A prospective feasibility study of sentinel node biopsy by modified Indigocarmine blue dye methods after neoadjuvant chemotherapy for breast cancer

Performance of sentinel lymph node biopsy after neoadjuvant chemotherapy in clinically node-positive breast cancer patients: systematic review and meta-analysis

BACKGROUND

The reliability of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) in patients with initially node-positive breast cancer is still controversial. This meta-analysis is conducted to investigate the feasibility and accuracy of SLNB after NACT in patients with initially positive axillary nodes.

METHODS

We conducted a literature search using Medline, PubMed, Embase, Central, and SCOPUS up until April 2021 for studies on the performance of SLNB following NACT. We included prospective studies including breast cancer patients with positive lymph nodes at diagnosis and received NACT before undergoing SLNB irrespective of their molecular subtypes or stage. Our main outcomes of interest were the identification rate (IR) and the false negative rate (FNR) of SLNB.

RESULTS

We included an aggregate of 33 studies in this meta-analysis enrolling 4624 patients. The reported IR ranged from a minimum of 77.6% to a maximum of 100% and resulted in a pooled IR of 88% (95% confidence interval [CI]: 86-90, I2 : 80.9%). The FNR reported in the studies ranged from a minimum of 5.1% to a maximum of 43% and showed a pooled FNR of 13% (95% CI: 11-15, I2 : 72.31%). The subgroup analysis demonstrated that the usage of dual mapping technique could decrease the FNR and increase the IR. Moreover, the number of lymph nodes retrieved inversely correlated with FNR ( P < 0.01).

CONCLUSIONS

Our findings support the feasibility and accuracy of SLNB after NACT in initially node-positive breast cancer patients, that converted to clinically node-negative when performed in properly selected cases. SLNB offers a less invasive approach in selected patients sparing them the morbidity associated with ALND. This approach aligns with efforts to de-escalate surgical management in breast cancer and reinforces that SLNB post-NACT should be incorporated into clinical practice, provided that stringent patient selection and procedural standards are maintained.

The efficacy and oncological safety of minimally invasive axillary procedures in patients with node-positive breast cancer receiving neoadjuvant chemotherapy: A network meta-regression and trial sequential analysis

BACKGROUND

Neoadjuvant chemotherapy (NAC) can downstage axillary nodes in breast cancer, prompting debate over the optimal axillary management after NAC. While axillary dissection (ALND) provides detailed assessment of node status, minimally invasive methods such as sentinel lymph node biopsy (SLNB), marked lymph node biopsy (MLNB) and targeted axillary dissection (TAD) are showing promise. This meta-analysis aims to assess the efficacy and safety of these strategies.

METHODS

A systematic search of Medline, Embase and Cochrane Central was conducted and relevant RCTs were identified. Random-effects meta-analysis, meta-regression and trial sequential analysis (TSA) were conducted for diagnostic outcomes (identification rates [IFR], false negative rates [FNR] and negative predictive value [NPV]) and survival outcomes (overall survival [OS], disease-free survival [DFS]) to compare SLNB, MLNB and TAD with ALND.

RESULTS

Twenty-eight studies (SLNB, n = 3392; MLNB, n = 1130; TAD, n = 946) investigated diagnostic outcomes and nine studies investigated survival outcomes (n = 5647). The pooled IFR, FNR and NPV of TAD was 96.8 %, 4.7 % and 93.2 %, respectively, and all values were superior to SLNB (91.9 %, 13.7 % and 84.8 %; meta-regression, p < 0.001) (SLNB vs. MLNB concordance = 73 %). The FNR of SLNB decreased with the number of nodes removed (≥3 nodes, 8.1 %) but remained inferior to TAD (p = 0.001). The IFR of SLNB in the ycN0 group was statistically lower than all patients (ycN0/+), 85.8 % vs. 91.9 % (p < 0.001). Pooled hazard ratios for DFS in SLNB/TAD, SLNB and TAD were 0.90 (95%CI, 0.77-1.04; p = 0.45), 0.89 (95%CI, 0.74-1.08; p = 0.25) and 0.91 (95%CI, 0.64-1.29; p = 0.58) (TSA 2.08>threshold). Indirect comparison between TAD and SLNB demonstrated no significant difference in DFS (HR 0.98; 0.64-1.32; 95%CI, p = 0.95).

