Neoadjuvant dual HER2-targeted therapy with lapatinib and trastuzumab improves pathologic complete response in patients with early stage HER2-positive breast cancer: a meta-analysis of randomized prospective clinical trials

Personalized treatment using predictive biomarkers in solid organ malignancies: A review

In recent years, the influence of specific biomarkers in the diagnosis and prognosis of solid organ malignancies has been increasingly prominent. The relevance of the use of predictive biomarkers, which predict cancer response to specific forms of treatment provided, is playing a more significant role than ever before, as it affects diagnosis and initiation of treatment, monitoring for efficacy and side effects of treatment, and adjustment in treatment regimen in the long term. In the current review, we explored the use of predictive biomarkers in the treatment of solid organ malignancies, including common cancers such as colorectal cancer, breast cancer, lung cancer, prostate cancer, and cancers associated with high mortalities, such as pancreatic cancer, liver cancer, kidney cancer and cancers of the central nervous system. We additionally analyzed the goals and types of personalized treatment using predictive biomarkers, and the management of various types of solid organ malignancies using predictive biomarkers and their relative efficacies so far in the clinical settings.

Shifting the Paradigm: The Transformative Role of Neoadjuvant Therapy in Early Breast Cancer

The use of neoadjuvant systemic therapy (NST) has become increasingly important in the treatment of breast cancer because of its various advantages. These include the ability to downstage tumors without compromising locoregional control and the potential to obtain valuable information about clinical and biological response to therapy with implications for individual prognoses. Surgical response assessment paves the way for response-adapted therapy, and pathological complete response (pCR; defined as ypT0/is ypN0) serves as an additional endpoint for drug development trials. Recommended NST regimens commonly consist of anthracyclines and taxane, with dose-dense anthracyclines and weekly paclitaxel often preferred, whenever feasible. For patients with human epidermal growth factor receptor-2 (HER2)-positive tumors, dual anti-HER2 therapy (trastuzumab and pertuzumab) is indicated together with NST in case of elevated risk of recurrence. For patients with triple-negative breast cancer (TNBC), adding carboplatin to NST correlates with improved pCR and survival rates, as does the addition of immune checkpoint inhibitors. For hormone receptor (HR)-positive/HER2-negative cancers, emerging data on NST including immune checkpoint inhibitors may elevate the significance of NST in high-risk luminal breast cancer. Here, we present a synthesis of the results from neoadjuvant clinical trials that aim at optimizing treatment options for patients with high-risk breast cancer.

Dual neoadjuvant blockade plus chemotherapy versus monotherapy for the treatment of women with non-metastatic HER2-positive breast cancer: a systematic review and meta-analysis

BACKGROUND

We aimed to determine the effect of dual anti-HER2 blockade compared to monotherapy on clinically important outcomes.

METHODS

We carried out a systematic review updated until July 2022. The outcomes included pathological complete response (pCR), clinical response, event-free survival, and overall survival.

RESULTS

We identified eleven randomized clinical trials (2836 patients). When comparing paclitaxel plus dual treatment versus paclitaxel plus trastuzumab or lapatinib, dual treatment was associated with a higher probability of achieving a pathological complete response (OR 2.88, 95% CI 2.02-4.10). Addition of a taxane to an anthracycline plus cyclophosphamide and fluorouracil, plus lapatinib or trastuzumab, showed that the dual treatment was better than lapatinib alone (OR 2.47, 95% CI 1.41-4.34), or trastuzumab alone (OR 1.89, 95% CI 1.13-3.16). Dual treatment may result in an increase in survival outcomes and tumour clinical response, although such benefits are not consistent for all the combinations studied.

CONCLUSIONS

The use of dual blockade with combinations of trastuzumab and pertuzumab can be recommended for the neoadjuvant treatment of women with HER2-positive breast cancer. PROSPERO Registration number: CRD42018110273.

Anticancer effect of zanubrutinib in HER2-positive breast cancer cell lines

Small molecule Bruton's tyrosine kinase (BTK) inhibitors have been developed for the treatment of various haemato-oncological diseases, and ibrutinib was approved as the first BTK inhibitor for anticancer therapy in 2013. Previous reports proved the receptor kinase human epidermal growth factor receptor 2 (HER2) to be a valid off-target kinase of ibrutinib and potentially other irreversible BTK inhibitors, as it possesses a druggable cysteine residue in the active site of the enzyme. These findings suggest ibrutinib as a candidate drug for repositioning in HER2-positive breast cancer (BCa). This subtype of breast cancer belongs to one of the most common classes of breast tumours, and its prognosis is characterized by a high rate of recurrence and tumour invasiveness. Based on their similar kinase selectivity profiles, we investigated the anticancer effect of zanubrutinib, evobrutinib, tirabrutinib and acalabrutinib in different BCa cell lines and sought to determine whether it is linked with targeting the epidermal growth factor receptor family (ERBB) pathway. We found that zanubrutinib is a potential inhibitor of the HER2 signalling pathway, displaying an antiproliferative effect in HER2-positive BCa cell lines. Zanubrutinib effectively inhibits the phosphorylation of proteins in the ERBB signalling cascade, including the downstream kinases Akt and ERK, which mediate key signals ensuring the survival and proliferation of cancer cells. We thus propose zanubrutinib as another suitable candidate for repurposing in HER2-amplified solid tumours.

