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

Tumor-Infiltrating Lymphocytes and Associations With Pathological Complete Response and Event-Free Survival in HER2-Positive Early-Stage Breast Cancer Treated With Lapatinib and Trastuzumab: A Secondary Analysis of the NeoALTTO Trial

IMPORTANCE

The presence of tumor-infiltrating lymphocytes (TILs) is associated with improved outcomes in human epidermal growth factor receptor 2 (HER2)-positive early breast cancer treated with adjuvant trastuzumab and chemotherapy. The prognostic associations in the neoadjuvant setting of other anti-HER2 agents and combinations are unknown.

OBJECTIVE

To determine associations between presence of TILs, pathological complete response (pCR), and event-free survival (EFS) end points in patients with early breast cancer treated with trastuzumab, lapatinib, or the combination.

DESIGN, SETTING, AND PARTICIPANTS

The NeoALTTO trial (Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization) randomly assigned 455 women with HER2-positive early-stage breast cancer between January 5, 2008, and May 27, 2010, to 1 of 3 neoadjuvant treatment arms: trastuzumab, lapatinib, or the combination for 6 weeks followed by the addition of weekly paclitaxel for 12 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide after surgery. The primary end point used in this study was pCR in the breast and lymph nodes, with a secondary end point of EFS. We evaluated levels of percentage of TILs using hematoxylin-eosin-stained core biopsy sections taken at diagnosis (prior to treatment) in a prospectively defined retrospective analysis.

MAIN OUTCOMES AND MEASURES

Levels of TILs were examined for their associations with efficacy end points adjusted for prognostic clinicopathological factors including PIK3CA genotype.

RESULTS

Of the 455 patients, 387 (85.1%) tumor samples were used for the present analysis. The median (interquartile range [IQR]) level of TILs was 12.5% (5.0%-30.0%), with levels lower in hormone receptor-positive (10.0% [5.0%-22.5%]) vs hormone receptor-negative (12.5% [3.0%-35.0%]) samples (P = .02). For the pCR end point, levels of TILs greater than 5% were associated with higher pCR rates independent of treatment group (adjusted odds ratio, 2.60 [95% CI, 1.26-5.39]; P = .01). With a median (IQR) follow-up time of 3.77 (3.50-4.22) years, every 1% increase in TILs was associated with a 3% decrease in the rate of an event (adjusted hazard ratio, 0.97 [95% CI, 0.95-0.99]; P = .002) across all treatment groups.

CONCLUSIONS AND RELEVANCE

The presence of TILs at diagnosis is an independent, positive, prognostic marker in HER2-positive early breast cancer treated with neoadjuvant anti-HER2 agents and chemotherapy for both pCR and EFS end points.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00553358.

Hormone Receptor/Human Epidermal Growth Factor Receptor 2-positive breast cancer: Where we are now and where we are going

Near 75% of all breast cancers (BC) express estrogen receptors (ER) and/or progesterone receptors (PgR), while up to 20% of BC show an overexpression/amplification of Human Epidermal Growth Factor Receptor 2 (HER2). Around 50% of all HER2-overexpressing BC show the coexistence of both HER2 overexpression/amplification and ER and/or PgR overexpression. Numerous in vitro and in vivo studies suggest the existence of a cross-talk between their downstream pathways, which seem to affect the natural history, response to therapy and outcome of patients affected by this subset of BC. Meta-analyses or subgroup analysis of numerous neo-/adjuvant trials demonstrated significant clinical implications deriving from ER/HER2 co-existence, consisting in a different pattern of relapse and dissimilar outcome in response to anti-HER2 therapy. However, only two randomized trials in early disease and three in advanced disease specifically addressed the issue whether a combined approach with both hormonal and anti-HER2 therapy would have a better therapeutic impact in this subset of BC compared to the lone anti-HER2 or hormonal therapies (HT). None of these trials demonstrated improvements in overall survival, even though several efficacy end-points such as progression free survival, in advanced setting, or pCR rates in neoadjuvant setting, often favored the combined hormonal and anti-HER2 therapeutic approach. In the next few years, a certain number of ongoing randomized trials, both in neoadjuvant and advanced setting, will evaluate the efficacy of new anti-HER2 drugs, T-DM1 and pertuzumab, in combination with HT, helping to improve the therapeutic strategy for this specific subtype of breast tumors.

Mechanisms Behind the Resistance to Trastuzumab in HER2-Amplified Breast Cancer and Strategies to Overcome It

The introduction of trastuzumab therapy markedly improved the poor prognosis associated with HER2-amplified breast cancers. Despite this, the presence of primary and acquired resistance to trastuzumab treatment remains a significant common challenge. The identification of resistance mechanisms and the incorporation of new drugs that achieve a better blockade of HER family receptors signaling have resulted in improved outcomes. The phosphatidylinositol 3′-kinase/protein kinase B/mammalian target of rapamycin pathway, cross-talk with estrogen receptors, immune response, cell cycle control mechanisms, and other tyrosine kinase receptors such as insulin-like growth factor I receptor are potential pathways involved in trastuzumab resistance. Different therapeutic interventions targeting these pathways are currently under evaluation.

Translating neoadjuvant therapy into survival benefits: one size does not fit all

Neoadjuvant therapy has been established as an effective therapeutic approach for patients with locally advanced breast cancer. Similar outcomes between neoadjuvant and adjuvant chemotherapy have been demonstrated in several trials. Nevertheless, neoadjuvant therapy has some advantages over adjuvant therapy, including tumour downstaging, in vivo assessment of therapeutic efficacy, reduced treatment durations, and the need to enrol fewer patients for clinical trials to reach their preplanned objectives. The number of neoadjuvant trials in patients with breast cancer has increased substantially in the past 5 years, particularly in the context of HER2-positive disease. Substantial improvements in the pathological complete response rate to anti-HER2 therapy, a proposed surrogate end point for long-term clinical benefit, have been observed with neoadjuvant dual-agent HER2 blockade. Thus, it was hypothesized that this approach would provide additional survival benefits over standard-of-care therapy with the anti-HER2 antibody trastuzumab in the adjuvant setting. Emerging data, however, are calling this notion into question. We discuss potential reasons why results of neoadjuvant trials of targeted therapies have not been mirrored in the adjuvant setting, and other than inherent differences in clinical-trial designs and statistical power, we consider how the biology of the disease, patient characteristics, and drug administration and schedule might influence the results.

Risk of Gastrointestinal Events During Lapatinib Therapy: A Meta-Analysis From 12,402 Patients With Cancer

Lapatinib, a tyrosine kinase inhibitor used as an anticancer therapeutic agent, has adverse events associated with treatment resulting in noncompliance and withdrawal from the therapy. Here, we performed meta-analysis of published clinical trials to determine relative risk (RR) and incidence of gastrointestinal events during lapatinib therapy in patients with cancer. A comprehensive literature search was performed and summary incidence, RR, and 95% confidence intervals (CI) were calculated using fixed-effects or random-effects models, depending on the heterogeneity of trials. Thirty-six trials with 12,402 patients were included; summary incidences of all-grade gastrointestinal events in patients with cancer were diarrhea 57.8%, nausea 30.8%, and vomiting 19.6%. Lapatinib combination with chemotherapy or any anti-HER2 mAbs were associated with significant risk of all-grade diarrhea [(RR 3.64, 95% CI, 2.96-4.49), (RR 2.89, 95% CI, 2.21-3.79), respectively] and high-grade diarrhea [(RR 11.25, 95% CI, 7.31-17.33), (RR 9.96, 95% CI, 7.23-13.72), respectively], and lapatinib combination with chemotherapy group showed a significantly increased risk of all-grade nausea (RR 1.54, 95% CI, 1.25-1.89). Lapatinib combination with chemotherapy or any anti-HER2 mAbs were associated with significant risk of all-grade vomiting [(RR 1.47, 95% CI, 1.12-1.93), (RR 1.30, 95% CI, 1.11-1.52), respectively]. Lapatinib combination with any anti-HER2 mAbs was associated with a significant risk of high-grade vomiting (RR 2.25, 95% CI, 1.41-3.61). This study revealed a significantly increased risk of diarrhea, nausea, and vomiting in patients with cancer receiving lapatinib, suggesting that appropriate clinical intervention and gastrointestianal protective agents should be emphasized.

