. Comparisons were conducted between the HER2-low and HER2-zero population. The primary endpoint was overall survival (OS) after the diagnosis of BCBM. Survival outcomes were assessed using Kaplan-Meier curves with log-rank test and Cox proportional hazards model.

RESULTS

In this study, we analyzed 71 patients with the HER2-low breast cancer subtype and 64 patients with the HER2-zero subtype. Despite the limited sample size, our findings revealed a significantly better OS for patients with HER2-low cancer compared to their HER2-zero counterparts (26 m vs 20 m, p = 0.0017). This trend was particularly notable in the HR-negative group (26 m vs 13 m, p = 0.0078), whereas no significant difference was observed among the HR-positive patients. Furthermore, Cox regression analysis revealed that the HER2-low status was an independent prognostic factor for better survival in the HR-negative patients (p = 0.046 in multivariate analysis).

CONCLUSIONS

Patients diagnosed with HER2-low BCBM exhibited a more favorable prognosis than those with HER2-zero BCBM, particularly within the HR-negative subgroup. The low expression of HER2 is supposed to be linked to the prolonged survival of BCBM patients.

Safety and Efficacy of Tucatinib, Letrozole, and Palbociclib in Patients with Previously Treated HR+/HER2+ Breast Cancer

PURPOSE

To overcome resistance to antihormonal and HER2-targeted agents mediated by cyclin D1-CDK4/6 complex, we proposed an oral combination of the HER2 inhibitor tucatinib, aromatase inhibitor letrozole, and CDK4/6 inhibitor palbociclib (TLP combination) for treatment of HR+/HER2+ metastatic breast cancer (MBC).

PATIENTS AND METHODS

Phase Ib/II TLP trial (NCT03054363) enrolled patients with HR+/HER2+ MBC treated with ≥2 HER2-targeted agents. The phase Ib primary endpoint was safety of the regimen evaluated by NCI CTCAE version 4.3. The phase II primary endpoint was efficacy by median progression-free survival (mPFS).

RESULTS

Forty-two women ages 22 to 81 years were enrolled. Patients received a median of two lines of therapy in the metastatic setting, 71.4% had visceral disease, 35.7% had CNS disease. The most common treatment-emergent adverse events (AE) of grade ≥3 were neutropenia (64.3%), leukopenia (23.8%), diarrhea (19.0%), and fatigue (14.3%). Tucatinib increased AUC10-19 hours of palbociclib 1.7-fold, requiring palbociclib dose reduction from 125 to 75 mg daily. In 40 response-evaluable patients, mPFS was 8.4 months, with similar mPFS in non-CNS and CNS cohorts (10.0 months vs. 8.2 months; P = 0.9). Overall response rate was 44.5%, median duration of response was 13.9 months, and clinical benefit rate was 70.4%; 60% of patients were on treatment for ≥6 months, 25% for ≥1 year, and 10% for ≥2 years. In the CNS cohort, 26.6% of patients remained on study for ≥1 year.

CONCLUSIONS

TLP combination was safe and tolerable. AEs were expected and manageable with supportive therapy and dose reductions. TLP showed excellent efficacy for an all-oral chemotherapy-free regimen warranting further testing. See related commentary by Huppert and Rugo, p. 4993.

Differential response of HER2-positive breast cancer to anti-HER2 therapy based on HER2 protein expression level

BACKGROUND

Increasing data indicate that HER2-positive (HER2 + ) breast cancer (BC) subtypes exhibit differential responses to targeted anti-HER2 therapy. This study aims to investigate these differences and the potential underlying molecular mechanisms.

METHODS

A large cohort of BC patients (n = 7390) was utilised. The clinicopathological characteristics and differential gene expression (DGE) of HER2+ immunohistochemical (IHC) subtypes, specifically HER2 IHC 3+ and IHC 2 + /Amplified, were assessed and correlated with pathological complete response (pCR) and survival in the neoadjuvant and adjuvant settings, respectively. The role of oestrogen receptor (ER) status was also investigated.

RESULTS

Compared to HER2 IHC 3+ tumours, BC patients with IHC 2 + /Amplified showed a significantly lower pCR rate (22% versus 57%, P < 0.001), shorter survival regardless of HER2 gene copy number, were less classified as HER2 enriched, and enriched for trastuzumab resistance and ER signalling pathway genes. ER positivity significantly decreased response to anti-HER2 therapy in IHC 2 + /Amplified, but not in IHC 3 + BC patients.

CONCLUSION

In HER2 + BC, overexpression of HER2 protein is the driver of the oncogenic pathway, and it is the main predictor of response to anti-HER2 therapy. ER signalling pathways are more dominant in BC with equivocal HER2 expression. personalised anti-HER2 therapy based on IHC classes should be considered.

Genetic analysis of oligo-recurrence breast cancer: correlation with clinical outcomes

BACKGROUND

We aimed to identify the relationship between the genomic characteristics and clinical outcomes of oligo-metastatic breast cancer.

METHODS

Oligo-metastatic breast cancer diagnosed by pathology from January 2001 and August 2019 were reviewed and we matched the poly-metastatic patients based on the clinicopathological features of patients included. Clinicopathological values and data of genomic alterations were collected. Oligo-recurrence (oligo-R) was defined as a situation where disease progression occurred in less than 5 anatomical sites and other anatomic areas still suppressed by the ongoing therapy.

RESULTS

A total of 26 breast cancer patients were enrolled in our study, including 14 patients with strict oligo-metastatic disease (oligo-R > 6 months) and 12 with simultaneous poly-metastatic disease. PIK3CA, TP53 and ERBB2 were the most common shared alterations identified in patients included. Based on the median time of oligo-R, we divided the patients with oligo-metastasis into longer oligo-R group (oligo-R > 31.04 months) and shorter oligo-R group (oligo-R ≤ 31.04 months). The analysis of PIK3CA mutation sites showed that H1047R mutation was closely associated with oligo-metastasis, rather than poly-metastasis. H1047R mutation also predicted a better prognosis (oligo-R > 31.04 months) in oligo-metastatic breast cancer. In addition, HER2 positive was more likely to be related to a good outcome in patients with oligo-metastasis.

CONCLUSIONS

Through the genetic analysis of samples from oligo-metastasis, we found the prognostic values of PIK3CA H1047R and HER2 in oligo- and poly-metastasis. We improved the stratification of prognosis and provided new insights for biological behaviors of oligo-metastatic breast cancer.

