Identification of hub genes and diagnostic efficacy for triple-negative breast cancer through WGCNA and Mendelian randomization.

OBJECTIVE: Triple-negative breast cancer (TNBC) represents a particularly aggressive form of breast cancer with a poor prognosis due to a lack of targeted treatments resulting from limited a understanding of the underlying mechanisms. The aim of this study was the identification of hub genes for TNBC and assess their clinical applicability in predicting the disease. METHODS: This study employed a combination of weighted gene co-expression network analysis (WGCNA) and differentially expressed genes (DEGs) to identify new susceptible modules and central genes in TNBC. The potential functional roles of the central genes were investigated using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. Furthermore, a predictive model and ROC curve were developed to assess the diagnostic performance of the identified central genes. The correlation between CCNB1 and immune cells proportion was also investigated. At last, a Mendelian randomization (MR) analysis utilizing Genome-Wide Association Study (GWAS) data was analyzed to establish the causal effect of CCNB1 level on TNBC. RESULTS: WGCNA was applied to determine gene co-expression maps and identify the most relevant module. Through a screening process, 1585 candidate hub genes were subsequently identified with WGCNA and DEGs. GO and KEGG function enrichment analysis indicated that these core genes were related to various biological processes, such as organelle fission, chromosome segregation, nuclear division, mitotic cell cycle phase transition, the cell cycle, amyotrophic lateral sclerosis, and motor proteins. Using STRING and Cytoscape, the top five genes with high degrees were identified as CDC2, CCNB1, CCNA2, TOP2A, and CCNB2. The nomogram model demonstrated good performance in predicting TNBC risk and was proven effective in diagnosis, as evidenced by the receiver operating characteristic (ROC) curve. Further investigation revealed a causal association between CCNB1 and immune cell infiltrates in TNBC. Survival analysis revealed high expression of the CCNB1 gene leads to poorer prognosis in TNBC patients. Additionally, analysis using inverse variance weighting revealed that CCNB1 was linked to a 2.8% higher risk of TNBC (OR: 1.028, 95% CI 1.002-1.055, p = 0.032). CONCLUSION: We established a co-expression network using the WGCNA methodology to detect pivotal genes associated with TNBC. This finding holds promise for advancing the creation of pre-symptomatic diagnostic tools and deepening our comprehension of the pathogenic mechanisms involved in TNBC risk genes.

Evaluation of the Efficacy and Safety of Pedicled Perforator Flap Technique for Salvage Nipple Reconstruction in Breast Cancer Patients: A Pilot Study.

OBJECTIVE: We propose a pedicled perforator flap technique for salvage nipple reconstruction after initial nipple reconstruction fails in breast cancer patients. METHODS: This is a pilot study. A total of 21 female breast cancer patients who underwent nipple reconstruction following initial nipple reconstruction fails were enrolled, and salvage nipple reconstruction based pedicled perforator flap were performed between 2016 and 2020. Operative time, perforator design, postoperative complications, follow-up duration, projection of nipple, as well as patient-reported outcomes measured by the BREAST-Q and visual analogue scale (VAS) were assessed. RESULTS: Sixteen patients underwent fifth lateral intercostal artery perforator reconstruction, while 5 patients underwent fifth anterior intercostal artery perforator flap reconstruction. The surgeries were successful without intraoperative complications, with a mean operative time of 67 minutes. Postoperative complications were absent. The mean follow-up duration was 18 months. The mean nipple projection was 8 mm (range, 6-10 mm) with a shrinkage of 20% at 6 months after surgery. The average scores for psychosocial well-being, satisfaction with breasts, and satisfaction with nipples domains of the BREAST-Q significantly increased (P < .01) at 6 months post-reconstruction. Sexual well-being subdomain showed no statistical difference (P = .9369). The VAS scores for cosmesis and patient satisfaction with surgery were 9 and 9.3, respectively. CONCLUSION: The pedicled perforator flap technique for salvage nipple reconstruction is a safe and effective approach.

Elucidating the relationship between metabolites and breast cancer: A Mendelian randomization study.