CONCLUSION

Targeted axillary dissection is the optimal minimally invasive axillary technique in terms of diagnostic accuracy. De-escalation of axillary surgery following NAC does not negatively impact DFS in patients with node-positive breast cancer.

Feasibility of an indocyanine green-hyaluronic acid mixture (LuminoMark™) for targeting suspicious axillary lymph nodes in patients with breast cancer

PURPOSE

During breast cancer surgery, the use of dyes such as indigo carmine, methylene blue, or indocyanine green (ICG) for targeting axillary lymph nodes (ALNs) under ultrasound guidance can result in rapid diffusion, complicated tissue differentiation, and disruption of staining. LuminoMark™, a novel ICG-hyaluronic acid mixture, can provide real-time visualization and minimize dye spread, thereby ensuring a clear surgical field. The aim of our study was to evaluate the efficacy of LuminoMark™ for targeting ALNs in patients with breast cancer.

METHODS

A total of 13 patients with breast cancer (mean age 56.5 years; 92.3% female) and suspicious ALNs underwent targeted axillary surgery (TAS) with activated charcoal and LuminoMark™ injected into the LNs in the surgical field. The clinicopathological variables of the patients and diagnostic performance were assessed. The LNs injected with LuminoMark™ were examined for consistency with sentinel LNs (SLNs) and non-SLNs, as well as with charcoal-tattooed LNs.

RESULTS

The identification of SLNs took approximately 15.6 min from the start of skin incision, and it required 25.6 and 17.7 min, for charcoal-tattooed and LuminoMarkTM-illuminated LNs, respectively. The identification rate was 92.3% with charcoal and 100% with LuminoMark™. The concordance rate between LuminoMark™ illumination and SLNs was higher than that between charcoal tattooing and SLNs. The concordance rate between the two methods was 76.9% (n = 10). Three months after surgery, the charcoal tattoo remained visible on the skin; however, LuminoMark™ was not visible.

CONCLUSION

Although both methods demonstrated high detection rates, the rate was higher using LuminoMark™. As LuminoMark™ was administered directly into LNs, this improved the accuracy of identifying LNs.

The Feasibility and Reliability of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Breast Cancer Patients With Negative Axillary Lymph Nodes-A Meta-analysis

Background

The application of sentinel lymph node biopsy (SLNB) has expanded from early breast cancer to locally advanced breast cancer with neoadjuvant chemotherapy (NAC). For patients with negative axillary lymph nodes, performing SLNB before or after NAC remains controversial.

Objectives

To evaluate the diagnostic feasibility and reliability of SLNB after NAC in breast cancer patients with negative axillary nodes at initial diagnosis.

Design

To calculate pooled identification rate (IR) and false negative rate (FNR) of SLNB after NAC on breast cancer patients with initially negative axillary nodes by enrolling relevant studies and perform subgroup analysis by the type of tracer and the number of biopsied sentinel lymph nodes in average.

Data sources and methods

The PubMed, Embase, Cochrane, Web of Science, and Scopus databases from January 1, 2002, to March 1, 2022, were searched for studies. The QUADAS-2 tool and MINORS item were employed to evaluate the quality of the included studies. I2 and Q tests were used to evaluate the heterogeneity among the studies. Random-effects model and fixed-effects model were employed to calculate the pooled IR, FNR, and 95% confidence interval (CI). Publication bias was evaluated, and sensitivity analysis was performed. Subgroup analysis was performed according to the type of tracer (single/double) and the number of biopsied sentinel lymph nodes in average (⩽2/>2).

Results

A total of 21 studies covering 1716 patients were enrolled in this study (IR = 93%, 95% CI = 90-96; FNR = 8%, 95% CI = 6-11).

Conclusion

The SLNB after NAC can serve as a feasible and reliable approach in breast cancer patients with negative axillary lymph node. In our study, no significant impact of tracer was found on the IR and FNR of SLNB, and the number of biopsy nodes >2 leads to the decreased FNR of SLNB.