Cardiovascular Toxicity and Management of Targeted Cancer Therapy

The advent of effective oral, molecular-targeted drugs in oncology has changed many incurable malignancies such as chronic myeloid leukemia into chronic diseases similar to coronary artery disease and diabetes mellitus. Oral agents including monoclonal antibodies, kinase inhibitors and hormone receptor blockers offer patients with cancer incremental improvements in both overall survival and quality of life. As it is imperative to recognize and manage side effects of platelet inhibitors, beta blockers, statins, human immunodeficiency virus drugs and fluoroquinolones by all healthcare providers, the same holds true for these newer targeted therapies; patients may present to their generalist or other subspecialist with drug-related symptoms. Cardiovascular adverse events are among the most frequent, and potentially serious, health issues in outpatient clinics, and among the most frequent side effects of targeted chemotherapy. Data support improved patient outcomes and satisfaction when primary care and other providers are cognizant of chemotherapy side effects, allowing for earlier intervention and reduction in morbidity and healthcare costs. With the implementation of accountable care and pay for performance, improved communication between generalists and subspecialists is essential to deliver cost-effective patient care.

Emerging drugs targeting human epidermal growth factor receptor 2 (HER2) in the treatment of breast cancer

INTRODUCTION

Human epidermal growth factor 2 (HER2) overexpression is present in 20% of breast cancer patients. It is associated with more aggressive disease and worse clinical outcome. New drugs are thus needed. Approved and future treatments will be discussed in this review.

AREAS COVERED

The monoclonal antibodies trastuzumab and pertuzumab, the tyrosine kinase inhibitor lapatinib and the antibody-drug conjugate trastuzmab emtansine are approved for HER2 positive breast cancer. The combination of trastuzumab, pertuzumab and docetaxel is currently the first-line treatment in the metastatic setting. New therapies are still needed due to frequent relapse and resistance. These include mammalian target of rapamycin inhibitors, heat shock protein 90 inhibitors, pan-HER2 tyrosine kinase inhibitors, antibody-drug conjugates, immunotherapy agents (antibodies and vaccines), radioimmunotherapy and HER2 specific affinity proteins. Possible developmental issues are the complexity of the molecular biology of the HER2 positive cancer cell, the occurrence of resistance, toxicity and the high cost.

EXPERT OPINION

The determination of the right sequence of use of old and new therapies remains a challenging issue. The selection of patients who do or don't benefit from potentially toxic chemotherapy is also difficult. Central nervous system metastases are a common problem in HER2 positive breast cancer that needs to be addressed in future trials.

Neoadjuvant therapy for breast cancer: controversies in clinical trial design and standard of care

Neoadjuvant therapy for breast cancer has been increasingly used in recent years as first-line treatment for operable breast cancer-serving as both a management strategy and a research tool. In addition to the established clinical benefits of down-staging more locally advanced cancers and improving breast-conservation rates, investigators have recognized the potential advantages of this approach in developing new therapies. Preoperative systemic therapy provides the opportunity for in vivo assessment of pharmacodynamic markers to assess biologic effects and allows new compounds to be tested in a more responsive, treatment-naive population. In addition, early surrogates of response, such as pathologic complete response (pCR) and residual cancer burden, provide proximate measures that correlate with long-term outcomes, thus potentially shortening the time needed to identify effective adjuvant therapies. Despite the advantages of neoadjuvant therapy for research and clinical practice, its use is characterized by persistent controversy and healthy debate regarding how to optimally use research findings and when to integrate them into the standard of care for daily management. Among the controversies surrounding neoadjuvant therapy use are questions about defining the best endpoint for assessing treatment efficacy, deciding when results from research should be used in daily clinical practice, and how the growing use of neoadjuvant therapy affects locoregional treatments.

Does primary neoadjuvant systemic therapy eradicate minimal residual disease? Analysis of disseminated and circulating tumor cells before and after therapy

BACKGROUND

Patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT) may experience metastatic relapse despite achieving a pathologic complete response. We analyzed patients with BC before and after NACT for disseminated tumor cells (DTCs) in the bone marrow(BM); comprehensively characterized circulating tumor cells (CTCs), including stem cell-like CTCs (slCTCs), in blood to prove the effectiveness of treatment on these cells; and correlated these findings with response to therapy, progression-free survival (PFS), and overall survival (OS).

METHODS

CTCs (n = 135) and slCTCs (n = 91) before and after NACT were analyzed using the AdnaTest BreastCancer, AdnaTest TumorStemCell, and epithelial-mesenchymal transition (QIAGEN Hannover GmbH Germany). The expression of estrogen receptor, progesterone receptor, and the resistance marker excision repair cross-complementing rodent repair deficiency, complementation group 1 (ERCC1), nuclease were studied in separate single-plex reverse transcription polymerase chain reaction experiments. DTCs were evaluated in 142 patients before and 165 patients after NACT using the pan-cytokeratin antibody A45-B/B3 for immunocytochemistry.

RESULTS

The positivity rates for DTCs, CTCs, and slCTCs were 27 %, 24 %, and 51 % before and 20 %, 8 %, and 20 % after NACT, respectively. Interestingly, 72 % of CTCs present after therapy were positive for ERCC1, and CTCs before (p = 0.005) and after NACT (p = 0.05) were significantly associated with the presence of slCTCs. Whereas no significant associations with clinical parameters were found for CTCs and slCTCs, DTCs were significantly associated with nodal status (p = 0.03) and histology (0.046) before NACT and with the immunohistochemical subtype (p = 0.02) after NACT. Univariable Cox regression analysis revealed that age (p = 0.0065), tumor size before NACT (p = 0.0473), nodal status after NACT (p = 0.0137), and response to NACT (p = 0.0136) were significantly correlated with PFS, whereas age (p = 0.0162) and nodal status after NACT (p = 0.0243) were significantly associated with OS. No significant correlations were found for DTCs or any CTCs before and after therapy with regard to PFS and OS.

CONCLUSIONS

Although CTCs were eradicated more effectively than DTCs, CTCs detected after treatment seemed to be associated with tumor cells showing tumor stem cell characteristics as well as with resistant tumor cell populations that might indicate a worse outcome in the future. Thus, these patients might benefit from additional second-line treatment protocols including bisphosphonates for the eradication of DTCs.

Neratinib after trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer (ExteNET): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Neratinib, an irreversible tyrosine-kinase inhibitor of HER1, HER2, and HER4, has clinical activity in patients with HER2-positive metastatic breast cancer. We aimed to investigate the efficacy and safety of 12 months of neratinib after trastuzumab-based adjuvant therapy in patients with early-stage HER2-positive breast cancer.

METHODS

We did this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 495 centres in Europe, Asia, Australia, New Zealand, and North and South America. Eligible women (aged ≥18 years, or ≥20 years in Japan) had stage 1-3 HER2-positive breast cancer and had completed neoadjuvant and adjuvant trastuzumab therapy up to 2 years before randomisation. Inclusion criteria were amended on Feb 25, 2010, to include patients with stage 2-3 HER2-positive breast cancer who had completed trastuzumab therapy up to 1 year previously. Patients were randomly assigned (1:1) to receive oral neratinib 240 mg per day or matching placebo. The randomisation sequence was generated with permuted blocks stratified by hormone receptor status (hormone receptor-positive [oestrogen or progesterone receptor-positive or both] vs hormone receptor-negative [oestrogen and progesterone receptor-negative]), nodal status (0, 1-3, or ≥4), and trastuzumab adjuvant regimen (sequentially vs concurrently with chemotherapy), then implemented centrally via an interactive voice and web-response system. Patients, investigators, and trial sponsors were masked to treatment allocation. The primary outcome was invasive disease-free survival, as defined in the original protocol, at 2 years after randomisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00878709.

