PERSEPHONE: are we ready to de-escalate adjuvant trastuzumab for HER2-positive breast cancer?

Management of early-stage HER2-positive breast cancer and attitudes towards HER2DX test in Spain: insights from a nationwide survey

PURPOSE

This study aimed to investigate the current therapeutic management of patients with early-stage HER2-positive (HER2+) breast cancer in Spain, while also exploring the perceptions surrounding HER2DX in terms of its credibility, clinical relevance, and impact on therapeutic decision-making. Understanding these aspects is crucial for optimizing treatment strategies and enhancing patient outcomes in the context of HER2+ breast cancer.

METHODS

An online questionnaire was conducted by an independent third-party between April and May 2022 across 70 medical oncologists highly specialized in breast cancer management in Spain. The survey included 37 questions regarding treatment decision making in HER2+ early breast cancer.

RESULTS

The management of patients with HER2+ early breast cancer exhibited a high degree of heterogeneity. Among the interviewed oncologists, 53% would recommend upfront surgery for node negative tumors measuring 1 cm or less. Interestingly, 69% and 56% of interviewers were open to deescalate the duration of adjuvant trastuzumab in pT1a and pT1b N0 tumors, respectively. Certain clinicopathological characteristics, such as high grade, high Ki-67, and young age, influenced the decision to prescribe neoadjuvant treatment for patients with clinical stage 1 disease. In cases where neoadjuvant treatment was prescribed for cT1-2 N0 tumors, there was a wide variation in the choice of chemotherapeutic and anti-HER2 regimens. Regarding the use of adjuvant trastuzumab emtansine (T-DM1) in patients with residual disease after neoadjuvant therapy, there was diversity in practice, and a common concern emerged that T-DM1 might be overtreating some patients. HER2DX, as a diagnostic tool, was deemed trustworthy, and the reported scores were considered clinically useful. However, 86% of interviewees believed that a prospective trial was necessary before fully integrating the test into routine clinical practice.

CONCLUSION

In the context of early-stage HER2+ breast cancer in Spain, a notable diversity in therapeutic approaches was observed. The majority of interviewed medical oncologists acknowledged HER2DX as a clinically valuable test for specific patients, in line with the 2022 SEOM-GEICAM-SOLTI clinical guidelines for early-stage breast cancer. To facilitate the full integration of HER2DX into clinical guidelines, conducting prospective studies to further validate its efficacy and utility was recommended.

Prognostic value of HER2DX in early-stage HER2-positive breast cancer: a comprehensive analysis of 757 patients in the Sweden Cancerome Analysis Network-Breast dataset (SCAN-B)

BACKGROUND

The HER2DX risk-score has undergone rigorous validation in prior investigations involving patients with early-stage human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer. In this study, we present the outcomes of the HER2DX risk-score within the most recent release of the Sweden Cancerome Analysis Network-Breast (SCAN-B) HER2+ cohort. This updated examination benefits from a larger patient sample, an extended follow-up duration, and detailed treatment information.

MATERIALS AND METHODS

Clinical and RNAseq data from the SCAN-B dataset were retrieved from Gene Expression Omnibus (GSE81538). Among the 6600 patients, 819 had HER2+ breast cancer, with 757 individuals with research-based HER2DX risk-scores and corresponding survival outcomes. The HER2DX risk-score was evaluated (i) as a continuous variable and (ii) using predefined cut-offs. The primary endpoint for this study was overall survival (OS). The Kaplan-Meier method and Cox models were used to estimate OS and a multistate model with four states was fitted to better characterize patients' follow-up.

RESULTS

The median follow-up time was 7.5 years (n = 757). The most common systemic therapy was chemotherapy with trastuzumab (82.0%) and most tumors were classified as T1-T2 (97.1%). The HER2DX risk-score as a continuous variable was significantly associated with OS after adjustment for clinical variables and treatment regimen [hazard ratios (HR) per 10-unit increment = 1.31, 95% confidence interval (CI) 1.13-1.51, P < 0.001] as well as within predefined risk groups (high versus low; HR = 2.57, 95% CI 1.36-4.85, P < 0.001). Patients classified as HER2DX high-risk also had higher risk of (i) breast cancer recurrence and (ii) death without previous recurrence. Within the subgroup of HER2+ T1N0 tumors (n = 297), those classified as high-risk demonstrated inferior OS compared to low-risk tumors (7-year OS 77.8% versus 96.8%, P < 0.001). The HER2DX mRNA ERBB2 score was associated with clinical HER2 status (area under the receiver operating characteristic curve = 0.91).

CONCLUSIONS

In patients with early-stage HER2+ breast cancer, HER2DX risk-score provides prognostic information beyond clinicopathological variables, including treatment regimen with or without trastuzumab.

Alternative Trastuzumab Dosing Schedules Are Associated With Reductions in Health Care Greenhouse Gas Emissions

PURPOSE

Cancer care-related greenhouse gas (GHG) emissions harm human health. Many cancer drugs are administered at greater-than-necessary doses, frequencies, and durations. Alternative dosing strategies may enable reductions in cancer care GHG emissions without compromising patient outcomes.

MATERIALS AND METHODS

We used streamlined life-cycle analysis in a case-control simulation to estimate the relative reductions in GHG emissions that would be expected to result from using each of three alternative dosing strategies of trastuzumab (6-month adjuvant treatment duration, once every 4-week dosing, and both) in human epidermal growth factor receptor 2 (HER2)+ breast cancer. Using primary data and conversion factors from the environmental science literature, we estimated per-patient relative reduction in GHG emissions and, using SEER data, health impacts (in terms of disability-adjusted life-years [DALYs] and excess mortality per kg CO2) on bystanders for each alternative dosing strategy.