Predictive biomarkers for molecularly targeted therapies and immunotherapies in breast cancer

Globally, breast cancer is the most common malignancy in women. Substantial efforts have been made to develop novel therapies, including targeted therapies and immunotherapies, for patients with breast cancer who do not respond to standard therapies. Consequently, new targeted therapies, such as cyclin-dependent kinase 4 and 6 inhibitors, poly (ADP-ribose) polymerase inhibitors, phosphoinositide 3-kinase inhibitor, and antibody-drug conjugates targeting human epidermal growth factor receptor 2 or trophoblast cell surface antigen-2, and immune checkpoint inhibitor targeting programmed cell death-1, have been developed and are now in clinical use. However, only some patients have benefited from these novel therapies; therefore, the identification and validation of reliable or more accurate biomarkers for predicting responses to these agents remain a major challenge. This review summarizes the currently available predictive biomarkers for breast cancer and describes recent efforts undertaken to identify potential predictive markers for molecularly targeted therapies and immune checkpoint inhibitors.

Elastic meta-analytic-predictive prior for dynamically borrowing information from historical data with application to biosimilar clinical trials

A biosimilar is a biological product that is highly similar to and has no clinically meaningful differences from an approved reference product. Focusing on two-arm randomized clinical trials that aim to establish the equivalence between a test biosimilar product and the reference product, we propose the elastic meta-analytic-predictive (EMAP) prior method to leverage rich historical data available on the reference product to improve the power of the biosimilar trials. We first extract the prior information from multiple historical studies through meta-analysis, and then we discount the resulting meta-analytic-predictive (MAP) prior adaptively according to the congruence between the historical reference data and the trial reference arm data via an elastic function. The EMAP prior method is information-borrowing consistent in that asymptotically it achieves full information borrowing when trial reference arm data are congruent to historical reference data, and no information borrowing when trial reference arm data are not congruent to historical reference data. As a result, the method asymptotically controls the type I error rate at the nominal value. Extensive simulation studies show that the EMAP prior outperforms the robust MAP prior. The EMAP prior generates comparable or higher power and provides better-controlled type I errors. We illustrate the proposed methodology using two trial examples.

Pim1 Kinase Inhibitors Exert Anti-Cancer Activity Against HER2-Positive Breast Cancer Cells Through Downregulation of HER2

The proviral integration site for moloney murine leukemia virus 1 (Pim1) is a serine/threonine kinase and able to promote cell proliferation, survival and drug resistance. Overexpression of Pim1 has been observed in many cancer types and is associated with the poor prognosis of breast cancer. However, it remains unclear whether Pim1 kinase is a potential therapeutic target for breast cancer patients. In this study, we found that Pim1 expression was strongly associated with HER2 expression and that HER2-overexpressing breast cancer cells were more sensitive to Pim1 inhibitor-induced inhibitions of cell viability and metastatic ability. Mechanistically, Pim1 inhibitor suppressed the expression of HER2 at least in part through transcriptional level. More importantly, Pim1 inhibitor overcame the resistance of breast cancer cells to HER2 tyrosine kinase inhibitor lapatinib. In summary, downregulation of HER2 by targeting Pim1 may be a promising and effective therapeutic approach not only for anti-cancer growth but also for circumventing lapatinib resistance in HER2-positive breast cancer patients.

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE

To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options.

RESULTS

A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.

Current Biomarkers for Precision Medicine in Breast Cancer

Breast cancer has become the prototypical solid tumor where targets have been identified within the tumor allowing for personalized approach for systemic therapy. Biomarkers are beginning to play an important role in preparing the way for precision treatment. Mandatory biomarkers for every newly diagnosed case of breast cancer are estrogen receptors and progesterone receptors in selecting patients for endocrine treatment and HER2 for identifying patients likely to benefit from antiHER2 therapy. Although methodological problems exist in the determination of Ki67, because of its clearly established clinical value, wide availability, and low costs relative to the available multianalyte signatures, Ki67 may be used for determining prognosis, especially if values are low or high. Also, the androgen receptor (AR) pathway is emerging as a potential therapeutic target in breast cancer. AR-targeted treatments for breast cancer are in development and have shown promising preliminary results. While, most established biomarkers in breast cancer require tissue samples, serum tumor markers are easily accessible and require a less invasive procedure. Among them, tissue polypeptide-specific antigen (TPS), a specific epitope structure of a peptide in serum associated with human cytokeratin 18, is linked to the proliferative activity of tumors. TPS may be a valuable and independent prognostic biomarker for breast cancer.In order to accelerate progress towards precision treatment for women with breast cancer, we need additional predictive biomarker, especially for enhancing the positive predictive value for endocrine and antiHER2 therapies, as well as biomarkers for predicting response to specific forms of chemotherapy.

The application of methylene blue coloration technique in axillary lymph node dissection of breast cancer

Background

To analyze the associated factors that affect the coloration of methylene blue (MB) in axillary lymph node dissection (ALND) of patients with breast cancer and to explore the tracer effect of MB in high axillary lymph node metastasis, to guide surgical treatment.

Methods

We recruited 170 patients who underwent ALND, all of them were injected MB before operation. We analyzed the relationships between the clinical factors of age, body mass index (BMI), molecular typing, TNM staging, neoadjuvant chemotherapy, injection time and position and the MB coloration by univariate and multivariate analyses. A total of 84 cases were selected for observation of the application value of MB during intervention involving the lymph nodes upper axillary vein.

