Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): survival outcomes of a randomised, open-label, multicentre, phase 3 trial and their association with pathological complete response

Targeted lapatinib anti-HER2/ErbB2 therapy resistance in breast cancer: opportunities to overcome a difficult problem

Approximately 20% of invasive breast cancers have upregulation/gene amplification of the oncogene human epidermal growth factor receptor-2 (HER2/ErbB2). Of these, some also express steroid receptors (the so-called Luminal B subtype), whereas others do not (the HER2 subtype). HER2 abnormal breast cancers are associated with a worse prognosis, chemotherapy resistance, and sensitivity to selected anti-HER2 targeted therapeutics. Transcriptional data from over 3000 invasive breast cancers suggest that this approach is overly simplistic; rather, the upregulation of HER2 expression resulting from gene amplification is a driver event that causes major transcriptional changes involving numerous genes and pathways in breast cancer cells. Most notably, this includes a shift from estrogenic dependence to regulatory controls driven by other nuclear receptors, particularly the androgen receptor. We discuss members of the HER receptor tyrosine kinase family, heterodimer formation, and downstream signaling, with a focus on HER2 associated pathology in breast carcinogenesis. The development and application of anti-HER2 drugs, including selected clinical trials, are discussed. In light of the many excellent reviews in the clinical literature, our emphasis is on recently developed and successful strategies to overcome targeted therapy resistance. These include combining anti-HER2 agents with programmed cell death-1 ligand or cyclin-dependent kinase 4/6 inhibitors, targeting crosstalk between HER2 and other nuclear receptors, lipid/cholesterol synthesis to inhibit receptor tyrosine kinase activation, and metformin, a broadly inhibitory drug. We seek to facilitate a better understanding of new approaches to overcome anti-HER2 drug resistance and encourage exploration of two other therapeutic interventions that may be clinically useful for HER+ invasive breast cancer patients.

Phase II trial of eribulin in patients who do not achieve pathologic complete response (pCR) following neoadjuvant chemotherapy

PURPOSE

Women with residual invasive breast cancer at the primary site or axillary lymph nodes following neoadjuvant chemotherapy have a high risk of recurrence. Eribulin improves survival in patients with metastatic breast cancer who progress after anthracycline and taxane therapy. This phase 2 trial assessed the efficacy of postoperative eribulin in breast cancer patients who did not achieve a pCR following standard neoadjuvant chemotherapy.

METHODS

Women with localized breast cancer who had residual invasive cancer following ≥ 4 cycles of standard anthracycline and/or taxane-containing neoadjuvant chemotherapy received adjuvant eribulin treatment. HER2-positive patients also received trastuzumab for 1 year. Adjuvant hormonal therapy and locoregional radiotherapy were administered as per institutional guidelines. Primary endpoint was the 2-year DFS rate. Three patient cohorts were analyzed: TNBC (Cohort A), HR+/HER2- (Cohort B), and HER2+ (Cohort C).

RESULTS

One hundred twenty-six patients (Cohort A-53, Cohort B-42, and Cohort C-31) were enrolled. Neoadjuvant chemotherapy included a taxane and an anthracycline in 70%. Eribulin was well tolerated; 84% of patients received the planned 6 cycles. After a median follow-up of 28 months, the 24-month DFS rates were 56% (95% CI 42, 69), 83% (95% CI 67, 91), and 73% (95% CI 53, 86) for Cohorts A, B, and C, respectively. The most common grade 3/4 treatment-related adverse events were neutropenia (26%), leukopenia (13%), and neuropathy (7%).

CONCLUSION

Administration of adjuvant eribulin after neoadjuvant chemotherapy was feasible and well tolerated. The 24-month DFS rate did not reach the study target levels in any of the cohorts and was similar to DFS previously described in these cohorts following neoadjuvant chemotherapy alone.

Analysis of Tau Protein Expression in Predicting Pathological Complete Response to Neoadjuvant Chemotherapy in Different Molecular Subtypes of Breast Cancer

PURPOSE

Tau is a microtubule-associated protein that can be found in both normal and abnormal breast cells. Whether the expression of Tau protein can predict the response to neoadjuvant chemotherapy (NACT) is still unclear. In this study, we assessed the role of Tau protein expression in predicting a pathological complete response (pCR) to NACT for different subtypes of breast cancer.

METHODS

Four hundred and sixty-eight eligible patients were retrospectively recruited in our study. The relationship between clinicopathologic factors, including Tau protein expression, and pCR in different subtypes was evaluated using logistic regression analysis. Correlation between Tau and disease-free survival (DFS) and overall survival (OS) was performed using Kaplan-Meier analysis.

RESULTS

The expression of Tau protein was negatively correlated with pCR, especially in triple-negative breast cancer (TNBC). No significant difference was observed in the luminal human epidermal growth factor receptor-2 (HER2)-negative subtype and HER2-positive subtype. Patients with pCR were associated with better DFS and OS (p < 0.05). However, Tau protein expression had no association with either DFS or OS (p > 0.05).

CONCLUSION

Tau protein expression can predict pCR before NACT in TNBC, but there was no correlation between Tau expression and DFS or OS.

A Proposal to Redefine Pathologic Complete Remission as Endpoint following Neoadjuvant Chemotherapy in Early Breast Cancer

Many analyses of the efficacy of neoadjuvant treatment (NAT) for early breast cancer including a meta-analysis derived from 10 randomized trials came to the conclusion that patients who would achieve pathologic complete response (pCR) following NAT would experience significant improvement in disease-free and overall survival (OS). Thus, pCR was proposed as a surrogate endpoint for OS, with pCR representing a robust prognostic marker for survival at an individual level. In the current analysis, we argue that OS following NAT-induced pCR might have reflected the initial prognosis of patients mainly defined - among other factors - by the initial pathological lymph node status while being largely independent on the type of administrated treatment, thus pleading against the pCR surrogacy hypothesis. We therefore propose to redefine pCR as a surrogate endpoint of NAT trials by the involvement of additional biologic parameters.

Breast cancer in young black women

BACKGROUND

Young age at breast cancer diagnosis is associated with negative prognostic outcomes, and breast cancer in black women often manifests at a young age. This study evaluated the effect of age on breast cancer management and outcomes in black women.

METHODS

This was a retrospective cohort study of all black women treated for invasive breast cancer between 2005 and 2010 at a specialized tertiary-care cancer centre. Clinical and treatment characteristics were compared by age. Kaplan-Meier methodology was used to estimate overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 666 black women were identified. Median BMI was 30 (range 17-56) kg/m² and median tumour size was 16 (1-155) mm. Most tumours were oestrogen receptor-positive (66·4 per cent). Women were stratified by age: less than 40 years (74, 11·1 per cent) versus 40 years or more (592, 88·9 per cent). Younger women were significantly more likely to have a mastectomy, axillary lymph node dissection and to receive chemotherapy, and were more likely to have lymphovascular invasion and positive lymph nodes, than older women. The 5-year OS rate was 88·0 (95 per cent c.i. 86·0 to 91·0) per cent and the 5-year DFS rate was 82·0 (79·0 to 85·0) per cent. There was no statistically significant difference in OS by age (P = 0·236). Although DFS was inferior in younger women on univariable analysis (71 versus 88 per cent; P < 0·001), no association was found with age on multivariable analysis.

CONCLUSION

Young black women with breast cancer had more adverse pathological factors, received more aggressive treatment, and had worse DFS on univariable analysis. Young age at diagnosis was, however, not an independent predictor of outcome.