RESULTS

Compared with the trastuzumab dosing strategy commonly used at baseline (12-month duration of adjuvant therapy and once every 3-week dosing in all settings), adoption of both 6-month adjuvant trastuzumab and once every 4-week trastuzumab dosing would reduce GHG emissions by 4.5%, 18.7%, and 14.6% in the neoadjuvant, adjuvant, and metastatic settings, respectively. We estimate that US-based adoption of alternative trastuzumab dosing would reduce annual DALYs and excess lives lost due to environmental impact of US-based trastuzumab therapy for HER2+ breast cancer by 1.5 and 0.9, respectively.

CONCLUSION

Alternative dosing strategies may materially reduce the population health impacts of cancer care by reducing environmental impact. Regulatory decision making and health technology assessments should consider a treatment's environmental and population health impacts. Clinical trials of alternative dosing strategies are justified on the basis of environmental and population health impacts.

Appraisal of Systemic Treatment Strategies in Early HER2-Positive Breast Cancer-A Literature Review

BACKGROUND

The overexpression of the human epidermal growth factor receptor 2 (HER2+) accounts for 15-20% of all breast cancer phenotypes. Even after the completion of the standard combination of chemotherapy and trastuzumab, relapse events occur in approximately 15% of cases. The neoadjuvant approach has multiple benefits that include the potential to downgrade staging and convert previously unresectable tumors to operable tumors. In addition, achieving a pathologic complete response (pCR) following preoperative systemic treatment is prognostic of enhanced survival outcomes. Thus, optimal evaluation among the suitable strategies is crucial in deciding which patients should be selected for the neoadjuvant approach.

METHODS

A literature search was conducted in the Embase, Medline, and Cochrane electronic libraries.

CONCLUSION

The evaluation of tumor and LN staging and, hence, stratifying BC recurrence risk are decisive factors in guiding clinicians to optimize treatment decisions between the neoadjuvant versus adjuvant approaches. For each individual case, it is important to consider the most likely postsurgical outcome, since, if the patient does not obtain pCR following neoadjuvant treatment, they are eligible for adjuvant T-DM1 in the case of residual disease. This review of HER2-positive female BC outlines suitable neoadjuvant and adjuvant systemic treatment strategies for guiding clinical decision making around the selection of an appropriate therapy.

Effect of monosodium glutamate on serum sex hormones and uterine histology in female rats along with its molecular docking and in-silico toxicity

Monosodium glutamate (MSG) is commonly used worldwide as a food flavour enhancer by the food industry. The current study investigated the in vivo toxic effects of MSG on the uterus in adult female Sprague Dawley rats and in vitro using MCF-7 and MDA-MB-231 cells, computational toxicity and molecular docking. The average levels of progesterone and oestrogen in the MSG-treated animals significantly altered. Besides, the average uterine lumen area (μm²) was smaller than the control group. MSG showed high-affinity binding to acetylcholine receptors and disrupted the normal nerve signal with a predicted LD50 of 4500 mg/kg. MSG also demonstrated good binding affinity to human oestrogen receptors beta and some other proteins that have an oxidative stress role in the female reproductive organs. Therefore, a precaution should be taken when utilising this compound, especially for females under the risk factor of hormonal abnormality.

Clinicopathological features and androgen receptor expression in triple negative breast cancer at Lagos, Nigeria

INTRODUCTION

Androgen receptor (AR) is one of the predominant nuclear hormone receptors in invasive breast cancer and can be explored as a biomarker of response for targeted anti-androgen therapy, especially in the setting of triple negative breast cancer (TNBC). Luminal AR is a distinct subtype amongst TNBC cases following gene expression studies. TNBC is higher in Africans (23%-82%) and African-Americans (29.8%) compared to Caucasian (10%-15%) breast cancer patients; however, there is a paucity of data on AR expression in this population. The aim of this study is to determine the expression of AR and the proportion of AR positive cancers in TNBCs at the Lagos University Teaching Hospital, Lagos, Nigeria.

METHODOLOGY

Out of 99 reviewed cases, 78 formalin fixed, paraffin embedded TNBC cases were assembled into a tissue microarray, stained and analysed for AR expression using immunohistochemistry.

RESULTS

The mean age of the TNBC patients was 49.3 years (range: 20-80 years). The histologic types in this study were invasive carcinoma (no special type) 75.4%; metaplastic carcinoma 21.4%; lobular carcinoma and mucinous carcinoma 1.6% each. Of 61 TNBC cases analysed, 37.7% were AR positive and 62.3% were AR negative, making the latter to become quadruple negative breast cancers. There was a significant association between age and AR expression (p = 0.02). In the subjects that expressed AR positivity, patients below 50 years accounted for 34.8% (8 of 23) while 65.2% (15 of 23) were above 50 years. There was no significant association between AR expression and histologic type or tumour grade.

CONCLUSION

Over a third of this Nigerian TNBC cohort study is AR+. This warrants further exploration of the predictive and prognostic significance of its expression amongst TNBC and the potential for targeted therapy, specifically androgen antagonists to improve the outcome of this disease with limited therapeutic options.

Clinical outcomes of cyclin-dependent kinase 4-6 (CDK 4-6) inhibitors in patients with male breast cancer: A multicenter study

BACKGROUND

Since breast cancer is less common in men than in women, data on the use of new therapeutic agents, including cyclin-dependent kinase 4-6 (CDK 4-6) inhibitors, are limited in patients with metastatic hormone receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) male breast cancer. Therefore; we aimed to investigate the treatment responses of metastatic HR+, HER2-male breast cancer patients treated with CDK 4-6 inhibitors in a multicenter real-life cohort.