Localization of Ectopic Mediastinal Parathyroid Adenomas Using Indigo Carmine Injection for Surgical Management: A Preliminary Report

An ectopic parathyroid adenoma (EPA) is a rare entity. The aim of this study was to report our experience in the preoperative localization and surgical management of EPAs. This was a multicenter retrospective study involving patients diagnosed with an EPA (three males and seven females) from January 2005 to November 2021. The clinical features, preoperative management, and surgical procedures were analyzed. A cervical neck ultrasound was performed in all patients and showed a focus in eight patients. Cervicothoracic enhanced computed tomography was performed in all patients and showed a focus in nine patients. The ^99mTc-MIBI scintigraphy was performed in eight patients and showed uptake in six of them. We performed a neck dissection and thoracotomy in one patient, a thoracoscopy in one patient, surgery with a focused approach in seven patients, four of whom were injected with indigo carmine blue, and surgery with a bilateral approach in one patient. 1 h following the parathyroidectomy, the parathyroid hormone (PTH) concentration was decreased to 40–80% of the baseline value. Establishing a preoperative diagnosis of an EPA is challenging for the surgeon, despite the progress in the morphologic assessment. An intraoperative PTH assay and injection of indigo carmine have been shown to be valuable tools in the appropriate surgical management of an EPA.

Nanoparticle-assisted axillary staging: an alternative approach after neoadjuvant chemotherapy in patients with pretreatment node-positive breast cancers

PURPOSE

In order to achieve an optimized method of axillary staging after neoadjuvant chemotherapy (NAC) in breast cancer patients with pretreatment positive axillary lymph nodes, we evaluated the feasibility and accuracy of nanoparticle-assisted axillary staging (NAAS) which combines carbon nanoparticles with standard sentinel lymph node biopsy (SLNB) with radioisotope and blue dye.

METHODS

Invasive breast cancer patients with pre-NAC positive axillary lymph nodes who converted to ycN0 and received surgeries from November 2020 to March 2021 were included. All patients underwent ipsilateral NAAS followed by axillary lymph node dissection. Detection rate (DR), false-negative rate (FNR), negative predictive value (NPV) and accuracy of axillary staging were calculated.

RESULTS

Eighty of 136 (58.8%) breast cancer patients converted to ycN0 after NAC and received NAAS. The DR, NPV and accuracy was 95.0%, 93.3% and 97.4% for NAAS, respectively. And the FNR was 4.2% (2/48) for NAAS, which was lower than that of standard dual-tracer SLNB (SD-SLNB) (9.5%, 4/42). Pretreatment clinical T4 classification was a risk factor for detection failure in NAAS (p = 0.016). When patients with pretreatment inflammatory breast cancers were excluded from analysis, FNR dropped to 2.2% (1/45) for NAAS.

CONCLUSION

NAAS revealed great performance in invasive breast cancer patients with pre-NAC positive axillary lymph nodes who converted to ycN0. The application of NAAS reached a better balance between more accurate axillary evaluation and less intervention. Trial registration Chictr.org.cn (ChiCTR2000039814). Registered Nov 11, 2020.

Outcomes of Sentinel Node Biopsy for Women with Breast Cancer After Neoadjuvant Therapy: Systematic Review and Meta-Analysis of Real-World Data

BACKGROUND

Evidence on the accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant therapy (NAT) for patients with breast cancer is inconclusive. This study reviewed the real-world data to determine the acceptability of SLNB after NAT.

METHODS

The study searched for articles in the PubMed, EMBASE, and Cochrane Library databases. The primary outcomes were the identification rate for sentinel lymph nodes (SLNs) and the false-negative rate (FNR) for SLNB. The study also evaluated the FNR in subgroups defined by tumor stage, nodal stage, hormone receptor status, human epidermal growth factor receptor-2 status, tumor response, mapping technique, and number of SLNs removed.

RESULTS

The study retrieved 61 prospective and 18 retrospective studies with 10,680 initially cN± patients. The pooled estimate of the identification rate was 0.906 (95 % confidence interval [CI], 0.891-0.922), and the pooled FNR was 0.118 (95 % CI, 0.103-0.133). In subgroup analysis, the FNR was significantly higher for the patients with estrogen receptor (ER)-negative status and fewer than three SLNs removed. The FNR did not differ significantly between the patients with and those without complete tumor response. Among the patients with initial clinical negative axillary lymph nodes, the incidence of node metastasis was 26.8 % (275/1041) after NAT.

CONCLUSION

Real-world evidence indicates that the FNR of SLNB after NAT in breast cancer is 11.8 %, exceeding only slightly the commonly adopted threshold of 10 %. The FNR is significantly higher for patients with ER-negative status and removal of fewer than three SLNs. Using a dual tracer and removing at least three SLNs may increase the accuracy of SLNB after NAT.

