Trastuzumab and vinorelbine as first-line therapy for HER2-overexpressing metastatic breast cancer: multicenter phase II trial with clinical outcomes, analysis of serum tumor markers as predictive factors, and cardiac surveillance algorithm

Detection of ERBB2 and CEN17 signals in fluorescent in situ hybridization and dual in situ hybridization for guiding breast cancer HER2 target therapy

The overexpression of the human epidermal growth factor receptor 2 (HER2) is a predictive biomarker in therapeutic effects for metastatic breast cancer. Accurate HER2 testing is critical for determining the most suitable treatment for patients. Fluorescent in situ hybridization (FISH) and dual in situ hybridization (DISH) have been recognized as FDA-approved methods to determine HER2 overexpression. However, analysis of HER2 overexpression is challenging. Firstly, the boundaries of cells are often unclear and blurry, with large variations in cell shapes and signals, making it challenging to identify the precise areas of HER2-related cells. Secondly, the use of sparsely labeled data, where some unlabeled HER2-related cells are classified as background, can significantly confuse fully supervised AI learning and result in unsatisfactory model outcomes. In this study, we present a weakly supervised Cascade R-CNN (W-CRCNN) model to automatically detect HER2 overexpression in HER2 DISH and FISH images acquired from clinical breast cancer samples. The experimental results demonstrate that the proposed W-CRCNN achieves excellent results in identification of HER2 amplification in three datasets, including two DISH datasets and a FISH dataset. For the FISH dataset, the proposed W-CRCNN achieves an accuracy of 0.970±0.022, precision of 0.974±0.028, recall of 0.917±0.065, F1-score of 0.943±0.042 and Jaccard Index of 0.899±0.073. For DISH datasets, the proposed W-CRCNN achieves an accuracy of 0.971±0.024, precision of 0.969±0.015, recall of 0.925±0.020, F1-score of 0.947±0.036 and Jaccard Index of 0.884±0.103 for dataset 1, and an accuracy of 0.978±0.011, precision of 0.975±0.011, recall of 0.918±0.038, F1-score of 0.946±0.030 and Jaccard Index of 0.884±0.052 for dataset 2, respectively. In comparison with the benchmark methods, the proposed W-CRCNN significantly outperforms all the benchmark approaches in identification of HER2 overexpression in FISH and DISH datasets (p<0.05). With the high degree of accuracy, precision and recall , the results show that the proposed method in DISH analysis for assessment of HER2 overexpression in breast cancer patients has significant potential to assist precision medicine.

A Soft Label Deep Learning to Assist Breast Cancer Target Therapy and Thyroid Cancer Diagnosis

According to the World Health Organization Report 2022, cancer is the most common cause of death contributing to nearly one out of six deaths worldwide. Early cancer diagnosis and prognosis have become essential in reducing the mortality rate. On the other hand, cancer detection is a challenging task in cancer pathology. Trained pathologists can detect cancer, but their decisions are subjective to high intra- and inter-observer variability, which can lead to poor patient care owing to false-positive and false-negative results. In this study, we present a soft label fully convolutional network (SL-FCN) to assist in breast cancer target therapy and thyroid cancer diagnosis, using four datasets. To aid in breast cancer target therapy, the proposed method automatically segments human epidermal growth factor receptor 2 (HER2) amplification in fluorescence in situ hybridization (FISH) and dual in situ hybridization (DISH) images. To help in thyroid cancer diagnosis, the proposed method automatically segments papillary thyroid carcinoma (PTC) on Papanicolaou-stained fine needle aspiration and thin prep whole slide images (WSIs). In the evaluation of segmentation of HER2 amplification in FISH and DISH images, we compare the proposed method with thirteen deep learning approaches, including U-Net, U-Net with InceptionV5, Ensemble of U-Net with Inception-v4, Inception-Resnet-v2 encoder, and ResNet-34 encoder, SegNet, FCN, modified FCN, YOLOv5, CPN, SOLOv2, BCNet, and DeepLabv3+ with three different backbones, including MobileNet, ResNet, and Xception, on three clinical datasets, including two DISH datasets on two different magnification levels and a FISH dataset. The result on DISH breast dataset 1 shows that the proposed method achieves high accuracy of 87.77 ± 14.97%, recall of 91.20 ± 7.72%, and F1-score of 81.67 ± 17.76%, while, on DISH breast dataset 2, the proposed method achieves high accuracy of 94.64 ± 2.23%, recall of 83.78 ± 6.42%, and F1-score of 85.14 ± 6.61% and, on the FISH breast dataset, the proposed method achieves high accuracy of 93.54 ± 5.24%, recall of 83.52 ± 13.15%, and F1-score of 86.98 ± 9.85%, respectively. Furthermore, the proposed method outperforms most of the benchmark approaches by a significant margin (p <0.001). In evaluation of segmentation of PTC on Papanicolaou-stained WSIs, the proposed method is compared with three deep learning methods, including Modified FCN, U-Net, and SegNet. The experimental result demonstrates that the proposed method achieves high accuracy of 99.99 ± 0.01%, precision of 92.02 ± 16.6%, recall of 90.90 ± 14.25%, and F1-score of 89.82 ± 14.92% and significantly outperforms the baseline methods, including U-Net and FCN (p <0.001). With the high degree of accuracy, precision, and recall, the results show that the proposed method could be used in assisting breast cancer target therapy and thyroid cancer diagnosis with faster evaluation and minimizing human judgment errors.

Response of Leptomeningeal Metastasis of Breast Cancer With a HER2/neu Activating Variant to Tucatinib: A Case Report

Metastatic breast cancer demonstrates HER2/neu amplification approximately 15% of the time. However, HER2 mutations, which often stimulate tumor growth, occur in only 3% to 5% of patients, and are seen more frequently in metastatic versus primary tumors. They are more frequent in lobular carcinoma, including triple-negative lobular cancer. Many of these variants are resistant to trastuzumab and lapatinib. However, neratinib can be efficacious, and recent data suggest that antibody-drug conjugates (ADCs) such as ado-trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan may also be helpful. Laboratory and clinical data raise the possibility that simultaneous treatment with ADCs plus neratinib may be even more efficacious. Tucatinib, which has demonstrated significant activity in the central nervous system, has also been shown in vitro to be active against a number of these HER2 variants. This report describes a patient with metastatic estrogen receptor-positive, HER2-nonamplified breast cancer with an activating HER2 mutation whose tumor became resistant to neratinib as well as capecitabine, but whose subsequent leptomeningeal disease had a dramatically successful response to tucatinib plus capecitabine. As the frequency of HER2 mutations increases during the evolution of metastatic breast cancer, it is important to obtain genomic evaluation on these tumors with either repeat tissue or liquid biopsy as they progress over time.

Anti-HER2 monoclonal antibodies intensify the susceptibility of human gastric cancer cells to etoposide by promoting apoptosis, but not autophagy

BACKGROUND

Gastric cancer (GC) is a multifactorial disease with high mortality. Anti-HER2 therapy is a promising strategy in GC treatment and trastuzumab was approved by FDA (Food and Drug Administration) as the first and the second line of treatment of the disease.

PURPOSE

The aim of the study was to examine the effectiveness of a combination of etoposide with trastuzumab or pertuzumab in AGS gastric cancer cells and breast cancer cells such as MCF-7, MDA-MB-231 and HCC1954.