METHODS

Male patients with a diagnosis of HR+ and HER2-metastatic breast cancer, treated with any CDK 4-6 inhibitor, were included in the study. Demographic and clinical characteristics of the patients were recorded. We aimed to determine progression-free survival (PFS) time, response rates and drug related side effects.

RESULTS

A total 25 patients from 14 institutions were recruited. The mean age at diagnosis was 57 years. Median follow-up was 19.53 (95% CI: 14.04-25.02) months. The overall response rate was 60%. While the median PFS was 20.6 months in the whole cohort, it wasn't reached in those using CDK 4-6 inhibitors in first line and 10 months in the subsequent lines (p:0.009). No new adverse events were encountered.

CONCLUSION

In our study, we found that CDK 4-6 inhibitors are effective and safe options in men with HR+ and HER2-metastatic breast cancer as in women. Our results support the use of CDK 4-6 inhibitor-based combinations in the first-line treatment of HR+ and HER2-metastatic male breast cancer.

Perioperative HER2 targeted treatment in early stage HER2-positive breast cancer

Although human epidermal growth factor receptor 2 (HER2)-positive breast cancer was associated with poor prognosis, it has been changed after the development of trastuzumab. There has been great progress in perioperative HER2-targeting treatment, and investigations of several novel drugs and their combinations are ongoing. Adjuvant trastuzumab with or without pertuzumab for 1 year in combination with concomitant chemotherapy has become a standard treatment in high-risk node-negative tumors or node-positive HER2-positive early breast cancer patients without residual disease or who have not received neoadjuvant treatment. For low-risk HER2-positive early breast cancer patients, adjuvant paclitaxel and 1-year trastuzumab are possible alternatives. For residual disease after neoadjuvant treatment, adjuvant trastuzumab emtansine (T-DM1) for 14 cycles is a standard treatment. Non-anthracycline chemotherapy with dual anti-HER2 targeting of trastuzumab and pertuzumab represents one of the preferred neoadjuvant regimens to achieve higher pathologic complete response (pCR) rates and better clinical outcomes. Further research is needed to develop and validate potential biomarkers to predict pCR, which could help escalate or de-escalate anti-HER2 therapy. Trials incorporating novel agents such as T-DM1, trastuzumab deruxtecan (T-DXd), and immune checkpoint inhibitors and trying to de-escalate treatments in neoadjuvant setting are ongoing. In the future, tailored treatments such as no adjuvant therapy, various HER2-directed therapies alone with chemotherapy, combinations of various HER2-directed therapies and chemotherapy, addition of immune checkpoint inhibitors, and omission of surgery will be individualized in HER2-positive early breast cancer patients.

ESR1 mutant breast cancers show elevated basal cytokeratins and immune activation

Estrogen receptor alpha (ER/ESR1) is frequently mutated in endocrine resistant ER-positive (ER+) breast cancer and linked to ligand-independent growth and metastasis. Despite the distinct clinical features of ESR1 mutations, their role in intrinsic subtype switching remains largely unknown. Here we find that ESR1 mutant cells and clinical samples show a significant enrichment of basal subtype markers, and six basal cytokeratins (BCKs) are the most enriched genes. Induction of BCKs is independent of ER binding and instead associated with chromatin reprogramming centered around a progesterone receptor-orchestrated insulated neighborhood. BCK-high ER+ primary breast tumors exhibit a number of enriched immune pathways, shared with ESR1 mutant tumors. S100A8 and S100A9 are among the most induced immune mediators and involve in tumor-stroma paracrine crosstalk inferred by single-cell RNA-seq from metastatic tumors. Collectively, these observations demonstrate that ESR1 mutant tumors gain basal features associated with increased immune activation, encouraging additional studies of immune therapeutic vulnerabilities.

Alternative trastuzumab dosing strategies in HER2-positive early breast cancer are associated with patient out-of-pocket savings

Patients with breast cancer frequently experience financial hardship, often due to the high costs of anti-cancer drugs. We sought to develop alternative trastuzumab dosing strategies, compare their pharmacokinetic effectiveness to standard dosing, and assess the expected financial implications of transitioning to them. We extracted clinical data from the records of 135 retrospectively identified patients with HER2-positive early breast cancer at a single, urban comprehensive cancer center who were treated with trastuzumab between 2017 and 2019. We performed pharmacokinetic simulations on a range of trastuzumab dose levels and frequencies, assessing efficacy by trough trastuzumab concentration (Ctrough) and population and individual likelihoods of Ctrough exceeding trastuzumab minimum effective concentration (MEC). We performed deterministic financial modeling to estimate the treatment-associated financial savings from alternative dosing strategies. Trastuzumab maintenance doses of 4 mg/kg every 3 weeks (Q3W) and 6 mg/kg every 4 weeks (Q4W) had nearly identical probabilities of Ctrough being above MEC as standard of care 6 mg/kg every 3 weeks. In the primary financial analysis, both trastuzumab 4 mg/kg Q3W and 6 mg/kg Q4W were associated with significant drug- and administration-related out-of-pocket cost savings over the duration of therapy, ranging from $765 (neoadjuvant, Q4W) to $2791 (adjuvant, Q4W). In particular, Q4W trastuzumab increased savings related to lost wages and travel cost avoidance. Low-dose and reduced frequency trastuzumab in appropriately selected patients may significantly reduce total drug utilization and meaningfully reduce patient financial toxicity. Prospective clinical trials evaluating low-dose or reduced-frequency administration of therapeutic monoclonal antibodies are warranted and needed.