Results

Of 170 cases, 138 cases (81.17%) were colored. Univariate analysis showed that significant differences were observed between differing BMI’s (χ²=24.074, P<0.0001) and injection times (χ²=41.207, P<0.0001). Multivariate analysis showed that injection time (P=0.016) was the clinical factor associated with MB coloration. More than 60 minutes before surgery and MB injection, the possibility of methylene blue colored was 0.088 times higher than 10 minutes (P=0.010, 95% CI, 0.014, 0.554). MB was used to track the lymph node upper axillary vein with a sensitivity of 12.5%, a specificity of 100%, a false negative rate of 87.50%, and a false positive rate of 0; the kappa coefficient was 0.051 (χ²=0.679, P=0.404).

Conclusions

Among the clinical factors, MB coloration was worse more than 60 minutes before ALND. Using the technology of MB color, lymph nodes can be clearly identified. It has great guiding value for the doctors who learn the operation initially. However, it is still prudent to use MB for high lymph node dissection.

Pathologic complete response and outcomes by intrinsic subtypes in NSABP B-41, a randomized neoadjuvant trial of chemotherapy with trastuzumab, lapatinib, or the combination

Purpose

NSABP B-41, a phase three randomized trial, evaluated neoadjuvant lapatinib, trastuzumab, or the combination with chemotherapy in patients with HER2-positive operable breast cancer. Though no significant difference in pathologic complete response (pCR) was found among the three arms, pCR was associated with prolonged survival. We analyzed tumor intrinsic subtypes with Prediction Analysis of Microarray 50 in a subset of B-41 patients to determine their value in predicting HER2-targeting benefit.

Methods

Pearson’s Chi square test and logistic regression were used to compare pCR in the breast and nodes (ypT0/Tis ypN0). Kaplan–Meier estimates and Cox models were used to compare event-free and overall survival among subtypes.

Results

Intrinsic subtypes were determined in 271 baseline core biopsy samples. The pCR rate among patients with HER2-enriched (HER2E) subtype was greater compared to other subtypes combined (120/197, 60.9% versus 19/74, 25.7%; p < 0.001). In multivariate analysis among patients receiving trastuzumab-containing regimens (with clinical factors and HER2E subtype as factors), HER2E subtype was most strongly associated with pCR [OR 8.41 (95% CI 2.52–28.1) p < 0.001]. Patients with HER2E tumors did not benefit more from dual HER2-targeted therapy versus trastuzumab. The pCR rate was higher among HER2E tumors versus other subtypes in both estrogen receptor-positive and -negative tumors (p ≤ 0.001). Higher ESR1 gene expression was associated with lower pCR rate. No association was observed between subtype and long-term outcomes.

Conclusion

Patients with HER2E tumors were most likely to attain pCR versus other subtypes. HER2E subtype represents a favorable marker for predicting HER2-targeting benefit, particularly with trastuzumab-based therapies.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05398-3) contains supplementary material, which is available to authorized users.

Neo-adjuvant chemotherapy and axillary de-escalation management for patients with clinically node-negative breast cancer

This study aimed to explore the optimal time of sentinel lymph node biopsy (SLNB) and neo-adjuvant chemotherapy (NAC) and to assess the feasibility of selective elimination of axillary surgery after NAC in clinically node-negative (cN0) patients. From April 2010 to August 2018, 845 patients undergoing surgery after NAC were included in this retrospective study to analyze the correlation between different clinicopathological characteristics of cN0 patients and negative axillary lymph node after NAC (ypN0). Among the 148 cN0 patients, 83.1% (123/148) were ypN0. The rates of ypN0 in patients with hormone receptor positive (HR+)/HER2-, HR+/HER2+, HR-/HER2+, and triple-negative (TN) breast cancer were 75.4% (46/61), 82.6% (19/23), 85.2% (23/27), and 94.6% (35/37), respectively (P < 0.001). The rates of ypN0 in TN and HER2+ patients were 94.6% and 95.5%, which were significantly higher than that in HR+/HER2- patients (P < 0.05). Molecular subtypes, clinical stage, radiologic complete response, and pathologic complete response (bpCR) of the breast tumor correlated with ypN0 after full-course NAC (P < 0.05). Molecular subtypes (OR = 2.374, P = 0.033), clinical stage (OR = 0.320, P = 0.029), and bpCR (OR = 0.454, P = 0.012) were independent predictors for ypN0. The optimal time of SLNB and NAC in cN0 patients might be different among different molecular subtypes: it would be preferable to perform SLNB prior to NAC for HR+/HER2- patients, and SLNB after NAC for TN and HER2+ patients to reduce the risk of axillary lymph node dissection. In view of the high ypN0 rate in cN0 patients, axillary surgical staging might be selectively eliminated, especially for HER2+ and TN patients.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The evolving role of receptors as predictive biomarkers for metastatic breast cancer

INTRODUCTION

In breast cancer, estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) are essential biomarkers to predict response to endocrine and anti-HER2 therapies, respectively. In metastatic breast cancer, the use of these receptors and targeted therapies present additional challenges: temporal heterogeneity, together with limited sampling methodologies, hinders receptor status assessment, and the constant evolution of the disease invariably leads to resistance to treatment. Areas covered: This review summarizes the genomic abnormalities in ER and HER2, such as mutations, amplifications, translocations, and alternative splicing, emerging as novel biomarkers that provide an insight into underlying mechanisms of resistance and hold potential predictive value to inform treatment selection. We also describe how liquid biopsies for sampling of circulating markers and ultrasensitive detection technologies have emerged which complement ongoing efforts for biomarker discovery and analysis. Expert commentary: While evidence suggests that genomic aberrations in ER and HER2 could contribute to meeting the pressing need for better predictive biomarkers, efforts need to be made to standardize assessment methods and better understand the resistance mechanisms these markers denote. Taking advantage of emerging technologies, research in upcoming years should include prospective trials incorporating these predictors into the study design to validate their potential clinical value.