HER2-Low Breast Cancer: Current Landscape and Future Prospects

More than 50% of breast cancers are currently defined as "Human epidermal growth factor receptor 2 (HER2) low breast cancer (BC)", with HER2 immunohistochemistry (IHC) scores of +1 or +2 with a negative fluorescence in situ hybridization (FISH) test. In most studies that compared the clinical and biological characteristics of HER2-low BC with HER2-negative BC, HER2-low was not associated with unique clinical and molecular characteristics, and it seems that the importance of HER2 in these tumors is being a docking site for the antibody portion of antibody drug conjugates (ADCs). Current pathological methods may underestimate the proportion of BCs that express low levels of HER2 due to analytical limitations and tumor heterogeneity. In this review we summarize and contextualize the most recent literature on HER2-low breast cancers, including clinical and translational studies We also review the challenges of assessing low HER2 expression in BC and discuss the current and future therapeutic landscape for these tumors.

Neratinib as adjuvant therapy in patients with HER2 positive breast cancer: expert opinion

Neratinib is a tyrosine kinase receptor inhibitor used in the extended adjuvant therapy of early-stage breast cancer. After adjuvant trastuzumab therapy, neratinib reduces the risk of recurrence and, if taken within 1 year from trastuzumab, significantly improves the invasive disease-free survival of patients with early-stage human epidermal growth factor receptor-2 positive (HER2+) breast cancer with no increased risk of long-term toxicity. Diarrhea, the most common adverse event associated with neratinib use, deters some clinicians from prescribing this drug. However, neratinib-related toxicity is predictable, short-lived, mostly limited to the first month of treatment and can be managed with dose-escalation and prophylactic strategies. Thus, close surveillance and prompt management, relying on supportive care and administration schedule modification, allows discontinuation of treatment to be avoided.

Estrogen/HER2 receptor crosstalk in breast cancer: combination therapies to improve outcomes for patients with hormone receptor-positive/HER2-positive breast cancer

The human epidermal growth factor receptor 2 (HER2) is overexpressed in 13-22% of breast cancers (BC). Approximately 60-70% of HER2+ BC co-express hormone receptors (HRs). HR/HER2 co-expression modulates response to both anti-HER2-directed and endocrine therapy due to "crosstalk" between the estrogen receptor (ER) and HER2 pathways. Combined HER2/ER blockade may be an effective treatment strategy for patients with HR+/HER2+ BC in the appropriate clinical setting(s). In this review, we provide an overview of crosstalk between the ER and HER2 pathways, summarize data from recently published and ongoing clinical trials, and discuss clinical implications for targeted treatment of HR+/HER2+ BC.

Analysis of prognostic factors and construction of prognostic models for triple-positive breast cancer

Objective

By identifying the clinicopathological characteristics and prognostic influences of patients with triple-positive breast cancer (TPBC) at Xijing Hospital in China compared with those in the United States, this study aims to construct a nomogram model to forecast the overall survival rate (OS) of TPBC patients.

Method

The Surveillance, Epidemiology, and End Results (SEER) database was used to screen 5769 patients as the training cohort, and 191 patients from Xijing Hospital were used as the validation cohort. Cox risk-proportional model was applied to select variables and the nomogram model was constructed based on the training cohort. The performance of the model was evaluated by calculating the C-index and generating calibration plots in the training and validation cohorts.

Results

Cox multifactorial analysis showed that age, chemotherapy, radiotherapy, M-stage, T-stage, N-stage, and the mode of surgery were all independent risk factors for the prognosis of TPBC patients (all P<0.05). With this premise, the nomogram model was constructed and evaluated. The C-index value of the nomogram model was 0.830 in the training group and 0.914 in the validation group. Moreover, both the calibration and ROC curves for the proposed model exhibited reliable performance, and the clinical decision curve analysis showed that the proposed model can bring clinical benefits.

Conclusions

The constructed nomogram can accurately predict individual survival probabilities and may serve as a clinical decision support tool for clinicians to optimize treatment in individuals.

Significance and possible causes of hormone receptor expression loss in metastatic breast cancer. Phenotypic evolution of luminal <i>BRCA1</i>-associated breast cancer to triple negative subtype in lung metastasis and PARP inhibition strategy in early-line therapy

Current clinical recommendations indicate the need for a biopsy of a metastatic focus in metastatic breast cancer (BC), but the optimal frequency of additional molecular analysis remains unclear. The discordance of hormonal receptors (HR) between the primary tumor and metastatic foci has prognostic significance, while the transition from HR-positive BC to a triple negative phenotype is associated with a worse clinical prognosis. Acquisition of HR expression in primary triple negative BC is more favorable due to the wide range of options for HR-positive BC treatment. Over the past few years, PARP inhibitors have become an important therapeutic option for the treatment of various tumor types, including BC and luminal surrogate subtypes. However, some questions still remain unresolved, the most important of which are: what is the optimal sequence of the use of CDK4 / 6 inhibitors as part of combined hormone therapy and PARP inhibitors in luminal types of BRCA-associated BC and how effective is the strategy of PARP inhibition after the use of combined hormone therapy with CDK4 / 6 inhibitors? It is obvious that the answers to the questions can be partially obtained by performing a biopsy of the most clinically significant metastatic focus and selecting therapy according to the phenotypic surrogate subtype. A clinical case of the phenotypic evolution of HR-positive BRCA1-associated BC into a triple negative phenotype during metastasis to the lungs and the luminal phenotype of tumor metastasis in soft tissues is presented. Biopsy of the most clinically significant metastatic lesion in the lungs in this case changed the strategy of early-line therapy for estrogen-receptor-positive disease, when in the absence of a biopsy, a combined hormone therapy regimen with CDK4 / 6 inhibitors could be applied. At the same time, the strategy of using PARP inhibitor talazoparib, which has shown efficacy in all surrogate subtypes, should certainly be prescribed in the early line of therapy for BRCA-associated disease with loss of estrogen receptor expression. Despite the luminal phenotype of metastasis in the soft tissues of the back and the unknown status of bone metastases, the drug demonstrates efficacy in these cases as well. It should be noted that partial response according on RECIST 1.1 months with an improvement in the quality of life and the disappearance of pain syndrome was evaluated after 10 weeks of treatment. The response duration was an unprecedented 10 months.

Efficacy and Safety of Pyrotinib in Human Epidermal Growth Factor Receptor 2-Positive Advanced Breast Cancer: A Multicenter, Retrospective, Real-World Study

Purpose

Pyrotinib, a novel human epidermal growth factor receptor 2 (HER2)-targeted tyrosine kinase inhibitor (TKI), has led to remarkable survival outcomes in HER2-positive advanced breast cancer (ABC) in clinical trials and was approved for second-line standards of treatment for HER2+ ABC in China. However, the clinical trials could not fully reflect reality of clinical practice, and predictive factors were still lacking. This study aimed to assess the actual efficacy and safety of pyrotinib in HER2+ ABC in real-world setting.

Patients and Methods

In this multicenter, retrospective, observational real-world study, we analyzed 171 patients with HER2+ ABC, who received pyrotinib-based treatment from November 2017 to November 2020. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety.