METHODS AND FINDINGS

The cytotoxic effects of the tested compounds against gastric and breast cancer cells were checked by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay. The anti-proliferative potential was analyzed by the incorporation of [3H]-thymidine into DNA. Fluorescent microscopy and flow cytometry was used to demonstrate the effect of the compounds on apoptosis. The mitochondrial membrane potential, and the activity of caspase-8 and caspase-9 were assessed. Autophagosomes and autolysosomes formation was checked by flow cytometry. The concentrations of Beclin-1, LC3A and LC3B were performed using ELISA. The expression of LC3A/B was also determined. The results from our study proved that the combination of etoposide with anti-HER2 antibodies was not cytotoxic against breast cancer cells, whereas the combination of etoposide with anti-HER2 antibodies decreased viability and DNA biosynthesis in gastric cancer cells. The interaction of etoposide with pertuzumab or trastuzumab induced programmed cell death via extrinsic and intrinsic apoptotic pathways in AGS gastric cancer cells, but did not affect autophagy, where a decrease of Beclin-1, LC3A and LC3B was observed in comparison with the untreated control.

CONCLUSIONS

The study demonstrated that etoposide (12.5 μM) with pertuzumab represent a promising strategy in gastric cancer treatment, but further in vivo examinations are also required.

Serum HER2 levels predict treatment efficacy and prognosis in patients with HER2-positive breast cancer undergoing neoadjuvant treatment

Background

Controversy remains regarding the predictive and prognostic value of serum human epidermal growth factor receptor 2 (HER2) in breast cancer. The purpose of this retrospective study was to determine the clinical utility and efficacy of serum HER2 (sHER2) in predicting treatment response and prognosis in patients with HER2-positive breast cancer undergoing neoadjuvant chemotherapy and trastuzumab treatment.

Methods

A total of 309 HER2-positive breast cancer patients diagnosed at Fudan University Shanghai Cancer Center from July 2015 to January 2019 were analyzed. Baseline sHER2 levels were obtained for all patients and sHER2 levels were collected after 2 cycles of treatment in 208 patients. A sHER2 level ≥15 ng/mL was regarded as "high expression" and sHER2 <15 ng/mL was regarded as "low expression". Outcome measures of treatment efficacy and prognosis were pathological complete response (pCR) and invasive disease-free survival (iDFS), respectively.

Results

In patients with high baseline sHER2, more were ER-negative (P=0.029), had larger tumor size (P=0.006), more advanced clinical stage (P=0.002), higher Miller-Payne grade (P=0.024) and higher likelihood of iDFS events (P=0.015). Patients with high sHER2 levels after 2 cycles of treatment had lower pCR rates (P=0.038), higher Miller-Payne grade (P=0.013) and higher likelihood of iDFS events (P=0.003). Kaplan-Meier analysis showed significant differences in iDFS between patients with high and low sHER2 levels at baseline (P=0.019) and after 2 cycles of treatment (P=0.000). Further analyses according to cancer subtypes found baseline sHER2 to be significantly correlated with the iDFS of Luminal B patients (p=0.002), while sHER2 levels after 2 cycles of treatment was significantly correlated with the iDFS of HER2-enriched patients (P=0.000). Univariate analysis showed significant association between iDFS and tumor size (P=0.026), lymph node status (P=0.008), clinical stage (P=0.031), baseline sHER2 (P=0.024), overall tumor response (P=0.011), pCR (P=0.043) and Miller-Payne grade (P=0.001). Multivariate analysis found Miller-Payne grade (P=0.037) to be significantly associated with iDFS.

Conclusions

Our results demonstrate the clinical value of sHER2 in a population of Chinese breast cancer patients, suggesting that sHER2 levels after 2 cycles of neoadjuvant therapy may be more predictive of treatment outcomes and that the prognostic value of sHER2 may be time point and subtype dependent.

Incidence of central nervous system metastases in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer treated with trastuzumab: A meta-analysis

This study aimed to estimate the incidence of central nervous system (CNS) metastases in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) treated with trastuzumab. Studies were identified through a literature search of electronic databases. Random-effects meta-analyses were performed to estimate the incidence rate of CNS metastases, trastuzumab therapy duration, and time from trastuzumab therapy to CNS metastasis diagnosis. A meta-analysis of odds ratios was performed to evaluate the significance of a difference in CNS metastasis incidence between patients with and without trastuzumab treatment. Thirty studies (8121 trastuzumab-treated and 3972 control patients) were included. The follow-up duration was 18.9 months (95% confidence interval [CI]: 13.8, 24.1). The trastuzumab treatment duration was 9.0 months (95% CI: 7.0, 11.0). The median interval between the start of trastuzumab therapy and CNS metastasis diagnosis was 12.2 months (95% CI: 9.5, 14.7). The incidence of CNS metastasis after the start of trastuzumab therapy was 22% (95% CI: 16, 27). The incidence of CNS metastases was significantly higher in trastuzumab-treated than in non-trastuzumab-treated patients (odds ratio: 1.39 [95% CI: 1.06, 1.82], p=0.02). The survival time from the start of the study was 23.4 months (95% CI: 19.7, 27.1) in trastuzumab-treated patients and 18.4 months (95% CI: 12.7, 24.1) in patients treated with control regimens. The survival time after the development of CNS metastases in trastuzumab-treated patients was 19.2 months (95% CI: 15.6, 25.9). Approximately 22% of patients with HER2-positive MBC who were treated with trastuzumab developed CNS metastases. However, trastuzumab-treated patients had a longer survival than patients who were not treated with trastuzumab.

NCAPG confers trastuzumab resistance via activating SRC/STAT3 signaling pathway in HER2-positive breast cancer

HER2+ breast cancer (BC) is characterized by rapid growth, early recurrence, early metastasis, and chemoresistance. Trastuzumab is the most effective treatment for HER2+ BC and effectively reduces the risk of recurrence and death of patients. Resistance to trastuzumab results in cancer recurrence and metastasis, leading to poor prognosis of HER2+ BC. In the present study, we found that non-structural maintenance of chromosome condensin 1 complex subunit G (NCAPG) expression was highly upregulated in trastuzumab-resistant HER2+ BC. Ectopic NCAPG was positively correlated with tumor relapse and shorter survival in HER2+ BC patients. Moreover, overexpression of NCAPG promoted, while silencing of NCAPG reduced, the proliferative and anti-apoptotic capacity of HER2+ BC cells both in vitro and in vivo, indicating NCAPG reduces the sensitivity of HER2+ BC cells to trastuzumab and may confer trastuzumab resistance. Furthermore, our results suggest that NCAPG triggers a series of biological cascades by phosphorylating SRC and enhancing nuclear localization and activation of STAT3. To summarize, our study explores a crucial role for NCAPG in trastuzumab resistance and its underlying mechanisms in HER2+ BC, and suggests that NCAPG could be both a potential prognostic marker as well as a therapeutic target to effectively overcome trastuzumab resistance.

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.

Trastuzumab and Vinorelbine as Highly Effective and Safe Therapy for HER-2-Overexpressing Metastatic Breast Cancer. A Single Institution Experience

Aims and Background

Trastuzumab-based therapy has improved survival of women with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic breast cancer.

Study Design

From September 2002 to July 2006, 45 women with metastatic breast cancer HER2 3+, or 2+ and positive for HER2 gene amplification, were enrolled in the study and received a combination therapy with vinorelbine, 25 mg/m2 weeks 1 and 2, plus trastuzumab, 4 mg/kg loading dose and then 2 mg/kg weekly, in a three weeks cycle. Eligibility criteria included measurable disease and a baseline ejection fraction ≥50%. Forty-two percent of the patients were not pretreated, whereas 58% had received a previous chemotherapy regimen for metastatic disease, including anthracy-clines and/or taxanes (47%), and trastuzumab plus taxol (11%).