Reactive stroma and trastuzumab resistance in HER2-positive early breast cancer

We investigated the value of reactive stroma as a predictor for trastuzumab resistance in patients with early HER2-positive breast cancer receiving adjuvant therapy. The pathological reactive stroma and the mRNA gene signatures that reflect reactive stroma in 209 HER2-positive breast cancer samples from the FinHer adjuvant trial were evaluated. Levels of stromal gene signatures were determined as a continuous parameter, and pathological reactive stromal findings were defined as stromal predominant breast cancer (SPBC; ≥50% stromal) and correlated with distant disease-free survival. Gene signatures associated with reactive stroma in HER2-positive early breast cancer (N = 209) were significantly associated with trastuzumab resistance in estrogen receptor (ER)-negative tumors (hazard ratio [HR] = 1.27 p interaction = 0.014 [DCN], HR = 1.58, p interaction = 0.027 [PLAU], HR = 1.71, p interaction = 0.019 [HER2STROMA, novel HER2 stromal signature]), but not in ER-positive tumors (HR = 0.73 p interaction = 0.47 [DCN], HR = 0.71, p interaction = 0.73 [PLAU], HR = 0.84; p interaction = 0.36 [HER2STROMA]). Pathological evaluation of HER2-positive/ER-negative tumors suggested an association between SPBC and trastuzumab resistance. Reactive stroma did not correlate with tumor-infiltrating lymphocytes (TILs), and the expected benefit from trastuzumab in patients with high levels of TILs was pronounced only in tumors with low stromal reactivity (SPBC <50%). In conclusion, reactive stroma in HER2-positive/ER-negative early breast cancer tumors may predict resistance to adjuvant trastuzumab therapy.

Refining the indications for neoadjuvant chemotherapy for patients with HER2+ breast cancer: A single institution experience

BACKGROUND

We aim to compare the clinical outcomes of patients with early-stage HER2+ breast cancer treated with adjuvant chemotherapy (AC) and neoadjuvant chemotherapy (NAC).

METHODS

Patients with non-metastatic HER2+ breast cancer treated from 2009 to 2018 at our institution comprised our study cohort (n = 1254). Pathologic complete response (pCR) was defined as the absence of invasive disease in the breast and axilla after NAC. Log-rank, Kaplan-Meier, and inverse probability of treatment weighting were used to assess differences in disease-free and overall survival between groups stratified by AC vs. NAC and pCR vs. non-pCR.

RESULTS

The majority received AC (n = 787 or 62.8%) while 467 (37.2%) patients received NAC. Median follow up for AC and NAC groups was 46 and 28 months, respectively. The crude disease-free survival and overall survival of our study cohort were 92.2% and 89.1% for AC, 89.1% and 82.2% for NAC pCR, and 68.1% and 60.0% for NAC non-pCR, respectively. For clinical stage ≥IIB patients, NAC conferred a positive but statistically nonsignificant treatment effect over AC in multivariate analysis.

CONCLUSIONS

After adjusting for imbalances in our subgroups, we found that, regardless of the sequence of chemotherapy (AC vs. NAC), patients with early-stage HER2+ breast cancer had excellent outcomes.

CD47 blockade augmentation of trastuzumab antitumor efficacy dependent on antibody-dependent cellular phagocytosis

The HER2-specific monoclonal antibody (mAb), trastuzumab, has been the mainstay of therapy for HER2+ breast cancer (BC) for approximately 20 years. However, its therapeutic mechanism of action (MOA) remains unclear, with antitumor responses to trastuzumab remaining heterogeneous and metastatic HER2+ BC remaining incurable. Consequently, understanding its MOA could enable rational strategies to enhance its efficacy. Using both murine and human versions of trastuzumab, we found its antitumor activity dependent on Fcγ receptor stimulation of tumor-associated macrophages (TAMs) and antibody-dependent cellular phagocytosis (ADCP), but not cellular cytotoxicity (ADCC). Trastuzumab also stimulated TAM activation and expansion, but did not require adaptive immunity, natural killer cells, and/or neutrophils. Moreover, inhibition of the innate immune ADCP checkpoint, CD47, significantly enhanced trastuzumab-mediated ADCP and TAM expansion and activation, resulting in the emergence of a unique hyperphagocytic macrophage population, improved antitumor responses, and prolonged survival. In addition, we found that tumor-associated CD47 expression was inversely associated with survival in HER2+ BC patients and that human HER2+ BC xenografts treated with trastuzumab plus CD47 inhibition underwent complete tumor regression. Collectively, our study identifies trastuzumab-mediated ADCP as an important antitumor MOA that may be clinically enabled by CD47 blockade to augment therapeutic efficacy.

An RB-1 loss of function gene signature as a tool to predict response to neoadjuvant chemotherapy plus anti-HER2 agents: a substudy of the NeoALTTO trial (BIG 1-06)

BACKGROUND

Chemotherapy added to anti-HER2 agents (H) is the treatment of choice in patients with HER2+ early breast cancer. However, HER2+ tumours are clinically and biologically heterogeneous, and treatment response varies significantly by hormone receptor (HR) status and molecular subtype. Predictive biomarkers are needed in this context. This study assessed whether an RB-1 loss of function gene signature (RBsig) is predictive of response to neoadjuvant chemotherapy in combination with trastuzumab, lapatinib or both, within the NeoALTTO trial.

METHODS

We collected RNA-sequencing data from pretreatment biopsies derived from the NeoALTTO trial. RBsig expression was computed retrospectively and correlated with pathological complete response (pCR) using receiver-operating characteristic (ROC) curves. The RBsig was dichotomised as High/Low in correspondence to the 25th percentile. Reported p values resulted from Fisher's exact test.

RESULTS

Of 455 NeoALTTO patients, 244 were eligible for this substudy (HR+ n = 129; HR- n = 115). Overall, pCR rate was significantly higher in patients with RBsig High tumours than those with RBsig Low (35% versus 18% respectively; p = 0.01). The area under the ROC curve (AUC) was 0.60 (95% CI 0.52-0.67). A remarkably low pCR rate of 11% was seen in HR+/RBsig Low patients versus 28% in HR+/RBsig High.

CONCLUSIONS

These results indicate RBsig may add valuable information to HER2 and HR expression, which may in turn inform treatment choices. HR+/HER2+/RBsig Low breast cancers exhibited the poorest pathological response following chemotherapy plus H. Accordingly, in such patients, endocrine therapy in combination with H and, possibly, a CDK4/6 inhibitor, may potentially prove to be a more effective treatment.

Contextualizing pertuzumab approval in the treatment of HER2-positive breast cancer patients

The use of adjuvant pertuzumab in HER2-positive early-stage breast cancer has recently been approved by the EMA on the basis of data from the APHINITY trial. Accordingly, we have produced this opinion article with the aim of putting the study data in perspective against other add-on therapeutic strategies, to clarify methodological or statistical doubts about the study, and to define the population of high-risk patients with hormone receptor-negative breast cancer that we agree, in general, should be treated. With this approval, physicians must be well prepared to place the APHINITY study data in context. It is now up to each country to ratify the EMA-approved indications and to agree on reimbursement, and doctors must optimize their use based on knowledge and discussion with patients.

Contralateral Prophylactic Mastectomy Use After Neoadjuvant Chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NAC) for breast cancer increases breast-conserving surgery (BCS) rates, but many women opt for mastectomy with contralateral prophylactic mastectomy (CPM). Here we evaluate factors associated with CPM use in women undergoing mastectomy post-NAC.

METHODS

A retrospective institutional NAC database review identified women with clinical stage I-III, unilateral invasive breast cancer undergoing unilateral mastectomy (UM) or CPM mastectomy from 9/2013 to 12/2017. Clinical/pathologic characteristics, imaging, and presence of contraindications to BCS post-NAC were compared, with subset analysis of BCS candidates. The multivariable analysis was adjusted for potential confounders.

RESULTS

Five hundred sixty-nine women underwent mastectomy after NAC, 297 (52%) UM and 272 (48%) CPM. On univariable analysis, younger age, BRCA+, lower pre-NAC clinical stage, pathologic complete response, and axillary surgery extent were associated with CPM (all p < 0.01). Favorable post-NAC clinical factors of no residual palpable disease, clinically negative nodes, complete response on breast imaging, and no post-NAC contraindication to BCS were also associated with CPM (all p < 0.01). On multivariable analysis, young age (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.91-0.95), lower pre-NAC stage (OR 0.51, 95% CI 0.34-0.77), and no contraindication to BCS (OR 3.12, 95% CI 2.02-4.82) were significantly associated with CPM. Among the 203 (35%) women who had no contraindications to BCS post-NAC, 145 (71%) underwent CPM. BRCA+ and family history were reasons more frequently cited for mastectomy among CPM than UM (p < 0.001).

CONCLUSIONS

CPM was performed in 48% of women undergoing mastectomy after NAC; younger women with earlier-stage cancers were more likely to undergo CPM. While increased use of CPM in women with more favorable disease is medically appropriate, our findings indicate a lost opportunity for use of BCS.