FINDINGS

Between July 9, 2009, and Oct 24, 2011, we randomly assigned 2840 women to receive neratinib (n=1420) or placebo (n=1420). Median follow-up time was 24 months (IQR 20-25) in the neratinib group and 24 months (22-25) in the placebo group. At 2 year follow-up, 70 invasive disease-free survival events had occurred in patients in the neratinib group versus 109 events in those in the placebo group (stratified hazard ratio 0·67, 95% CI 0·50-0·91; p=0·0091). The 2-year invasive disease-free survival rate was 93·9% (95% CI 92·4-95·2) in the neratinib group and 91·6% (90·0-93·0) in the placebo group. The most common grade 3-4 adverse events in patients in the neratinib group were diarrhoea (grade 3, n=561 [40%] and grade 4, n=1 [<1%] vs grade 3, n=23 [2%] in the placebo group), vomiting (grade 3, n=47 [3%] vs n=5 [<1%]), and nausea (grade 3, n=26 [2%] vs n=2 [<1%]). QT prolongation occurred in 49 (3%) patients given neratinib and 93 (7%) patients given placebo, and decreases in left ventricular ejection fraction (≥grade 2) in 19 (1%) and 15 (1%) patients, respectively. We recorded serious adverse events in 103 (7%) patients in the neratinib group and 85 (6%) patients in the placebo group. Seven (<1%) deaths (four patients in the neratinib group and three patients in the placebo group) unrelated to disease progression occurred after study drug discontinuation. The causes of death in the neratinib group were unknown (n=2), a second primary brain tumour (n=1), and acute myeloid leukaemia (n=1), and in the placebo group were a brain haemorrhage (n=1), myocardial infarction (n=1), and gastric cancer (n=1). None of the deaths were attributed to study treatment in either group.

INTERPRETATION

Neratinib for 12 months significantly improved 2-year invasive disease-free survival when given after chemotherapy and trastuzumab-based adjuvant therapy to women with HER2-positive breast cancer. Longer follow-up is needed to ensure that the improvement in breast cancer outcome is maintained.

FUNDING

Wyeth, Pfizer, Puma Biotechnology.

Cardiac safety of simultaneous anti-HER2 and anthracycline therapy

A long established oncological dogma requires that trastuzumab should not be given in combination with anthracyclines due to excessive synergistic cardiac morbidity. However, trastuzumab has been recently granted a license in the neoadjuvant setting with concurrent anthracylines. We discuss the role of anti-HER2 agents in breast cancer and their associated toxicities. Anthracycline chemotherapies are a central component of most adjuvant and neoadjuvant breast cancer regimens. Cardiac toxicity due to anthracyclines is explored. Finally, in this article, we will discuss the evidence for concurrent administration of anthracyclines and HER2-targeted agents.

Resistance to Targeted Therapies in Breast Cancer

Seventy five percent of all breast cancer (BC) patients express estrogen receptor (ER) but a quarter to half of patients with ER positive BC relapse on ET (endocrine therapy), tamoxifen, aromatase inhibitors (AIs), surgical castration, amongst other treatment strategies. ER positive BC at relapse loses ER expression in 20 % of cases and reduces quantitative ER expression most of the time. ER is not the only survival pathway driving ER positive BC and escape pathways intrinsic or acquired are activated during ET. This overview gives an account of ligand-independent ER activation, namely by receptor networks cross talk, and by the various genomic factors and mechanisms leading to ET response failure. Also the mechanisms of Her1 and Her2 inhibition resistance are dealt within this overview, along with the therapeutic indications and limitations of tyrosine kinase inhibitors, PARP inhibitors, PI3K/AKT/mTOR inhibitors, RAS/RAF/MEK/ERK/MAPK inhibitors, and antiangiogenic drugs. In spite of the many advances in controlling the division of BC cells and the progression of BC tumors these still remain the main cause of death among women in age range of 20-50 years requiring even more efforts in new therapeutic approaches besides the drugs within the scope of the overview.

Neoadjuvant Bevacizumab plus Chemotherapy versus Chemotherapy Alone to Treat Non-Metastatic Breast Cancer: A Meta-Analysis of Randomised Controlled Trials

Purpose

Results from previous randomised controlled trials (RCTs) investigating whether the addition of bevacizumab to neoadjuvant chemotherapy (NAC) could statistically significantly increase the pathological complete response (pCR) and to identify which subgroup would benefit most from such regimens have produced conflicting results. This meta-analysis was designed to assess the efficacy and safety of bevacizumab plus chemotherapy compared with chemotherapy alone in the neoadjuvant setting.

Methods

A literature search of MEDLINE, EMBASE, Web of Science, and the Cochrane library was performed to identify eligible studies. The primary endpoint of interest was pCR. The secondary endpoints were clinical complete rate (cCR), surgery rate, breast-conserving surgery (BCS) rate, and toxicity. The meta-analysis was performed using Review Manager software version 5.3.

Results

Nine RCTs matched the selection criteria, yielding a total of 4967 patients (bevacizumab plus chemotherapy: 50.1%, chemotherapy alone: 49.9%). The results of this meta-analysis demonstrated that the addition of bevacizumab to NAC significantly increased the pCR rate (odds ratio [OR] = 1.34 [1.18–1.54]; P < 0.0001) compared with chemotherapy alone. Subgroup analysis showed that the effect of bevacizumab was more pronounced in patients with HER2-negative cancer (OR = 1.34 [1.17–1.54]; P < 0.0001) compared with HER2-positive cancer (OR = 1.69 [0.90–3.20]; P = 0.11). Similarly, in patients with HER2-negative cancer, the effect of bevacizumab was also more pronounced in patients with HR-negative cancer (OR = 1.38 [1.09–1.74]; P = 0.007) compared with HR-positive cancer (OR = 1.36 [0.78–2.35]; P = 0.27). No significant differences were observed between the groups with respect to cCR, surgery rate, or BCS rate. Additionally bevacizumab was associated with a higher incidence of neutropenia, febrile neutropenia, and hand–foot syndrome.

Conclusions

Higher proportions of patients achieved pCR when bevacizumab was added to NAC compared with when they received chemotherapy alone; acceptable toxicities were also found. Subgroup analysis demonstrated that patients with histologically confirmed HER2-negative and HR-negative breast cancer benefited the most.

The importance of molecular markers for diagnosis and selection of targeted treatments in patients with cancer

The past 30 years have seen the introduction of a number of cancer therapies with the aim of restricting the growth and spread of primary and metastatic tumours. A shared commonality among these therapies is their targeting of various aspects of the cancer hallmarks, that is traits that are essential to successful tumour propagation and dissemination. The evolution of molecular-scale technology has been central to the identification of new cancer targets, and it is not a coincidence that improved therapies have emerged at the same time as gene expression arrays and DNA sequencing have enhanced our understanding of cancer genetics. Modern tumour pathology is now viewed at the molecular level ranging from IHC biomarkers, to gene signature classifiers and gene mutations, all of which provide crucial information about which patients will respond to targeted therapy regimens. In this review, we briefly discuss the general types of targeted therapies used in a clinical setting and provide a short background on immunohistochemical, gene expression and DNA sequencing technologies, before focusing on three tumour types: breast, lung and colorectal cancers. For each of these cancer types, we provide a background to the disease along with an overview of the current standard therapies and then focus on the relevant targeted therapies and the pathways they inhibit. Finally, we highlight several strategies that are pivotal to the successful development of targeted anti-cancer drugs.

Ultrasound is at least as good as magnetic resonance imaging in predicting tumour size post-neoadjuvant chemotherapy in breast cancer

BACKGROUND

The aim of this study was to evaluate the accuracy of clinical imaging of the primary breast tumour post-neoadjuvant chemotherapy (NAC) related to the post-neoadjuvant histological tumour size (gold standard) and whether this varies with breast cancer subtype. In this study, results of both magnetic resonance imaging (MRI) and ultrasound (US) were reported.

METHODS

Patients with invasive breast cancer were enrolled in the INTENS study between 2006 and 2009. We included 182 patients, of whom data were available for post-NAC MRI (n=155), US (n=123), and histopathological tumour size.