Results

We observed 14 (31%) complete responses and 21 (47%) partial responses, with an overall response rate of 78%. Stable disease >6 months was assessed for 5 (11%) patients with a clinical benefit of 89%. Five (11%) patients progressed. With a median follow-up of 11 months, median time to progression was 9 months and median duration of response was 7.6 months for complete remissions and 4 months for partial remissions. Median survival was 29 months.

Conclusions

In spite of a smaller dose intensity of vinorelbine than previously reported, the regimen evaluated was notably effective in terms of response rate, time to progression and survival, with very mild toxicity.

Circulating Tumor Cells in HER-2 Positive Metastatic Breast Cancer Patients Treated with Trastuzumab and Chemotherapy

The detection of circulating tumor cells (CTCs) in peripheral blood may have important prognostic and predictive implications in breast cancer treatment. A limitation in this field has been the lack of a validated method of accurately measuring CTCs. While sensitivity has improved using RT-PCR, specificity remains a major challenge. The goal of this paper is to present a sensitive and specific methodology of detecting CTCs in women with HER-2-positive metastatic breast cancer, and to examine its role as a marker that tracks disease response during treatment with trastuzumab-containing regimens.

The study included patients with HER-2-positive metastatic breast cancer enrolled on two different clinical protocols using a trastuzumab-containing regimen. Serial CTCs were measured at planned time points and clinical correlations were made. Immunomagnetic selection of circulating epithelial cells was used to address the specificity of tumor cell detection using cytokeratin 19 (CK19). In addition, the extracellular domain of the HER-2 protein (HER-2/ECD) was measured to determine if CTCs detected by CK19 accurately reflect tumor burden.

The presence of CTCs at first restaging was associated with disease progression. We observed an association between CK19 and HER-2/ECD. The association of HER-2/ECD with clinical response followed a similar pattern to that seen with CK19. Finally, the absence of HER-2/ECD at best overall response and a change of HER-2/ECD from positive at baseline to negative at best overall response was associated with favorable treatment response.

Our study supports the prognostic and predictive role of the detection of CTCs in treatment of HER-2-positive metastatic breast cancer patients. The association between CK19 and markers of disease burden is in line with the concept that CTCs may be a reliable measure of tumor cells in the peripheral blood of patients with metastatic breast cancer. The association of CTCs at first restaging with treatment failure indicates that CTCs may have a role as surrogate markers to monitor treatment response.

Lisinopril or Coreg CR in reducing cardiotoxicity in women with breast cancer receiving trastuzumab: A rationale and design of a randomized clinical trial

BACKGROUND

Trastuzumab (TZB) is an established therapy for HER2-positive breast cancer. The use of TZB is commonly associated with cardiotoxicity manifesting as asymptomatic decrease in left ventricular ejection fraction (LVEF) or overt heart failure. Several studies demonstrated favorable effects of angiotensin-converting enzyme (ACE) inhibitors and β-blockers (BBs) in the prevention of chemotherapy-induced cardiotoxicity. We hypothesize that patients, randomized to receive an ACE inhibitor or a BB during trastuzumab therapy for breast cancer, will maintain a higher LVEF than patients randomized to placebo.

METHODS AND RESULTS

We designed a prospective, multicenter, randomized, phase II placebo-controlled clinical trial to evaluate the effects of an ACE inhibitor (lisinopril) and a BB (carvedilol phosphate-extended release) on cardiotoxicity in patients with breast cancer who are receiving adjuvant or neoadjuvant TZB therapy. The primary objectives include (1) comparison of incidence of cardiotoxicity and (2) comparison of LVEF as a continuous variable in between the arms. Cardiotoxicity was defined as an absolute decrease in LVEF from baseline of ≥10% at follow-up or an absolute decrease of ≥5% in LVEF from baseline for individuals with <50% LVEF at follow-up. The target accrual is 468 participants, representing patients both with and without anthracycline exposure. The enrollment is completed. The trial is co-sponsored by University of South Florida and National Cancer Institute. The LVEF is being evaluated by echocardiography or multigated acquisition scan.

CONCLUSIONS

If we can demonstrate that the use of an ACE inhibitor or a BB can reduce the degree of TZB-induced cardiotoxicity, it is hoped that patients will receive complete and uninterrupted TZB therapy for breast cancer without compromising cardiac function.

Safety and efficacy of vinorelbine in combination with pertuzumab and trastuzumab for first-line treatment of patients with HER2-positive locally advanced or metastatic breast cancer: VELVET Cohort 1 final results

BACKGROUND

Pertuzumab, trastuzumab, and docetaxel is standard of care for first-line treatment of HER2-positive metastatic breast cancer (MBC). However, alternative chemotherapy partners are required to align with patient/physician preferences and to increase treatment flexibility. We report VELVET Cohort 1 results in which the efficacy and safety of pertuzumab and trastuzumab, administered sequentially in separate infusions, followed by vinorelbine, were evaluated. Cohort 2, where pertuzumab and trastuzumab were administered in a single infusion, followed by vinorelbine, recruited after Cohort 1 was fully enrolled, will be reported later.

METHODS

In this multicenter, two-cohort, open-label, phase II study, patients with HER2-positive locally advanced or MBC who had not received chemotherapy or biological therapy for their advanced disease received 3-weekly pertuzumab (840 mg loading, 420 mg maintenance doses) and trastuzumab (8 mg/kg loading, 6 mg/kg maintenance doses), followed by vinorelbine (25 mg/m² initial dose, 30-35 mg/m² maintenance doses) on days 1 and 8 or 2 and 9 of each 3-weekly cycle. Study treatment was given until investigator-assessed disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed objective response rate (ORR) in patients with measurable disease at baseline per RECIST v1.1. Secondary endpoints included progression-free survival (PFS) and safety.

RESULTS

Cohort 1 enrolled 106 patients. Investigator-assessed ORR was 74.2% (95% CI 63.8-82.9) in intent-to-treat patients with measurable disease (89/106 [84.0%]). Median PFS was 14.3 months (95% CI 11.2-17.5) in the intent-to-treat population. Treatment was reasonably well tolerated, with no unexpected toxicities. Diarrhea (61/106 patients [57.5%]) and neutropenia (54/106 [50.9%]) were the most common adverse events (AEs); neutropenia (33/106 [31.1%]) and leukopenia (14/106 [13.2%]) were the most common grade ≥3 AEs. Serious AEs were reported in 32/106 (30.2%) patients. AEs led to study drug discontinuation in 36/106 patients (34.0%). Eighteen of 106 patients (17.0%) had AEs suggestive of congestive heart failure; however, there were no confirmed cases.

CONCLUSIONS

The vinorelbine, pertuzumab, and trastuzumab combination is active and reasonably well tolerated. This regimen offers an alternative for patients who cannot receive docetaxel for first-line treatment of HER2-positive locally advanced or MBC.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01565083 , registered on 26 March 2012.

Trastuzumab cardiotoxicity: from clinical trials to experimental studies

Epidermal growth factor receptor-2 (HER-2) is overexpressed in 20 to 25% of human breast cancers, which is associated with aggressive tumour growth and poor prognosis. Trastuzumab (Herceptin®) is a humanized monoclonal antibody directed against HER-2, the first highly selective form of therapy targeting HER-2 overexpressing tumours. Although initial trials indicated high efficacy and a favourable safety profile of the drug, the first large, randomized trial prompted a retrospective analysis of cardiac dysfunction in earlier trials utilizing trastuzumab. There has been ongoing debate on the cardiac safety of trastuzumab ever since, initiating numerous clinical and preclinical investigations to better understand the background of trastuzumab cardiotoxicity and evaluate its effects on patient morbidity. Here, we have given a comprehensive overview of our current knowledge on the cardiotoxicity of trastuzumab, primarily focusing on data from clinical trials and highlighting the main molecular mechanisms proposed.