Development and validation of the new HER2DX assay for predicting pathological response and survival outcome in early-stage HER2-positive breast cancer

Background

Both clinical and genomic data independently predict survival and treatment response in early-stage HER2-positive breast cancer. Here we present the development and validation of a new HER2DX risk score, and a new HER2DX pathological complete response (pCR) score, both based on a 27-gene expression plus clinical feature-based classifier.

Methods

HER2DX is a supervised learning algorithm incorporating tumour size, nodal staging, and 4 gene expression signatures tracking immune infiltration, tumour cell proliferation, luminal differentiation, and the expression of the HER2 amplicon, into a single score. 434 HER2-positive tumours from the Short-HER trial were used to train a prognostic risk model; 268 cases from an independent cohort were used to verify the accuracy of the HER2DX risk score. In addition, 116 cases treated with neoadjuvant anti-HER2-based chemotherapy were used to train a predictive model of pathological complete response (pCR); two independent cohorts of 91 and 67 cases were used to verify the accuracy of the HER2DX pCR likelihood score. Five publicly available independent datasets with >1,000 patients with early-stage HER2-positive disease were also analysed.

Findings

In Short-HER, HER2DX variables were associated with good risk outcomes (i.e., immune, and luminal) and poor risk outcomes (i.e., proliferation, and tumour and nodal staging). In an independent cohort, continuous HER2DX risk score was significantly associated with disease-free survival (DFS) (p=0·002); the 5-year DFS in the low-risk group was 97·4% (94·4-100·0%). For the neoadjuvant pCR predictor training cohort, HER2DX variables were associated with pCR (i.e., immune, proliferation and HER2 amplicon) and non-pCR (i.e., luminal, and tumour and nodal staging). In both independent test set cohorts, continuous HER2DX pCR likelihood score was significantly associated with pCR (p<0·0001). A weak negative correlation was found between the HER2DX risk score versus the pCR score (correlation coefficient -0·19).

Interpretation

The two HER2DX tests provide accurate estimates of the risk of recurrence, and the likelihood to achieve a pCR, in early-stage HER2-positive breast cancer.

Funding

This study received funding from Reveal Genomics, IDIBAPS and the University of Padova.

Effect of Primary Systemic Therapy on PD-1, PD-L1, and PD-L2 mRNA Expression in Advanced Breast Cancer

OBJECTIVE

The association between PD-1, PD-L1, and PD-L2 expression and prognosis has been extensively studied in various cancers but remained controversial in breast cancer. Besides, little is known about the prognostic value of PD-1, PD-L1, and PD-L2 upregulation or downregulation following systemic therapy (chemotherapy and hormonal therapy) in breast cancer. Therefore, we aim to investigate the change of PD-1, PD-L1, and PD-L2 expression in mRNA level after primary systemic therapy in breast cancer patients and its clinical implications.

METHODS

Expression of PD-1, PD-L1, and PD-L2 mRNA were measured before-after chemotherapy and hormonal therapy with real-time PCR in 80 advanced breast cancer patients. The correlation between alteration of PD-1, PD-L1, and PD-L2 expression and clinicopathological characteristics as well as overall survival was also statistically analyzed.

RESULTS

Chemotherapy and hormonal therapy altered PD-1, PD-L1, and PD-L2 expression in breast cancer with most patients have an increase expression. As much as 57.1%, 62.9% and 60% patients have an increase PD-1, PD-L1, and PD-L2 expression after chemotherapy, while 60%, 60%, and 64% patients have an increase PD-1, PD-L1, and PD-L2 expression after hormonal therapy. Alteration of PD-1, PD-L1, and PD-L2 expression was not correlated with all clinicopathological characteristics. Increase in PD-1, PD-L1, and PD-L2 expression was significantly associated with better OS (p=0.031, p=0.019, and p=0.019 for PD-1, PD-L1, and PD-L2, respectively), which remained significant in multivariate analysis including age, stage, primary systemic therapy, histology grade, subtype and primary tumor histology (HR PD-1 0.5 (95% CI 0.28-0.88) p=0.031; HR PD-L1 0.43 (95% CI 0.24-0.8) p=0.019; HR PD-L2 (95% CI 0.24-0.87) p=0.019).  Conclusion: Expression of PD-1, PD-L1, and PD-L2 in breast cancer patients is mostly enhanced after chemotherapy and hormonal therapy, and the enhancement is associated with good OS. This result revealed the potential of measuring PD-1, PD-L1, and PD-L2 mRNA expression in predicting clinical outcome.

Genetic interactions among Brca1, Brca2, Palb2, and Trp53 in mammary tumor development

Inherited mutations in BRCA1, BRCA2, and PALB2 cause a high risk of breast cancer. Here, we conducted parallel conditional knockout (CKO) of Brca1, Palb2, and Brca2, individually and in combination, along with one copy of Trp53, in the mammary gland of nulliparous female mice. We observed a functional equivalence of the three genes in their basic tumor-suppressive activity, a linear epistasis of Palb2 and Brca2, but complementary roles of Brca1 and Palb2 in mammary tumor suppression, as combined ablation of either Palb2 or Brca2 with Brca1 led to delayed tumor formation. Whole-exome sequencing (WES) revealed both similarities and differences between Brca1 and Palb2 or Brca2 null tumors. Analyses of mouse mammary glands and cultured human cells showed that combined loss of BRCA1 and PALB2 led to high levels of reactive oxygen species (ROS) and increased apoptosis, implicating oxidative stress in the delayed tumor development in Brca1;Palb2 double CKO mice. The functional complementarity between BRCA1 and PALB2/BRCA2 and the role of ROS in tumorigenesis require further investigation.