Results

Up to November 30, 2021, the median PFS (mPFS) was 12.0 months for all patients. One hundred and sixty-two patients (94.7%) with measurable lesions had been included in efficacy assessment. The ORR and CBR were 45.1% and 81.5%, respectively. A significantly longer PFS was reported in patients who received pyrotinib as first-line treatment, had the ECOG-PS of 0–1, as well as those who were lapatinib-naive. In addition, multivariable analysis indicated that ECOG-PS of 2–4, positive hormone receptor (HR) status, and presence of visceral metastasis were independent negative predictors of PFS. As far as we know, this study first reported the survival outcome of pyrotinib cross-line treatment, with a mPFS of 5.0 months. All grades of adverse events (AEs) occurred in 171 patients (100%), and the most common AE was diarrhea (86.5%).

Conclusion

This study further demonstrated the outstanding efficacy and safety of pyrotinib and reported the potential predictors of survival in HER2+ ABC.

The TRAR gene classifier to predict response to neoadjuvant therapy in HER2-positive and ER-positive breast cancer patients: an explorative analysis from the NeoSphere trial

As most erb-b2 receptor tyrosine kinase 2 (HER2)-positive breast cancer (BC) patients currently receive dual HER2-targeting added to neoadjuvant chemotherapy, improved methods for identifying individual response, and assisting postsurgical salvage therapy, are needed. Herein, we evaluated the 41-gene classifier trastuzumab advantage risk model (TRAR) as a predictive marker for patients enrolled in the NeoSphere trial. TRAR scores were computed from RNA of 350 pre- and 166 post-treatment tumor specimens. Overall, TRAR score was significantly associated with pathological complete response (pCR) rate independently of other predictive clinico-pathological variables. Separate analyses according to estrogen receptor (ER) status showed a significant association between TRAR score and pCR in ER-positive specimens but not in ER-negative counterparts. Among ER-positive BC patients not achieving a pCR, those with TRAR-low scores in surgical specimens showed a trend for lower distant event-free survival. In conclusion, in HER2-positive/ER-positive BC, TRAR is an independent predictor of pCR and represents a promising tool to select patients responsive to anti-HER2-based neoadjuvant therapy and to assist treatment escalation and de-escalation strategies in this setting.

Few, but Efficient: The Role of Mast Cells in Breast Cancer and Other Solid Tumors

Tumor outcome is determined not only by cancer cell-intrinsic features but also by the interaction between cancer cells and their microenvironment. There is great interest in tumor-infiltrating immune cells, yet mast cells have been less studied. Recent work has highlighted the impact of mast cells on the features and aggressiveness of cancer cells, but the eventual effect of mast cell infiltration is still controversial. Here, we review multifaceted findings regarding the role of mast cells in cancer, with a particular focus on breast cancer, which is further complicated because of its classification into subtypes characterized by different biological features, outcome, and therapeutic strategies.

Dalpiciclib Combined With Pyrotinib and Letrozole in Women With HER2-Positive, Hormone Receptor-Positive Metastatic Breast Cancer (LORDSHIPS): A Phase Ib Study

Purpose

The LORDSHIPS study aimed to explore the safety and efficacy of a novel fully oral triplet combination of dalpiciclib (a potent cyclin-dependent kinase 4/6 inhibitor), pyrotinib (a HER2 tyrosine kinase inhibitor) and endocrine therapy letrozole in patients with HER2-positive, hormone receptor (HR)-positive metastatic breast cancer (MBC) in the front-line setting.

Patients and Methods

Postmenopausal women with HER2-positive, HR-positive MBC were recruited in the dose-finding phase Ib trial. A standard 3 + 3 design was used to determine safety, tolerability, and recommended phase II dose (RP2D) for the combination.

Results

A total of 15 patients were enrolled to three dose combination cohorts (letrozole/pyrotinib/dalpiciclib, level/I: 2.5/400/125 mg, n=5; level/L1: 2.5/400/100 mg, n=6; level/L2: 2.5/320/125 mg, n=4). Three patients experienced dose-limiting toxicities (level/I, n=2; level/L1, n=1) and level/L2 was identified as RP2D. The most frequent grade 3-4 adverse events were neutropenia (46.7%), leukopenia (40.0%), oral mucositis (26.7%) and diarrhea (20.0%). The confirmed objective response rate (ORR) was 66.7% (95% CI: 38.4% to 88.2%). The confirmed ORR of study treatment as first line (1L) and second line (2L) HER2-targeted therapy was 85.7% (6/7) and 50.0% (4/8), respectively. Median progression-free survival (PFS) was 11.3 months (95% CI: 5.3 months to not reached). PFS in 1L setting was not reached yet, while PFS in 2L setting was 10.9 months (95% CI: 1.8 to 13.7 months).

Conclusions

The fully oral combination of dalpiciclib, pyrotinib and letrozole is a promising chemotherapy-sparing treatment option for HER2-positive, HR-positive MBC patients. The planned dose-expansion phase II study is ongoing.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03772353.

The initial hormone receptor/HER2 subtype is the main determinator of subtype discordance in advanced breast cancer: a study of the SONABRE registry

Purpose

The hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) are the main parameters in guiding systemic treatment choices in breast cancer, but can change during the disease course. This study aims to evaluate the biopsy rate and receptor subtype discordance rate in patients diagnosed with advanced breast cancer (ABC).

Methods

Patients diagnosed with ABC in seven hospitals in 2007–2018 were selected from the SOutheast Netherlands Advanced BREast cancer (SONABRE) registry. Multivariable logistic regression analyses were performed to identify factors influencing biopsy and discordance rates.

Results

Overall, 60% of 2854 patients had a biopsy of a metastatic site at diagnosis. One of the factors associated with a reduced biopsy rate was the HR + /HER2 + primary tumor subtype (versus HR + /HER2- subtype: OR = 0.68; 95% CI: 0.51–0.90). Among the 748 patients with a biopsy of the primary tumor and a metastatic site, the overall receptor discordance rate was 18%. This was the highest for the HR + /HER2 + primary tumor subtype, with 55%. In 624 patients with metachronous metastases, the HR + /HER2 + subtype remained the only predictor significantly related to a higher discordance rate, irrespective of prior (neo-)adjuvant therapies (OR = 7.49; 95% CI: 3.69–15.20).

Conclusion

The HR + /HER2 + subtype has the highest discordance rate, but the lowest biopsy rate of all four receptor subtypes. Prior systemic therapy was not independently related to subtype discordance. This study highlights the importance of obtaining a biopsy of metastatic disease, especially in the HR + /HER2 + subtype to determine the most optimal treatment strategy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06472-5.