LINKED ARTICLES

This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Targeted Agents for HER2-Positive Breast Cancer: Optimal Use in Older Patients

The HER2 gene is overexpressed in 15-20 % of all breast cancers. With the advent of HER2-directed therapies, HER2 overexpression is no longer considered an adverse prognostic factor. Despite significant improvements in clinical outcomes with the use of trastuzumab [herceptin (H)], women aged >65 years remain under-represented in most clinical trials. Cardiac safety in the elderly woman is a major concern because of pre-existing comorbidities. However, many studies suggest that elderly patients with HER2-positive disease derive the same benefit from trastuzumab as do their younger counterparts in both adjuvant and metastatic settings. Data are limited guiding safety and efficacy of other HER2 inhibitors such as pertuzumab and trastuzumab emtansine in elderly patients; however, in general, these drugs have a favorable toxicity profile.

Precision Oncology Medicine: The Clinical Relevance of Patient-Specific Biomarkers Used to Optimize Cancer Treatment

Precision medicine in oncology is the result of an increasing awareness of patient-specific clinical features coupled with the development of genomic-based diagnostics and targeted therapeutics. Companion diagnostics designed for specific drug-target pairs were the first to widely utilize clinically applicable tumor biomarkers (eg, HER2, EGFR), directing treatment for patients whose tumors exhibit a mutation susceptible to an FDA-approved targeted therapy (eg, trastuzumab, erlotinib). Clinically relevant germline mutations in drug-metabolizing enzymes and transporters (eg, TPMT, DPYD) have been shown to impact drug response, providing a rationale for individualized dosing to optimize treatment. The use of multigene expression-based assays to analyze an array of prognostic biomarkers has been shown to help direct treatment decisions, especially in breast cancer (eg, Oncotype DX). More recently, the use of next-generation sequencing to detect many potential "actionable" cancer molecular alterations is further shifting the 1 gene-1 drug paradigm toward a more comprehensive, multigene approach. Currently, many clinical trials (eg, NCI-MATCH, NCI-MPACT) are assessing novel diagnostic tools with a combination of different targeted therapeutics while also examining tumor biomarkers that were previously unexplored in a variety of cancer histologies. Results from ongoing trials such as the NCI-MATCH will help determine the clinical utility and future development of the precision-medicine approach.

Radiomics: Images Are More than Pictures, They Are Data

In the past decade, the field of medical image analysis has grown exponentially, with an increased number of pattern recognition tools and an increase in data set sizes. These advances have facilitated the development of processes for high-throughput extraction of quantitative features that result in the conversion of images into mineable data and the subsequent analysis of these data for decision support; this practice is termed radiomics. This is in contrast to the traditional practice of treating medical images as pictures intended solely for visual interpretation. Radiomic data contain first-, second-, and higher-order statistics. These data are combined with other patient data and are mined with sophisticated bioinformatics tools to develop models that may potentially improve diagnostic, prognostic, and predictive accuracy. Because radiomics analyses are intended to be conducted with standard of care images, it is conceivable that conversion of digital images to mineable data will eventually become routine practice. This report describes the process of radiomics, its challenges, and its potential power to facilitate better clinical decision making, particularly in the care of patients with cancer.

Retinal metastasis regression with eribulin in a heavily pretreated breast cancer patient

The authors present the case of a heavily pretreated young woman with retinal and brain metastases from breast cancer who was successfully treated with eribulin. Eribulin was given at 1.1 mg/m2 on day 1 and 8, every 3 weeks for a total of 12 courses. A significant reduction in the size of brain and retinal lesions was achieved after three cycles. The treatment was continued for 12 cycles, with a good profile of tolerability. In this clinical case, eribulin demonstrated to be active on brain and retinal metastases from breast cancer, although preclinical data showed limited ability to cross the blood–brain barrier.

Trends in Survival for Patients with Metastatic Breast Cancer: Is Survival Improving?

Introduction

The treatment of patients with metastatic breast cancer (mBC) is one of the most difficult problems in clinical oncology. Clinical trial results suggest that novel therapies may be having a favorable impact on the survival of mBC patients, but the real impact of new therapies on OS rates has yet to be established. The aim of this outcome study was to evaluate the most reliable parameters to define the long-term result in terms of OS of different treatment strategies for mBC patients in a real-world clinical practice.

Materials and Methods

A retrospective analysis of consecutive patients diagnosed with mBC between February 2001 and December 2008 and treated at our medical oncology unit was performed.

Results

We evaluated 70 female patients. At the last follow-up all patients had died. Median OS was 31.55 months (range, 2.33-100.13). There was no statistically significant difference in OS (p = 0.284) between the period 2001-2004 and the period 2005-2008. We did not find any statistically significant difference in OS even in the transition from one year to the next (p = 0.154).

Conclusions

The results of the current analysis suggest that the OS of women with mBC has not improved in the last years. However, these results should be interpreted with caution, considering the difficulty of determining changes in survival over time. Larger studies are needed to corroborate our findings.

Efficacy of lapatinib monotherapy on occult breast cancer presenting with cutaneous metastases: A case report

The case of a 72-year-old female who identified a lymph node enlargement in the left axilla is reported in the present study. A lymph node biopsy revealed a metastatic adenocarcinoma of the axillary lymph node. Following various assessments, the patient was diagnosed with occult breast cancer and lymph node metastases, for which treatment was initiated. Trastuzumab monotherapy was administered as the patient was elderly, positive for the hepatitis B virus and exhibited the following immunostaining/immunohistochemical analysis results: Estrogen receptor (ER) negative (−), progesterone receptor (PgR) negative (−) and human epidermal growth factor receptor 2 (HER2) positive (3+). Breast ultrasonography was performed 10 months after the initial trastuzumab administration and the left axillary lymph node enlargement had reduced in size and severity. However, a skin rash (erythema) was observed encompassing the left breast and extending into the axilla. As determined by the result of a skin biopsy of this area, the patient was diagnosed with occult breast cancer with cutaneous metastases. The immunohistochemical analysis results obtained from the skin biopsy were similar to those obtained from the lymph nodes: ER (−), PgR (−) and HER2 (3+). Therefore, the patient was switched from trastuzumab to lapatinib monotherapy. The erythema completely disappeared after two months of treatment. At present (34 months following lapatinib monotherapy initiation) no new lesions or severe side-effects have been observed.

The trastuzumab and vinorelbine combination: an alternative to taxane-based chemotherapy for early-stage and locally advanced her2-positive breast cancer

BACKGROUND

Anthracyclines and taxanes have historically constituted the backbone of chemotherapy regimens for patients with breast cancer positive for the human epidermal growth factor receptor 2 (her2). For a subset of patients who categorically refuse alopecia, or for those with a contraindication to those drugs, there is an urgent need to define alternative regimens. Here, we report our institutional experience with trastuzumab and vinorelbine (tv), a combination with good clinical activity and a good side effect profile for patients with her2-positive breast cancer.

METHODS

In a retrospective analysis, outcomes data were extracted for patients receiving tv as their only chemotherapy in the non-metastatic setting at the Jewish General Hospital. For the most part, tv was administered weekly for 6 months, followed by trastuzumab for 6 months.

RESULTS

The analysis identified 46 patients (mean age: 64 years) who received tv between 2003 and 2012 (n = 36 adjuvant, n = 10 neoadjuvant). Of the patients in the adjuvant group, 81% had stage i disease. In the neoadjuvant group, 3 patients experienced a complete pathologic response. Only 1 patient experienced local recurrence after a short course (3 months) of adjuvant tv. Overall survival and breast cancer-specific survival were 94% and 98% respectively at a median 5 years of follow-up. Febrile neutropenia-induced sepsis resulted in the death of 1 patient with significant medical comorbidities; 2 other patients died of comorbidities unrelated to their cancer or treatment. Grades 3 or 4 adverse events included neutropenia (23%), febrile neutropenia (10%), fatigue (2%), and anemia (2%).