RESULTS

MRI estimated residual tumour size with <10-mm discordance in 54% of patients, overestimated size in 28% and underestimated size in 18% of patients. With US, this was 63%, 20% and 17%, respectively. The negative predictive value in hormone receptor-positive tumours for both MRI and US was low, 26% and 33%, respectively. The median deviation in clinical tumour size as percentage of pathological tumour was 63% (P25=26, P75=100) and 49% (P25=22, P75=100) for MRI and US, respectively (P=0.06).

CONCLUSIONS

In this study, US was at least as good as breast MRI in providing information on residual tumour size post-neoadjuvant chemotherapy. However, both modalities suffered from a substantial percentage of over- and underestimation of tumour size and in addition both showed a low negative predictive value of pathologic complete remission (Gov nr: NCT00314977).

Niclosamide inhibits epithelial-mesenchymal transition and tumor growth in lapatinib-resistant human epidermal growth factor receptor 2-positive breast cancer

Acquired resistance to lapatinib, a human epidermal growth factor receptor 2 kinase inhibitor, remains a clinical problem for women with human epidermal growth factor receptor 2-positive advanced breast cancer, as metastasis is commonly observed in these patients. Niclosamide, an anti-helminthic agent, has recently been shown to exhibit cytotoxicity to tumor cells with stem-like characteristics. This study was designed to identify the mechanisms underlying lapatinib resistance and to determine whether niclosamide inhibits lapatinib resistance by reversing epithelial-mesenchymal transition. Here, two human epidermal growth factor receptor 2-positive breast cancer cell lines, SKBR3 and BT474, were exposed to increasing concentrations of lapatinib to establish lapatinib-resistant cultures. Lapatinib-resistant SKBR3 and BT474 cells exhibited up-regulation of the phenotypic epithelial-mesenchymal transition markers Snail, vimentin and α-smooth muscle actin, accompanied by activation of nuclear factor-кB and Src and a concomitant increase in stem cell marker expression (CD44(high)/CD24(low)), compared to naive lapatinib-sensitive SKBR3 and BT474 cells, respectively. Interestingly, niclosamide reversed epithelial-mesenchymal transition, induced apoptosis and inhibited cell growth by perturbing aberrant signaling pathway activation in lapatinib-resistant human epidermal growth factor receptor 2-positive cells. The ability of niclosamide to alleviate stem-like phenotype development and invasion was confirmed. Collectively, our results demonstrate that lapatinib resistance correlates with epithelial-mesenchymal transition and that niclosamide inhibits lapatinib-resistant cell viability and epithelial-mesenchymal transition. These findings suggest a role of niclosamide or derivatives optimized for more favorable bioavailability not only in reversing lapatinib resistance but also in reducing metastatic potential during the treatment of human epidermal growth factor receptor 2-positive breast cancer.

Systemic treatment in breast cancer: a primer for radiologists

Abstract

Cytotoxic chemotherapy, hormonal therapy and molecular targeted therapy are the three major classes of drugs used to treat breast cancer. Imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), ¹⁸F-FDG positron emission tomography (PET)/CT and bone scintigraphy each have a distinct role in monitoring response and detecting drug toxicities associated with these treatments. The purpose of this article is to elucidate the various systemic therapies used in breast cancer, with an emphasis on the role of imaging in assessing treatment response and detecting treatment-related toxicities.

Teaching Points

• Cytotoxic chemotherapy is often used in combination with HER2-targeted and endocrine therapies.

• Endocrine and HER2-targeted therapies are recommended in hormone-receptor- and HER2-positive cases.

• CT is the workhorse for assessment of treatment response in breast cancer metastases.

• Alternate treatment response criteria can help in interpreting pseudoprogression in metastasis.

• Unique toxicities are associated with cytotoxic chemotherapy and with endocrine and HER2-targeted therapies.

Hormone receptor status predicts the clinical outcome of human epidermal growth factor 2-positive metastatic breast cancer patients receiving trastuzumab therapy: a multicenter retrospective study

Objectives

Trastuzumab, a humanized monoclonal antibody that binds human epidermal growth factor receptor 2 (HER2), dramatically improves the clinical outcomes of HER2-positive breast cancer. Emerging evidence implied that the clinical behavior and sensitivity to targeted agents in HER2-positive breast cancer differed by hormone receptor (HR) status. The objective of this study was to determine the effect of the HR status on survival benefit of HER2-positive metastatic breast cancer when treated with anti-HER2-targeted therapy in People’s Republic of China.

Methods

Metastatic breast cancer patients with HER2-positive diseases across six cancer centers in People’s Republic of China were retrospectively analyzed in our study. Patients were classified into four groups according to HR/HER2 status and trastuzumab treatment: HER2+/HR+ patients with first-line trastuzumab treatment, HER2+/HR+ patients with no trastuzumab treatment, HER2+/HR− patients with first-line trastuzumab treatment, and HER2+/HR− patients with no trastuzumab treatment. Kaplan–Meier analysis, log-rank test, and multivariate analysis were performed during analysis.

Results

A total of 295 patients were included in the final analysis. The median overall survival was 30 months (95% confidence interval: 27.521–32.479). Among patients with HER2+/HR− disease, significant survival benefit was observed when treated with trastuzumab (30 vs 21 months, P=0.000). However, in patients with HER2+/HR+ disease, trastuzumab administration had a survival improvement trend but no significant statistical differences (36 vs 30 months, P=0.258). In the multivariate analysis, HR status was an independent predictor of overall survival and trastuzumab treatment had significantly decreased risk of death in HER2+/HR− patients (hazard ratio =0.330).

Conclusion

HR status is an independent predictor of overall survival in HER2-positive metastatic breast cancer patients and patients with HER2+/HR− subtype might be associated with more survival benefits when treated with trastuzumab-based regimens.

Statistical controversies in clinical research: assessing pathologic complete response as a trial-level surrogate end point for early-stage breast cancer

BACKGROUND

A trial-level surrogate end point for a randomized clinical trial may allow assessment of the relative benefits of the treatment to be performed at an earlier time point and potentially with a smaller sample size. However, determining whether an end point is a reliable trial-level surrogate based on results of previous trials is not straightforward. The question of trial-level surrogacy is easily confused with the question of individual-level surrogacy, and this confusion can lead to controversy. A recent example concerns the evaluation of pathologic complete response (pCR) as a surrogate for event-free survival (EFS) and overall survival (OS) in early-stage breast cancer.

MATERIALS AND METHODS

The differences between individual-level surrogacy (i.e. for patients receiving a specific treatment, the surrogate end point predicts the definitive end point) and trial-level surrogacy (the results of the trial for the surrogate end point predict the results of the trial for the definitive end point) are discussed. Trial-level data used in two previous meta-analyses evaluating pCR as a trial-level surrogate for EFS and OS were re-analyzed using methods that appropriately account for the variability in pCR rates as well as the variability in the hazard ratios for EFS and OS.

RESULTS

There is no evidence that pCR is a trial-level surrogate for EFS or OS, nor is there evidence that pCR could be used reliably to screen out nonpromising agents from further drug development.

CONCLUSIONS

At present, neoadjuvant RCTs should continue to follow patients to observe EFS and OS to assess clinical benefit, and they should be designed with sufficient sample size to reliably assess EFS. However, one cannot rule out the possibility that future meta-analyses involving more trials and in which the patient population or class of treatments is restricted could suggest the validity of pCR as a trial-level surrogate for EFS or OS in some focused settings.

Better Together: Targeted Combination Therapies in Breast Cancer

Recent discoveries both in cell proliferation and survival mechanisms and new antineoplastic agents have led to deep change in the breast cancer treatment paradigm. Nonetheless, all of the progress in knowledge and strategy has not been enough to overcome mechanisms of escape and resistance put in place by the tumor cells. New targeted agents mean new possibilities for combinations, a viable option to try to stop compensatory pathways of tumor growth activated in response to therapeutics. The main challenges in designing a combined therapy come from the variety of subtypes of breast cancer (luminal A, luminal B, HER2-enriched, and basal-like) and from the multitude of pathways each subtype can exploit. Recent research has focused on dual blockade of HER2 (trastuzumab-lapatinib; trastuzumab-pertuzumab) and concomitant blockade of the endocrine driver and other pathways such as the PI3K/AKT/mTOR pathway (everolimus-exemestane), HER2 (trastuzumab/lapatinib-endocrine therapy) and the cell cycle through cyclin-dependent kinase inhibition (letrozole-palbociclib). This combined and personalized approach to treatment needs a profound knowledge of the mechanisms leading to proliferation in each tumor subtype. Deepening our understanding of tumor growth is mandatory to keep improving the efficacy of combination therapy.