Nomogram for predicting axillary lymph node pathological response in node-positive breast cancer patients after neoadjuvant chemotherapy

Background:

Pathological complete response (pCR) of axillary lymph nodes (ALNs) is frequently achieved in patients with clinically node-positive breast cancer after neoadjuvant chemotherapy (NAC), and ALN status is an important prognostic factor for breast cancer patients. This study aims to develop a new predictive clinical model to assess the ALN pCR rate after NAC.

Methods:

This was a retrospective series of 467 patients who had biopsy-proven positive ALNs at diagnosis and underwent ALN dissection from 2007 to 2014 at the National Cancer Center/Cancer Hospital of the Chinese Academy of Medical Sciences. We analyzed the clinicopathologic features of the patients and developed a nomogram to predict the probability of ALN pCR. A multivariable logistic regression stepwise model was used to construct a nomogram to predict ALN pCR in node-positive patients. The adjusted area under the receiver operating characteristic curve (AUC) was calculated to quantify the ability to rank patients by risk. Internal validation was performed using the 50/50 hold-out validation method. The nomogram was externally validated with prospective cohorts of 167 patients from 2016 to 2018 at the Cancer Hospital of the Chinese Academy of Medical Sciences and 114 patients from 2018 to 2020 at Beijing Tiantan Hospital.

Results:

In this retrospective study, 115 (24.6%) patients achieved ALN pCR after NAC. Multivariate analysis showed that clinical tumor stage (Odds ratio [OR]: 0.321, 95% confidence interval [CI]: 0.121–0.856; P = 0.023); primary tumor response (OR: 0.189; 95% CI: 0.123–0.292; P < 0.001), and estrogen receptor status (OR: 0.530, 95% CI: 0.304–0.925; P = 0.025) were independent predictors of ALN pCR. The nomogram was constructed based on the result of multivariate analysis. In the internal validation of performance of nomogram, the AUCs for the training and test sets were 0.719 and 0.753, respectively. The nomogram was validated in external cohorts with AUCs of 0.720, which demonstrated good discriminatory power in these data sets.

Conclusion:

We developed a nomogram to predict the likelihood of axillary pCR in node-positive breast cancer patients after NAC. The predictive model performed well in multicenter prospective external validation. This practical tool could provide information to surgeons regarding whether to perform additional ALN dissection after NAC.

Trial registration:

ChiCTR.org.cn, ChiCTR1800014968.

Techniques for sentinel node biopsy in breast cancer

INTRODUCTION

Sentinel node biopsy (SNB) is the standard of care in women with breast cancer (BC) and clinically non suspicious axillary lymph nodes (LNs), due to its high negative predictive value (NPV) in the assessment of nodal status. SNB has significantly reduced complications related to the axillary lymph node dissection, such as lymphedema and upper limb dysfunction.

EVIDENCE ACQUISITION

The gold standard technique for SNB is the blue dye (BD) and technetium labelled nanocolloid (Tc-99m) double technique. However, nuclear medicine is not available in all Institutions and several new tracers and devices have been proposed, such as indocyanine green (ICG) and superparamagnetic iron oxides (SPIO). All these techniques show an accuracy and detection rate not inferior to that of the standard technique, with different specific pros and cons. The choice of how to perform a SNB primarily depends on the surgeon's confidence with the procedure, the availability of nuclear medicine and the economic resources of the Institutions. In this setting, new tracers, hybrid tracers and imaging techniques are being evaluated in order to improve the detection rate of sentinel lymph nodes (SNs) and minimize the number of unnecessary axillary surgeries through an accurate preoperative assessment of nodal status and to guide new minimally invasive diagnostic procedures of SNs. In particular, the contrast-enhanced ultrasound (CEUS) is an active field of research but cannot be recommended for clinical use at this time.

EVIDENCE SYNTHESIS

The ICG fluorescence technique was superior in terms of DR, as well as having the lowest FNR. The DR descending order was SPIO, Tc, dual modality (Tc/BD), CEUS and BD.

CONCLUSIONS

This paper is a narrative review of the most common SNB techniques in BC with a focus on recent innovations.

Assessment of sentinel lymph node biopsy after neoadjuvant chemotherapy for breast cancer in two subgroups: Initially node negative and node positive converted to node negative - A systemic review and meta-analysis

BACKGROUND

Neoadjuvant chemotherapy (NAC) is increasingly used to treat patients with breast cancer, but the reliability of sentinel lymph node biopsy (SLNB) following chemotherapy is in doubt. In this meta-analysis, we aimed to evaluate studies that examine the results of SLNB after NAC to assess identification rate (IR) and false-negative rate (FNR).