Meta-analysis of the effects of anti-epidermal growth factor receptor on recurrent/metastatic head and neck squamous cell carcinoma

BACKGROUND

We performed a meta-analysis to compare the efficacy and safety of anti-epidermal growth factor receptor (EGFR) therapy and non-anti-EGFR therapy in recurrent/metastatic (RM) head and neck squamous cell carcinoma (HNSCC).

METHODS

The Cochrane library, WanFang Data, PubMed, Medline, VIP, CBM, and EBSCO databases were searched for relevant studies. The objective response rate (ORR, defined as complete response or partial response according to RECTST version 1.1) and grade 3 to 4 adverse effects were used.

RESULTS

Ten studies involving 2260 patients were included. Primary meta-analysis showed that anti-EGFR therapy improved the ORR [odds ratio (OR): 1.79, 95% confidence interval 1.44-2.21, P <.00001]. Subgroup analyses revealed that the ORR of patients with RM HNSCC could be improved by monoclonal antibodies (OR: 1.89, 1.46-2.45, P <.00001) and tyrosine kinase inhibitors (OR: 1.57, 1.07-2.31, P = .02). Analysis of grade 3 to 4 adverse effects demonstrated that diarrhea (3.15, [1.90, 5.20]), rash/desquamation (13.66, [6.86, 27.20]), hypomagnesemia (1.83, [1.28, 2.62]), vomiting (1.99, [1.00, 3.95]), anorexia (3.34, [1.45, 7.73]), dehydration (2.22, [1.19, 4.12]), and hypokalemia (1.63, [1.09, 2.42]) were significantly associated with anti-EGFR therapy.

CONCLUSION

Anti-EGFR therapy is recommended for patients with RM HNSCC. Adverse effects, such as diarrhea, anorexia, hypomagnesemia, and hypokalemia, should be carefully monitored during anti-EGFR therapy.

Survival benefit of neoadjuvant chemotherapy for resectable breast cancer: A meta-analysis

BACKGROUND

Neoadjuvant chemotherapy (NAC) increases breast conservation rates in patients with resectable breast cancer at the associated cost of higher locoregional recurrence rates; however, the magnitude of the survival benefits of NAC for these patients remains undefined. Therefore, we aimed to clarify the survival benefit of NAC versus postoperative chemotherapy by conducting an updated meta-analysis of randomized clinical trials (RCTs).

METHODS

The authors searched the Cochrane Library, PubMed, Embase, Web of Science, Chinese biomedical literature database, and Chinese Scientific Journals full-text database from their inception to December 2016. The authors identified relevant RCTs that compared NAC with postoperative chemotherapy in the treatment of operable breast cancer. The main endpoints were overall survival (OS) and recurrence-free survival (RFS).

RESULTS

A total of 21 citations representing 16 unique studies were eligible. There were 787 deaths among 2794 patients assigned to NAC groups and 816 deaths among 2799 patients assigned to adjuvant chemotherapy groups. A meta-analysis of data indicated that there was no significant benefit in terms of OS ([hazard ratio [HR] = 1.03, 95% confidence interval [CI]: 0.94-1.13, P = .51) and RFS (HR = 1.01, 95% CI: 0.93-1.10, P = .80) between the NAC and postoperative chemotherapy groups. The pooled HR estimate for OS was not influenced by NAC cycles, the total number of chemotherapy cycles, administration of tamoxifen, administration of adjuvant chemotherapy, or type of NAC regimen. Subgroup analysis showed that the pooled HR estimate for RFS was influenced by anthracycline-containing regimens. Patients with a pathological complete response had superior survival outcomes compared with patients who had residual disease.

CONCLUSION

The survival benefits for patients with operable breast cancer who received either NAC or adjuvant chemotherapy based on anthracycline regimens were comparable.

Total pathological complete response versus breast pathological complete response in clinical trials of reference and biosimilar trastuzumab in the neoadjuvant treatment of breast cancer

INTRODUCTION

Trastuzumab is a key drug in the neoadjuvant treatment of breast cancers that overexpress the human epidermal growth factor receptor 2 (HER2). Pathological complete response (pCR) is commonly used as an endpoint in neoadjuvant clinical trials of trastuzumab as evidence suggests it may be a surrogate for long-term survival. Several biosimilar candidates of originator or 'reference' trastuzumab are in development and have used pCR as a primary endpoint to assess therapeutic equivalence between treatments. The exact definition of pCR has varied across studies. Areas covered: Here we look at the clinical relevance of pCR and compare rates of total pCR (defined as ypT0/is ypN0) and breast pCR (defined as ypT0/is) in clinical trials of reference and biosimilar trastuzumab. Expert commentary: In order to evaluate the efficacy of neoadjuvant systemic therapies in a uniform way, standardization of trial endpoints is necessary. Future studies in HER2-positive breast cancer should include full assessment of the breast and lymph node basin before and after neoadjuvant systemic therapy, and the use of total pCR as the primary outcome.