Flubendazole Plays an Important Anti-Tumor Role in Different Types of Cancers

Flubendazole, belonging to benzimidazole, is a broad-spectrum insect repellent and has been repurposed as a promising anticancer drug. In recent years, many studies have shown that flubendazole plays an anti-tumor role in different types of cancers, including breast cancer, melanoma, prostate cancer, colorectal cancer, and lung cancer. Although the anti-tumor mechanism of flubendazole has been studied, it has not been fully understood. In this review, we summarized the recent studies regarding the anti-tumor effects of flubendazole in different types of cancers and analyzed the related mechanisms, in order to provide the theoretical reference for further studies in the future.

Triple Targeting of Breast Tumors Driven by Hormonal Receptors and HER2

Breast cancers that express hormonal receptors (HR) and HER2 display resistance to targeted therapy. Tumor-promotional signaling from the HER2 and estrogen receptor (ER) pathways converges at the cyclin D1 and cyclin-dependent kinases (CDK) 4 and 6 complex, which drives cell-cycle progression and development of therapeutic resistance. Therefore, we hypothesized that co-targeting of ER, HER2, and CDK4/6 may result in improved tumoricidal activity and suppress drug-resistant subclones that arise on therapy. We tested the activity of the triple targeted combination therapy with tucatinib (HER2 small-molecule inhibitor), palbociclib (CKD4/6 inhibitor), and fulvestrant (selective ER degrader) in HR⁺/HER2⁺ human breast tumor cell lines and xenograft models. In addition, we evaluated whether triple targeted combination prevents growth of tucatinib or palbociclib-resistant subclones in vitro and in vivo Triple targeted combination significantly reduced HR⁺/HER2⁺ tumor cell viability, clonogenic survival, and in vivo growth. Moreover, survival of HR⁺/HER2⁺ cells that were resistant to the third drug in the regimen was reduced by the other two drugs in combination. We propose that a targeted triple combination approach will be clinically effective in the treatment of otherwise drug-resistant tumors, inducing robust responses in patients.

3D Visualization of the Dynamic Bidirectional Talk Between ER/PR and Her2 Pathways

Background: Extensive amounts of archived formalin fixed paraffin embedded (FFPE) human tumor tissues are the ultimate resource to investigate signaling network underlying tumorigenesis in human. Yet, their usage is severely limited for lacking of suitable protein techniques. In this study, a quantitative, objective, absolute, and high throughput immunoblot method, quantitative dot blot (QDB), was explored to address this issue by investigating the putative relationship between estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2) pathways in breast cancer tumorigenesis. Methods: In this descriptive observational retrospective study, ER, PR, Her2, and Ki67 protein levels were measured absolutely and quantitatively in 852 FFPE breast cancer tissues using the QDB method. ER, PR, and Her2 levels were charted on the X, Y, and Z-axes to observe samples distribution in a 3D scatterplot. Results: A “seesaw” relationship between ER/PR and Her2 pathways was observed in ER–PR–Her2 space, characterized by the expression levels of these 3 proteins. Specimens with strong expressions of ER/PR proteins were found spreading along the ER/PR floor while those with strong Her2 expression were found wrapping around the Her2 axis. Those lacking strong expressions of all 3 proteins were found accumulating at the intersection of the ER, PR, and Her2 axes. Few specimens floated in the ER–PR–Her2 space to suggest the lack of co-expression of all 3 proteins simultaneously. Ki67 levels were found to be significantly reduced in specimens spreading in the ER–PR space. Conclusions: The unique distribution of specimens in ER–PR–Her2 space prior to any clinical intervention provided visual support of bidirectional talk between ER/PR and Her2 pathways in breast cancer specimens. Clinical interventions to suppress these 2 pathways alternatively warrant further exploration for breast cancer patients accordingly. Our study also demonstrated that the QDB method is an effective tool to analyze archived FFPE cancer specimens in biomedical research.

Intratumoral Heterogeneity and Immune Response Indicators to Predict Overall Survival in a Retrospective Study of HER2-Borderline (IHC 2+) Breast Cancer Patients

Breast cancer (BC) categorized as human epidermal growth factor receptor 2 (HER2) borderline [2+ by immunohistochemistry (IHC 2+)] presents challenges for the testing, frequently obscured by intratumoral heterogeneity (ITH). This leads to difficulties in therapy decisions. We aimed to establish prognostic models of overall survival (OS) of these patients, which take into account spatial aspects of ITH and tumor microenvironment by using hexagonal tiling analytics of digital image analysis (DIA). In particular, we assessed the prognostic value of Immunogradient indicators at the tumor–stroma interface zone (IZ) as a feature of antitumor immune response. Surgical excision samples stained for estrogen receptor (ER), progesterone receptor (PR), Ki67, HER2, and CD8 from 275 patients with HER2 IHC 2+ invasive ductal BC were used in the study. DIA outputs were subsampled by HexT for ITH quantification and tumor microenvironment extraction for Immunogradient indicators. Multiple Cox regression revealed HER2 membrane completeness (HER2 MC) (HR: 0.18, p = 0.0007), its spatial entropy (HR: 0.37, p = 0.0341), and ER contrast (HR: 0.21, p = 0.0449) as independent predictors of better OS, with worse OS predicted by pT status (HR: 6.04, p = 0.0014) in the HER2 non-amplified patients. In the HER2-amplified patients, HER2 MC contrast (HR: 0.35, p = 0.0367) and CEP17 copy number (HR: 0.19, p = 0.0035) were independent predictors of better OS along with worse OS predicted by pN status (HR: 4.75, p = 0.0018). In the non-amplified tumors, three Immunogradient indicators provided the independent prognostic value: CD8 density in the tumor aspect of the IZ and CD8 center of mass were associated with better OS (HR: 0.23, p = 0.0079 and 0.14, p = 0.0014, respectively), and CD8 density variance along the tumor edge predicted worse OS (HR: 9.45, p = 0.0002). Combining these three computational indicators of the CD8 cell spatial distribution within the tumor microenvironment augmented prognostic stratification of the patients. In the HER2-amplified group, CD8 cell density in the tumor aspect of the IZ was the only independent immune response feature to predict better OS (HR: 0.22, p = 0.0047). In conclusion, we present novel prognostic models, based on computational ITH and Immunogradient indicators of the IHC biomarkers, in HER2 IHC 2+ BC patients.

Analysis of the estrogen receptor-associated lncRNA landscape identifies a role for ERLC1 in breast cancer progression

Estrogen receptor alpha (ERα) plays a vital role in the development of normal breast tissue and in breast cancer. By cross-analyzing The Cancer Genome Atlas (TCGA) database, ERα-regulated long noncoding RNA 1 (ERLC1) was identified as a long noncoding RNA exhibiting a strong association with ERα signaling and high specificity of expression in breast tissue. ERLC1 was transcriptionally activated by ERα, and ERLC1 stabilized the ESR1 transcript by sequestering miR-129 and tethering FXR1 to maintain a positive feedback loop that potentiated ERα signaling. ERLC1 was elevated in tamoxifen-resistant breast cancer cells, where ERLC1 depletion restored sensitivity to tamoxifen and increased the efficacy of palbociclib or fulvestrant therapy. Collectively, these data warrant further investigation of ERLC1 as a modulator of therapeutic response and potential therapeutic target in ER+ breast cancer.