MATERIALS AND METHODS

Systemic searches were performed in the PubMed, ISI Web of Sciences, Scopus, and Cochrane databases from January 1, 2000, to November 30, 2016, for studies of SLNB after NAC for breast cancer and followed by axillary lymph node (LN) dissection in two subgroups: initially node negative and node positive converted to node negative. Two reviewers independently review quality of included studies. A random-effects model was used to pool IR and FNR with 95% confidence intervals (CI), and heterogeneity among studies was assessed by I 2 and Q-test.

RESULTS

A total of 23 studies with 1521 patients in the initially node-negative subgroup and 13 studies with 1088 patients in the node-positive converted to node-negative subgroup, were included in this meta-analysis with IR and FNR of 94% (95% CI: 92-96) and 7% (95% CI: 5-9) in the initially node-negative subgroup and 89% (95% CI: 85-94) and 13% (95% CI: 7-18) in the node-positive converted to node-negative subgroup, respectively.

CONCLUSION

Our meta-analysis showed acceptable IR and FNR in initially node-negative group and it seems feasible in these patients, but these parameters did not reach to predefined value in node-positive converted to node-negative group, and thus, it is not recommended in these patients.

Comparison of the indocyanine green dye method versus the combined method of indigo carmine blue dye with indocyanine green fluorescence imaging for sentinel lymph node biopsy in breast conservative therapy for stage ≤IIA breast cancer

BACKGROUND

Fluorescence imaging (FI) is one of the methods to identify sentinel lymph nodes (SLNs). However, the procedure is technically complicated and requires procedural skills, as SLN biopsy must be conducted in dim light conditions. As an improved version of this method, we introduced a combined method (Combined mixed dye and fluorescence; CMF) consisting of indigo carmine blue dye and FI. The direct visualization of SLNs under shadowless surgical light conditions is facilitated by the addition of the blue dye. We compared the SLN detection rates of CMF with that of the indocyanine green (ICG) dye method (ICG-D).

METHODS

A total of 202 patients with stage ≤IIA breast cancer who underwent breast conservative therapy with separate incision from January 2004 to February 2017 were reviewed. Details of the two methods are as follows: (1) ICG-D: 10 mg of ICG was used and the green-stained SLNs were resected via a 3-4 cm axillary incision; (2) CMF: A combination of 5 mg of ICG and 4-8 mg of indigo carmine was used. After a 1.5-2 cm incision was made near the point of disappearance of the fluorescence using Photodynamic Eye (PDE), the blue-stained SLNs were resected under shadowless surgical light conditions.

RESULTS

There were 92 ICG-D and 110 CMF cases. CMF resulted in a significantly higher SLN detection rate than ICG-D (96.4% vs. 83.7%; p = 0.003). This difference was particularly notable in those aged ≥60 years (98.3% vs. 74.3%) and individuals with body mass index (BMI) ≥25 kg/m² (90.3% vs. 58.3%).

CONCLUSION

CMF is an effective method to identify SLNs which is safe and efficient. CMF achieves a high SLN identification rate and most of this procedure is feasible under shadowless surgical light conditions. CMF can reliably perform SLN biopsy even in those aged ≥60 years and individuals with BMI ≥ 25 kg/m².

Evolution in sentinel lymph node biopsy in breast cancer

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in clinically node-negative (cN0) breast cancer patients without neoadjuvant chemotherapy (NAC). The application of SLNB in patients receiving NAC has also been explored. Evidence supports its use after NAC in pretreatment cN0 patients. Nonetheless, its routine use in all the pretreatment node-positive patients who become cN0 after NAC is unjustified due to the unacceptably high false-negative rate, which can be improved in a subset of patients. Axillary surgery omission in selected patients with a low risk of ALN metastasis has gained more and more research interest because the SLNs are tumor-free in more than 70% of all patients. To avoid drawbacks of conventional mapping methods, novel techniques for SLN detection have been developed and shown to be highly accurate in patients with early breast cancer. This article reviews the progress in SLNB in patients with breast cancer.