CONCLUSIONS

For patients with non-metastatic breast cancer refusing alopecia, or for patients who are not candidates for standard chemotherapy, tv is a reasonable alternative to standard adjuvant chemotherapy.

In vitro assessment of the effects of anti-HER2 monoclonal antibodies on proliferation of HER2-overexpressing breast cancer cells

BACKGROUND

HER2 proto-oncogene is critical in the biology of breast cancer and an important therapeutic target of monoclonal antibodies (mAbs). We have recently established a panel of anti-HER2 mAbs recognizing different epitopes within the extracellular domain of HER2.

MATERIALS & METHODS

In the present study the antiproliferative effect of these mAbs was investigated on HER2-overexpressing human breast cancer cell line BT474, using radioactive thymidine incorporation assay.

RESULTS

Our results demonstrated that while two of the mAbs (1T0 and 2A8) inhibited cell proliferation dose dependently, similar to trastuzumab, six mAbs (1F2, 1B5, 1H9, 4C7, 1H6 and 2A9) augmented cell proliferation. Treatment of BT474 cells with different combinations of two mAbs induced either synergistic inhibitory or stimulatory effects.

DISCUSSION

Our findings indicate that combination of some stimulatory mAbs could completely abolish the inhibitory effect of other mAbs against HER2. Employment of some combinations of mAbs with significant synergistic inhibitory function may improve the therapeutic efficacy of HER2-specific mAbs.

Molecular features and survival outcomes of the intrinsic subtypes within HER2-positive breast cancer

Background

The clinical impact of the biological heterogeneity within HER2-positive (HER2+) breast cancer is not fully understood. Here, we evaluated the molecular features and survival outcomes of the intrinsic subtypes within HER2+ breast cancer.

Methods

We interrogated The Cancer Genome Atlas (n = 495) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) datasets (n = 1730) of primary breast cancers for molecular data derived from DNA, RNA and protein, and determined intrinsic subtype. Clinical HER2 status was defined according to American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines or DNA copy-number aberration by single nucleotide polymorphism arrays. Cox models tested the prognostic significance of each variable in patients not treated with trastuzumab (n = 1711).

Results

Compared with clinically HER2 (cHER2)-negative breast cancer, cHER2+ breast cancer had a higher frequency of the HER2-enriched (HER2E) subtype (47.0% vs 7.1%) and a lower frequency of Luminal A (10.7% vs 39.0%) and Basal-like (14.1% vs 23.4%) subtypes. The likelihood of cHER2-positivity in HER2E, Luminal B, Basal-like and Luminal A subtypes was 64.6%, 20.0%, 14.4% and 7.3%, respectively. Within each subtype, only 0.3% to 3.9% of genes were found differentially expressed between cHER2+ and cHER2-negative tumors. Within cHER2+ tumors, HER2 gene and protein expression was statistically significantly higher in the HER2E and Basal-like subtypes than either luminal subtype. Neither cHER2 status nor the new 10-subtype copy number-based classification system (IntClust) added independent prognostic value to intrinsic subtype.

Conclusions

When the intrinsic subtypes are taken into account, cHER2-positivity does not translate into large changes in the expression of downstream signaling pathways, nor does it affect patient survival in the absence of HER2 targeting.

Biweekly combination of trastuzumab, docetaxel and gemcitabine for HER2-positive metastatic breast cancer: results of a Phase II GOIM study

ABSTRACT: 

Aims: Clinical activity of chemotherapy plus trastuzumab in HER2 overexpressing advanced breast cancer has been documented. We report the activity and safety results of biweekly combination of trastuzumab, docetaxel and gemcitabine as first-line therapy in HER2-positive advanced breast cancer. Patients & methods: Patients were biweekly treated with trastuzumab (4 mg/kg), gemcitabine (1000 mg/m2) and docetaxel (50 mg/m2). The primary end point was overall response rate, secondary time to progression, clinical benefit rate (partial response plus complete response plus stable disease for ≥ 24 weeks) and tolerability. Results: A total of 65 patients with HER2-positive advanced breast cancer have been enrolled. In total, 47 patients responded (73%; 95% CI, 60–84), 11 achieved complete response (17%; 95% CI: 8.9–28.7), 36 achieved partial response (56%; 95% CI: 43–68.6). The clinical benefit rate was 87.5% (95% CI: 77–94). Three patients (4.7%) experienced progressive disease. The median time to progression was 14.2 months (95% CI: 10.6–17.8), the median overall survival was 39.3 months and the 36-month survival rate was 55.5% (95% CI: 58–73). The worst toxicities were grade 3 neutropenia (12%), thrombocytopenia (6%) and diarrhea (6%). No cardiac toxicity was reported. Conclusion: As first-line therapy, this combination allowed the delivery of polychemotherapy in association to targeted therapy, with clinical activity and mild toxicity. The promising results should be further explored in Phase III randomized clinical trials.

Clinicopathological features among patients with advanced human epidermal growth factor-2-positive breast cancer with prolonged clinical benefit to first-line trastuzumab-based therapy: a retrospective cohort study

BACKGROUND

The magnitude of benefit of trastuzumab for the treatment of advanced HER2-positive breast cancer varies widely. In this retrospective study, we investigated the clinicopathological features associated with prolonged first-line trastuzumab-based treatment duration.

PATIENTS AND METHODS

A total of 164 patients diagnosed with advanced HER2-positive breast cancer and treated with first-line trastuzumab-based therapy from 1999 to 2009 were identified. Duration of treatment was classified according to tertiles. Different logistic regression models including age, disease-free interval, number of metastatic sites, visceral disease, hormone receptor, and adjuvant trastuzumab were fitted to investigate associations with benefit of prolonged trastuzumab-based therapies. The predictive value of each model was assessed using C-statistics.

RESULTS

At a median follow-up of 5.8 years (range, 0.7-22.1 years), patients in the short-, intermediate-, and long-term treatment duration groups were given first-line trastuzumab-based therapy for < 7.2 months, 7.2 to 14 months, and > 14 months, respectively. In the multivariate analysis, patients with long-term clinical benefit had a higher likelihood of having hormone receptor-positive tumors (odds ratio [OR]positive vs. negative = 2.39 [95% confidence interval (CI), 1.08-5.31]; P = .032); and a lower likelihood of having received adjuvant trastuzumab (ORadjuvant trastuzumab vs. no adjuvant trastuzumab = 0.30 [95% CI, 0.10-0.96]; P = .043]. C-statistics varied between 0.634 and 0.699.

CONCLUSION

Long-term benefit of trastuzumab-based therapy is associated with hormone receptor positivity and the absence of previous adjuvant trastuzumab. Nevertheless, clinicopathological features had a low predictive value for prolonged treatment duration. The validation of the current findings and the identification of molecular features associated the magnitude of trastuzumab benefit should be encouraged.

Lapatinib in the treatment of breast cancer

Within the past 2 years, four separate groups have reported marked improvement in relapse-free survival when trastuzumab was added to adjuvant chemotherapy in patients with HER2-overexpressing breast cancer. These results add further credence to the relevance of this receptor as a tumor target. Despite the significant benefits observed in early and advanced HER2-positive breast cancer, overexpression of the receptor is still associated with a poorer prognosis and an increased risk of disease relapse, even in patients with primary operable disease. Besides cytotoxic chemotherapy, and possibly hormonal therapy, patients whose tumors exhibit resistance to trastuzumab have few molecular-targeted options available. Recently, lapatinib, a small molecule dual inhibitor of both HER2 and EGF receptors, has been developed to expand the options for treating HER-positive breast cancer.