Meta-Analysis of HER2-Enriched Subtype Predicting the Pathological Complete Response Within HER2-Positive Breast Cancer in Patients Who Received Neoadjuvant Treatment

Background

This meta-analysis aimed to better elucidate the predictive value of human epidermal growth factor receptor 2 (HER2)-enriched subtype of pathological complete response (pCR) rate within HER2-positive breast cancer patients receiving neoadjuvant treatment.

Methods

We identified prospective trials that evaluated the correlation between an HER2-enriched subtype and pCR rate in HER2-positive breast cancer. Pooled odds ratio (OR) values with 95% confidence intervals (CIs) were computed.

Results

Fifteen studies comprising 2,190 patients met the inclusion criteria. The HER2-enriched subtype was associated with increased odds of achieving a pCR (OR = 4.12, 95% CI = 3.38 to 5.03, P < 0.001) in patients overall. Moreover, it was correlated with improved pCR when single or dual HER2-targeted agent-based therapy was employed (OR = 3.36, 95% CI = 2.25 to 5.02, P < 0.001; OR = 4.66, 95% CI = 3.56 to 6.10, P < 0.001, respectively), but not when HER2-targeted agent-free chemotherapy was used (OR = 2.52, 95% CI = 0.98 to 6.49, P = 0.05). Moreover, an HER2-enriched subtype predicted higher pCR rates irrespective of HER2-targeted agents (trastuzumab, lapatinib, pertuzumab, or T-DM1); chemotherapy agents (taxane-based, or anthracyclines plus taxane-based); endocrine therapy and hormone receptor [all the differences were statistically significant (P all ≤ 0.001)].

Conclusions

The HER2-enriched subtype can more effectively and specifically predict pCR for HER2-targeted agent-based neoadjuvant treatment, irrespective of the number (single or dual) or category of HER2-targeted agent, including chemotherapy and endocrine therapy, or hormone receptor in cases of HER2-positive breast cancer.

Clinical characteristics and disease outcomes in ER+ breast cancer: a comparison between HER2+ patients treated with trastuzumab and HER2- patients

Background

Trastuzumab has changed the prognosis of HER2+ breast cancer. We aimed to investigate the prognosis of ER+/HER2+ patients treated with trastuzumab, thus to guide escalation endocrine treatment in ER+ breast cancer.

Methods

ER-positive early breast cancer patients operated at Ruijin Hospital between Jan. 2009 and Dec. 2017 were retrospectively included. Eligible patients were grouped as HER2-negative (HER2-neg) or HER2-positive with trastuzumab treatment (HER2-pos-T). Kaplan-Meier analysis and Cox proportional hazards model were used to compare the disease-free survival (DFS) and overall survival (OS) between these two groups.

Results

A total of 3761 patients were enrolled: 3313 in the HER2-neg group and 448 in the HER2-pos-T group. Patients in the HER2-pos-T group were associated with pre/peri-menopause, higher histological grade, LVI, higher Ki-67 level, lower ER and PR levels (all P <  0.05). At a median follow-up of 62 months, 443 DFS events and 191 deaths were observed. The estimated 5-year DFS rate was 89.7% in the HER2-neg group and 90.2% in the HER2-pos-T group (P = 0.185), respectively. Multivariable analysis demonstrated that patients in the HER2-pos-T group had a better DFS than patients in the HER2-neg group (HR 0.52, 95% CI: 0.37–0.73, P <  0.001). The estimated 5-year OS rates were 96.0% and 96.3% in the two groups, respectively (P = 0.133). Multivariate analysis found that HER2-pos-T group was still associated with significantly better OS compared with the HER2-neg group (HR 0.38, 95% CI: 0.22–0.67, P = 0.037).

Conclusion

ER+/HER2+ breast cancer patients treated with trastuzumab were associated with superior outcome compared with ER+/HER2- patients, indicating HER2-positivity itself may not be an adverse factor for ER+ patients in the era of trastuzumab.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08555-4.

The Clinical Efficacy and Safety of Neratinib in Combination with Capecitabine for the Treatment of Adult Patients with Advanced or Metastatic HER2-Positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) positive cancers account for 15–20% of all breast tumors. Several drugs have been approved in the metastatic setting, including monoclonal antibodies, tyrosine kinase inhibitors (TKI) and, more recently, antibody-drug conjugates. Neratinib is a pan-HER, irreversible TKI with potent preclinical activity against trastuzumab-resistant breast cancer models. Based on Phase I and II clinical trials, the combination of neratinib plus capecitabine was compared to lapatinib and capecitabine, an established regimen for trastuzumab-resistant disease, in the randomized, Phase III NALA trial. In this trial, neratinib yielded increased progression-free survival, response duration and a benefit in time to intervention for CNS progression. However, there was no overall survival benefit, no increase in overall response rate and no improvement in QoL. The most frequent adverse event in the neratinib arm was diarrhea, which was manageable with prophylactic treatment with loperamide. Conclusion: Neratinib is a valuable addition to the therapeutic armamentarium to treat metastatic, HER2-positive breast cancer. The current positioning of the combination of neratinib and capecitabine based on the results of the NALA trial needs to consider the rapidly evolving scenario due to the recent introduction of new drugs, like the pure-HER2 TKI tucatinib and the antibody drug-conjugate trastuzumab-deruxtecan.

Retrospective observational study of HER2 immunohistochemistry in borderline breast cancer patients undergoing neoadjuvant therapy, with an emphasis on Group 2 (HER2/CEP17 ratio ≥2.0, HER2 copy number <4.0 signals/cell) cases

BACKGROUND

The ASCO/CAP guidance on HER2 testing in breast cancer (BC) has recently changed. Group 2 tumours with immunohistochemistry score 2+ and HER2/CEP17 ratio ≥2.0 and HER2 copy number <4.0 signals/cell were re-classified as HER2 negative. This study aims to examine the response of Group 2 tumours to neoadjuvant chemotherapy (NACT).

METHODS

749 BC cases were identified from 11 institutions. The association between HER2 groups and pathological complete response (pCR) was assessed.

RESULTS

54% of immunohistochemistry HER2 positive (score 3+) BCs showed pCR, compared to 19% of immunohistochemistry 2+ FISH amplified cases. 27% of Group 2 treated with HER2 targeted therapy achieved pCR, compared to 19 and 11% in the combined Groups 1 + 3 and Groups 4 + 5, respectively. No difference in pCR rates was identified between Group 2 and Group 1 or combined Groups 1 + 3. However, Group 2 response rate was higher than Groups 4 + 5 (p = 0.017).