Dual HER2 blockade in the neoadjuvant and adjuvant treatment of HER2-positive breast cancer

Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase transmembrane receptor that is overexpressed on the surface of 15%–20% of breast tumors and has been associated with poor prognosis. Consistently improved pathologic response and survival rates have been demonstrated with use of trastuzumab in combination with standard chemotherapy in both early and advanced breast cancer. However, resistance to trastuzumab may pose a major problem in the effective treatment of HER2-positive breast cancer. Dual HER2 blockade, using agents that work in a complimentary fashion to trastuzumab, has more recently been explored to evade resistance in both the preoperative (neoadjuvant) and adjuvant settings. Increased effectiveness of dual anti-HER2 agents over single blockade has been recently reported in clinical studies. Pertuzumab in combination with trastuzumab and taxane is currently approved in the metastatic and neoadjuvant treatment of HER2-positive breast cancer. Various biomarkers have also been investigated to identify subsets of patients with HER2-positive tumors who would likely respond best to these targeted therapy combinations. In this article, available trial data regarding efficacy and toxicity of treatment with combination HER2 agents in the neoadjuvant and adjuvant setting have been reviewed, and relevant correlative biomarker data from these trials have been discussed.

Meta-analysis of randomized controlled trials for the incidence and risk of treatment-related mortality in patients with breast cancer treated with HER2 blockade

PURPOSE

The association between human epidermal growth factor receptor-2 (HER2) blockades and risk of fatal adverse events (FAEs) has not been well described. We carried out a meta-analysis regarding this issue.

METHODS

An electronic search of Medline, Embase and The Cochrane Central Register of Controlled Trials was conducted to investigate the effects of anti-HER2 therapies on cancer patients. Only randomized controlled trials were included. Random or fixed-effect meta-analytical models were used to evaluate the risk ratio (RR) of FAEs due to the use of HER2 blockades.

RESULTS

Twenty two trials were included. The incidence of FAEs related to HER2 blockades was 0.34%, and there was no statistically significant increase in the risk of FAEs for HER2 blockades versus control in overall population (RR = 1.16, 95%CI: 0.78-1.73). Furthermore, when we performed several subgroup analyses according to drug type (trastuzumab, lapatinib, and pertuzumab), treatment strategy (dual HER2 blockade vs. mono HER2 therapy), and study setting (adjuvant trials vs. metastatic trials), we did not observe any significant differences among the groups. No evidence of publication bias was observed.

CONCLUSION

Compared with control, the addition of HER2 blockades may not increase the risk of FAEs among patients with breast cancer.

Advances in Medical Management of Early Stage and Advanced Breast Cancer: 2015

Standard management of early stage and advanced breast cancer has been improved over the past few years by knowledge gained about the biology of the disease, results from a number of eagerly anticipated clinical trials and the development of novel agents that offer our patients options for improved outcomes or reduced toxicity or both. This review highlights recent major developments affecting the systemic therapy of breast cancer, broken down by clinically relevant patient subgroups and disease stage, and briefly discusses some of the ongoing controversies in the treatment of breast cancer and promising therapies on the horizon.

New directions in the neoadjuvant treatment of HER2+ breast cancer

Approximately 20% of breast cancer demonstrates amplification of the HER2 gene resulting in overexpression of the HER2 protein on the cell surface. Effective targeting with anti-HER2 monoclonal antibodies (trastuzumab, pertuzumab, trastuzumab-emtansine) and tyrosine kinase inhibitors (lapatinib) dramatically improves the natural history of this aggressive disease. Patients with HER2-overexpressing breast cancer (HER2+) achieve higher rates of pathologic complete response (pCR) to cytotoxic chemotherapy and HER2-targeted therapy in neoadjuvant trials compared with less aggressive subtypes. Moreover, a trend toward a positive correlation between pCR and improved long-term survival appears to be emerging in neoadjuvant clinical trials. This article reviews the various definitions of pCR as an end point in neoadjuvant clinical trials and summarizes the use of anti-HER2-targeted agents in the neoadjuvant setting for HER2+ disease.

Neoadjuvant treatment of breast cancer: maximizing pathologic complete response rates to improve prognosis

PURPOSE OF REVIEW

Neoadjuvant therapy is very often an adequate alternative to adjuvant therapy. This review summarizes the recent advances made in the area of neoadjuvant therapy in breast cancer. The focus will lie on recently published clinical trials, but will not further highlight surgical, imaging and radio-oncological issues related to neoadjuvant therapy.

RECENT FINDINGS

Within the past year, it has been discussed if neoadjuvant treatment can be used as a faster way to get access to new therapies, based on new data in HER2+ breast cancer, suggesting a higher pathological complete response rate when a dual anti-HER2 therapy was used. Nevertheless, this higher pathological complete response rate does not necessarily always translate into a better survival. In triple negative breast cancer, carboplatin could be identified as an asset for patients, especially in patients with gBRCA mutations. However, mature long-term data are still missing. The neoadjuvant approach is ideal to identify new biomarkers which predict response or resistance to the given treatment. Tumour-infiltrating lymphocytes and PIK3CA mutations are amongst the most promising markers.

SUMMARY

Neoadjuvant treatment should be considered for all patients with HER2-positive or triple negative breast cancer. Clinical trials in this setting are currently investigating new approaches.

Clinical implications of the intrinsic molecular subtypes of breast cancer

Gene-expression profiling has had a considerable impact on our understanding of breast cancer biology. During the last 15 years, 5 intrinsic molecular subtypes of breast cancer (Luminal A, Luminal B, HER2-enriched, Basal-like and Claudin-low) have been identified and intensively studied. In this review, we will focus on the current and future clinical implications of the intrinsic molecular subtypes beyond the current pathological-based classification endorsed by the 2013 St. Gallen Consensus Recommendations. Within hormone receptor-positive and HER2-negative early breast cancer, the Luminal A and B subtypes predict 10-year outcome regardless of systemic treatment administered as well as residual risk of distant recurrence after 5 years of endocrine therapy. Within clinically HER2-positive disease, the 4 main intrinsic subtypes can be identified and dominate the biological and clinical phenotype. From a clinical perspective, patients with HER2+/HER2-enriched disease seem to benefit the most from neoadjuvant trastuzumab, or dual HER2 blockade with trastuzumab/lapatinib, in combination with chemotherapy, and patients with HER2+/Luminal A disease seem to have a relative better outcome compared to the other subtypes. Finally, within triple-negative breast cancer (TNBC), the Basal-like disease predominates (70-80%) and, from a biological perspective, should be considered a cancer-type by itself. Importantly, the distinction between Basal-like versus non-Basal-like within TNBC might predict survival following (neo)adjvuvant multi-agent chemotherapy, bevacizumab benefit in the neoadjuvant setting (CALGB40603), and docetaxel vs. carboplatin benefit in first-line metastatic disease (TNT study). Overall, this data suggests that intrinsic molecular profiling provides clinically relevant information beyond current pathology-based classifications.