Deciphering HER2 Breast Cancer Disease: Biological and Clinical Implications

The main obstacle for designing effective treatment approaches in breast cancer is the extensive and the characteristic heterogeneity of this tumor. The vast majority of critical genomic changes occurs during breast cancer progression, creating a significant variability within primary tumors as well as between the primary breast cancer and their metastases, a hypothesis have already demonstrated in retrospective studies (1). A clear example of this is the HER2-positive breast cancer. In these tumors, we can find all of the transcriptional subtypes of breast cancer, even the basal like or luminal A subtypes. Although the HER2-enriched is the most representative transcriptional subtype in the HER2-positive breast cancer, we can find it too in breast cancers with HER2-negative status. This intrinsic subtype shows a high expression of the HER2 and is associated with proliferation-related genes clusters, among other features. Therefore, two hypotheses can be suggested. First, the HER2 amplification can be a well-defined driver event present in all of the intrinsic subtypes, and not a subtype marker isolated. Secondly, HER2-enriched subtype can have a distinctive transcriptional landscape independent of HER2 amplification. In this review, we present an extensive revision about the last highlights and advances in clinical and genomic settings of the HER2-positive breast cancer and the HER2-enriched subtype, in an attempt to improving the knowledge of the underlying biology of both entities and to explaining the intrinsic heterogeneity of HER2-positive breast cancers.

Breast Cancer during Pregnancy-Current Paradigms, Paths to Explore

Breast cancer is the most common form of malignancy in pregnant women. The prevalence of pregnancy-associated breast cancer (PABC) is up to 0.04% of pregnancies and is expected to rise in developed countries. PABC represents a unique clinical scenario which requires a delicate balance of risks and benefits for both maternal and fetal well-being. Currently, there is paucity of data regarding the short- and long-term outcomes of in-utero exposure to anti-neoplastic agents. In general, when possible, treatment for PABC should follow the same guidelines as in non-pregnant patients. Surgery, including sentinel lymph node biopsy, is possible during all trimesters of pregnancy. Radiotherapy is contraindicated during pregnancy, although it might be considered in highly selected patients based on risk-benefit assessment. Evidence supports that administration of chemotherapy may be safe during the second and third trimesters, with cessation of treatment three weeks prior to expected delivery. Currently, hormonal therapy and anti-HER2 agents are contraindicated during pregnancy and should be postponed until after delivery. Prematurity is associated with worse neonatal and long-term outcomes, and thus should be avoided. While current data on the long-term effects of anti-neoplastic treatments are reassuring, grade of evidence is lacking, hence additional large prospective studies with long-term follow-up are essential to rule out any treatment-induced adverse effects.

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.

Neoadjuvant Trastuzumab Emtansine and Pertuzumab in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: Three-Year Outcomes From the Phase III KRISTINE Study

PURPOSE

The KRISTINE study compared neoadjuvant trastuzumab emtansine plus pertuzumab (T-DM1+P) with docetaxel, carboplatin, trastuzumab plus P (TCH+P) for the treatment human epidermal growth factor receptor 2-positive stage II to III breast cancer. T-DM1+P led to a lower pathologic complete response rate (44.4% v 55.7%; P = .016), but fewer grade 3 or greater and serious adverse events (AEs). Here, we present 3-year outcomes from KRISTINE.

METHODS

Patients were randomly assigned to neoadjuvant T-DM1+P or TCH+P every 3 weeks for six cycles. Patients who received T-DM1+P continued adjuvant T-DM1+P, and patients who received TCH+P received adjuvant trastuzumab plus pertuzumab. Secondary end points included event-free survival (EFS), overall survival, patient-reported outcomes (measured from random assignment), and invasive disease-free survival (IDFS; measured from surgery).

RESULTS

Of patients, 444 were randomly assigned (T-DM1+P, n = 223; TCH+P, n = 221). Median follow-up was 37 months. Risk of an EFS event was higher with TDM-1+P (hazard ratio [HR], 2.61 [95% CI, 1.36 to 4.98]) with more locoregional progression events before surgery (15 [6.7%] v 0). Risk of an IDFS event after surgery was similar between arms (HR, 1.11 [95% CI, 0.52 to 2.40]). Pathologic complete response was associated with a reduced risk of an IDFS event (HR, 0.24 [95% CI, 0.09 to 0.60]) regardless of treatment arm. Overall, grade 3 or greater AEs (31.8% v 67.7%) were less common with T-DM1+P. During adjuvant treatment, grade 3 or greater AEs (24.5% v 9.9%) and AEs leading to treatment discontinuation (18.4% v 3.8%) were more common with T-DM1+P. Patient-reported outcomes favored T-DM1+P during neoadjuvant treatment and were similar to trastuzumab plus pertuzumab during adjuvant treatment.

CONCLUSION

Compared with TCH+P, T-DM1+P resulted in a higher risk of an EFS event owing to locoregional progression events before surgery, a similar risk of an IDFS event, fewer grade 3 or greater AEs during neoadjuvant treatment, and more AEs leading to treatment discontinuation during adjuvant treatment.

Sequential Anti-PD1 Therapy Following Dendritic Cell Vaccination Improves Survival in a HER2 Mammary Carcinoma Model and Identifies a Critical Role for CD4 T Cells in Mediating the Response

Patients with metastatic HER2 breast cancer (MBC) often become resistant to HER 2 targeted therapy and have recurrence of disease. The Panacea trial suggested that HER2 MBC patients were more likely to respond to checkpoint therapy if TIL were present or if tumor expressed PD-L1. We assessed whether type I polarized dendritic cells (DC1) could improve checkpoint therapy in a preclinical model of HER2+ breast cancer. TUBO bearing mice were vaccinated with either MHC class I or class II HER2 peptide pulsed DC1 (class I or class II HER2-DC1) concurrently or sequentially with administration of anti-PD-1 or anti-PDL1. Infiltration of tumors by immune cells, induction of anti-HER2 immunity and response to therapy was evaluated. Class I or class II HER2-DC1 vaccinated mice generated anti-HER2 CD8 or CD4+ T cell immune responses and demonstrated delayed tumor growth. Combining both MHC class I and II HER2-pulsed DC1 did not further result in inhibition of tumor growth or enhanced survival compared to individual administration. Interestingly class II HER2-DC1 led to both increased CD4 and CD8 T cells in the tumor microenvironment while class I peptides typically resulted in only increased CD8 T cells. Anti-PD-1 but not anti-PD-L1 administered sequentially with class I or class II HER2-DC1 vaccine could improve the efficacy of HER2-DC1 vaccine as measured by tumor growth, survival, infiltration of tumors by T cells and increase in systemic anti-HER2 immune responses. Depletion of CD4+ T cells abrogated the anti-tumor efficacy of combination therapy with class II HER2-DC1 and anti-PD-1, suggesting that tumor regression was CD4 dependent. Since class II HER2-DC1 was as effective as class I, we combined class II HER2-DC1 vaccine with anti-rat neu antibodies and anti-PD-1 therapy. Combination therapy demonstrated further delay in tumor growth, and enhanced survival compared to control mice. In summary, Class II HER2-DC1 drives both a CD4 and CD8 T cell tumor infiltration that leads to increased survival, and in combination with anti-HER2 therapy and checkpoint blockade can improve survival in preclinical models of HER2 positive breast cancer and warrants exploration in patients with HER2 MBC.