Advances in studies of tyrosine kinase inhibitors and their acquired resistance

Protein tyrosine kinase (PTK) is one of the major signaling enzymes in the process of cell signal transduction, which catalyzes the transfer of ATP-γ-phosphate to the tyrosine residues of the substrate protein, making it phosphorylation, regulating cell growth, differentiation, death and a series of physiological and biochemical processes. Abnormal expression of PTK usually leads to cell proliferation disorders, and is closely related to tumor invasion, metastasis and tumor angiogenesis. At present, a variety of PTKs have been used as targets in the screening of anti-tumor drugs. Tyrosine kinase inhibitors (TKIs) compete with ATP for the ATP binding site of PTK and reduce tyrosine kinase phosphorylation, thereby inhibiting cancer cell proliferation. TKI has made great progress in the treatment of cancer, but the attendant acquired acquired resistance is still inevitable, restricting the treatment of cancer. In this paper, we summarize the role of PTK in cancer, TKI treatment of tumor pathways and TKI acquired resistance mechanisms, which provide some reference for further research on TKI treatment of tumors.

Does dual HER-2 blockade treatment increase the risk of severe toxicities of special interests in breast cancer patients: A meta-analysis of randomized controlled trials

Although dual HER-2 blockade treatment could offer greater clinical efficacy in breast cancer, the risk of severe toxicities of special interest related to this combined regimen in breast cancer remained unknown. We systematically searched public databases (MEDLINE, EMBASE, Cochrane library) to identify relevant studies that comparing anti-HER2 monotherapy (lapatinib or trastuzumab or pertuzumab) with dual HER-2 blockade treatment (pertuzumab plus trastuzumab or trastuzumab plus lapatinib) in breast cancer. A total of 11,941 breast cancer patients from 9 trials were included for analysis. Meta-analysis showed that dual HER2 blockade treatment significantly increased the risk of severe diarrhea (OR 2.52, p<0.001) and treatment discontinuation (OR 1.52, p=0.014), but not for severe rash (OR 1.06, p=0.81), liver toxicities (OR 1.16, p=0.28), CHF (OR 1.46, p=0.09), LVEF decline (OR 1.09, p=0.40) and FAEs (OR 0.97, p=0.91). Similar results were observed in sub-group analysis according to anti-HER2 regimens in terms of severe diarrhea and treatment discontinuation. Additionally, trastuzumab plus lapatinib significantly increased the risk of LVEF decline in comparison with lapatinib alone (OR 1.48, p=0.002). Our analysis indicated that dual anti-HER2 blockade treatment significantly increased the risk of developing severe diarrhea and treatment discontinuation in comparison with anti-HER2 monotherapy. These were no evidence of an increased risk of fatal adverse events with dual-HER2 blockade treatment.

Systemic Therapies for Nonmetastatic Breast Cancer: The Role of Neoadjuvant and Adjuvant Chemotherapy and the Use of Endocrine Therapy

Breast cancer is a heterogenous disease, comprised of at least 3 major subtypes: hormone receptor-positive/HER2-(HR+), HER2+, and HR-/HER2-(triple negative) breast cancers. The medical management of each subype is distinct. In this article, we review contemporary data supporting the use of chemotherapy, endocrine therapy and biologic therapies, especially HER2-directed agents, in the adjuvant and neoadjuvant setting in patients with newly diagnosed nonmetastatic (stage I-III) breast cancer.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Evolution of anti-HER2 therapies for cancer treatment

The development of HER2-directed monoclonal antibodies and tyrosine kinase inhibitors have provided benefits to cancer patients, as well as produced many insights into the biology of the ErbB receptor family. Current therapies based on ErbB family members have resulted in improved overall survival with associated improvements in quality of life for the cancer patients that respond to treatment. Compared to monotherapy using either two antibodies to block the HER2 receptor blockade or combinatorial approaches with HER2 antibodies and standard therapies has provided additional benefits. Despite the therapeutic success of existing HER2 therapies, personalising treatment and overcoming resistance to these therapies remains a significant challenge. The heterogeneous intra-tumoural HER2 expression and lack of fully predictive and prognostic biomarkers remain significant barriers to improving the use of HER2 antibodies. Imaging modalities using radiolabelled pertuzumab and trastuzumab allow quantitative assessment of intra-tumoural HER2 expression, HER2 antibody saturation and the success of different drug delivery systems to be assessed. Molecular imaging with HER2 antibodies has the potential to be a non-invasive, predictive and prognostic technique capable of influencing therapeutic decisions, predicting response and failure of treatments as well as providing insights into receptor recycling and signalling. Similarly, conjugating HER2 antibodies with novel toxic payloads or combining HER2 antibodies with cellular immunotherapy provide exciting new opportunities for the management of tumours overexpressing HER2. Future research will lead to higher therapeutic responses, lower toxicities and providing insight into the mechanisms of resistance to HER2-targeted treatments.

The role of neratinib in HER2-driven breast cancer

Up to 25% of patients with early-stage HER2+ breast cancer relapse despite adjuvant trastuzumab-based regimens and virtually all patients with metastatic disease eventually die from resistance to existing treatment options. In addition, recent studies indicate that activating HER2 mutations without gene amplification could drive tumor growth in a subset of HER2-negative breast cancer that is not currently eligible for HER2-targeted agents. Neratinib is an irreversible HER kinase inhibitor with activity as extended adjuvant therapy following standard trastuzumab-based adjuvant treatment in a Phase III trial. Phase II trials of neratinib demonstrate promising activity in combination with cytotoxic agents in trastuzumab resistant metastatic HER2+ breast cancer, and either as monotherapy or in combination with fulvestrant for HER2-mutated breast cancers. We anticipate a potential role for neratinib in the therapy of these patient populations.