Optimal adjuvant treatment for patients with HER2-positive breast cancer in 2015

The introduction of trastuzumab as adjuvant treatment for patients with HER2-positive breast cancer changed the natural course of early-stage disease. Currently, one year of trastuzumab given concurrently with a taxane and following an anthracycline regimen is the preferred standard of care in Europe. The first attempt to escalate this approach, though the implementation of dual HER2 blockade with lapatinib added to trastuzumab, as assessed by the ALTTO trial, failed to improve further clinical outcomes; clinical assessment of the adjuvant trastuzumab/pertuzumab regimen is still ongoing in the APHINITY trial. Negative results were also reported for the addition of bevacizumab to adjuvant trastuzumab treatment within the context of the BETH study. Similarly, efforts to de-escalate through shortening the duration of adjuvant trastuzumab treatment failed (the PHARE trial), whereas others are still ongoing. Of note, evidence supports the use of lighter chemotherapy regimens with one year of adjuvant trastuzumab as backbone, for women with small HER2-positive breast tumors, where the omission of anthracyclines did not compromise the clinical outcome. Despite the successes achieved so far, a proportion of women with early-stage HER2-positive breast cancer, will still experience disease recurrence. The identification of these women is urgently needed, as well as the identification of predictive biomarkers to dictate the optimal treatment strategy. So far, HER2 expression status has been the only validated predictive biomarker for this patient population. Despite the clear association of pCR achieved through neoadjuvant trastuzumab-based chemotherapy with clinical outcome, results from neoadjuvant trials have not been always consistent with what was seen in the adjuvant setting. Similarly, inconsistent results have been reported for the predictive ability of alterations affecting the PI3K signaling pathway or the quantification of tumor infiltrating lymphocytes. In the era of personalized oncology, rigorous translational and clinical collaborative efforts are needed to further advance the field of treatment of patients with HER2-positive breast cancer.

Tailoring therapies--improving the management of early breast cancer: St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2015

The 14th St Gallen International Breast Cancer Conference (2015) reviewed substantial new evidence on locoregional and systemic therapies for early breast cancer. Further experience has supported the adequacy of tumor margins defined as 'no ink on invasive tumor or DCIS' and the safety of omitting axillary dissection in specific cohorts. Radiotherapy trials support irradiation of regional nodes in node-positive disease. Considering subdivisions within luminal disease, the Panel was more concerned with indications for the use of specific therapies, rather than surrogate identification of intrinsic subtypes as measured by multiparameter molecular tests. For the treatment of HER2-positive disease in patients with node-negative cancers up to 1 cm, the Panel endorsed a simplified regimen comprising paclitaxel and trastuzumab without anthracycline as adjuvant therapy. For premenopausal patients with endocrine responsive disease, the Panel endorsed the role of ovarian function suppression with either tamoxifen or exemestane for patients at higher risk. The Panel noted the value of an LHRH agonist given during chemotherapy for premenopausal women with ER-negative disease in protecting against premature ovarian failure and preserving fertility. The Panel noted increasing evidence for the prognostic value of commonly used multiparameter molecular markers, some of which also carried prognostic information for late relapse. The Panel noted that the results of such tests, where available, were frequently used to assist decisions about the inclusion of cytotoxic chemotherapy in the treatment of patients with luminal disease, but noted that threshold values had not been established for this purpose for any of these tests. Multiparameter molecular assays are expensive and therefore unavailable in much of the world. The majority of new breast cancer cases and breast cancer deaths now occur in less developed regions of the world. In these areas, less expensive pathology tests may provide valuable information. The Panel recommendations on treatment are not intended to apply to all patients, but rather to establish norms appropriate for the majority. Again, economic considerations may require that less expensive and only marginally less effective therapies may be necessary in less resourced areas. Panel recommendations do not imply unanimous agreement among Panel members. Indeed, very few of the 200 questions received 100% agreement from the Panel. In the text below, wording is intended to convey the strength of Panel support for each recommendation, while details of Panel voting on each question are available in supplementary Appendix S2, available at Annals of Oncology online.

A Retrospective Comparison of Trastuzumab Plus Cisplatin and Trastuzumab Plus Capecitabine in Elderly HER2-Positive Advanced Gastric Cancer Patients

A combination of trastuzumab and cisplatin or trastuzumab and capecitabine has been confirmed to be effective for treating adverse effects in with HER2-positive advanced gastric cancer (AGC) patients. We retrospectively compared the activity and safety of trastuzumab plus cisplatin (HP) and trastuzumab plus capecitabine (HX) for elderly HER2-positive AGC patients.Ninety two HER2-positive AGC patients were included in this study; of those 48 patients received trastuzumab (course 1, 8 mg/kg followed by course 2, onward, 6 mg/kg on day 1) plus cisplatin (60 mg/m) intravenously on day 1 of a 3-week cycle and 44 patients received trastuzumab (course 1, 8 mg/kg; course 2 onward, 6 mg/kg) plus intravenous oral capecitabine (1000 mg/m twice daily on days 1-14), every 3 weeks. The primary end point was overall survival (OS). The secondary end points included objective response rate (ORR), progression-free survival (PFS), and toxicity.The median age was 71 years in both groups. The median OS was 15.5 months in the HP group and 17.0 months in the HX group, with no significant difference between the 2 groups (P = 0.78). There were also no significant differences in PFS (median 6.6 months vs 7.2 months, respectively; P = 0.90) and ORR (58.3% vs 59.1%, respectively; P = 1.00) between the HP group and the HX group. The major grade 3 or 4 adverse events in the HP group and the HX group were neutropenia (35.4% vs 29.5%, respectively), followed by anorexia (25.0% vs 22.7%, respectively), and anemia (16.7% vs 13.6%, respectively), no significant differences were observed.HP and HX were associated with similar efficacy and safety in HER2-positive AGC patients.

Do clinical, histological or immunohistochemical primary tumour characteristics translate into different (18)F-FDG PET/CT volumetric and heterogeneity features in stage II/III breast cancer?

PURPOSE

The aim of this retrospective study was to determine if some features of baseline (18)F-FDG PET images, including volume and heterogeneity, reflect clinical, histological or immunohistochemical characteristics in patients with stage II or III breast cancer (BC).

METHODS

Included in the present retrospective analysis were 171 prospectively recruited patients with stage II/III BC treated consecutively at Saint-Louis hospital. Primary tumour volumes were semiautomatically delineated on pretreatment (18)F-FDG PET images. The parameters extracted included SUVmax, SUVmean, metabolically active tumour volume (MATV), total lesion glycolysis (TLG) and heterogeneity quantified using the area under the curve of the cumulative histogram and textural features. Associations between clinical/histopathological characteristics and (18)F-FDG PET features were assessed using one-way analysis of variance. Areas under the ROC curves (AUC) were used to quantify the discriminative power of the features significantly associated with clinical/histopathological characteristics.

RESULTS

T3 tumours (>5 cm) exhibited higher textural heterogeneity in (18)F-FDG uptake than T2 tumours (AUC <0.75), whereas there were no significant differences in SUVmax and SUVmean. Invasive ductal carcinoma showed higher SUVmax values than invasive lobular carcinoma (p = 0.008) but MATV, TLG and textural features were not discriminative. Grade 3 tumours had higher FDG uptake (AUC 0.779 for SUVmax and 0.694 for TLG), and exhibited slightly higher regional heterogeneity (AUC 0.624). Hormone receptor-negative tumours had higher SUV values than oestrogen receptor-positive (ER-positive) and progesterone receptor-positive tumours, while heterogeneity patterns showed only low-level variation according to hormone receptor expression. HER-2 status was not associated with any of the image features. Finally, SUVmax, SUVmean and TLG significantly differed among the three phenotype subgroups (HER2-positive, triple-negative and ER-positive/HER2-negative BCs), but MATV and heterogeneity metrics were not discriminative.

CONCLUSION

SUV parameters, MATV and textural features showed limited correlations with clinical and histopathological features. The three main BC subgroups differed in terms of SUVs and TLG but not in terms of MATV and heterogeneity. None of the PET-derived metrics offered high discriminative power.