Assessing the impact of the 2018 American Society of Clinical Oncology/College of American Pathologists recommendations on human epidermal growth factor receptor 2 testing by fluorescence in situ hybridization in breast carcinoma

The American Society of Clinical Oncology/College of American Pathologists recently updated their recommendations on human epidermal growth factor receptor 2 (HER2) testing by fluorescence in situ hybridization (FISH) in invasive breast cancer, with a focus on the clarification of less common test patterns of ISH. We assessed the impact of the updated ASCO/CAP guidelines on 1044 FISH tested tumors by comparing categorization according to the 2007, 2013, and 2018 ISH classification criteria. The 2013 guidelines increased the number of positive cases (17.4% vs 10.7%) identifying 70 (6.7%) additional patients who met the eligibility criteria for consideration for HER2-targeted therapy compared with the 2007 guidelines. There was a reduction in equivocal tumors (7.7%) with tumors classified as equivocal by the 2007 guidelines (n = 136) redistributed into positive (74, 54.4%) and negative (49, 36.0%) groups. The 2018 guidelines reclassified 10.8% of tumors in our series with a reduction in the number of positive tumors (7.1%). While the proportion of positive tumors (10.2%) was similar to that in 2007 (10.7%), the composition of this group was significantly altered. HER2 equivocal cases, a group which under the 2013 guidelines caused diagnostic and treatment difficulties, were largely eliminated. Our findings suggest that the 2018 update represents a potentially significant change in therapeutic options for a substantial proportion of patients with 2.9% of FISH-positive tumors according to the 2007 and 2013 guidelines now categorized as HER2 negative and, thus, ineligible for HER2-targeted therapy.

Progress in adjuvant systemic therapy for breast cancer

The prognosis of patients with early stage breast cancer has greatly improved in the past three decades. Following the first adjuvant endocrine therapy and chemotherapy trials, continuous improvements of clinical outcomes have been achieved through intense therapeutic escalation, albeit with increased health-care costs and treatment-related toxicities. In contrast to the advances achieved in surgery or radiotherapy, the identification of the patient subgroups that will derive clinical benefit from therapeutic escalation has proved to be a daunting process hindered by a lack of collaboration between scientific groups and by the pace of drug development. In the past few decades, initiatives towards de-escalation of systemic adjuvant treatment have achieved success. Herein, we summarize attempts to escalate and de-escalate adjuvant systemic treatment for patients with breast cancer and argue that new, creative trial designs focused on patients' actual needs rather than on maximizing drug market size are needed. Ultimately, the adoption of effective treatments that do not needlessly expose patients and health-care systems to harm demands extensive international collaboration between academic groups, governments, and pharmaceutical companies.

Cardiotoxicities of Modern Treatments in Breast Cancer

PURPOSE OF REVIEW

This paper will focus on novel breast cancer therapies used in clinical practice today, as well as review our understanding of standard therapies and their potential impact on cardiovascular health.

RECENT FINDINGS

Established and novel treatments such as anthracyclines, HER2-targeted agents, and immunotherapy have contributed to improvements in breast cancer outcomes; however, these treatments may be associated with an increased risk of cardiovascular injury. The number of available breast cancer treatments continues to expand, as does the need for health care providers to understand the potential impact of these treatments on cardiovascular health. Collaborative approaches in the development of risk stratification, prevention, and surveillance strategies for patients exposed to established and novel breast cancer treatments will facilitate improvements in patient outcomes without compromising their cardiovascular health.

MAP3K kinases and kidney injury

Mitogen-activated protein kinases (MAP kinases) are functionally connected kinases that regulate key cellular process involved in kidney disease such as all survival, death, differentiation and proliferation. The typical MAP kinase module is composed by a cascade of three kinases: a MAP kinase kinase kinase (MAP3K) that phosphorylates and activates a MAP kinase kinase (MAP2K) which phosphorylates a MAP kinase (MAPK). While the role of MAPKs such as ERK, p38 and JNK has been well characterized in experimental kidney injury, much less is known about the apical kinases in the cascade, the MAP3Ks. There are 24 characterized MAP3K (MAP3K1 to MAP3K21 plus RAF1, BRAF and ARAF). We now review current knowledge on the involvement of MAP3K in non-malignant kidney disease and the therapeutic tools available. There is in vivo interventional evidence clearly supporting a role for MAP3K5 (ASK1) and MAP3K14 (NIK) in the pathogenesis of experimental kidney disease. Indeed, the ASK1 inhibitor Selonsertib has undergone clinical trials for diabetic kidney disease. Additionally, although MAP3K7 (MEKK7, TAK1) is required for kidney development, acutely targeting MAP3K7 protected from acute and chronic kidney injury; and targeting MAP3K8 (TPL2/Cot) protected from acute kidney injury. By contrast MAP3K15 (ASK3) may protect from hypertension and BRAF inhibitors in clinical use may induced acute kidney injury and nephrotic syndrome. Given their role as upstream regulators of intracellular signaling, MAP3K are potential therapeutic targets in kidney injury, as demonstrated for some of them. However, the role of most MAP3K in kidney disease remains unexplored.

Neoadjuvant zoledronic acid for HER2-positive breast cancer: the Zo-NAnTax trial

BACKGROUND

Preclinical evidence suggests that zoledronic acid (ZOL) works synergistically with chemotherapy by enhancing anti-tumor activity. ZOL blocks the mevalonate pathway and may indirectly interact with human epidermal growth factor receptor 2 (HER2) pathway activation. The clinical efficacy and biological rationale of chemotherapy plus anti-HER2 therapy and ZOL as a part of neoadjuvant therapy has not been previously tested.

PATIENTS AND METHODS

We conducted a phase II clinical trial to evaluate the efficacy and safety of ZOL as part of a neoadjuvant treatment in patients with HER2-positive breast cancer (BC). The protocol consisted of four cycles of doxorubicin/cyclophosphamide with ZOL, followed by four cycles of docetaxel with trastuzumab and ZOL prior to surgery. The primary endpoint was the pathologic complete response (pCR) rate. Secondary endpoints were safety and the identification of clinicopathological characteristics associated with pCR.

RESULTS

A total of 71 patients with stage IIA to IIIB BC were included, with 60 eligible for the safety assessment and 58 for the efficacy analysis. Overall, the pCR rate was 42%, with higher rates in hormone receptor (HR)-positive tumors (40%), which contrasts with the results of pivotal trials. The most commonly observed grade 3 and 4 events were febrile neutropenia (grade 3, 20%; grade 4, 3%) and diarrhea (grade 3, 12%).

CONCLUSIONS

The addition of ZOL as a repositioning drug in neoadjuvant treatment was an effective and well-tolerated therapy. This drug combination might overcome endocrine and anti-HER2 resistance. The higher pCR rates in the HR-positive subgroup deserve further translational investigation.

Dual-targeting strategy using trastuzumab and lapatinib in a patient with HER2 gene amplification in recurrent metachronous metastatic gallbladder carcinoma

Gallbladder carcinoma (GBC) is a rare and highly aggressive tumor. Early diagnosis is challenging, which results in a poor prognosis using systemic therapy. Recent studies have identified a subset of GBC patients with HER2 gene (ERBB2) amplification that could benefit from HER2-targeted therapy. Here, we report one patient with recurrent metachronous GBC with metastasis, who received the combination of trastuzumab and lapatinib. This approach achieved a partial response for both the brain and the lung metastases. This study demonstrated that HER2 inhibition is a promising therapeutic strategy for GBC with HER2 amplification and, combined with lapatinib, it can effectively target brain metastasis.

Cardiotoxicity of Contemporary Breast Cancer Treatments

OPINION STATEMENT

Treatment-related cardiotoxicity remains a significant concern for breast cancer patients undergoing cancer treatment and extends into the survivorship period, with adverse cardiovascular (CV) outcomes further compounded by the presence of pre-existing CV disease or traditional CV risk factors. Awareness of the cardiotoxicity profiles of contemporary breast cancer treatments and optimization of CV risk factors are crucial in mitigating cardiotoxicity risk. Assessment of patient- and treatment-specific risk with appropriate CV surveillance is another key component of care. Mismatch between baseline cardiotoxicity risk and intensity of cardiotoxicity surveillance can lead to unnecessary downstream testing, increased healthcare expenditure, and interruption or discontinuation of potentially life-saving treatment. Efforts to identify early imaging and/or circulating biomarkers of cardiotoxicity and develop effective management strategies are needed to optimize the CV and cancer outcomes of breast cancer survivors.

A nomogram for predicting the HER2 status in female patients with breast cancer in China: a nationwide, multicenter, 10-year epidemiological study

BACKGROUND

The concordance rate of human epidermal growth factor receptor 2 (HER2) status between core needle biopsy (CNB) and subsequent excisional biopsies of the same tumor varies from 81 to 96%, which may cause inappropriate neoadjuvant therapy that impair the potential benefit from HER2 targeted therapy for patients. This study aimed to establish a nomogram to predict the HER2 status pre-operatively as an auxiliary diagnosis to CNB assessment.