Gemcitabine in metastatic breast cancer

Gemcitabine is a pyrimidine antimetabolite which has shown activity in metastatic breast cancer both as a single agent, but also in various combination regimens. It is characterized by a unique mechanism of action which includes cytotoxic self-potentiation, masked DNA chain termination and potent inhibition of DNA repair. The clinical application of gemcitabine is supported by a favorable toxicity profile. In metastatic breast cancer, several Phase II trials document the activity of gemcitabine in pretreated and unpretreated patients. In a single Phase III trial performed in elderly patients not pretreated, gemcitabine was inferior to epirubicin. High activity has, however, been obtained by the combination of gemcitabine with taxanes such as paclitaxel or docetaxel. In a randomized trial performed in anthracycline-pretreated patients, the combined use of gemcitabine and paclitaxel induced a significant improvement not only of response rate and time to disease progression, but also caused a significant increase in quality of life and survival when compared with paclitaxel alone. The combination of gemcitabine with vinorelbine and cisplatin has been validated in numerous Phase II trials and promises reliable activity in anthracycline- and/or taxane-pretreated patients. Triple-agent regimens such as gemcitabine/epirubicin/paclitaxel provided consistently high response rates in Phase II trials, but failed to show superiority over the 5-fluorouracil/epirubicin/cyclophosphamide regimen in a randomized Phase III trial. Based on high response rates and pathological complete remission rates achieved by preoperative induction therapy with gemcitabine/epirubicin/taxane regimens, ongoing trials focus on the incorporation of gemcitabine into neoadjuvant and adjuvant regimens.

Potential use of humanized antibodies in the treatment of breast cancer

With the growing knowledge of key cellular pathways in tumor induction and evolution, targeted therapies make up an increasing proportion of new drugs entering clinical testing. In the treatment of breast cancer, humanized antibodies have become a major option. The humanized monoclonal antibody trastuzumab (Herceptin); Genentech, Inc., CA, USA) for HER2-overexpressing, metastatic breast cancer, represents a successful agent associated with impressive survival benefits when combined with chemotherapy. Based on impressive results, trastuzumab will become a standard in the adjuvant treatment of HER2-overexpressing breast cancer. The role of trastuzumab in the neoadjuvant setting is promising, but must be further evaluated in large prospective, randomized trials. However, there is still a large proportion of patients overexpressing HER2 that do not respond to trastuzumab. Regarding this patient cohort, the optimal combination of trastuzumab with other agents needs further evaluation. In breast cancer lacking HER2 amplification, the role of the new antibody pertuzumab remains to be defined. The role of antibodies interfering with angiogenesis, tumor stroma or glycoproteins is of a preliminary nature and warrants further investigation. Here, an overview of humanized antibodies in human breast cancer is provided, with emphasis on the recent advances and future prospects in treating malignant breast cancer.

Circulating HER2 Extracellular Domain: A Specific and Quantitative Biomarker of Prognostic Value in all Breast Cancer Patients?

The HER2 oncoprotein has emerged as an essential biomarker in the treatment of breast cancer patients. Once the primary breast cancer is removed, there is an increasing need to detect breast cancer recurrence as early as possible with the hope that earlier intervention with new anti-HER2 therapies will improve quality of life and increase overall survival. Numerous publications have shown that increasing blood levels of circulating HER2 is an early indicator of progression, particularly in HER2-positive patients and that the rise and fall parallels the clinical course of disease and independent of therapy. Many studies show that the HER2 status of the primary tumor may not fully and accurately reflect the HER2 status of recurrent cancer. Thus, elevated serum HER2 levels may be an early signal of the emergence of a HER2-positive metastatic tumor and therefore alert the physician to re-assess HER2 status using a tissue test.

The predictive role of phosphatase and tensin homolog (PTEN) loss, phosphoinositol-3 (PI3) kinase (PIK3CA) mutation, and PI3K pathway activation in sensitivity to trastuzumab in HER2-positive breast cancer: a meta-analysis

OBJECTIVE

Phosphatase and tensin homolog (PTEN) loss or activating mutations of phosphoinositol-3 (PI3) kinase (PIK3CA) may be related to trastuzumab resistance in in vitro studies; however, this issue in clinical studies is controversial. Therefore, we conducted a meta-analysis to assess the association between PTEN loss, PIK3CA mutation and the efficacy of trastuzumab-based treatment in HER2-positive breast cancer patients.

METHODS

A computerized search was performed through the PubMed database, the online proceedings of the American Society of Clinical Oncology Annual Meetings, the San Antonio Breast Cancer Symposium and the International St. Gallen Breast Cancer Conference. Ten eligible studies including 1889 cases were identified.

RESULTS

In HER2-positive locally advanced breast cancer patients, neither PTEN loss, PIK3CA mutation nor PI3K activation was associated with the response rate of trastuzumab-based neoadjuvant treatment (PTEN loss: RR = 0.687, 95% CI: 0.439-1.074, P = 0.099; PIK3CA mutation: RR = 1.114, 95% CI: 0.453-2.735, P = 0.814; PI3K activation: RR = 0.787, 95% CI: 0.417-1.484, P = 0.459; RR = 0.772, 95% CI: 0.387-1.539, P = 0.462). In HER2-positive early stage breast cancer patients, PTEN loss was not associated with the disease-free survival (DFS) rate of trastuzumab-based adjuvant treatment (HR = 1.096, 95% CI: 0.706-1.700, P = 0.684). In HER2-positive recurrent or metastatic breast cancer patients, PTEN loss was significantly correlated with poorer efficacy of trastuzumab-based salvage treatment (RR = 0.682, 95% CI: 0.550-0.846, P = 0.000).

CONCLUSIONS

In HER2-positive recurrent or metastatic breast cancer patients PTEN loss might indicate resistance to trastuzumab-based salvage treatment. Due to the small sample size and the considerable heterogeneity in the chemotherapy treatment regimens, further research is needed to clarify the association between PTEN loss, PIK3CA mutation and the efficacy of trastuzumab-based treatment in neoadjuvant and adjuvant settings.

A phase II study of bevacizumab in combination with vinorelbine and trastuzumab in HER2-positive metastatic breast cancer

We aimed to evaluate the efficacy and feasibility of combining trastuzumab/vinorelbine with bevacizumab in patients with first-or second-line HER2-positive, metastatic breast cancer (MBC). Eligible patients had HER2-positive measureable MBC, with no more than one prior line of chemotherapy, and were treated with trastuzumab (4 mg/kg × 2 mg/kg weekly thereafter), vinorelbine (25 mg/m(2) weekly), and bevacizumab (10 mg/kg every 2 weeks). Co-primary endpoints were (a) the proportion of patients alive and progression-free at 1 year and (b) safety profile/feasibility. Feasibility was defined as a rate of grade 3/4 non-hematologic toxicity attributable to protocol-based therapy <20 %. Twenty-nine patients were enrolled (n = 22 first-line, n = 7 second-line). Median age was 48 years (range 37-68). The median number of cycles received was 8 (1-23) and median duration on treatment was 7.4 months (range 1-22). The study was closed early due to higher-than-expected rates of grade 3/4 non-hematologic toxicities, with 50 events in 20 patients. A total of six patients (21 %) were taken off study for treatment-related toxicity. Most common treatment-related toxicities included fatigue (n = 7), febrile neutropenia (n = 4), and headache (n = 3). At 1 year, 8/22 first-line (36 %) and 2/7 second-line (29 %) patients were alive and progression-free. Median PFS was 9.9 months and 7.8 months in the first- and second-line cohorts, respectively. Objective responses were observed in 16/22 (73 %) and 5/7 (71 %) patients in the first- and second-line settings. Although the combination of vinorelbine, trastuzumab, and bevacizumab showed notable activity in HER2-positive MBC, the proportion of first-line patients alive and progression-free at 1 year was deemed unlikely to reach the pre-defined threshold for declaring success. Additionally, unacceptable toxicity was observed, at rates greater than previously reported with vinorelbine/trastuzumab or vinorelbine/bevacizumab doublet combinations.