The evidence about the causal roles of metabolites in breast cancer is lacking. This study conducted a systematic evaluation of the potential causal relationship between 1091 human blood metabolites, 309 metabolite ratios, and the likelihood of developing breast cancer and its subtype by employing a two-sample bidirectional Mendelian randomization (MR) approach Four metabolites, including tryptophan betaine (Odds Ratio [OR] = 1.07, 95%CI = 1.04-1.10, Bonferroni-corrected P = 0.007), X-21312 (OR = 0.90, 95%CI = 0.86-0.94, Bonferroni-corrected P = 0.02), 3-bromo-5-chloro-2,6-dihydroxybenzoic acid (OR = 0.94, 95%CI = 0.91-0.96, Bonferroni-corrected P = 0.03) and X-18921 (OR = 0.96, 95%CI = 0.94-0.98, Bonferroni-corrected P = 0.04) were significantly associated with overall breast cancer using inverse-variance weighted (IVW) method. Tryptophan betaine was also significantly associated with estrogen receptor (ER)-positive breast cancer (OR = 1.08, 95%CI = 1.04-1.11, Bonferroni-corrected P = 0.03). X-23680 (OR = 1.10, 95%CI = 1.05-1.15, Bonferroni-corrected P = 0.04) and glycine to phosphate ratio (OR = 1.07, 95%CI = 1.04-1.10, Bonferroni-corrected P = 0.04) were associated with ER-negative breast cancer. Reverse MR analysis showed no significant associations between breast cancer and metabolites. This MR study indicated compelling evidence of a causal association between metabolites and the risk of breast cancer and its subtypes, underscoring the potential impact of metabolic interference on breast cancer risk and indicating the drug targets for breast cancer.

Reduced representative methylome profiling of cell-free DNA for breast cancer detection.

BACKGROUND: Whole-genome methylation sequencing of cfDNA is not cost-effective for tumor detection. Here, we introduce reduced representative methylome profiling (RRMP), which employs restriction enzyme for depletion of AT-rich sequence to achieve enrichment and deep sequencing of CG-rich sequences. METHODS: We first verified the ability of RRMP to enrich CG-rich sequences using tumor cell genomic DNA and analyzed differential methylation regions between tumor cells and normal whole blood cells. We then analyzed cfDNA from 29 breast cancer patients and 27 non-breast cancer individuals to detect breast cancer by building machine learning models. RESULTS: RRMP captured 81.9% CpG islands and 75.2% gene promoters when sequenced to 10 billion base pairs, with an enrichment efficiency being comparable to RRBS. RRMP allowed us to assess DNA methylation changes between tumor cells and whole blood cells. Applying our approach to cfDNA from 29 breast cancer patients and 27 non-breast cancer individuals, we developed machine learning models that could discriminate between breast cancer and non-breast cancer controls (AUC = 0.85), suggesting possibilities for truly non-invasive cancer detection. CONCLUSIONS: We developed a new method to achieve reduced representative methylome profiling of cell-free DNA for tumor detection.

The effectiveness of interventions to reduce cancer-related stigma: An integrative review.

AIMS: The clinical significance of cancer-related stigma on patients' well-being has been widely established. Stigma can be perceived and internalised by cancer patients or implemented by the general population and healthcare workers. Various interventions have been carried out to reduce cancer-related stigma, but their effectiveness is not well-understood. This review aims to synthesise evidence on the effectiveness of interventions to reduce cancer-related stigma. DESIGN: An integrative review. METHODS: This integrative review combined both qualitative and quantitative studies and followed five steps to identify problems, search for the literature, appraise the literature quality, analyse data, and present data. Mixed Methods Appraisal Tool (version 2018) was applied to evaluate the quality of the included studies. DATA SOURCES: Databases included Web of Science, MEDLINE, SpringerLink, Wiley Online Journals, Cochrane Library, ScienceDirect, OVID, and China National Knowledge Infrastructure (from the inception of each database to 30 April 2021). RESULTS: Eighteen quantitative, six qualitative, and five mixed-methods studies were included in this review. Cultural factors should be considered when conducting interventions to reduce cancer-related stigma. For cancer patients, multi-component interventions have demonstrated a positive effect on their perceived stigma. For general population, interactive interventions show promise to reduce their implemented stigma towards cancer patients. For healthcare workers, there is a paucity of studies to reduce their implemented stigma. Existing studies reported inconclusive evidence, partially due to the lack of a robust study design with an adequate sample size. CONCLUSIONS: Multi-component and interactive interventions show promise to relieve cancer-related stigma. More methodologically robust studies should be conducted in different cultures to elucidate the most appropriate interventions for different populations to reduce cancer-related stigma. IMPLICATION FOR THE PROFESSION AND PATIENT CARE: These findings will facilitate healthcare workers to design and implement interventions to reduce cancer-related stigma, thus improving the quality of life for cancer patients. PATIENT AND PUBLIC CONTRIBUTION: No patient and public contribution.