Identifying and targeting tumor-initiating cells in the treatment of breast cancer

Breast cancer is the most common cancer in women (excluding skin cancer), and it is the second leading cause of cancer-related deaths. Although conventional and targeted therapies have improved survival rates, there are still considerable challenges in treating breast cancer, including treatment resistance, disease recurrence, and metastasis. Treatment resistance can be either de novo - because of traits that tumor cells possess before treatment - or acquired - because of traits that tumor cells gain in response to treatment. A recently proposed mechanism of de novo resistance invokes the existence of a specialized subset of cancer cells defined as tumor-initiating cells (TICs), or cancer stem cells (CSCs). TICs have the capacity to self-renew and to generate new tumors that consist entirely of clonally derived cell types present in the parental tumor. There are data to suggest that TICs are resistant to many conventional cancer therapies and that they can survive treatment in spite of dramatic shrinkage of the tumor. Residual TICs can then eventually regrow, which results in disease relapse. It has also been hypothesized that TIC may be responsible for metastatic disease. If these hypotheses are correct, targeting TICs may be imperative for achieving a cure. In the present review, we discuss evidence for breast TICs and their apparent resistance to conventional chemotherapy and radiotherapy as well as to various targeted therapies. We also address the potential impact of breast TIC plasticity and metastatic potential on therapeutic strategies. Finally, we describe several genes and signaling pathways that appear to be important for TIC function and may represent promising therapeutic targets.

Anti-HER2 CD4(+) T-helper type 1 response is a novel immune correlate to pathologic response following neoadjuvant therapy in HER2-positive breast cancer

INTRODUCTION

A progressive loss of circulating anti-human epidermal growth factor receptor-2/neu (HER2) CD4(+) T-helper type 1 (Th1) immune responses is observed in HER2(pos)-invasive breast cancer (IBC) patients relative to healthy controls. Pathologic complete response (pCR) following neoadjuvant trastuzumab and chemotherapy (T + C) is associated with decreased recurrence and improved prognosis. We examined differences in anti-HER2 Th1 responses between pCR and non-pCR patients to identify modifiable immune correlates to pathologic response following neoadjuvant T + C.

METHODS

Anti-HER2 Th1 responses in 87 HER2(pos)-IBC patients were examined using peripheral blood mononuclear cells pulsed with 6 HER2-derived class II peptides via IFN-γ ELISPOT. Th1 response metrics were anti-HER2 responsivity, repertoire (number of reactive peptides), and cumulative response across 6 peptides (spot-forming cells [SFC]/10(6) cells). Anti-HER2 Th1 responses of non-pCR patients (n = 4) receiving adjuvant HER2-pulsed type 1-polarized dendritic cell (DC1) vaccination were analyzed pre- and post-immunization.

RESULTS

Depressed anti-HER2 Th1 responses observed in treatment-naïve HER2(pos)-IBC patients (n = 22) did not improve globally in T + C-treated HER2(pos)-IBC patients (n = 65). Compared with adjuvant T + C receipt, neoadjuvant T + C - utilized in 61.5 % - was associated with higher anti-HER2 Th1 repertoire (p = 0.048). While pCR (n = 16) and non-pCR (n = 24) patients did not differ substantially in demographic/clinical characteristics, pCR patients demonstrated dramatically higher anti-HER2 Th1 responsivity (94 % vs. 33 %, p = 0.0002), repertoire (3.3 vs. 0.3 peptides, p < 0.0001), and cumulative response (148.2 vs. 22.4 SFC/10(6), p < 0.0001) versus non-pCR patients. After controlling for potential confounders, anti-HER2 Th1 responsivity remained independently associated with pathologic response (odds ratio 8.82, p = 0.016). This IFN-γ(+) immune disparity was mediated by anti-HER2 CD4(+)T-bet(+)IFN-γ(+) (i.e., Th1) - not CD4(+)GATA-3(+)IFN-γ(+) (i.e., Th2) - phenotypes, and not attributable to non-pCR patients' immune incompetence, host-level T-cell anergy, or increased immunosuppressive populations. In recruited non-pCR patients, anti-HER2 Th1 repertoire (3.7 vs. 0.5, p = 0.014) and cumulative response (192.3 vs. 33.9 SFC/10(6), p = 0.014) improved significantly following HER2-pulsed DC1 vaccination.

CONCLUSIONS

Anti-HER2 CD4(+) Th1 response is a novel immune correlate to pathologic response following neoadjuvant T + C. In non-pCR patients, depressed Th1 responses are not immunologically "fixed" and can be restored with HER2-directed Th1 immune interventions. In such high-risk patients, combining HER2-targeted therapies with strategies to boost anti-HER2 Th1 immunity may improve outcomes and mitigate recurrence.

International Expert Consensus on Primary Systemic Therapy in the Management of Early Breast Cancer: Highlights of the Fifth Symposium on Primary Systemic Therapy in the Management of Operable Breast Cancer, Cremona, Italy (2013)

Expert consensus-based recommendations regarding key issues in the use of primary (or neoadjuvant) systemic treatment (PST) in patients with early breast cancer are a valuable resource for practising oncologists. PST remains a valuable therapeutic approach for the assessment of biological antitumor activity and clinical efficacy of new treatments in clinical trials. Neoadjuvant trials provide endpoints, such as pathological complete response (pCR) to treatment, that potentially translate into meaningful improvements in overall survival and disease-free survival. Neoadjuvant trials need fewer patients and are less expensive than adjuvant trial, and the endpoint of pCR is achieved in months, rather than years. For these reasons, the neoadjuvant setting is ideal for testing emerging targeted therapies in early breast cancer. Although pCR is an early clinical endpoint, its role as a surrogate for long-term outcomes is the key issue. New and better predictors of treatment efficacy are needed to improve treatment and outcomes. After PST, accurate management of post-treatment residual disease is mandatory. The surgery of the sentinel lymph-node could be an acceptable option to spare the axillary dissection in case of clinical negativity (N0) of the axilla at the diagnosis and/or after PST. No data exists yet to support the modulation of the extent of locoregional radiation therapy on the basis of the response attained after PST although trials are underway.

Benefit to neoadjuvant anti-human epidermal growth factor receptor 2 (HER2)-targeted therapies in HER2-positive primary breast cancer is independent of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) status

BACKGROUND

Assessment of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) might be an important tool in identifying human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients unlikely to derive benefit from anti-HER2 therapies. However, studies to date have failed to demonstrate its predictive role in any treatment setting.

PATIENTS AND METHODS

Prospectively collected baseline core biopsies from 429 early-stage HER2-positive breast cancer patients treated with trastuzumab, lapatinib, or their combination in the Neo-ALTTO study were stained using two anti-PTEN monoclonal antibodies (CST and DAKO). The association of PTEN status and PI3K pathway activation (defined as either PTEN loss and/or PIK3CA mutation) with total pathological complete response (tpCR) at surgery, event-free survival (EFS), and overall survival (OS) was evaluated.

RESULTS

PTEN loss was observed in 27% and 29% of patients (all arms, n = 361 and n = 363) for CST and DAKO, respectively. PTEN loss was more frequently observed in hormone receptor (HR)-negative (33% and 36% with CST and DAKO, respectively) compared with HR-positive tumours (20% and 22% with CST and DAKO, respectively). No significant differences in tpCR rates were observed according to PTEN status. PI3K pathway activation was found in 47% and 48% of patients (all arms, n = 302 and n = 301) for CST and DAKO, respectively. Similarly, tpCR rates were not significantly different for those with or without PI3K pathway activation. Neither PTEN status nor PI3K pathway activation were predictive of tpCR, EFS, or OS, independently of treatment arm or HR status. High inter-antibody and inter-observer agreements were found (>90%). Modification of scoring variables significantly affected the correlation between PTEN and HR status but not with tpCR.

CONCLUSION

These data show that PTEN status determination is not a useful biomarker to predict resistance to trastuzumab and lapatinib-based therapies. The lack of standardization of PTEN status determination may influence correlations between expression and relevant clinical end points.

CLINICAL TRIALS

This trial is registered with ClinicalTrials.gov: NCT00553358.

Cost-effectiveness analysis of neoadjuvant pertuzumab and trastuzumab therapy for locally advanced, inflammatory, or early HER2-positive breast cancer in Canada

OBJECTIVE

The NeoSphere trial demonstrated that the addition of pertuzumab to trastuzumab and docetaxel for the neoadjuvant treatment of HER2-positive locally advanced, inflammatory, or early breast cancer (eBC) resulted in a significant improvement in pathological complete response (pCR). Furthermore, the TRYPHAENA trial supported the benefit of neoadjuvant dual anti-HER2 therapy. Survival data from these trials is not yet available; however, other studies have demonstrated a correlation between pCR and improved event-free survival (EFS) and overall survival (OS) in this patient population. This study represents the first Canadian cost-effectiveness analysis of pertuzumab in the neoadjuvant treatment of HER2-positive eBC.