METHODS

Among 4211 breast cancer patients cataloged in the Nation-wide Multicenter 10-year Retrospective Clinical Epidemiological Study of Breast Cancer in China, 2291 patients with complete relevant information were included in this study, which were further randomized 3:1 and divided into a training set and a validation set. The nomogram was established based on independent predictors of HER2 positivity recognized by logistic regression analysis and further validated internally and externally.

RESULTS

The multivariate logistic regression analysis showed that T-stage, N-stage, estrogen receptor (ER) status, progesterone receptor (PR) status were independent predictors for HER2 status. The nomogram was thereby constructed by those independent predictors as well as histology type. The areas under the receiver operating characteristic curve (AUC) of the training set and the validation set were 0.636 and 0.681, respectively. The calibration plots demonstrated good fitness of the nomogram for HER2 status prediction. With the optimal cutoff value, the nomogram yielded 80.0% sensitivity, 43.1% specificity in the training set and 81.1% sensitivity, 49.8% specificity in the validation set.

CONCLUSIONS

The present nomogram can provide valuable information on HER2 status and combined with standard CNB assessment, clinicians could make more appropriate decision on neoadjuvant therapy of breast cancer.

Neoadjuvant Management of Early Breast Cancer: A Clinical and Investigational Position Statement

BACKGROUND

Neoadjuvant treatment is increasingly one of the preferred therapeutic options for early breast cancer and may have some unique outcomes, such as identifying predictive and prognostic factors of response or increasing the knowledge of individual tumor biology.

DESIGN

A panel of experts from different specialties reviewed published clinical studies on the neoadjuvant management of breast cancer. Recommendations were made that emphasized the clinical multidisciplinary management and the investigational leverage in early breast cancer.

RESULTS

Neoadjuvant therapy has equivalent efficacy to adjuvant therapy, and it has some additional benefits that include increasing breast conservation, assessing tumor response, establishing prognosis based on the pathological response, and providing a "second opportunity" for nonresponding patients. Achieving pathological complete remission because of neoadjuvant therapy has been correlated with long-term clinical benefit, particularly in HER2-positive and triple-negative breast cancer. In addition, the neoadjuvant setting is a powerful model for the development of new drugs and the identification of prognostic markers. Finally, neoadjuvant therapy has proven to be cost-effective by reducing nondrug costs, avoiding radical surgery, and reducing hospital stays when compared with other treatment approaches.

CONCLUSION

Neoadjuvant therapy has clinical benefits in early breast cancer and provides in vivo information of individual breast cancer biology while allowing the investigation of new treatment approaches. Access to neoadjuvant therapy should be an option available to all patients with breast cancer through multidisciplinary tumor management.

IMPLICATIONS FOR PRACTICE

Neoadjuvant treatment should be strongly considered as a therapeutic option for localized breast cancer and is a powerful tool for understanding breast cancer biology and investigating new treatment approaches.

Changing pattern of recurrences in patients with early HER2-positive breast cancer receiving neoadjuvant chemotherapy in the era of dual anti-HER2 therapy

BACKGROUND

Over the last 10 years, there has been a major treatment revolution for early human epidermal growth factor receptor 2 (HER2)-positive breast cancer. We aimed to explore the outcome of different neoadjuvant chemotherapy in a tertiary breast cancer centre with early HER2-positive breast cancer as well as factors associated with pathological complete response (pCR) and recurrence-free survival (RFS). The pattern of recurrence was also studied.

METHODS

This retrospective study analysed the outcome of neoadjuvant chemotherapy during the period 2005 to 2016 in a tertiary referral centre in Hong Kong. Patients were divided into three groups according to the neoadjuvant chemotherapy they received: chemotherapy only (Chemo), chemotherapy plus trastuzumab (Chemo-H) and chemotherapy plus double anti-HER2 therapy (Chemo-DH).

RESULTS

There were 226 cases analysed during the study period. The rate of pCR was 5%, 26% and 60% in Chemo, Chemo-H and Chemo-DH groups, respectively (Chemo vs pooled Chemo-H/DH: p<0.0001; Chemo-H vs Chemo-DH: p<0.0001). This was accompanied by a trend of increased rate of breast conservation therapy in Chemo-DH cohort (p=0.046). Use of double anti-HER2 therapy, older age (>50 years) and hormone receptor negativity were associated with more pCR. pCR was associated with better RFS. Among those with recurrence, the proportion of patients with brain as the only site of recurrence increased remarkably with more efficacious anti-HER2 treatment (0% in Chemo, 8% in Chemo-H, 67% in Chemo-DH).

CONCLUSION

pCR remains an important predictive factor for improved RFS. In the era of dual anti-HER2 neoadjuvant therapy, brain-only recurrence poses a challenge to disease surveillance and treatment.

Heterologous Prime-Boost Enhances the Antitumor Immune Response Elicited by Plant-Virus-Based Cancer Vaccine

New cancer vaccine strategies are required to vanquish the self-tolerance and elicit robust immune responses against tumor-associated antigens and/or neoantigens. Contemporary approaches in nanomedicine center on the use of a single nanocarrier modified with multiple copies of multiple different functional domains, e.g., epitopes for vaccines. Therefore, we set out to develop a combinatorial approach toward the next-generation concept of epitope delivery: a prime-boost strategy in which the same epitope is delivered using different nanocarriers. We tested this concept in the setting of HER2⁺ breast cancer. We synthesized HER2-based cancer vaccines using three icosahedral plant viruses as carriers and evaluated the immune response as a result of repetitive, homologous immunization using BALB/c mice. Two of the vaccines induced a Th2-predominant response and the other a Th1-predominant response. To enhance the immunogenicity of the vaccines, we developed a heterologous prime-boost strategy with each of the vaccines administered only once, yielding higher titers of HER2-specific immunoglobulins and increasing the toxicity of the antisera toward cancer cells. The prime-boost also induced a Th1-predominant response. An in vivo tumor challenge showed that the prime-boost regimen reduced tumor growth and improved survival in mice. This novel strategy to elicit robust immune responses against weakly immunogenic antigens in principle could be broadly applicable to cancers and other diseases.

De-escalated neoadjuvant therapy with nanoparticle albumin-bound paclitaxel and trastuzumab for low-risk pure HER2 breast cancer

PURPOSE

Neoadjuvant trastuzumab combined with anthracycline and taxane is now considered a standard regimen for human epidermal growth factor receptor 2 (HER2)-positive breast cancer. A less toxic, non-anthracycline regimen has been considered as a treatment option for patients with node-negative small tumors. Estrogen receptor-negative and HER2-positive (pure HER2) tumors are more likely to achieve a pathological complete response (pCR). This study evaluates the activity and safety of neoadjuvant nanoparticle albumin-bound paclitaxel (nab-PTX) plus trastuzumab for pure HER2 breast cancer in patients with low risk of relapse.

METHODS

We treated patients with tumors measuring ≤ 3 cm, node-negative, pure HER2 breast cancer using neoadjuvant nab-PTX 260 mg/m2 with trastuzumab every 3 weeks for four cycles. The primary endpoint was the pCR rate. The secondary endpoints included the clinical response rate, disease-free survival, pathologic response rate (defined as pCR or minimal residual invasive disease only in the breast), breast-conserving surgery conversion rate, safety, and disease-free survival. Depending on the pathological findings of surgical specimens, the administration of adjuvant anthracycline could be omitted.

RESULTS

Eighteen patients were enrolled. No patient required dose delays or reductions; none showed disease progression, and all patients underwent surgery as scheduled. Of the 18 patients, 66.7% achieved pCR, and the adjuvant anthracycline regimen was omitted for all patients. The incidence of severe adverse events was quite low.

CONCLUSION

This less toxic, anthracycline-free regimen appears to be a significantly effective neoadjuvant therapy for patients with pure HER2 breast cancer at low relapse risk.

Targeting promiscuous heterodimerization overcomes innate resistance to ERBB2 dimerization inhibitors in breast cancer

Background

The oncogenic receptor tyrosine kinase (RTK) ERBB2 is known to dimerize with other EGFR family members, particularly ERBB3, through which it potently activates PI3K signalling. Antibody-mediated inhibition of this ERBB2/ERBB3/PI3K axis has been a cornerstone of treatment for ERBB2-amplified breast cancer patients for two decades. However, the lack of response and the rapid onset of relapse in many patients now question the assumption that the ERBB2/ERBB3 heterodimer is the sole relevant effector target of these therapies.