Elucidating the relationship between breast cancer and brain cortical structure: a Mendelian randomization study.

Cancer-associated cognitive impairment is a significant challenge for individuals who have survived breast cancer, affecting their quality of life. In this study, we conducted an inaugural comprehensive Mendelian randomization analysis discerning the causal relationship between breast cancer, including its two subtypes, and the cerebral cortical structure. Our analysis indicated that estrogen receptor-negative breast cancer significantly decreased surface area (ß = -593.01 mm2, 95% CI: -1134.9 to -51.1 mm2, P = 0.032). At the regional level, estrogen receptor-negative breast cancer showed a significant association with surface area and thickness in 17 cortical regions. These regions included the insula, posterior cingulate, superior frontal, precuneus, fusiform, lateral occipital, and rostral middle frontal. Specifically, estrogen receptor-negative breast cancer had a significant impact on decreasing the surface area of the insula without considering global weight (ß = -14.09 mm2, 95% CI: -22.91 to -5.27 mm2, P = 0.0017). The results from meta-analysis and LD Score Regression provide support for our findings. This investigation unveils the correlations between breast cancer, its various subcategories, and the cerebral cortical structure. Notably, breast cancer of the estrogen receptor-negative variety may elicit more widespread cerebral atrophy.

Clinical Features and Prognosis of Uncommon Metastatic Breast Cancer: A Retrospective Analysis of 82 Cases.

With the improvement of diagnostic techniques, numerous uncommon metastases derived from breast cancer were reported. However, very few studies explored the clinical characteristics and prognostic patterns of these patients. A total of 82 cases of uncommon metastatic breast cancer (MBC) registered at our hospital from January 1, 2010, to July 1, 2022, were selected for this retrospective study. The diagnoses of uncommon metastases were based on pathology, and the potential prognostic indicators (overall survival [OS], uncommon disease-free interval [uDFI], and remaining survival [RS]) were estimated. The uncommon metastases involved distant soft tissue, parotid gland, thyroid, digestive system, urinary system, reproductive system, bone marrow, and pericardium. Stepwise multivariate Cox regression analysis indicates age ≤ 35 is an independent risk factor of poor outcome of OS, uDFI, and RS in uncommon MBC patients. Meanwhile, uncommon metastasis combined with common visceral metastasis is an independent risk factor for poor RS of uncommon MBC patients, with a hazard ratio of 6.625 (95% confidence interval = 1.490-29.455, P = .013). Post hoc pairwise comparisons showed that uncommon MBC patients who developed bone-only metastasis survived longer than those concomitant with common visceral metastasis (P = .029). Although the incidence is low, uncommon MBC may involve multiple metastatic sites. The delayed diagnosis of uncommon metastases could lead to systemic progression of the disease. However, patients who only develop uncommon metastasis have a significantly better prognosis than that of those combined with common visceral metastasis. Even for those complicated by bone-only metastasis, active treatment of bone metastases can still achieve substantially longer survival.

Ampelopsin induces MDA-MB-231 cell cycle arrest through cyclin B1-mediated PI3K/AKT/mTOR pathway in vitro and in vivo.

Breast cancer is one of the most common malignant tumors in women and it is the most frequently diagnosed cancer in the world. Ampelopsin (AMP) is a purified component from the root of Ampelopsis grossedentata. It is reported that AMP could significantly inhibit the proliferation of breast cancer cells. However, the antitumor mechanism against breast cancer has not yet been fully elucidated. The purpose of this work was to study the role of AMP against breast cancer MDA-MB-231 cells and to further investigate the underlying mechanism. PI3K/AKT/mTOR plays a very important role in tumor cell growth and proliferation and we hypothesize that AMP may inhibit this pathway. In the present work, the results showed that AMP could significantly inhibit the growth of breast cancer MDA-MB-231 cells in vitro and in vivo. In addition, treatment with AMP decreased the levels of PI3K, AKT and mTOR, as well as cyclin B1 expression, followed by p53/p21 pathway activation to arrest the cell cycle at G2/M. Moreover, it demonstrated a positive association between cyclin B1 and PI3K/AKT/mTOR levels. Importantly, this pathway was found to be regulated by cyclin B1 in MDA-MB-231 cells treated with AMP. Also, it was observed that cyclin B1 overexpression attenuated cell apoptosis and weakened the inhibitory effects of AMP on cell proliferation. Together, AMP could inhibit breast cancer MDA-MB-231 cell proliferation in vitro and in vivo, due to cell cycle arrest at G2/M by inactivating PI3K/AKT/mTOR pathway regulated by cyclin B1.