Targeted agents in second-line bladder cancer therapy

The treatment of metastasized urothelial cancer has been evolving in recent years. In particular, in the second-line setting after the failure of platinum-containing therapy, options are few and besides vinflunine, the recently approved standard in Europe, well-designed highly selective clinical trials may be possible alternatives for patients in this palliative situation. However, targeted therapy approaches have not achieved the same results in urothelial cancer as for instance in renal cell carcinoma. Many of the new targeted drugs have been investigated as single agents in phase II clinical trials without convincing oncologic outcome. This review aims to highlight the most relevant clinical studies examining targeted agents in the second-line setting of metastasized transitional carcinoma of the urothelium.

Overcoming resistance and restoring sensitivity to HER2-targeted therapies in breast cancer

BACKGROUND

Approximately 15%-23% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2), which leads to the activation of signaling pathways that stimulate cell proliferation and survival. HER2-targeted therapy has substantially improved outcomes in patients with HER2-positive breast cancer. However, both de novo and acquired resistance are observed.

DESIGN

A literature search was performed to identify proposed mechanisms of resistance to HER2-targeted therapy and identified novel targets in clinical development for treating HER2-resistant disease.

RESULTS

Proposed HER2-resistance mechanisms include impediments to HER2-inhibitor binding, signaling through alternative pathways, upregulation of signaling pathways downstream of HER2, and failure to elicit an appropriate immune response. Although continuing HER2 inhibition beyond progression may provide an additional clinical benefit, the availability of novel therapies targeting different mechanisms of action could improve outcomes. The developmental strategy with the most available data is targeting the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) pathway. The oral mTOR inhibitor everolimus has shown promising activity in combination with chemotherapy and trastuzumab in trastuzumab-refractory, advanced breast cancer.

CONCLUSIONS

Non-HER2-targeted therapy is a promising means of overcoming resistance to HER2-targeted treatment. Ongoing clinical studies will provide additional information on the efficacy and safety of novel targeted therapies in HER2-resistant advanced breast cancer.

Therapeutic antibodies against cancer

Antibody-based therapeutics against cancer are highly successful and currently enjoy unprecedented recognition of their potential; 13 monoclonal antibodies (mAbs) have been approved for clinical use in the European Union and in the United States. Bevacizumab, rituximab, and trastuzumab had sales in 2010 of more than $5 billion each. Hundreds of mAbs, including bispecific mAbs and multispecific fusion proteins, mAbs conjugated with small-molecule drugs, and mAbs with optimized pharmacokinetics, are in clinical trials. However, deeper understanding of mechanisms is needed to overcome major problems including resistance to therapy, access to targets, complexity of biological systems, and individual variations.

Profiling phospho-signaling networks in breast cancer using reverse-phase protein arrays

Measuring the states of cell signaling pathways in tumor samples promises to advance the understanding of oncogenesis and identify response biomarkers. Here, we describe the use of Reverse Phase Protein Arrays (RPPAs or RPLAs) to profile signaling proteins in 56 breast cancers and matched normal tissue. In RPPAs, hundreds to thousands of lysates are arrayed in dense regular grids and each grid is probed with a different antibody (100 in the current work, of which 71 yielded strong signals with breast tissue). Although RPPA technology is quite widely used, measuring changes in phosphorylation reflective of protein activation remains challenging. Using repeat deposition and well-validated antibodies, we show that diverse patterns of phosphorylation can be monitored in tumor samples and changes mapped onto signaling networks in a coherent fashion. The patterns are consistent with biomarker-based classification of breast cancers and known mechanisms of oncogenesis. We explore in detail one tumor-associated pattern that involves changes in the abundance of the Axl receptor tyrosine kinase (RTK) and phosphorylation of the cMet RTK. Both cMet and Axl have been implicated in breast cancer, or in resistance to anticancer drugs, but the two RTKs are not known to be linked functionally. Protein depletion and overexpression studies in a 'triple-negative' breast cell line reveal cross talk between Axl and cMet involving Axl-mediated modification of cMet, a requirement for cMet in efficient and timely signal transduction by the Axl ligand Gas6 and the potential for the two receptors to interact physically. These findings have potential therapeutic implications, as they imply that bi-specific receptor inhibitors (for example, ATP-competitive small-kinase inhibitors such as GSK1363089, BMS-777607 or MP470) may be more efficacious than the mono-specific therapeutic antibodies currently in development (for example, Onartuzumab).

Antimitotic inhibitors

Of the agents available in the treatment of both solid and hematologic cancers, microtubule-targeted agents are among the most widely used and exploiting other mechanisms involving the microtubule and its role in mitosis is an area of continued interest. This review will focus on novel microtubule-targeted agents, both recently approved (eg, ixabepilone and eribulin) and in later-stage clinical trials, and kinase inhibitors that aim to directly inhibit the mitotic spindle, such as the aurora kinase, pololike kinase, and kinsein-spindle protein inhibitors.

Trastuzumab and Gemcitabine in Pretreated HER2 Overexpressing Metastatic Breast Cancer Patients: Retrospective Analysis of Our Series

Trastuzumab-based regimes improved clinical outcome in women with overexpressing HER2 metastatic breast cancer, mainly due to the availability of different combination therapies, clinically active and well tolerated. In this study we retrospectively evaluated clinical activity and toxicity of trastuzuamb plus gemcitabine regimen in heavily pretreated HER2 positive metastatic breast cancer patients. Although the observed population was heavily pretreated, the evaluated regimen was notably effective in terms of response rate, time to progression and survival, with very mild toxicity. These data suggest that in over expressing HER2 metastatic breast cancer patients, sequential trastuzumab based chemotherapeutic regimens can achieve good response rate with prolonged TTP in responding patients, even after other target therapy such as lapatinib based combinations.

Emerging drugs in metastatic breast cancer: an update

INTRODUCTION

The incidence of breast cancer at an advanced stage has decreased in the modern world due to screening programs and usage of novel chemotherapy agents at an adjuvant setting. Recurrence is the major problem seen in > 50% of breast cancer patients diagnosed at an early stage. Developing new drugs for metastatic breast cancer is a huge and challenging research area.

AREAS COVERED

Emerging drugs showed positive results in clinical studies and agents in routine clinical usage are updated. Current treatment strategies as a combination of biologic agents and overcoming drug resistance are discussed. Literature search is made from PubMed, ASCO and San Antonio Breast Cancer Symposium Meeting abstracts.

EXPERT OPINION

A number of drugs caused survival benefit for advanced breast cancer. Hundreds of new studies with tens of agents are conducted for treatment of metastatic breast cancer. Tumor resistance and treatment related toxicities are unavoidable which are two main search areas for improving metastatic breast cancer management. Understanding the pathways of genesis and progression yielded many targets for treatment. However, cure in metastatic breast cancer is still a far aim and new agents and treatment strategies are needed.