Road Map to Safe and Well-Designed De-escalation Trials of Systemic Adjuvant Therapy for Solid Tumors

An important challenge in the field of cancer is finding the balance between delivering effective treatments and avoiding adverse effects and financial toxicity caused by innovative, yet expensive, drugs. To address this, several treatment de-escalation trials have been conducted, but only a few of these have provided clear answers. A few trials had poor accrual or had design flaws that led to conflicting results. Members of the Breast International Group (BIG) and North American Breast Cancer Group (NABCG) believe the way forward is to understand the lessons from these trials and listen more carefully to what truly matters to our patients. We reviewed several adjuvant trials of different cancer types and developed a road map for improving the design and implementation of future de-escalation trials. The road map incorporates patients' insights obtained through focused group discussions across the BIG-NABCG networks. Considerations for the development of de-escalation trials for systemic adjuvant treatment, including noninferiority trial design, choice of end points, and prioritization of a patient's perspectives, are presented in this consensus article.

A multivariable prognostic score to guide systemic therapy in early-stage HER2-positive breast cancer: a retrospective study with an external evaluation

BACKGROUND

In early-stage HER2-positive breast cancer, escalation or de-escalation of systemic therapy is a controversial topic. As an aid to treatment decisions, we aimed to develop a prognostic assay that integrates multiple data types for predicting survival outcome in patients with newly diagnosed HER2-positive breast cancer.

METHODS

We derived a combined prognostic model using retrospective clinical-pathological data on stromal tumour-infiltrating lymphocytes, PAM50 subtypes, and expression of 55 genes obtained from patients who participated in the Short-HER phase 3 trial. The trial enrolled patients with newly diagnosed, node-positive, HER2-positive breast cancer or, if node negative, with at least one risk factor (ie, tumour size >2 cm, histological grade 3, lymphovascular invasion, Ki67 >20%, age ≤35 years, or hormone receptor negativity), and randomly assigned them to adjuvant anthracycline plus taxane-based combinations with either 9 weeks or 1 year of trastuzumab. Trastuzumab was administered intravenously every 3 weeks (8 mg/kg loading dose at first cycle, and 6 mg/kg thereafter) for 18 doses or weekly (4 mg/kg loading dose in the first week, and 2 mg/kg thereafter) for 9 weeks, starting concomitantly with the first taxane dose. Median follow-up was 91·4 months (IQR 75·1-105·6). The primary objective of our study was to derive and evaluate a combined prognostic score associated with distant metastasis-free survival (the time between randomisation and distant recurrence or death before recurrence), an exploratory endpoint in Short-HER. Patient samples in the training dataset were split into a training set (n=290) and a testing set (n=145), balancing for event and treatment group. The training set was further stratified into 100 iterations of Monte-Carlo cross validation (MCCV). Cox proportional hazard models were fit to MCCV training samples using Elastic-Net. A maximum of 92 features were assessed. The final prognostic model was evaluated in an independent combined dataset of 267 patients with early-stage HER2-positive breast cancer treated with different neoadjuvant and adjuvant anti-HER2-based combinations and from four other studies (PAMELA, CHER-LOB, Hospital Clinic, and Padova) with disease-free survival outcome data.

FINDINGS

From Short-HER, data from 435 (35%) of 1254 patients for tumour size (T1 vs rest), nodal status (N0 vs rest), number of tumour-infiltrating lymphocytes (continuous variable), subtype (HER2-enriched and basal-like vs rest), and 13 genes composed the final model (named HER2DX). HER2DX was significantly associated with distant metastasis-free survival as a continuous variable (p<0·0001). HER2DX median score for quartiles 1-2 was identified as the cutoff to identify low-risk patients; and the score that distinguished quartile 3 from quartile 4 was the cutoff to distinguish medium-risk and high-risk populations. The 5-year distant metastasis-free survival of the low-risk, medium-risk, and high-risk populations were 98·1% (95% CI 96·3-99·9), 88·9% (83·2-95·0), and 73·9% (66·0-82·7), respectively (low-risk vs high-risk hazard ratio [HR] 0·04, 95% CI 0·0-0·1, p<0·0001). In the evaluation cohort, HER2DX was significantly associated with disease-free survival as a continuous variable (HR 2·77, 95% CI 1·4-5·6, p=0·0040) and as group categories (low-risk vs high-risk HR 0·27, 0·1-0·7, p=0·005). 5-year disease-free survival in the HER2DX low-risk group was 93·5% (89·0-98·3%) and in the high-risk group was 81·1% (71·5-92·1).

INTERPRETATION

The HER2DX combined prognostic score identifies patients with early-stage, HER2-positive breast cancer who might be candidates for escalated or de-escalated systemic treatment. Future clinical validation of HER2DX seems warranted to establish its use in different scenarios, especially in the neoadjuvant setting.

FUNDING

Instituto Salud Carlos III, Save the Mama, Pas a Pas, Fundación Científica, Asociación Española Contra el Cáncer, Fundación SEOM, National Institutes of Health, Agenzia Italiana del Farmaco, International Agency for Research on Cancer, and the Veneto Institute of Oncology, and Italian Association for Cancer Research.

The Changing Paradigm for the Treatment of HER2-Positive Breast Cancer

For decades, HER2-positive breast cancer was associated with poor outcomes and higher mortality rates than other breast cancer subtypes. However, the advent of Trastuzumab (Herceptin) has significantly changed the treatment paradigm of patients afflicted with HER2-positive breast cancer. The discovery of newer HER2-targeted therapies, such as Pertuzumab (Perjeta), has further added to the armamentarium of treating HER2-positive breast cancers. This review highlights recent advancements in the treatment of HER2-positive diseases, including the newer HER2-targeted therapies and immunotherapies in clinical trials, which have paved (and will further update) the way for clinical practice, and become part of the standard of care in the neoadjuvant, adjuvant or metastatic setting.