Synergistic anti-tumor activity of Nimotuzumab in combination with Trastuzumab in HER2-positive breast cancer

Breast cancer is characterized with poor prognosis and high recurrence. HER2 is highly expressed in breast cancer and is a target for cancer therapy and prevention. Here, we investigated the anti-tumor activity of the combination of an HER2 inhibitor, trastuzumab with an EGFR-inhibitor, nimotuzumab in HER2-overexpressing breast cancer. Our data showed that a greater anti-tumor activity from the combination of trastuzumab and nimotuzumab than any alone usage of above antibody both in vitro and in vivo. Based on the combination index value, our data demonstrated that nimotuzumab synergistically enhanced trastuzumab-induced cell growth inhibition. Furthermore, we investigated the possible mechanism of this synergistic efficacy induced by trastuzumab plus nimotuzumab. Data showed that the combination was more potent in reducing the phosphorylation of HER2 and ERK1/2. We also found that the synergistic inhibition was partly attributed to the ROS generation and repression of NRF2 pathway that is known to promote cell growth. These results support the clinical development of this two-drug regimen for the treatment of HER2-amplified breast cancer.

The use of systemic therapies to prevent progression of inflammatory breast cancer: which targeted therapies to add on cytotoxic combinations?

INTRODUCTION

Inflammatory breast cancer is a rare but frequently fatal disease, essentially because of its high ability to develop distant metastases. Even though the prognosis of IBC was significantly improved by multimodal management, including the systematic use of cytotoxic-based induction, the prognosis remains largely dismal. Areas covered: This review presents the main achievements in the systemic treatment of IBC during the past 30 years. It focuses more specifically on recent results obtained with targeted therapies, including anti-HER2 and anti-angiogenic agents. Novel approaches under investigation are presented. Expert commentary: Current management of IBC is subtype-specific and the largest benefit has been achieved in HER2-positive disease. The identification of breakthrough therapeutic advances is eagerly awaited and will require the development of IBC-specific clinical trials. Future clinical investigations should not only aim to increase the pathological response rate but also to eradicate distant metastases, which ultimately lead to patient death.

Efficacy and safety of lapatinib and trastuzumab for HER2-positive breast cancer: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVES

The anti-HER2 monoclonal antibody trastuzumab and the tyrosine kinase inhibitor lapatinib have complementary mechanisms of action and synergistic antitumour actively in models of HER2-positive breast cancer. However, the efficacy of trastuzumab in combination with lapatinib remains controversial. Therefore, we conducted this meta-analysis to compare combination treatment with lapatinib and trastuzumab to trastuzumab or lapatinib alone in the treatment of HER2-positive breast cancer.

METHODS

Randomised controlled trials (RCTs), published in PubMed, Embase and Web of Science, were systematically reviewed to assess the survival benefits and toxicity profile of HER2-positive patients with breast cancer who were treated with lapatinib and trastuzumab. Outcomes included pathological complete response (pCR), event-free survival (EFS), overall survival (OS) and toxicities. Results were expressed as the risk ratio (RR) or HR with 95% CIs. Pooled estimates were calculated by using a fixed-effects model or a randomised-effects model.

RESULTS

A total of 7 RCTs involving 2084 patients met the inclusion criteria and were included in this meta-analysis. The combination of lapatinib and trastuzumab significantly improved pCR (RR=1.43, 95% CI 1.23 to 1.67; p<0.001), EFS (HR=0.75, 95% CI 0.60 to 0.93; p=0.009) and OS (HR=0.72, 95% CI 0.56 to 0.93; p=0.011) in the treatment of HER2-positive breast cancer compared with trastuzumab or lapatinib alone. The combination treatment also increased the pCR irrespective of hormone receptor status and tumour size. More frequent grade 3 or 4 adverse events, including diarrhoea, rash or erythema, neutropenia and hepatic adverse events, were found in the combination group than in the trastuzumab or lapatinib group.

CONCLUSIONS

On the basis of the current evidence, our results reveal that the addition of lapatinib to trastuzumab can significantly improve pCR, EFS and OS with a tolerated toxicity in patients with HER2-positive breast cancer. Further well-conducted, large-scale trials are needed to validate these findings.

Use and outcomes of targeted therapies in early and metastatic HER2-positive breast cancer in Australia: protocol detailing observations in a whole of population cohort

BACKGROUND

The management of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has changed dramatically with the introduction and widespread use of HER2-targeted therapies. However, there is relatively limited real-world information on patterns of use, effectiveness and safety in whole of population cohorts. The research programme detailed in this protocol will generate evidence on the prescribing patterns, safety monitoring and outcomes of patients with BC treated with HER2-targeted therapies in Australia.

METHODS/DESIGN

Our ongoing research programme will involve a series of retrospective cohort studies that include every patient accessing Commonwealth-funded HER2-targeted therapies for the treatment of early BC and advanced BC in Australia. At the time of writing, our cohorts consist of 11 406 patients with early BC and 5631 with advanced BC who accessed trastuzumab and lapatinib between 2001 and 2014. Pertuzumab and trastuzumab emtansine were publicly funded for metastatic BC in 2015, and future data updates will include patients accessing these medicines. We will use dispensing claims for cancer and other medicines, medical service claims and demographics data for each patient accessing HER2-targeted therapies to undertake this research.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Population Health Service Research Ethics Committee and data access approval has been granted by the Australian Department of Human Services (DHS) External Review Evaluation Committee. Our findings will be reported in peer-reviewed publications, conference presentations and policy forums. By providing detailed information on the use and outcomes associated with HER2-targeted therapies in a national cohort treated in routine clinical care, our research programme will better inform clinicians and patients about the real-world use of these treatments and will assist third-party payers to better understand the use and economic costs of these treatments.