Sentinel node biopsy for axillary management after neoadjuvant therapy for breast cancer: a single-center retrospective analysis with long follow-up

PURPOSE

Sentinel node biopsy (SNB) after neoadjuvant therapy (NAT) for breast cancer remains controversial. We conducted a retrospective study of patients who underwent SNB after NAT to evaluate the effectiveness of this procedure.

METHODS

A consecutive 105 women with locally advanced breast cancer (cT1-4, cN0-3, M0) were treated with NAT between 2006 and 2015. The subjects were 80 of these patients who became or remained clinically node-negative after NAT, 53 of whom had axillary management determined by SNB (group A) and the other 27 underwent axillary lymph node dissection (ALND) without SNB (group B). SNB was performed using a modified dye method.

RESULTS

The sentinel node (SN) identification rate was 94.3% and the mean number of removed SNs was 2.4. ALND was avoided in 33 patients, who were confirmed as SN-negative. There was no difference in recurrence-free and overall survival rates between groups A and B (p = 0.71 and p = 0.46, respectively) during the median follow-up time of 63 months. Of the 33 patients who did not undergo ALND, 10 suffered recurrence (33%). One patient (3%) had recurrence in an axillary lymph node and four had recurrence in a supraclavicular lymph node.

CONCLUSION

Axillary SNB after NAT did not affect the axillary failure rate or the prognosis. SNB may be a reliable procedure, even after NAT.

The Feasibility and Accuracy of Sentinel Lymph Node Biopsy in Initially Clinically Node-Negative Breast Cancer after Neoadjuvant Chemotherapy: A Systematic Review and Meta-Analysis

Background

With the increased use of neoadjuvant chemotherapy (NAC) in breast cancer, the timing of sentinel lymph node biopsy (SLNB) has become increasingly important. In this study, we aimed to evaluate the feasibility and accuracy of SLNB for initially clinically node-negative breast cancer after NAC by conducting a systematic review and meta-analysis.

Methods

We searched PubMed, Embase, and the Cochrane Library from January 1, 1993 to November 30, 2015 for studies on initially clinically node-negative breast cancer patients who underwent SLNB after NAC followed by axillary lymph node dissection (ALND).

Results

A total of 1,456 patients from 16 studies were included in this review. The pooled identification rate (IR) for SLNB was 96% [95% confidence interval (CI): 95%-97%], and the false negative rate (FNR) was 6% (95% CI: 3%-8%). The pooled sensitivity, negative predictive value (NPV) and accuracy rate (AR) were 94% (95% CI: 92%-97%, I² = 27.5%), 98% (95% CI: 98%-99%, I² = 42.7%) and 99% (95% CI: 99%-100%, I² = 32.6%), respectively. In the subgroup analysis, no significant differences were found in either the IR of an SLNB when different mapping methods were used (P = 0.180) or in the FNR between studies with and without immunohistochemistry (IHC) staining (P = 0.241).

Conclusion

Based on current evidence, SLNB is technically feasible and accurate enough for axillary staging in initially clinically node-negative breast cancer patients after NAC.

Myricetin suppresses p21-activated kinase 1 in human breast cancer MCF-7 cells through downstream signaling of the β-catenin pathway

As a main active compound in the bark of waxberry (Myrica rubra), myricetin is a macrocyclic diarylheptanoid, and can trigger the apoptosis of HeLa and PC3 cells. The aim of the present study was to elucidate the anticancer effect of myricetin on human breast cancer MCF-7 cells and to explore the possible mechanisms of action. MCF-7 cells were treated with different concentrations of myricetin (0-80 µM) for 12, 24 and 48 h. In the present study, we found that myricetin suppressed the cell viability of the MCF-7 cells at least partly through the induction of apoptosis as determined by MTT assay and flow cytometry. Western blot analysis revealed that myricetin effectively suppressed the protein expression of p21-activated kinase 1 (PAK1), MEK and phosphorylated extracellular mitogen-activated protein kinase (ERK1/2). In addition, treatment of myricetin activated glycogen synthase kinase-3β (GSK3β) and Bax protein expression, and inhibited β-catenin/cyclin D1/proliferating cell nuclear antigen (PCNA)/survivin and promoted caspase-3 activity in the MCF-7 cells. These results demonstrated that myricetin suppressed the cell viability of human breast cancer MCF-7 cells through PAK1/MEK/ERK/GSK3β/β-catenin/cyclin D1/PCNA/survivin/Bax-caspase-3 signaling.