Anti-HER2 therapy for breast cancer in older patients

Older patients now form between 30 and 40% of breast cancer (BC) patients. Managing older patients with BC is particularly challenging due to the limited availability of high-quality evidence. In this review we discuss the available evidence on the efficacy and safety of anti-HER2 agents in older patients with HER2-positive BC is presented, with a particular look at the latest results of promising new agents such trastuzumab-deruxtecan. The data suggest that older patients can expect similar efficacy when using standard regimens, with higher toxicity, particular cardiac toxicity and diarrhea. Anti-HER2 agents should thus be used in most older patients most as per standard of care as long as adequate follow-up is available to manage toxicities.

Systemic treatment of patients with early breast cancer: recent updates and state of the art

This review is focused on trials generating results that potentially impacted clinical practice since the 2017 St. Gallen Consensus; the most impactful trial was KATHERINE, which revealed a 11.3% absolute iDFS improvement with T-DM1 (compared to trastuzumab) in HER2-positive breast cancer patients who presented invasive residual disease following neoadjuvant treatment. These results, if reinforced by a subsequent overall survival benefit, will consolidate neoadjuvant treatment as the standard-of-care for most HER2-positive breast cancer patients. The addition of pertuzumab to adjuvant trastuzumab (APHINITY) or extending anti-HER2 therapy with 1 year of neratinib (ExteNET) also improved outcomes, but in a more modest way. In triple-negative early breast cancer patients presenting invasive residual disease after neoadjuvant chemotherapy, the CREATE-X trial demonstrated the benefit of post-neoadjuvant capecitabine. In patients with luminal tumours, updated results of the SOFT/TEXT trials confirmed the benefit of aromatase inhibitors plus ovarian suppression in high-risk premenopausal patients, and the 12-year results of the BIG1-98 trial demonstrated a sustained trend in favour of letrozole compared to tamoxifen in the adjuvant treatment of postmenopausal patients. The TAILOR-X study showed that, overall, patients with an intermediate recurrence risk score (11-25) in the OncotypeDX 21-gene assay did not benefit from adjuvant chemotherapy. A meta-analysis performed by the EBCTCG demonstrated that extended adjuvant aromatase inhibitors modestly reduced breast cancer recurrence risks, with a more pronounced benefit in patients previously treated with tamoxifen. Finally, an EBCTCG meta-analysis including patients with all breast cancer subtypes showed that dose-dense chemotherapy improved survival when compared to conventionally-timed chemotherapy.

Long-term cardiac outcomes of patients with HER2-positive breast cancer treated in the adjuvant lapatinib and/or trastuzumab Treatment Optimization Trial

BACKGROUND

Cardiotoxicity is the most significant adverse event associated with trastuzumab (T), the main component of HER2-positive breast cancer (BC) treatment. Less is known about the cardiotoxicity of dual HER2 blockade with T plus lapatinib (L), although this regimen is used in the metastatic setting.

METHODS

This is a sub-analysis of the ALTTO trial comparing adjuvant treatment options for patients with early HER2-positive BC. Patients randomised to either T or concomitant T + L were eligible. Cardiac events (CEs) rates were compared according to treatment arm.

RESULTS

With 6.9 years of median follow-up (FU) and 4190 patients, CE were observed in 363 (8.6%): 166 (7.9%) of patient in T + L arm vs. 197 (9.3%) in T arm (OR = 0.85 [95% CI, 0.68-1.05]). During anti-HER2 treatment 270 CE (6.4%) occurred while 93 (2.2%) were during FU (median time to onset = 6.6 months [IQR = 3.4-11.7]). While 265 CEs were asymptomatic (73%), 94 were symptomatic (26%) and four were cardiac deaths (1%). Recovery was observed in 301 cases (83.8%). Identified cardiac risk factors were: baseline LVEF < 55% (vs > 64%, OR 3.1 [95% CI 1.54-6.25]), diabetes mellitus (OR 1.85 [95% CI 1.25-2.75]), BMI > 30 kg/m2 (vs < 25 mg/kg2, OR 2.21 [95% CI 1.40-3.49]), cumulative dose of doxorubicin ≥240 mg/m2 (OR 1.36 [95% CI 1.01-1.82]) and of epirubicin≥ 480 mg/m2 (OR 2.33 [95% CI 1.55-3.51]).

CONCLUSIONS

Dual HER2 blockade with T + L is a safe regimen from a cardiac perspective, but cardiac-focused history for proper patient selection is crucial.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT00490139 (registration date: 22/06/2007); EudraCT Number: 2006-000562-36 (registration date: 04/05/2007); Sponsor Protocol Number: BIG2-06 /EGF106708/N063D.