Methods

Through a systematic protein-protein interaction screen, we have identified and validated alternative RTKs that interact with ERBB2. Using quantitative readouts of signalling pathway activation and cell proliferation, we have examined their influence upon the mechanism of trastuzumab- and pertuzumab-mediated inhibition of cell growth in ERBB2-amplified breast cancer cell lines and a patient-derived xenograft model.

Results

We now demonstrate that inactivation of ERBB3/PI3K by these therapeutic antibodies is insufficient to inhibit the growth of ERBB2-amplified breast cancer cells. Instead, we show extensive promiscuity between ERBB2 and an array of RTKs from outside of the EGFR family. Paradoxically, pertuzumab also acts as an artificial ligand to promote ERBB2 activation and ERK signalling, through allosteric activation by a subset of these non-canonical RTKs. However, this unexpected activation mechanism also increases the sensitivity of the receptor network to the ERBB2 kinase inhibitor lapatinib, which in combination with pertuzumab, displays a synergistic effect in single-agent resistant cell lines and PDX models.

Conclusions

The interaction of ERBB2 with a number of non-canonical RTKs activates a compensatory signalling response following treatment with pertuzumab, although a counter-intuitive combination of ERBB2 antibody therapy and a kinase inhibitor can overcome this innate therapeutic resistance.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1127-y) contains supplementary material, which is available to authorized users.

Pertuzumab for the treatment of breast cancer

Introduction: Pertuzumab, a humanized monoclonal antibody that binds the human epidermal growth factor receptor 2 (HER2), inhibits the heterodimerization of HER2 with other HER receptors. It has been approved both by the Food and Drug Administration and the European Medicine Agency in the metastatic, neoadjuvant and adjuvant setting.Areas covered: This review analyses and discusses preclinical and clinical studies of pertuzumab in breast cancer. In this article, we review the status of pertuzumab, the completed and ongoing trials, and its safety.Expert opinion: Pertuzumab is a key drug for the treatment of HER2-positive metastatic or early breast cancer. However, it is imperative to identify patients that will need dual-targeting and mechanisms of resistance. Moreover, the value of pertuzumab beyond progression needs to be evaluated.

Comparative Efficacy and Tolerability of Neoadjuvant Immunotherapy Regimens for Patients with HER2-Positive Breast Cancer: A Network Meta-Analysis

This network meta-analysis addresses the need for evidence-based best-practice treatment regimens for HER2-positive breast cancer. We compared the relative efficacy and tolerability of currently available HER2-positive neoadjuvant immunotherapy regimens based on systematic searches of available randomized controlled trials (RCTs) data. Based on intention-to-treat principle, pathological complete response (pCR), overall serious adverse events (SAEs), and breast-conserving surgery (BCS) rate were analyzed using random-effect, Bayesian network meta-analysis, and standard pairwise meta-analysis. 16 RCTs (3868 patients) were included. Analyzed treatment regimens were as follows: chemotherapy+trastuzumab+pertuzumab (CTP), trastuzumab emtansine+pertuzumab (MP), chemotherapy+trastuzumab (CT), chemotherapy+pertuzumab (CP), trastuzumab+pertuzumab (TP), chemotherapy+trastuzumab+lapatinib (CTL), and chemotherapy+lapatinib (CL), and chemotherapy (C) alone. We found that, for the chance of achieving pCR, CTP was ranked first (SUCRA: 97%), followed by CTL, MP, and CT (SUCRA: 80%, 75%, and 55%, resp.). MP provided the safest regimen (SUCRA: 97%), then TP, C, and TPC (SUCRA: 82%, 76%, and 47%, resp.). CTL proved the most toxic therapy (SUCRA: 7%). No significant difference between neoadjuvant regimens was identified for BCS. Hormone receptor status did not impact ORs for pCR in any regimen. In conclusion, our findings support CTP as the optimum neoadjuvant regimen for HER2-positive breast cancer, with the best pCR and acceptable toxicity compared with CT. MP provides a therapeutic option for patients with poor performance status.

Circulating Tumor DNA in HER2-Amplified Breast Cancer: A Translational Research Substudy of the NeoALTTO Phase III Trial

PURPOSE

In the neoadjuvant treatment (NAT) setting, dual HER2-targeted therapy is associated with increased pathologic complete response (pCR) rates compared with each therapy alone. Biomarkers allowing to predict treatment response during NAT are needed. We aim to evaluate whether circulating tumor DNA (ctDNA) is associated with response to anti-HER2-targeted therapy.

EXPERIMENTAL DESIGN

Plasma DNA collected before NAT, at week 2, and before surgery from patients enrolled in the NeoALTTO trial was assessed using digital PCR for PIK3CA and TP53 mutation detection.

RESULTS

A total of 69 of 455 (15.2%) patients had a PIK3CA and/or TP53 mutation detected in the baseline tumor sample and evaluable ctDNA results from baseline samples. CtDNA was detected in 41%, 20%, and 5% patients before NAT, at week 2, and before surgery, respectively. ctDNA detection before NAT was significantly associated with older age and ER-negative status. ctDNA detection before NAT was associated with decreased odds of achieving pCR (OR = 0.15; 95% CI, 0.034-0.7; P = 0.0089), but not with event-free survival (EFS). Analyses for EFS were underpowered. Interestingly, the patients with HER2-enriched subtype tumors and undetectable ctDNA at baseline had the highest pCR rates. In contrast, patients with persistent ctDNA detection at baseline and week 2 had the lowest rate of pCR.

CONCLUSIONS

ctDNA detection before neoadjuvant anti-HER2 therapies is associated with decreased pCR rates. Interestingly, patients with HER2-enriched tumors and undetectable ctDNA at baseline had the highest pCR rates, therefore appearing as the best candidates for treatment deescalation strategies.

Plasma miRNA Levels for Predicting Therapeutic Response to Neoadjuvant Treatment in HER2-positive Breast Cancer: Results from the NeoALTTO Trial

PURPOSE

To investigate the potential of circulating-miRNAs (ct-miRNA) as noninvasive biomarkers to predict the efficacy of single/dual HER2-targeted therapy in the NeoALTTO study.

EXPERIMENTAL DESIGN

Patients with plasma samples at baseline (T0) and/or after 2 weeks (T1) of treatment were randomized into training (n = 183) and testing (n = 246) sets. RT-PCR-based high-throughput miRNA profiling was employed in the training set. After normalization, ct-miRNAs associated with pathologic complete response (pCR) were identified by univariate analysis. Multivariate logistic regression models were implemented to generate treatment-specific signatures at T0 and T1, which were evaluated by RT-PCR in the testing set. Event-free survival (EFS) according to ct-miRNA signatures was estimated by Kaplan-Meier method and Cox regression model.

RESULTS

In the training set, starting from 51 ct-miRNAs associated with pCR, six signatures with statistically significant predictive capability in terms of area under the ROC curve (AUC) were identified. Four signatures were confirmed in the testing set: lapatinib at T0 and T1 [AUC 0.86; 95% confidence interval (CI), 0.73-0.98 and 0.71 (0.55-0.86)], respectively; trastuzumab at T1 (0.81; 0.70-0.92); lapatinib + trastuzumab at T1 (0.67; 0.51-0.83). These signatures were confirmed predictive after adjusting for known variables, including estrogen receptor status. ct-miRNA signatures failed to correlate with EFS. However, the levels of ct-miR-140-5p, included in the trastuzumab signature, were associated with EFS (HR 0.43; 95% CI, 0.22-0.84).

CONCLUSIONS

ct-miRNAs discriminate patients with and without pCR after neoadjuvant lapatinib- and/or trastuzumab-based therapy. ct-miRNAs at week two could be valuable to identify patients responsive to trastuzumab, to avoid unnecessary combination with other anti-HER2 agents, and finally to assist deescalating treatment strategies.

Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer

BACKGROUND

Patients who have residual invasive breast cancer after receiving neoadjuvant chemotherapy plus human epidermal growth factor receptor 2 (HER2)-targeted therapy have a worse prognosis than those who have no residual cancer. Trastuzumab emtansine (T-DM1), an antibody-drug conjugate of trastuzumab and the cytotoxic agent emtansine (DM1), a maytansine derivative and microtubule inhibitor, provides benefit in patients with metastatic breast cancer that was previously treated with chemotherapy plus HER2-targeted therapy.

METHODS

We conducted a phase 3, open-label trial involving patients with HER2-positive early breast cancer who were found to have residual invasive disease in the breast or axilla at surgery after receiving neoadjuvant therapy containing a taxane (with or without anthracycline) and trastuzumab. Patients were randomly assigned to receive adjuvant T-DM1 or trastuzumab for 14 cycles. The primary end point was invasive disease-free survival (defined as freedom from ipsilateral invasive breast tumor recurrence, ipsilateral locoregional invasive breast cancer recurrence, contralateral invasive breast cancer, distant recurrence, or death from any cause).

RESULTS

At the interim analysis, among 1486 randomly assigned patients (743 in the T-DM1 group and 743 in the trastuzumab group), invasive disease or death had occurred in 91 patients in the T-DM1 group (12.2%) and 165 patients in the trastuzumab group (22.2%). The estimated percentage of patients who were free of invasive disease at 3 years was 88.3% in the T-DM1 group and 77.0% in the trastuzumab group. Invasive disease-free survival was significantly higher in the T-DM1 group than in the trastuzumab group (hazard ratio for invasive disease or death, 0.50; 95% confidence interval, 0.39 to 0.64; P<0.001). Distant recurrence as the first invasive-disease event occurred in 10.5% of patients in the T-DM1 group and 15.9% of those in the trastuzumab group. The safety data were consistent with the known safety profile of T-DM1, with more adverse events associated with T-DM1 than with trastuzumab alone.

CONCLUSIONS

Among patients with HER2-positive early breast cancer who had residual invasive disease after completion of neoadjuvant therapy, the risk of recurrence of invasive breast cancer or death was 50% lower with adjuvant T-DM1 than with trastuzumab alone. (Funded by F. Hoffmann-La Roche/Genentech; KATHERINE ClinicalTrials.gov number, NCT01772472 .).

Comparison of tumor‑targeting properties of directly and indirectly radioiodinated designed ankyrin repeat protein (DARPin) G3 variants for molecular imaging of HER2

Evaluation of human epidermal growth factor receptor 2 (HER2) expression levels in breast and gastroesophageal cancer is used for the stratification of patients for HER2‑targeting therapies. The use of radionuclide molecular imaging may facilitate such evaluation in a non‑invasive way. Designed ankyrin repeat proteins (DARPins) are engineered scaffold proteins with high potential as probes for radionuclide molecular imaging. DARPin G3 binds with high affinity to HER2 and may be used to visualize this important therapeutic target. Studies on other engineered scaffold proteins have demonstrated that selection of the optimal labeling approach improves the sensitivity and specificity of radionuclide imaging. The present study compared two methods of labeling G3, direct and indirect radioiodination, to select an approach providing the best imaging contrast. G3‑H6 was labeled with iodine‑124, iodine‑125 and iodine‑131 using a direct method. A novel construct bearing a C‑terminal cysteine, G3‑GGGC, was site‑specifically labeled using [125I]I‑iodo‑[(4‑hydroxyphenyl)ethyl]maleimide (HPEM). The two radiolabeled G3 variants preserved binding specificity and high affinity to HER2‑expressing cells. The specificity of tumor targeting in vivo was demonstrated. Biodistribution comparison of [131I]I‑G3‑H6 and [125I]I‑HPEM‑G3‑GGGC in mice, bearing HER2‑expressing SKOV3 xenografts, demonstrated an appreciable contribution of hepatobiliary excretion to the clearance of [125I]I‑HPEM‑G3‑GGGC and a decreased tumor uptake compared to [131I]I‑G3‑H6. The direct label provided higher tumor‑to‑blood and tumor‑to‑organ ratios compared with the indirect label at 4 h post‑injection. The feasibility of high contrast PET/CT imaging of HER2 expression in SKOV3 xenografts in mice using [124I]I‑G3‑H6 was demonstrated. In conclusion, direct radioiodination is the preferable approach for labeling DARPin G3 with iodine‑123 and iodine‑124 for clinical single photon emission computed tomography and positron emission tomography imaging.

HER2-Targeted Tyrosine Kinase Inhibitors Cause Therapy-Induced-Senescence in Breast Cancer Cells

Prolonged treatment of HER2 positive breast cancer cells with tyrosine kinase inhibitors (TKIs) leads to the emergence of acquired resistance. However, the effects of continuous TKI exposure on cell fate, and the steps leading to the acquisition of a resistant phenotype are poorly understood. To explore this, we exposed five HER2 positive cells lines to HER2 targeted therapies for periods of up to 4 weeks and examined senescence associated β-galactosidase (SA-β-gal) activity together with additional markers of senescence. We found that lapatinib treatment resulted in phenotypic alterations consistent with a senescent phenotype and strong SA-β-gal activity in HER2-positive cell lines. Lapatinib-induced senescence was associated with elevated levels of p15 and p27 but was not dependent on the expression of p16 or p21. Restoring wild type p53 activity either by transfection or by treatment with APR-246, a molecule which reactivates mutant p53, blocked lapatinib-induced senescence and caused increased cell death. In contrast to lapatinib, SA-β-gal activity was not induced by exposing the cells to trastuzumab as a single agent but co-administration of lapatinib and trastuzumab induced senescence, as did treatment of the cells with the irreversible HER2 TKIs neratinib and afatinib. Neratinib- and afatinib-induced senescence was not reversed by removing the drug whereas lapatinib-induced senescence was reversible. In summary, therapy-induced senescence represents a novel mechanism of action of HER2 targeting agents and may be a potential pathway for the emergence of resistance.

The role of the phosphatase and tensin homolog status in predicting pathological complete response to neoadjuvant anti-HER2 therapies in HER2-positive primary breast cancer: A meta-analysis

PURPOSE

The addition of anti-HER2 therapies to neoadjuvant treatment significantly enhances pathological complete response (PCR) rate in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Selecting patients unlikely to benefit from neoadjuvant anti-HER2 therapies is increasingly important. In this study, we proposed to assess the role of the phosphatase and tensin homolog (PTEN) as a biomarker in predicting PCR to neoadjuvant anti-HER2 therapies by conducting meta-analysis.

METHODS

Our team searched Embase, Medline, and the Cochrane Library by the end of September 16, 2018, for trials on patients with HER2-positive breast cancer treated with neoadjuvant anti-HER2 therapies. The associations between PTEN expression and PCR rate were then assessed. Odds ratio (ORs) and hazard ratio (HRs) with 95% confidence intervals (CIs) with 2-sided P values were calculated. The Newcastle-Ottawa scale (NOS) was used to estimate the quality of the involved trials.

RESULTS

A total of 820 patients from 8 trials were included in this meta-analysis. Overall, the PTEN normal tumors was related to a significant increase in PCR rate (OR 0.55; 95% CI = 0.31-0.96; P = .04; I = 54%). In different anti-HER2 agents analysis, the PTEN normal tumors was related to a significant increase in PCR rate in patients treated with trastuzumab alone (OR 0.40; 95% CI = 0.24-0.67; P = .0005; I = 15%). Besides, no significant association between PTEN status and PCR rate was detected in patients treated with lapatinib alone (OR 1.90; 95% CI = 0.78-4.60; P = .16; I = 0%) or trastuzumab plus lapatinib (OR 1.27; 95% CI = 0.27-5.97; P = .76; I = 73%).

CONCLUSION

Based on current evidence, PTEN status could be n suitable biomarker in predicting PCR rate to neoadjuvant anti-HER2 therapies, especially in trastuzumab-treated patients.