Predictors of surgery choices in women with early-stage breast cancer in China: a retrospective study.

BACKGROUND: The breast-conserving surgery and reconstruction rate in China is relatively low when compared with those in Western countries. Moreover, predictors of surgical choices for women with breast cancer in China have not yet been explored. This study aims to explore differences in the surgical choices of women with different demographic and clinical characteristics and the predictors that influence surgical choices of women with early-stage breast cancer. METHODS: This retrospective study included women with early-stage (0-II) breast cancer who underwent surgeries at one of two Xiamen University-affiliated hospitals between 2009 and 2017. Using medical records, eleven variables were collected: the woman's age, year of diagnosis, hospital, marital status, payment method, cancer stage, presence of positive axillary lymph node, histology, neoadjuvant chemotherapy, radiotherapy, and the type(s) of surgery they chose. Binary logistic regression was used to analyse predictors of surgical choice. RESULTS: A total of 1,787 cases were included in this study. Of the total number of women with breast cancer, 61.3% underwent mastectomy without breast reconstruction, 26.4% underwent mastectomy with breast reconstruction, and the remaining 12.2% chose breast-conserving surgery. Women with different demographic and clinical characteristics underwent different types of surgery. Cancer stage, neoadjuvant chemotherapy, radiotherapy, and the choice of hospital were found to be predictors of breast-conserving surgery. Meanwhile, age, year of diagnosis, payment method, neoadjuvant chemotherapy, and the choice of hospital were found to be predictors of reconstruction after mastectomy in women with early-stage breast cancer. CONCLUSIONS: In China, surgical choices for women with breast cancer have diversified. Healthcare workers should understand the surgical preferences of women of different ages. For early detection of breast cancer, knowledge of breast self-examination and breast cancer screening should be provided. Adequate information about the safety of reconstruction and advocacy for medical insurance coverage of reconstruction should be offer. Breast surgeons need specialised training and standardising protocols towards different types of breast surgery. These actions will help women make better, well-informed decisions about their breast surgeries.

Early Application of Palbociclib Plus Endocrine Therapy in HR+/HER2- Metastatic Breast Cancer: A Better Choice Based on Data From the Chinese Population.

Background: Palbociclib is the most widely used cyclin-dependent kinase 4/6 inhibitor in China, but its early application efficacy on Chinese metastatic breast cancer (MBC) patients was reported deficiently. Methods: Between February 2019 to December 2021, 95 female hormone receptor-positive (HR+)/human epidermal growth factor receptor-2 negative (HER2-) patients with MBC received palbociclib combined with AI or fulvestrant were retrospectively analyzed in our center. The primary outcome was progression-free survival (PFS). The objective response rate and clinical benefit rate (CBR) were evaluated. Results: The median follow-up period was 15 months (range from 2 to 37). Palbociclib performed superiorly when applicated in first-and-second line therapy than in later lines (P = .002). Palbociclib combined with AI or fulvestrant had a median PFS of 34 months (95% confidence interval [CI] = 6.87-61.13) and 12 months (95%CI = 7.76-16.24), respectively. Univariate subgroup analysis showed that the previous history of salvage chemotherapy (P = .015) and the presence of liver metastases (P < .001) significantly affected the efficacy of palbociclib. Despite the existence of liver metastases and primary endocrine resistance, which are two independent predictors of poor prognosis, early application of palbociclib in advanced stage can bring further benefits to these two groups of patients, rather than choosing salvage chemotherapy in the first place. Conclusion: Palbociclib combined with endocrine therapy has a favorable efficacy and acceptable toxicity in HR+/HER2- Chinese MBC patients. Better performance can be seen when palbociclib was applicated in the early stage.

Postmastectomy radiation therapy can improve survival for breast cancer patients with 1-3 positive axillary lymph nodes: a retrospective cohort study using the SEER database.