Towards personalized treatment for early stage HER2-positive breast cancer

Advances in HER2-targeted therapies have improved the survival of patients with HER2-positive breast cancer. The standard-of-care treatment for localized disease has been chemotherapy and 1 year of adjuvant HER2-targeted therapy, typically with the anti-HER2 antibody trastuzumab. Despite the effectiveness of this treatment, disease relapse occurs in a subset of patients; thus, focus has been placed on escalating treatment by either combining different HER2-targeted agents or extending the duration of HER2-targeted therapy. Indeed, dual HER2-targeted therapies and extended-duration anti-HER2 therapy, as well as adjuvant therapy with the anti-HER2 antibody-drug conjugate T-DM1, have all been approved for clinical use. Emerging evidence suggests, however, that some patients do not derive sufficient benefit from these additional therapies to offset the associated toxicities and/or costs. Similarly, the universal use of chemotherapy might not benefit all patients, and treatment de-escalation through omission of chemotherapy has shown promise in clinical trials and is currently being explored further. The future of precision medicine should therefore involve tailoring of therapy based on the genetics and biology of each tumour and the clinical characteristics of each patient. Predictive biomarkers that enable the identification of patients who will benefit from either escalated or de-escalated treatment will be crucial to this approach. In this Review, we summarize the available HER2-targeted agents and associated mechanisms of resistance, and describe the current therapeutic landscape of early stage HER2-positive breast cancer, focusing on strategies for treatment escalation or de-escalation.

[Chemotherapy and young women in breast cancer: what management?]

Breast cancer in young women requires special vigilance because of the unique condition and complex management that is involved. The indication for chemotherapy should not be based on age alone but in association with the biological characteristics of the tumour. In addition, age is not considered as demonstrated predictor of chemosensitivity. The choice of adjuvant or neoadjuvant chemotherapy should be guided by the histological type of the tumour, the stage of the tumour and the patient's comorbidities. In this subgroup of patients, the recommendations for the use of molecular signatures follow those of the general population. This manuscript summarizes the main data and recommendations on the management of breast cancer in young women in term of chemotherapy.

Cardiotoxicity of trastuzumab given for 12 months compared to shorter treatment periods: a systematic review and meta-analysis of six clinical trials

BACKGROUND

Treatment de-escalation in early-stage, human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has been attempted in order to decrease costs and toxicities. One of the strategies pursued is decreasing trastuzumab treatment duration, with mixed results thus far. Trastuzumab-associated cardiotoxicity, however, may be more frequent with 12 months of trastuzumab compared with shorter treatment lengths. Therefore, we have conducted a meta-analysis to address this question.

MATERIALS AND METHODS

A meta-analysis of trials testing 12 months of adjuvant trastuzumab versus shorter regimens, reporting cardiac outcomes in patients with HER2-positive BC was performed with the random effects model with inverse variance weighting.

RESULTS

Clinical cardiac dysfunction associated with 12 months of trastuzumab versus shorter trastuzumab regimens, including 11 250 patients, showed a pooled OR (pOR) of 1.90 (95% CI 1.37 to 2.64; p value <0.001; I2=65.7%); in the subgroup comparison of 12 versus 6 months, the pOR was 1.57 (95% CI 1.30 to 1.90; p<0.001; I2=5.7%). pOR for low left ventricular ejection fraction was 1.45 (95% CI 1.19 to 1.75; p<0.001; I2=11.9%), 1.55 (95% CI 1.00 to 2.42; p=0.052; I2=0.0%) for congestive heart failure and 3.70 (95% CI 0.27 to 51.60; p=0.33; I2=78.8%) for premature trastuzumab discontinuation due to cardiotoxicity for 12 months versus shorter trastuzumab regimens. Funnel plot analyses indicated a low risk of publication bias.

CONCLUSIONS

Compared to shorter treatment durations, there is sufficient evidence that 12 months of trastuzumab yields higher odds for the occurrence of relevant cardiac events. An individual patient-level data meta-analysis is needed in order to provide adequate data on risk factors for cardiotoxicity.

HER2-enriched subtype and pathological complete response in HER2-positive breast cancer: A systematic review and meta-analysis

BACKGROUND

HER2-positive (HER2+) breast cancer (BC) comprises all the four PAM50 molecular subtypes. Among these, the HER2-Enriched (HER2-E) appear to be associated with higher pathological complete response (pCR) rates following anti-HER2-based regimens. Here, we present a meta-analysis to validate the association of the HER2-E subtype with pCR following anti-HER2-based neoadjuvant treatments with or without chemotherapy (CT).

METHODS

A systematic literature search was performed in February 2019. The primary objective was to compare the association between HER2-E subtype (versus others) and pCR. Selected secondary objectives were to compare the association between 1) HER2-E subtype and pCR in CT-free studies, 2) HER2-E subtype within hormone receptor (HR)-negative and HR+ disease and 3) HR-negative disease (versus HR+) and pCR in all patients and within HER2-E subtype. A random-effect model was applied. The Higgins' I² was used to quantify heterogeneity.

RESULTS

Sixteen studies were included, 5 of which tested CT-free regimens. HER2-E subtype was significantly associated with pCR in all patients (odds ratio [OR] = 3.50, p < 0.001, I² = 33%), in HR+ (OR = 3.61, p < 0.001, I² = 1%) and HR-negative tumors (OR = 2.28, p = 0.01, I² = 47%). In CT-free studies, HER2-E subtype was associated with pCR in all patients (OR = 5.52, p < 0.001, I² = 0%) and in HR + disease (OR = 4.08, p = 0.001, I² = 0%). HR-negative status was significantly associated with pCR compared to HR + status in all patients (OR = 2.41, p < 0.001, I² = 30%) and within the HER2-E subtype (OR = 1.76, p < 0.001, I² = 0%).

CONCLUSIONS

The HER2-E biomarker identifies patients with a higher likelihood of achieving a pCR following neoadjuvant anti-HER2-based therapy beyond HR status and CT use. Future trial designs to escalate or de-escalate systemic therapy in HER2+ disease should consider this genomic biomarker.