Effects of lapatinib or trastuzumab, alone and in combination, in human epidermal growth factor receptor 2-positive breast cancer: a meta-analysis of randomized controlled trials

This meta-analysis compared the efficiency and safety of lapatinib and trastuzumab, alone or in combination, administered with neoadjuvant chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. For dichotomous variables, the relative risk ratio (RR) and 95% confidence interval (CI) were used to investigate outcome measures: pathological complete response (pCR), neutropenia, diarrhea, dermatologic toxicity, and congestive heart failure (CHF). Eight randomized controlled trials of 2350 participants (837 receiving lapatinib, 913 trastuzumab, and 555 combination therapy) were selected to compare the efficiency and safety of lapatinib to trastuzumab. A significant difference was found between lapatinib and trastuzumab for pCR (RR = 0.82, 95% CI: 0.73-0.93; Z = 3.00; P = 0.003). In six studies, a significant difference was found between trastuzumab and combination therapy for pCR (RR = 1.33, 95% CI: 1.18-1.50; Z = 4.70; P < 0.00001), diarrhea (RR = 14.59, 95% CI: 7.69-27.67; Z = 8.20; P < 0.00001), and dermatologic toxicity (RR = 3.10, 95% CI: 1.61-5.96; Z = 3.39; P = 0.007), but none was found for neutropenia (RR = 1.38, 95% CI: 0.82-2.31; Z = 1.22; P = 0.22) or CHF (RR = 0.14, 95% CI: 0.02-1.17; Z = 1.02; P = 0.07). Combination therapy compared to trastuzumab alone increases the pCR rate of HER2-positive breast cancer patients with no additional cardiac events. Trastuzumab, which is still the first-line therapy in breast cancer, increases the pCR rate more than lapatinib.

Escalating and de-escalating treatment in HER2-positive early breast cancer

The current standard adjuvant systemic treatment of early HER2-positive breast cancer consists of chemotherapy plus 12months of trastuzumab, with or without endocrine therapy. Several trials have investigated modifications of the standard treatment that are shorter and less resource-demanding (de-escalation) or regimens that aim at dual HER2 inhibition or include longer than 12months of HER2-targeted treatment (escalation). Seven randomized trials investigate shorter than 12months of trastuzumab treatment duration. The shorter durations were not statistically inferior to the 1-year duration in the 3 trials with survival results available, but 2 of the trials were small and 1 had a relatively short follow-up time of the patients at the time of reporting. The pathological complete response (pCR) rates were numerically higher in all 9 randomized trials that compared chemotherapy plus dual HER2 inhibition consisting of trastuzumab plus either lapatinib, neratinib, or pertuzumab with chemotherapy plus trastuzumab as neoadjuvant treatments, but the superiority of chemotherapy plus dual HER2-inhibition over chemotherapy plus trastuzumab remains to be demonstrated in the adjuvant setting. One year of adjuvant trastuzumab was as effective as 2years of trastuzumab in the HERA trial, and was associated with fewer side-effects. Extending 1-year adjuvant trastuzumab treatment with 1year of neratinib improved disease-free survival in the ExteNET trial, but the patient follow-up times are still short, and no overall survival benefit was reported. Several important trials are expected to report results in the near future and may modify the current standard.

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NEOADJUVANT CHEMOTHERAPY IN HER2-POSITIVE AND TRIPLE-NEGATIVE BREAST CANCER: Neoadjuvant chemotherapy is a standard option in the management of operable breast cancer, as effective as adjuvant chemotherapy in term of survival and with the potential to increase the rate of breast conservation. In HER2+ and triple-negative breast cancers, neoadjuvant chemotherapy is associated with a high probability of pathological complete response, which strongly predicts survival outcome. In HER2+ breast cancer, trastuzumab, in combination with neoadjuvant chemotherapy, mostly anthracyclines and taxane-based, demonstrated a significant increase in pathological complete response rate. Recently, dual HER2 blockade strategies (lapatinib-trastuzumab or pertuzumab-trastuzumab) demonstrated a significant improvement in terms of pathological complete response over trastuzumab. In triple-negative breast cancer, recent data indicate that incorporating platinum compounds to neoadjuvant chemotherapy also significantly improves this parameter. Yet, in both subtypes, whether these substantial improvements may lead to significant benefits in terms of survival and breast conserving surgery remains to be demonstrated.

A mini-review on factors and countermeasures associated with false-negative sentinel lymph node biopsies in breast cancer

Sentinel lymph node biopsy (SLNB) is a new surgical technique for local axillary lymph nodes (ALNs) of breast cancer. Large-scale clinical trials have confirmed that undergoing SLNB and ALN dissection (ALND) showed no significant difference for sentinel lymph node (SLN)-negative patients in terms of disease-free survival, overall survival and recurrence-free survival. However, false-negative results are still the main concern of physicians as well as patients who undergo SLNB instead of ALND. The American Society of Breast Surgeons established a task force to suggest acceptable standards for SLNB. In 2000, the task force recommended that the identification rate for SLNB be 85% or higher and the false-negative rate be 5% or lower. This review focuses on clinical factors (tumor volume, multifocal/multi-center cancers, neoadjuvant chemotherapy and skip metastasis), tracer techniques and pathological factors affecting SLNB and explores methods for reducing the false-negative rate.