CONCLUSION

No difference in pCR was detected in tumours with a HER2/CEP17 ratio ≥2.0 and a HER2 score 2+ by IHC when stratified by HER2 gene copy number. Our data suggest that ASCO/CAP HER2 Group 2 carcinomas should be evaluated further with respect to eligibility for HER2 targeted therapy.

Current trends in the treatment of HR+/HER2+ breast cancer

Treatment for HR+/HER2+ patients has been debated, as some tumors within this luminal HER2+ subtype behave like luminal A cancers, whereas others behave like non-luminal HER2+ breast cancers. Recent research and clinical trials have revealed that a combination of hormone and targeted anti-HER2 approaches without chemotherapy provides long-term disease control for at least some HR+/HER2+ patients. Novel anti-HER2 therapies, including neratinib and trastuzumab emtansine, and new agents that are effective in HR+ cancers, including the next generation of oral selective estrogen receptor downregulators/degraders and CDK4/6 inhibitors such as palbociclib, are now being evaluated in combination. This review discusses current trials and results from previous studies that will provide the basis for current recommendations on how to treat newly diagnosed patients with HR+/HER2+ disease.

Arctigenin-mediated cell death of SK-BR-3 cells is caused by HER2 inhibition and autophagy-linked apoptosis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is well-known as the therapeutic marker in breast cancer. Therefore, we evaluated anti-cancer activity of arctigenin (ATG) on in SK-BR-3 HER2-overexpressing human breast cancer cells.

METHODS

Cell viability and cytotoxicity were analyzed with MTT and colony-forming assay and cell cycle analysis was performed by flow cytometry. The expression and/or phosphorylation of proteins in whole cell lysate and mitochondrial fraction were analyzed by Western blotting. Cellular levels of LC3 and sequestosome 1 (SQSTM1/P62) were observed by immunofluorescence analysis.

RESULTS

The result showed that ATG decreased cell viability of SK-BR-3 cells in a concentration-dependent manner. Moreover, ATG increased the sub G1 population linked to the suppression of HER2/EGFR1 signaling pathway. Furthermore, ATG increased the phosphorylation of H2AX and down-regulated RAD51 and survivin expressions, indicating that ATG induced DNA damage and inhibited the DNA repair system. We also found that cleavages of caspase-7 and PARP by releasing mitochondrial cytochrome c into the cytoplasm were induced by ATG treatment for 72 h through the reduction of Bcl-2 and Bcl-xL levels in mitochondria. In contrast, the levels of LC-3 and SQSTM1/P62 were increased by ATG for 24 h through the Akt/mTOR and AMPK signaling pathway.

CONCLUSIONS

Taken together, this study indicates that autophagy-linked apoptosis is responsible for the anti-cancer activity of ATG in SK-BR-3 cells, and suggests that ATG is considered a potential therapeutic for the treatment of HER2-overexpressing breast cancer.

Functional cooperation between co-amplified genes promotes aggressive phenotypes of HER2-positive breast cancer

MED1 (mediator subunit 1)co-amplifies with HER2, but its role in HER2-driven mammary tumorigenesis is still unknown. Here, we generate MED1 mammary-specific overexpression mice and cross them with mouse mammary tumor virus (MMTV)-HER2 mice. We observe significantly promoted onset, growth, metastasis, and multiplicity of HER2 tumors by MED1 overexpression. Further studies reveal critical roles for MED1 in epithelial-mesenchymal transition, cancer stem cell formation, and response to anti-HER2 therapy. Mechanistically, RNA sequencing (RNA-seq) transcriptome analyses and clinical sample correlation studies identify Jab1, a component of the COP9 signalosome complex, as the key direct target gene of MED1 contributing to these processes. Further studies reveal that Jab1 can also reciprocally regulate the stability and transcriptional activity of MED1. Together, our findings support a functional cooperation between these co-amplified genes in HER2⁺ mammary tumorigenesis and their potential usage as therapeutic targets for the treatment of HER2⁺ breast cancers.

In this study, Yang et al. generate a more clinically relevant MMTV-HER2/MMTV-MED1 mammary tumor mouse model and discover the critical roles and molecular mechanisms of MED1 overexpression in mediating the aggressive phenotypes of HER2⁺ tumor progression, metastasis, cancer stem cell formation, and therapy resistance.

Recent Discoveries of Macromolecule- and Cell-Based Biomarkers and Therapeutic Implications in Breast Cancer

Breast cancer is the most commonly diagnosed cancer type and the leading cause of cancer-related mortality in women worldwide. Breast cancer is fairly heterogeneous and reveals six molecular subtypes: luminal A, luminal B, HER2+, basal-like subtype (ER−, PR−, and HER2−), normal breast-like, and claudin-low. Breast cancer screening and early diagnosis play critical roles in improving therapeutic outcomes and prognosis. Mammography is currently the main commercially available detection method for breast cancer; however, it has numerous limitations. Therefore, reliable noninvasive diagnostic and prognostic biomarkers are required. Biomarkers used in cancer range from macromolecules, such as DNA, RNA, and proteins, to whole cells. Biomarkers for cancer risk, diagnosis, proliferation, metastasis, drug resistance, and prognosis have been identified in breast cancer. In addition, there is currently a greater demand for personalized or precise treatments; moreover, the identification of novel biomarkers to further the development of new drugs is urgently needed. In this review, we summarize and focus on the recent discoveries of promising macromolecules and cell-based biomarkers for the diagnosis and prognosis of breast cancer and provide implications for therapeutic strategies.

Phase III, Randomized Study of Dual Human Epidermal Growth Factor Receptor 2 (HER2) Blockade With Lapatinib Plus Trastuzumab in Combination With an Aromatase Inhibitor in Postmenopausal Women With HER2-Positive, Hormone Receptor–Positive Metastatic Breast Cancer: Updated Results of ALTERNATIVE

PURPOSE

Human epidermal growth factor receptor 2 (HER2) targeting plus endocrine therapy (ET) improved clinical benefit in HER2-positive, hormone receptor (HR)–positive metastatic breast cancer (MBC) versus ET alone. Dual HER2 blockade enhances clinical benefit versus single HER2 blockade. The ALTERNATIVE study evaluated the efficacy and safety of dual HER2 blockade plus aromatase inhibitor (AI) in postmenopausal women with HER2-positive/HR-positive MBC who received prior ET and prior neo(adjuvant)/first-line trastuzumab (TRAS) plus chemotherapy. This updated article reflects minor numerical corrections in some secondary efficacy analyses that resulted from programming errors and that do not change the major conclusions of the study.

METHODS

Patients were randomly assigned (1:1:1) to receive lapatinib (LAP) plus TRAS plus AI, TRAS plus AI, or LAP plus AI. Patients for whom chemotherapy was intended were excluded. The primary end point was progression-free survival (PFS; investigator assessed) with LAP plus TRAS plus AI versus TRAS plus AI. Secondary end points were PFS (comparison of other arms), overall survival (OS), overall response rate (ORR), clinical benefit rate (CBR), and safety.