SWOG S0215: a phase II study of docetaxel and vinorelbine plus filgrastim with weekly trastuzumab for HER2-positive, stage IV breast cancer

SWOG trial S0102 showed significant activity of the combination of docetaxel and vinorelbine in HER2-negative metastatic breast cancer (MBC). For HER2-positive patients, additional benefit may occur with the addition of trastuzumab due to its synergy with docetaxel and vinorelbine. Patients with HER2-positive MBC, but without prior chemotherapy for MBC or adjuvant taxane, were eligible. Docetaxel (60 mg/m²) was given intravenously on Day 1, vinorelbine (27.5 mg/m²) intravenously on Days 8 and 15, and filgrastim (5 µg/kg) on Days 2-21 of a 21-day cycle. In addition, patients received weekly infusions of trastuzumab (2 mg/kg) after an initial bolus of 4 mg/kg. The primary outcome was 1 year overall survival (OS), with secondary outcomes of progression-free survival (PFS), response rate, and toxicity. Due to slow accrual (February 2003-December 2006), enrollment was stopped after 76 of 90 planned patients. There have been 32 deaths and 51 progressions among the 74 eligible patients who received treatment. The estimated 1 year OS was 93% (95% CI 84-97%) with a median of 48 months. One-year PFS was 70% (95% CI 58-79%) with a median of 20 months. Response rate for measurable disease was 84%. No deaths were attributed to treatment. Grade 4 toxicities were reported for 19% with neutropenia the most common (15%). The most common grade 3 toxicities (33%) were leucopenia (14%) and fatigue (10%). The combination of trastuzumab, docetaxel, and vinorelbine is effective as first-line chemotherapy in HER2-positive MBC with minimal toxicity. One-year survival estimates are among the highest reported in this population.

Surgery following neoadjuvant therapy in patients with HER2-positive locally advanced or inflammatory breast cancer participating in the NeOAdjuvant Herceptin (NOAH) study

AIM

To describe surgical outcomes in patients with HER2-positive locally advanced (LABC) or inflammatory breast cancer (IBC) participating in the NeOAdjuvant Herceptin (NOAH) study (ISRCTN86043495).

PATIENTS AND METHODS

A total of 235 patients with HER2-positive disease were randomized to neoadjuvant trastuzumab plus chemotherapy (doxorubicin plus paclitaxel, followed by paclitaxel, followed by cyclophosphamide, methotrexate and fluorouracil) or neoadjuvant chemotherapy alone. Of these patients, 228 received their allocated treatment (115 received trastuzumab plus chemotherapy and 113 received chemotherapy alone) and were potentially eligible for surgery. Mastectomy was required for all patients with IBC and was recommended for all patients with LABC. However, breast-conserving therapy could be considered for patients with peripheral neoplasms measuring ≤ 4 cm in diameter at diagnosis, with a favorable ratio of tumor to breast volume, or at the patient's request if there had been a good response to treatment.

RESULTS

As previously reported, the addition of trastuzumab to neoadjuvant chemotherapy improved the overall, complete and pathological complete response to therapy and significantly improved event-free survival (the primary endpoint of the study). Trastuzumab also enabled more patients to have breast conserving surgery (BCS) (23% versus 13% respectively) without an apparent detrimental effect on local disease control (no patient treated with trastuzumab plus chemotherapy had experienced a local recurrence after BCS at the time of analysis).

CONCLUSIONS

Although this was not an aim of the trial, neoadjuvant trastuzumab given concurrently with chemotherapy enabled 23% of patients with HER2-positive LABC/IBC to avoid mastectomy (including a small number of patients with IBC).

Challenges and Pitfalls in the Introduction of Pharmacogenetics for Cancer

There have been several success stories in the field of pharmacogenetics in recent years, including the analysis of HER2 amplification for trastuzumab selection in breast cancer and VKORC1 genotyping for warfarin dosing in thrombosis. Encouraging results from these studies suggest that genetic factors may indeed be important determinants of drug response and toxicity for at least some drugs. However, to apply pharmacogenetics appropriately, a thorough understanding of the scope and limitations of this field is required. The challenges include an appreciation of biological variability, logistical issues pertaining to the proper management of information, the need for robust methods and adequate sample quality with well-designed workflows. At the same time, the economics of pharmacogenetic testing from the perspective of clinicians, patients, governments, insurance companies and pharmaceutical companies will play an important role in determining its future use. Ethical considerations such as informed consent and patient privacy, as well as the role of regulatory bodies in addressing these issues, must be fully understood. Only once these issues are properly dealt with can the full benefits of pharmacogenetics begin to be realised. Key words: Biomarkers, Diagnostics, Personalised medicine, Pharmacogenomics, Translational medicine

Current neoadjuvant treatment options for HER2-positive breast cancer

Approximately one quarter of patients with breast cancer demonstrate amplification of the human epidermal receptor type 2 (HER2) gene, the expression of which is associated with a relatively poor prognosis independent of other clinical and pathologic variables. Trastuzumab, a humanized recombinant monoclonal antibody specifically directed against the HER2 receptor, has been shown to be biologically active and of considerable clinical utility in HER2-positive breast cancer patients. Neoadjuvant chemotherapy has been used in breast cancer to downstage the tumor and increase the opportunity for breast-conserving surgery. Preoperative chemotherapy can also serve as an in vivo testing of chemotherapy sensitivity. Additionally, a pathologic complete response is usually a surrogate marker of disease-free survival. Following the successful use of trastuzumab in the metastatic and adjuvant settings, many clinical trials have recently reported the successful use of anti-HER2 therapy in combination with different chemotherapy regimens in the neoadjuvant setting with a significantly higher pathologic complete response. With the recent introduction of new anti-HER2 drugs, interest has shifted toward dual HER2 blockade. Two such studies were recently reported, both showing a significant advantage of dual anti-HER2 therapy using lapatinib or pertuzumab in addition to trastuzumab and chemotherapy. However, several key questions need to be investigated further, such as the preferred combination chemotherapy and the optimal duration of trastuzumab in patients who achieve a pathologic complete response following preoperative chemotherapy with trastuzumab. These issues and others are discussed in this review.

Evolving strategies for overcoming resistance to HER2-directed therapy: targeting the PI3K/Akt/mTOR pathway

Human epidermal growth factor receptor 2-positive (HER2+) breast cancers, which account for 25%-30% of breast cancers, are characterized by an aggressive course and a high propensity for recurrence in the 4 years following diagnosis. The use of trastuzumab-based chemotherapy in the adjuvant setting has markedly improved the outcome for patients with early stage HER2+ breast cancer. Likewise the use of trastuzumab in combination with chemotherapy in patients with metastatic HER2+ breast cancers has prolonged survival, with current expected median survival of about 3 years. Despite these major improvements in outcome, approximately 10% of patients develop a distant recurrence following adjuvant trastuzumab-based chemotherapy, and all patients with metastatic disease eventually develop disease progression. Known mechanisms of resistance to trastuzumab include increased signaling through upstream growth factors, phosphatase and tensin (PTEN) deficiency and alterations of the HER2 receptor. Many of these mechanisms are being targeted in the clinic in an attempt to improve outcome for patients with HER2+ breast cancers. The phosphatidylinositol 3-kinase (PI3K) pathway plays a key role in trastuzumab-resistance, through these and other mechanisms, and represents a logical target for drug development for trastuzumab-resistant breast cancers. The use of mammalian target of rapamycin (mTOR) inhibition has been demonstrated to potentially reverse resistance to trastuzumab in patients with HER2+, metastatic breast cancers. Phase I and II trials have produced encouraging results when the mTOR inhibitor, everolimus, was combined with trastuzumab with or without chemotherapy, in patients with trastuzumab-resistant HER2+ metastatic breast cancer. These results are being confirmed in ongoing phase III trials in the first-line and trastuzumab-resistant settings. The mechanism of how mTOR inhibitors reverse resistance to trastuzumab remains largely unexplained. Other agents targeting the PI3K pathway in trastuzumab-resistant breast cancers are in early phase clinical trials.