Targeted therapeutic options and future perspectives for HER2-positive breast cancer

Over the past 2 decades, there has been an extraordinary progress in the regimens developed for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Trastuzumab, pertuzumab, lapatinib, and ado-trastuzumab emtansine (T-DM1) are commonly recommended anti-HER2 target agents by the U.S. Food and Drug Administration. This review summarizes the most significant and updated research on clinical scenarios related to HER2-positive breast cancer management in order to revise the guidelines of everyday clinical practices. In this article, we present the data on anti-HER2 clinical research of neoadjuvant, adjuvant, and metastatic studies from the past 2 decades. We also highlight some of the promising strategies that should be critically considered. Lastly, this review lists some of the ongoing clinical trials, findings of which may soon be available.

6 versus 12 months of adjuvant trastuzumab for HER2-positive early breast cancer (PERSEPHONE): 4-year disease-free survival results of a randomised phase 3 non-inferiority trial

BACKGROUND

Adjuvant trastuzumab significantly improves outcomes for patients with HER2-positive early breast cancer. The standard treatment duration is 12 months but shorter treatment could provide similar efficacy while reducing toxicities and cost. We aimed to investigate whether 6-month adjuvant trastuzumab treatment is non-inferior to the standard 12-month treatment regarding disease-free survival.

METHODS

This study is an open-label, randomised phase 3 non-inferiority trial. Patients were recruited from 152 centres in the UK. We randomly assigned patients with HER2-positive early breast cancer, aged 18 years or older, and with a clear indication for chemotherapy, by a computerised minimisation process (1:1), to receive either 6-month or 12-month trastuzumab delivered every 3 weeks intravenously (loading dose of 8 mg/kg followed by maintenance doses of 6 mg/kg) or subcutaneously (600 mg), given in combination with chemotherapy (concurrently or sequentially). The primary endpoint was disease-free survival, analysed by intention to treat, with a non-inferiority margin of 3% for 4-year disease-free survival. Safety was analysed in all patients who received trastuzumab. This trial is registered with EudraCT (number 2006-007018-39), ISRCTN (number 52968807), and ClinicalTrials.gov (number NCT00712140).

FINDINGS

Between Oct 4, 2007, and July 31, 2015, 2045 patients were assigned to 12-month trastuzumab treatment and 2044 to 6-month treatment (one patient was excluded because they were double randomised). Median follow-up was 5·4 years (IQR 3·6-6·7) for both treatment groups, during which a disease-free survival event occurred in 265 (13%) of 2043 patients in the 6-month group and 247 (12%) of 2045 patients in the 12-month group. 4-year disease-free survival was 89·4% (95% CI 87·9-90·7) in the 6-month group and 89·8% (88·3-91·1) in the 12-month group (hazard ratio 1·07 [90% CI 0·93-1·24], non-inferiority p=0·011), showing non-inferiority of the 6-month treatment. 6-month trastuzumab treatment resulted in fewer patients reporting severe adverse events (373 [19%] of 1939 patients vs 459 [24%] of 1894 patients, p=0·0002) or stopping early because of cardiotoxicity (61 [3%] of 1939 patients vs 146 [8%] of 1894 patients, p<0·0001).

INTERPRETATION

We have shown that 6-month trastuzumab treatment is non-inferior to 12-month treatment in patients with HER2-positive early breast cancer, with less cardiotoxicity and fewer severe adverse events. These results support consideration of reduced duration trastuzumab for women at similar risk of recurrence as to those included in the trial.

FUNDING

UK National Institute for Health Research, Health Technology Assessment Programme.

Highlights of the 16th St Gallen International Breast Cancer Conference, Vienna, Austria, 20-23 March 2019: personalised treatments for patients with early breast cancer

The 16th St Gallen International Breast Cancer Conference took place in Vienna for the third time, from 20–23 March 2019. More than 3000 people from all over the world were invited to take part in this important bi-annual critical review of the ‘state of the art’ in the primary care of breast cancer (BC), independent of political and industrial pressure, with the aim to integrate the most recent research data and most important developments in BC therapies since St Gallen International Breast Cancer Conference 2017, with the ultimate goal of drawing up a consensus for the current optimal treatment and prevention of BC.

This year, the St Gallen Breast Cancer Award was won by Monica Morrow (Memorial Sloan Kettering Cancer Center, USA) for her extraordinary contribution in research and practise development in the treatment of BC. She opened the session with the lecture ‘Will surgery be a part of BC treatment in the future?’ Improved systemic therapy has decreased BC mortality and increased pathologic complete response (pCR) rates after neoadjuvant chemotherapy (NACT). Improved imaging and increased screening uptake have led to detect smaller cancers. These factors have highlighted two possible scenarios to omit surgery: for patients with small low-grade ductal carcinoma in situ (DCIS) and for those who have received NACT and had a clinical and radiological complete response. However, considering that 7%–20% of `low-risk’ DCIS patients have co-existing invasive cancer at diagnosis, that surgery has become progressively less morbid and less toxic than some systemic therapies with a lower cost-effectiveness ratio, and that identification of pathologic complete response (pCR) without surgery requires more intensive imaging follow-up (more biopsies, higher cost and more anxiety for the patient), surgery still appears to be an essential treatment for BC.

The Umberto Veronesi Memorial Award went to Lesley Fallowfield (Brighton and Sussex Medical School, UK) for her important research and activity in the field of the development of patient outcome, of better communication skills and quality of life for women. In her lecture, she remarked on the importance of improving BC personalised treatments, especially through co-operation between scientists, always considering the whole woman and not just her breast disease. This award was given by Paolo Veronesi, after a moving introduction which culminated with the following words of Professor Umberto Veronesi:

‘It is not possible to take care of the people’s bodies without taking care of their mind. My duty, the duty of all doctors, is to listen and be part of the emotions of those we treat every day’.