RESULTS

Three hundred fifty-five patients were included in this analysis: LAP plus TRAS plus AI (n = 120), TRAS plus AI (n = 117), and LAP plus AI (n = 118). Baseline characteristics were balanced. The study met its primary end point; superior PFS was observed with LAP plus TRAS plus AI versus TRAS plus AI (median PFS, 11 v 5.6 months; hazard ratio, 0.62 [95% CI, 0.45 to 0.88]; P = .0063). A consistent PFS benefit was observed in predefined subgroups. ORR, CBR, and OS also favored LAP plus TRAS plus AI. The median PFS with LAP plus AI versus TRAS plus AI was 8.3 versus 5.6 months (hazard ratio, 0.85 [95% CI, 0.62 to 1.17]; P = .3159). Common adverse events (AEs; ≥ 15%) with LAP plus TRAS plus AI, TRAS plus AI, and LAP plus AI were diarrhea (69%, 9%, and 51%, respectively), rash (36%, 2%, and 28%, respectively), nausea (22%, 9%, and 22%, respectively), and paronychia (30%, 0%, and 15%, respectively), mostly grade 1 or 2. Serious AEs were reported similarly across the 3 groups, and AEs leading to discontinuation were lower with LAP plus TRAS plus AI.

CONCLUSION

Dual HER2 blockade with LAP plus TRAS plus AI showed superior PFS benefit versus TRAS plus AI in patients with HER2-positive/HR-positive MBC. This combination offers an effective and safe chemotherapy-sparing alternative treatment regimen for this patient population.

Hormone Receptor Loss in Breast Cancer: Molecular Mechanisms, Clinical Settings, and Therapeutic Implications

Hormone receptor-positive breast cancer (HR+ BC) accounts for approximately 75% of new BC diagnoses. Despite the undisputable progresses obtained in the treatment of HR+ BC in recent years, primary or acquired resistance to endocrine therapies still represents a clinically relevant issue, and is largely responsible for disease recurrence after curative surgery, as well as for disease progression in the metastatic setting. Among the mechanisms causing primary or acquired resistance to endocrine therapies is the loss of estrogen/progesterone receptor expression, which could make BC cells independent of estrogen stimulation and, consequently, resistant to estrogen deprivation or the pharmacological inhibition of estrogen receptors. This review aims at discussing the molecular mechanisms and the clinical implications of HR loss as a result of the therapies used in the neoadjuvant setting or for the treatment of advanced disease in HR+ BC patients.

Therapeutic Strategies for the Management of Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Positive (HR+/HER2+) Breast Cancer: A Review of the Current Literature

Enormous advances have been made in the understanding and treatment of human epidermal growth factor receptor 2-positive breast cancer (HER2+ BC) in the last 30 years that have resulted in survival gains for affected patients. A growing body of evidence suggests that hormone receptor-positive (HR+)/HER2+ BC and HR-negative (HR-)/HER2+ BC are biologically different, with complex molecular bidirectional crosstalk between the estrogen receptor and HER2 pathway potentially affecting sensitivity to both HER2-targeted and endocrine therapy in patients with HR+/HER2+ BC. Subgroup analyses from trials enrolling patients with HER2+ BC and the results of clinical trials specifically designed to evaluate therapy in patients with HR+/HER2+ BC are helping to guide treatment decisions. In this context, encouraging results with strategies aimed at delaying or reversing drug resistance, including extended adjuvant therapy and the addition of drugs targeting alternative pathways, such as cyclin-dependent kinase (CDK) 4 and 6 inhibitors, have recently emerged. We have reached the point where tailoring the treatment according to risk and biology has become the paradigm in early BC. However, further clinical trials are needed that integrate translational research principles and identify and consider specific patient subgroups and biomarkers.

HER2 positivity is not associated with adverse prognosis in high-risk estrogen receptor-positive early breast cancer patients treated with chemotherapy and trastuzumab

Co-expression of human epidermal growth factor receptor-2 (HER2) and hormone receptor (HR) predicted worse prognosis in early breast cancer before trastuzumab was developed. We aimed to investigate whether HER2 positivity was still associated with worse outcome in high-risk estrogen receptor (ER) positive patients treated with trastuzumab and chemotherapy. In the present study, 227 ER+/HER2+ patients treated with trastuzumab and chemotherapy (HER2-pos-T group) and 1097 ER+/HER2-patients treated with chemotherapy alone (HER2-neg group) during 2009 and 2015 were retrospectively enrolled for the comparison of disease-free survival (DFS) and overall survival (OS). At a median follow-up of 59 months, 174 DFS events and 69 deaths were observed. The estimated 5-year DFS rate was 94.2% in the HER2-pos-T group and 87.4% in the HER2-neg group (Log-rank P = 0.014). HER2-pos-T group was associated with significantly better DFS in multivariate analysis (HR 0.38, 95% CI: 0.22–0.67, Log-rank P = 0.001). The estimated 5-year OS rates for the two groups were 97.2% and 95.7%, respectively (Log-rank P = 0.183). In multivariable analysis, patients in the HER2-pos-T group had significantly better OS compared with those in the HER2-neg group (HR 0.40, 95% CI: 0.17–0.95, Log-rank P = 0.037). We concluded that high-risk ER+/HER2+ breast cancer patients treated with chemotherapy and trastuzumab had superior prognosis compared with ER+/HER2-patients. Therefore, HER2 positivity itself may not be considered as an unfavorable factor for ER + patients in the era of trastuzumab.

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ER+/HER2+ early breast cancer patients treated with trastuzumab-based chemotherapy had superior prognosis.

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ER+/HER2+ early breast cancer patients had distinct patterns of relapse or death from those of ER+/HER2-patients.

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HER2 positivity itself may not be considered as an unfavorable factor for ER + patients in the era of trastuzumab.

Effect of level of hormone-receptor expression on treatment outcomes of "triple-positive" early-stage breast cancer

PURPOSE

Breast cancer that overexpresses the human epidermal growth factor receptor-2 (HER2) and both estrogen (ER) and progesterone (PR) receptors is recently recognized as a subtype (triple-positive) with distinctive behavior and response to treatment. In this study, we investigate the treatment outcomes and the beneficial effect of anti-HER2 treatment in relation to level of hormone-receptor (HR) expression.

METHODS

Consecutive breast cancer patients with triple-positive disease, diagnosed, treated and followed at our institution between 2006 and 2016 were enrolled. Disease-free survival (DFS) was studied in relation to the level of HR-positivity.