Th1 cytokines sensitize HER-expressing breast cancer cells to lapatinib

The HER family of receptor tyrosine kinases has been linked to deregulation of growth and proliferation for multiple types of cancer. Members have therefore become thefocus of many drug and immune-based therapy innovations. The targeted anti-cancer agent, lapatinib, is a small molecule inhibitor that directly interferes with EGFR (HER-1)and HER-2 signaling, and indirectly reduces HER-3 signaling, thus suppressing important downstream events. A recently-developed dendritic cell-based vaccine against early breast cancer (ductal carcinoma in situ; DCIS) that generates strong Th1-dominated immunity against HER-2 has induced pathologic complete response in about one-third of immunized individuals. In vitro studies suggested cytokines secreted by Th1 cells could be major contributors to the vaccine effects including induction of apoptosis and suppression of HER expression. With a view toward improving complete response rates, we investigated whether the principle Th1 cytokines (IFN-γ and TNF-α) could act in concert with lapatinib to suppress activity of breast cancer lines in vitro. Lapatinib-sensitive SKBR3, MDA-MB-468 and BT474 cells were incubated with Th1 cytokines, lapatinib, or both. It was found that combined treatment maximized metabolic suppression(Alamar Blue assay), as well as cell death (Trypan Blue) and apoptosis(Annexin V/Propidium Iodide and TMRE staining). Combined drug plus cytokine treatment also maximized suppression of both total and phosphorylated forms of HER-2 and HER-3. Interestingly, when lapatinib resistant lines MDA-MB-453 and JIMT-1 were tested, it was found that the presence of Th1 cytokines appeared to enhance sensitivity for lapatinib-induced metabolic suppression and induction of apoptotic cell death, nearly abrogating drug resistance. These studies provide pre-clinical data suggesting the possibility that targeted drug therapy may be combined with vaccination to enhance anti-cancer effects, and furthermore that robust immunity in the form of secreted Th1 cytokines may have the capacity to mitigate resistance to targeted drugs.

A brief report of toxicity end points of HER2 vaccines for the treatment of patients with HER2+ breast cancer

Human epidermal growth factor receptor 2 (HER2)-targeted vaccines are under development, but have so far demonstrated only modest clinical efficacy. Additionally, there has been a lack of adequate safety assessment in large-scale prospective clinical trials. Therefore, we performed a meta-analysis of available clinical trial data to summarize the toxicity profiles of these treatments. Literature search was conducted in February 2018. The trials analyzed had at least one study arm consisting of HER2 vaccine monotherapy. Heterogeneity across studies was analyzed using I² statistics. Data were analyzed using random-effects meta-analysis for absolute risk (AR). Eight trials and 248 patients were included. There was no evidence of heterogeneity between studies for grades 3/4 adverse events (AEs) or for death. The AR for treatment-related serious AEs was 5% with no treatment-related deaths. The AR of all-grade fatigue, injection site reaction, and fever/chills/rigors was 33%, 23%, and 31%, respectively. Asymptomatic drop in left ventricle ejection fraction was rare (8%). HER2 vaccines are well tolerated with increased AR of fatigue, injection site reactions, and fever/chills/rigors.

Assessment of HER2 Expression in Canine Urothelial Carcinoma of the Urinary Bladder

Canine urothelial carcinoma (UC) has a poor prognosis and high metastatic rate. Human epidermal growth factor receptor 2 (HER2), a receptor tyrosine kinase involved in cell proliferation and differentiation regulation, has been attracting interest as a therapeutic target molecule for human breast cancer. This study investigated expression of the canine homolog of HER2 (ERBB2) in canine UC, and its association with clinical factors. Since it has been controversial whether commercial anti-human HER2 antibody (Dako A0485) correctly recognizes the canine homolog of HER2, an application of the antibody using a canine UC cell line was validated first. By Western blot, a single band at the appropriate size for canine HER2 (185 kDa) was recognized. Immunohistochemistry for HER2 was performed on 23 samples of UC, 8 samples of polypoid cystitis, and 8 samples of normal urinary bladder, and the results were scored as either 0, 1+, 2+, or 3+ with reference to the evaluation method for human UC. Intense membranous HER2 immunoreactivity was frequently observed in neoplastic cells, especially in grade 2 UC. Minor HER2 expression was found in the epithelial cells of polypoid cystitis and normal bladder. The incidence of HER2 positivity (scores of 2+ or 3+) was 14 of 23 (60.9%) in UC, 3 of 8 (37.5%) in polypoid cystitis, and 0 of 8 (0%) in normal bladder. There was no significant correlation between HER2 positivity and clinical factors. While increased HER2 expression was observed in a subset of urothelial carcinomas, further mechanistic studies are needed to determine its role in the pathogenesis and targeted therapy of this cancer.

Targeted neoadjuvant therapy in the HER-2-positive breast cancer patients: a systematic review and meta-analysis

Aim

To evaluate efficacy and safety of lapatinib or trastuzumab alone or both plus chemotherapy for the treatment of breast cancer patients with positive HER-2 expression.

Methods

Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, OVID, Embase, Chinese Biomedical Literature Database, and China Academic Journals Database were searched from 1994 through December 2017 using the keywords "breast cancer", "preoperative", "neo-adjuvant", "lapatinib", "pertuzumab", "Herceptin", and "trastuzumab".

Results

Meta-analysis found that pathological complete response (PCR; risk ratio [RR]=0.82, 95% CI: 0.72-0.93) and tall PCR (tPCR; RR=0.77, 95% CI: 0.67-0.88) of chemotherapy plus lapatinib were significantly less effective or safe compared to that of chemotherapy plus trastuzumab (P<0.05). PCR (RR=1.30, 95% CI: 1.15-1.47) and tPCR (RR=1.32, 95% CI: 1.16-1.50) of chemotherapy plus both lapatinib and trastuzumab were significantly superior to that of chemotherapy plus trastuzumab alone (P<0.05). However, there was no significant difference in breast reservation rate between chemotherapy plus lapatinib vs chemotherapy plus trastuzumab (RR=0.91, 95% CI: 0.72-1.16) or chemotherapy plus both lapatinib and trastuzumab (RR=1.11, 95% CI: 0.73-1.68, P>0.05). Incidence of diarrhea, hepatic toxicity, and skin rash in the groups of chemotherapy plus lapatinib or chemotherapy plus both lapatinib and trastuzumab was significantly higher than that in chemotherapy plus trastuzumab (P<0.05).

Conclusion

Efficacy of lapatinib was less than that of trastuzumab, but incidence of adverse effect of lapatinib was higher than that of trastuzumab. Combination of chemotherapy plus both lapatinib and trastuzumab could significantly increase PCR and tPCR in breast cancer patients, but rate of breast conservation, event-free survival, and overall survival was not significantly improved. Incidence of diarrhea, hepatic toxicity, and skin rash was significantly increased in the groups using lapatinib.

Risk Factors Associated with Trastuzumab-induced Cardiotoxicity in Patients with Human Epidermal Growth Factor Receptor 2-positive Breast Cancer

Context:

Although trastuzumab is a highly effective and selective targeted therapy for human epidermal growth factor receptor 2 (HER2)-positive breast cancer, the drug-induced cardiotoxicity may confine its usefulness in patients.

Aim:

To explore risk factors associated with the development of cardiotoxicity in patients with HER2-positive breast cancer.

Settings and Design:

A retrospective review of medical records and chart review for all patients with breast cancer treated with trastuzumab was conducted at King Abdulaziz Medical City and King Abdullah Specialized Children Hospital in Riyadh, Kingdom of Saudi Arabia, between October 2015 and February 2018. Patients with declined left ventricular ejection fraction, either with or without cardiac symptoms, were recognized as those with cardiotoxicity due to trastuzumab administration.

Results:

A total of 146 patients were included in the study with an average age of 52.7 (standard deviation = 12.2) years. Thirty-two (21.9%) patients developed cardiotoxicity. However, only 24 (16.4%) were symptomatic with an apparent heart failure but it did not necessitate interruption of trastuzumab therapy. The majority of patients had prior underlying cardiovascular diseases. This study identified unilateral tumor site (62.5%), breast surgery (37.5%), and concomitant taxane chemotherapy (62.5%) as the main risk factors associated with significant increase in cardiotoxicity in patients with breast cancer (with P values of 0.0269, 0.0482, and 0.0225, respectively).

Conclusion:

The majority of patients (more than 90%) developed cardiotoxicity after completion of chemotherapy. However, recruiting a larger sample size should be warranted to confirm or negate these findings.