The efficiency and safety of trastuzumab and lapatinib added to neoadjuvant chemotherapy in Her2-positive breast cancer patients: a randomized meta-analysis

Background

The addition of human epidermal growth factor receptor 2 (Her2) therapies to neoadjuvant chemotherapy (NAC) during treatment of Her2-positive breast cancer has been proposed as an effective way to improve the prognosis. However, the treatment outcomes of adding trastuzumab, lapatinib, or both to NAC were not unequivocal in randomized clinical trials. Based on these data, a meta-analysis was performed.

Objective

The main objective was to evaluate the efficiency and safety of trastuzumab and lapatinib added to NAC for treatment of Her2-positive breast cancer.

Methods

ClinicalTrials.gov and PubMed were searched for randomized clinical trials that compared trastuzumab, lapatinib, or both, added to NAC. The main endpoint was a pathologically complete response (pCR) rate, in breast only or in breast and lymph nodes. The drug safety and the influence of hormone-receptor status, comparing the clinical response and the rate of breast conservation, were evaluated.

Results

A total of eight publications were included in the primary analysis, designed as two or three subgroups. The cumulative cases were 2,349 and the analyses of all the clinical trials showed that the pCR rate was significantly higher in the group receiving trastuzumab than that in the group with lapatinib, either in breast only (P=0.001) or in breast and lymph nodes (P=0.0001). Similar results could be seen in comparisons of the combination versus trastuzumab group. Further studies of subgroups divided into hormone receptor-positive or-negative patients showed that the addition of trastuzumab or dual Her2-targeted therapy significantly improved the pCR rate in patients who were hormone-insensitive. Regarding the toxic effects, we found more grade 3 and 4 toxic effects, such as diarrhea, skin disorder, and hepatic biochemical changes in the lapatinib and combination groups. No temporally significant differences were found when the clinical response and the rate of breast conservation in the groups were analyzed.

Conclusion

The combination of trastuzumab and lapatinib was superior to single-agent treatment for improved pCR rate. However, combination treatment was not effective in improving the rate of breast conservation. Furthermore, a higher risk for toxicity was associated with combined administration.

Minimal residual disease in breast cancer: an overview of circulating and disseminated tumour cells

Within the field of cancer research, focus on the study of minimal residual disease (MRD) in the context of carcinoma has grown exponentially over the past several years. MRD encompasses circulating tumour cells (CTCs)—cancer cells on the move via the circulatory or lymphatic system, disseminated tumour cells (DTCs)—cancer cells which have escaped into a distant site (most studies have focused on bone marrow), and resistant cancer cells surviving therapy—be they local or distant, all of which may ultimately give rise to local relapse or overt metastasis. Initial studies simply recorded the presence and number of CTCs and DTCs; however recent advances are allowing assessment of the relationship between their persistence, patient prognosis and the biological properties of MRD, leading to a better understanding of the metastatic process. Technological developments for the isolation and analysis of circulating and disseminated tumour cells continue to emerge, creating new opportunities to monitor disease progression and perhaps alter disease outcome. This review outlines our knowledge to date on both measurement and categorisation of MRD in the form of CTCs and DTCs with respect to how this relates to cancer outcomes, and the hurdles and future of research into both CTCs and DTCs.

Axillary Staging After Neoadjuvant Chemotherapy for Breast Cancer: A Pilot Study Combining Sentinel Lymph Node Biopsy with Radioactive Seed Localization of Pre-treatment Positive Axillary Lymph Nodes

BACKGROUND

Neoadjuvant chemotherapy (NAC) downstages axillary disease in 55 % of node-positive (N1) breast cancer. The feasibility and accuracy of sentinel lymph node biopsy (SLNB) after NAC for percutaneous biopsy-proven N1 patients who are clinically node negative (cN0) by physical examination after NAC is under investigation. ACOSOG Z1071 reported a false-negative rate of <10 % if ≥3 nodes are removed with dual tracer, including excision of the biopsy-proven positive lymph node (BxLN). We report our experience using radioactive seed localization (RSL) to retrieve the BxLN with SLNB (RSL/SLNB) for cN0 patients after NAC.

METHODS

We performed a retrospective review of a single-institution, prospectively maintained registry for the years 2013 to 2014. Patients with BxLN who received NAC and had RSL/SLNB were identified. All BxLNs were marked with a radiopaque clip before NAC to facilitate RSL.

RESULTS

Thirty patients with BxLN before NAC were cN0 after NAC and underwent RSL/SLNB. Median age was 55 years. Disease stage was IIA-IIIB. Twenty-nine of 30 had ductal cancer (12 triple negative and 16 HER-2 positive). One to 11 nodes were retrieved. Twenty-nine of 30 BxLN were successfully localized with RSL. Note was made of the BxLN-containing isotope and/or dye in 22 of 30. Nineteen patients had no residual axillary disease; 11 had persistent disease. All who remained node positive had disease in the BxLN.

CONCLUSIONS

RSL/SLNB is a promising approach for axillary staging after NAC in patients whose disease becomes cN0. The status of the BxLN after NAC predicted nodal status, suggesting that localization of the BxLN may be more accurate than SLNB alone for staging the axilla in the cN0 patient after NAC.

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.