RESULTS

During the study period, a total of 312 were enrolled; median age (range) was 47 (20-83) years. Fifty (16.0%) of the enrolled patients received adjuvant chemotherapy without trastuzumab (cohort A). All remaining patients were treated with both chemotherapy and trastuzumab and were divided into two groups: Cohort B with both ER and PR scores ≥ 50% (n = 130, 41.7%) and Cohort C with ER and/or PR < 50% (n = 132, 42.3%). After a median follow-up of 47 months, 14 (28.0%), 30 (23.1%) and 20 (15.2%) patients in cohorts A, B, and C had an event in a form of local/system relapse or death while disease-free. The estimated 5-year DFS was 56.2%, 75.4%, and 80.8%, respectively, and at 7 year was 56.2%, 67.1%, and 78.0%, respectively (p < 0.001).

CONCLUSIONS

HER2-positive tumors are not homogeneous; stronger ER/PR co-expression may weaken the beneficial effect of anti-HER2 therapy. Such findings may have potential implication on modifying anti-HER2 treatment based on the strength of HR expression.

Effect of level of hormone-receptor expression on treatment outcomes of "triple-positive" early-stage breast cancer

PURPOSE

Breast cancer that overexpresses the human epidermal growth factor receptor-2 (HER2) and both estrogen (ER) and progesterone (PR) receptors is recently recognized as a subtype (triple-positive) with distinctive behavior and response to treatment. In this study, we investigate the treatment outcomes and the beneficial effect of anti-HER2 treatment in relation to level of hormone-receptor (HR) expression.

METHODS

Consecutive breast cancer patients with triple-positive disease, diagnosed, treated and followed at our institution between 2006 and 2016 were enrolled. Disease-free survival (DFS) was studied in relation to the level of HR-positivity.

RESULTS

During the study period, a total of 312 were enrolled; median age (range) was 47 (20-83) years. Fifty (16.0%) of the enrolled patients received adjuvant chemotherapy without trastuzumab (cohort A). All remaining patients were treated with both chemotherapy and trastuzumab and were divided into two groups: Cohort B with both ER and PR scores ≥ 50% (n = 130, 41.7%) and Cohort C with ER and/or PR < 50% (n = 132, 42.3%). After a median follow-up of 47 months, 14 (28.0%), 30 (23.1%) and 20 (15.2%) patients in cohorts A, B, and C had an event in a form of local/system relapse or death while disease-free. The estimated 5-year DFS was 56.2%, 75.4%, and 80.8%, respectively, and at 7 year was 56.2%, 67.1%, and 78.0%, respectively (p < 0.001).

CONCLUSIONS

HER2-positive tumors are not homogeneous; stronger ER/PR co-expression may weaken the beneficial effect of anti-HER2 therapy. Such findings may have potential implication on modifying anti-HER2 treatment based on the strength of HR expression.

Synchronous and Metachronous Metastatic Breast Cancer, with Different Histology and Opposite Immunophenotype, Treated with Combination of Chemotherapy, Anti-Her2, and Endocrine Therapy: A Case Report

In the case of our patient, the synergic action of endocrine therapy and chemotherapy plus dual anti-HER2 combination allowed a complete disease control. Therapy should be scheduled by considering the two cancers as individual entities. The approach to breast cancer is changing from being considered a singular disease to a multiform one, according to current research focused on biological markers such as HER2, ERs, and PRs, with important implications in clinical, prognostic, and therapeutic features.

Hormone Receptor-Status Prediction in Breast Cancer Using Gene Expression Profiles and Their Macroscopic Landscape

The cost of next-generation sequencing technologies is rapidly declining, making RNA-seq-based gene expression profiling (GEP) an affordable technique for predicting receptor expression status and intrinsic subtypes in breast cancer patients. Based on the expression levels of co-expressed genes, GEP-based receptor-status prediction can classify clinical subtypes more accurately than can immunohistochemistry (IHC). Using data from The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA BRCA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) datasets, we identified common predictor genes found in both datasets and performed receptor-status prediction based on these genes. By assessing the survival outcomes of patients classified using GEP- or IHC-based receptor status, we compared the prognostic value of the two methods. We found that GEP-based HR prediction provided higher concordance with the intrinsic subtypes and a stronger association with treatment outcomes than did IHC-based hormone receptor (HR) status. GEP-based prediction improved the identification of patients who could benefit from hormone therapy, even in patients with non-luminal breast cancer. We also confirmed that non-matching subgroup classification affected the survival of breast cancer patients and that this could be largely overcome by GEP-based receptor-status prediction. In conclusion, GEP-based prediction provides more reliable classification of HR status, improving therapeutic decision making for breast cancer patients.

Efficacy of Neoadjuvant Chemotherapy with Epirubicin and Cyclophosphamide and Weekly Paclitaxel and Trastuzumab in Human Epidermal Growth Factor Receptor 2-Positive Breast Carcinoma: A Real-World Study

BACKGROUND

Trastuzumab has been introduced a decade ago and demonstrated improvement in the prognosis in patients with human epidermal growth factor receptor 2- (HER2-) positive (+) breast carcinoma (BC). This study is aimed at evaluating the efficacy of epirubicin/cyclophosphamide with weekly paclitaxel-trastuzumab as neoadjuvant chemotherapies in HER2+ BC patients.

METHODS

A total of 234 HER2+ BC patients were given neoadjuvant chemotherapy (NAC) between 2010 and 2016. The primary endpoints were pathologic complete response (pCR) and disease-free survival (DFS). Univariate and multivariate analyses of clinical and pathological factors associated with pCR and DFS were conducted.

RESULTS

The pCR (30.4% vs. 14.8%; P = 0.004) and DFS (P = 0.036) showed significant differences between patients administered with neoadjuvant trastuzumab therapy and those who did not. Multivariate logistic regression analysis showed that neoadjuvant trastuzumab treatment was regarded as an independent predictor of pCR. Patients with pCR had prolonged DFS (P = 0.025). In patients who did not achieve pCR (non-pCR), those who received trastuzumab had more prolonged DFS (P = 0.046). The luminal B/HER2+ subtypes had prolonged DFS when compared with nonluminal B/HER2+ subtypes (P = 0.010). The luminal B/HER2+ subgroup also showed improved DFS in non-pCR patients (P = 0.010). In the subgroup of non-pCR, the luminal B/HER2+ subgroup administered with trastuzumab showed no superior DFS (P = 0.168). However, a positive result was observed in patients without trastuzumab (P = 0.039). Multivariate analysis showed cT stage (P = 0.006) and tumor grade (P = 0.041), considering them as significant prognostic factors of DFS.

CONCLUSIONS

HER2+ BC patients showed improvement in pCR and DFS after neoadjuvant trastuzumab treatment. Patients without pCR had prolonged DFS after trastuzumab maintenance. Although the prognosis of luminal B/HER2+ BC showed favorable outcomes in the non-pCR subgroup, those receiving trastuzumab showed no survival advantage.