METHODS

A cost-utility analysis (CUA) was conducted using a three health state Markov model ('event-free', 'relapsed', and 'dead'). Two separate analyses were conducted; the first considering total pCR (ypT0/is ypN0) data from NeoSphere, and the second from TRYPHAENA. Published EFS and OS data partitioned for patients achieving/not achieving pCR were used in combination with the percentage achieving pCR in the pertuzumab trials to estimate survival. This CUA included published utility values and direct medical costs including drugs, treatment administration, management of adverse events, supportive care, and subsequent therapy. To address uncertainty, a probabilistic sensitivity analysis (PSA) and alternative scenarios were explored.

RESULTS

Both analyses suggested that the addition of pertuzumab resulted in increased life-years and quality-adjusted life-years (QALYs). The incremental cost per QALY ranged from $25,388 (CAD; NeoSphere analysis) to $46,196 (TRYPHAENA analysis). Sensitivity analyses further support the use of pertuzumab, with cost-effectiveness ratios ranging from $9230-$64,421. At a threshold of $100,000, the addition of pertuzumab was cost-effective in nearly all scenarios (93% NeoSphere; 79% TRYPHAENA).

CONCLUSION

Given the improvement in clinical efficacy and a favorable cost per QALY, the addition of pertuzumab in the neoadjuvant setting represents an attractive treatment option for HER2-positive eBC patients.

Pathologic complete response rates in triple-negative, HER2-positive, and hormone receptor-positive breast cancers after anthracycline-free neoadjuvant chemotherapy with carboplatin and paclitaxel with or without trastuzumab

BACKGROUND

Pathologic complete response (pCR) to neoadjuvant chemotherapy (NCT) is considered a surrogate for improved survival. Platinum-containing NCT, particularly in patients with HER2+ and triple-negative breast cancers (TNBC) may increase pCR rates.

METHODS

Tumor characteristics, pCR rates (no invasive disease in breast and lymph nodes), toxicities, and survival in patients who received carboplatin, a taxane, and trastuzumab (HER2+ disease) between April 2009 and December 2011, were reviewed.

RESULTS

Thirty eight patients (39 tumors) completed a median of 4 cycles of NCT. Eighteen of 39 (46%) tumors were HER2+, 8/18 (44%) responded with pCR; 13/18 HER2+ tumors were HR+ (72%) and 4/13 (31%) had a pCR. Ten of 39 (26%) tumors were TNBC; 6/10 (60%) had a pCR. At a median of 25-months no recurrences were observed in patients with pCR.

CONCLUSIONS

Prospective studies of anthracycline-free platinum-containing NCT are warranted in LABC patients with HER2+ and TNBC.

High HER2 expression correlates with response to the combination of lapatinib and trastuzumab

PURPOSE

Expression of p95HER2 has been associated with resistance to trastuzumab-based therapy in patients with metastatic breast cancer. Conversely, high levels of HER2 have been linked with increased clinical benefit from anti-HER2 therapy. In this work, we aimed to investigate whether the levels of p95HER2 and HER2 can predict response to anti-HER2 therapy in patients with breast cancer.

EXPERIMENTAL DESIGN

We measured p95HER2 and HER2 by VeraTag and HERmark, respectively, in primary tumors of patients enrolled in the neoadjuvant phase III study NeoALTTO and correlated these variables with pathologic complete response (pCR) and progression-free survival (PFS) following lapatinib (L), trastuzumab (T), or the combination of both agents (L+T).

RESULTS

A positive correlation between p95HER2 and HER2 levels was found in the 274 cases (60%) in which quantification of both markers was possible. High levels of these markers were predictive for pCR, especially in the hormone receptor (HR)-positive subset of patients. High HER2 expression was associated with increased pCR rate upon L+T irrespective of the HR status. To examine whether the levels of either p95HER2 or HER2 could predict for PFS in patients treated with lapatinib, trastuzumab or L+T, we fit to the PFS data in Cox models containing log2(p95HER2) or log2(HER2). Both variables correlated with longer PFS.

CONCLUSIONS

Increasing HER2 protein expression correlated with increased benefit of adding lapatinib to trastuzumab. HER2 expression is a stronger predictor of pCR and PFS than p95HER2 for response to lapatinib, trastuzumab and, more significantly, L+T.

PIK3CA mutations are associated with decreased benefit to neoadjuvant human epidermal growth factor receptor 2-targeted therapies in breast cancer

PURPOSE

We investigated whether mutations in the gene encoding the phosphatidylinositol 3-kinase (PI3K) catalytic subunit (PIK3CA) correlates with response to neoadjuvant human epidermal growth factor receptor 2 (HER2) -targeted therapies in patients with breast cancer.

PATIENTS AND METHODS

Baseline tissue biopsies were available from patients with HER2-positive early breast cancer who were enrolled onto the Neoadjuvant Lapatinib and/or Trastuzumab Treatment Optimization trial (NeoALTTO). Activating mutations in PIK3CA were identified using mass spectrometry-based genotyping.

RESULTS

PIK3CA mutations were identified in 23% of HER2-positive breast tumors, and these mutations were associated with poorer outcome in all of the treatment arms. Patients treated with a combination of trastuzumab and lapatinib who had wild-type PIK3CA obtained a total pathologic complete response (pCR) rate of 53.1%, which decreased to 28.6% in patients with tumors that carried PIK3CA activating mutations (P = .012).

CONCLUSION

Activating mutations in PIK3CA predicted poor pCR in patients with HER2-positive breast cancer treated with neoadjuvant therapies that target HER2. Consequently, the combination of anti-HER2 agents and PI3K inhibitors is being investigated.

Monitoring Trastuzumab Resistance and Cardiotoxicity: A Tale of Personalized Medicine

While approval of trastuzumab, a recombinant monoclonal antibody directed against HER2, along with a diagnostic kit to detect breast cancers which are positive for HER2 overexpression, has advanced a new era of stratified and personalized medicine, it also created several challenges to our scientific and clinical practice. These problems include trastuzumab resistance and trastuzumab-induced cardiotoxicity. In this review, we will summarize data from the literature regarding mechanisms of trastuzumab resistance and trastuzumab-induced cardiotoxicity and present some promising model systems that may advance our understanding of these mechanisms. Our discussion will include development of circulating tumor cells and circulating tumor DNA for monitoring tumor burden, of patient-derived xenograft models for preclinical testing of novel therapies, and of novel therapeutic strategies for trastuzumab-resistance and possible integration of these strategies in the design of co-clinical studies for testing in relevant patient subpopulations.

Neoadjuvant and Adjuvant Therapy for HER2 Positive Disease

Since the initial description of the HER2 proto-oncogene as a poor prognostic factor in breast cancer in 1987, to the first randomized trial of a monoclonal antibody directed against HER2 in combination with chemotherapy for the treatment of metastatic HER2-positive breast cancer published in 2001, to the American Society of Clinical Oncology (ASCO) 2005 Annual Meeting in which we saw the unprecedented collective presentations demonstrating the dramatic benefit of trastuzumab in the adjuvant setting-the clinical landscape of HER2-overexpressing breast cancer has forever changed. More recently, there has been increasing use of preoperative chemotherapy and anti-HER2 targeted therapies in primary operable HER2 disease in the research domain and in clinical practice. In the next few years, we will see if dual adjuvant anti-HER2 antibody inhibition produces clinically significant improvements in outcome; understand if there is a role of small molecule inhibitors of the HER family of receptors either in combination or sequential to trastuzumab; further refine the relationship between pathologic complete response (pCR) and long-term clinical outcomes; and find predictive biomarkers to identify cohorts of patients that may need differential combinations and/or durations of anti-HER2 therapies.