BACKGROUND: Postmastectomy radiation (PMRT) is an important adjuvant treatment for high-risk breast cancer. However, evidence concerning its efficacy in promoting survival of patients with 1-3 positive axillary lymph nodes remains insufficient. METHODS: We identified 57,793 patients, diagnosed from 2010-2015, from the Surveillance, Epidemiology, and End Results database, including 15,126 cases treated with beam radiation and 42,667 cases with none/unknown radiation. A Kaplan-Meier curve was utilized to compare survival of the two groups. We used univariate and multivariate Cox proportional hazard models to identify independent prognostic factors presented as hazard ratios (HRs) and 95% confidence intervals (CIs). For subgroup analysis, patients were stratified according to lymph node status, tumor size, and molecular subtypes. RESULTS: The PMRT group showed more aggressive clinicopathological features, including higher grades (P<0.001), larger tumor sizes (P<0.001), more lymph nodes (P<0.001), younger ages (P<0.001), more ER-negative cases (P<0.001), more PR-negative cases (P<0.001), and more HER2 overexpression (P<0.001). In addition, the PMRT group received more radical surgeries (P<0.001) and more chemotherapy (P<0.001). In the multivariate Cox proportional hazard regression analysis, the PMRT group exhibited improved survival in terms of breast cancer specific survival (BCSS) (HR, 0.74; 95% CI, 0.68-0.81; P<0.001) and overall survival (OS) (HR, 0.72; 95% CI, 0.67-0.78; P<0.001). After stratification according to positive axillary lymph nodes, the PMRT group showed improved BCSS and OS in the LN 1 to 3 subgroup (HR, 0.74; 95% CI, 0.64-0.85; P<0.001 and HR, 0.68; 95% CI, 0.60-0.78; P<0.001, respectively). For patients with 1-3 positive axillary lymph nodes and T1-2 tumors, the PMRT group still showed improved BCSS and OS (HR, 0.823; 95% CI, 0.69-0.99; P=0.04 and HR, 0.75; 95% CI, 0.64-0.88; P<0.001, respectively). In the subgroup analysis, PMRT remained a significant favorable prognostic factor in T2 and HER2-/HR+ subtype (P<0.05). CONCLUSIONS: This study suggests that PMRT can confer a survival benefit to breast cancer patients with 1-3 positive axillary lymph nodes, even with modern treatment options. Furthermore, for patients with 1-3 positive axillary lymph nodes and T1-2 tumors, PMRT can still provide survival benefits.

Extracellular matrix protein 1 recruits moesin to facilitate invadopodia formation and breast cancer metastasis.

Invadopodia are actin-based cortical protrusions of tumour cells, and required for stromal invasion and metastasis. Extracellular matrix protein 1 (ECM1) has long been regarded as a secretory protein, but the mechanism of its precise functions in tumour cells is still obscure. Recently published data suggested a function of ECM1 in remodelling the actin cytoskeleton; however, its role in invadopodia formation remains unknown. Here, we demonstrated for the first time that ECM1 was a membrane protein and was essential for invadopodia formation by breast cancer cells. ECM1 depletion attenuated the ability of tumour cells to matrix attachment, invasion, and spontaneous metastasis to the lungs of mice. Additionally, co-expression of ECM1 and moesin (MSN) was closely related to aggressive breast cancer phenotypes. ECM1 interacted with MSN and recruited it adjacent to the membrane in order to promote MSN membrane translocation and phosphorylation, which facilitated invadopodia formation by breast cancer cells. These results elucidate a novel mechanism underlying the role of ECM1 in breast cancer metastasis and suggest ECM1 as a potential therapeutic target for overcoming tumour dissemination.

Effect of 810 nm Near-Infrared Laser on Revascularization of Ischemic Flaps in Rats.

OBJECTIVE: To investigate the effect of 810 nm near-infrared (NIR) laser on the revascularization of ischemic flaps. BACKGROUND: It has long been proved that photobiomodulation therapy (PBMT) improves the blood supply of flaps. NIR laser improves the treatment of hypodermis-located lesions and of flap survival, but basic research on the use of 810 nm NIR laser for ischemic flap revascularization is still lacking. MATERIALS AND METHODS: We prepared two symmetrical long random-pattern flaps on the backs of 60 rats. Each flap was 6 cm long, 1 cm wide, and 1 cm to the middle line. The flaps were divided into an irradiated flap group and an internal control group. The irradiated flaps underwent postoperative 810 nm laser therapy with the energy density of 11.30 J/cm2 daily. The control flaps were covered by stainless steel to avoid laser irradiation. We observed the viability of the flaps. The flaps underwent Hematoxylin and Eosin (H&E) staining for the observation of histomorphology, immunohistochemical staining of factor VIII for the capillary count, α-smooth muscle actin for the small arterial count, and vascular endothelial growth factor for the integrated optical density (OD) of the positive stained color. RESULTS: The irradiated flaps showed significantly better flap survival than the control flaps. H&E staining showed that the irradiated flaps had clear tissue structure and little inflammatory cell infiltration. The control flaps demonstrated comparatively worse results. Vascular endothelial growth factor staining showed that the difference in integrated OD between the irradiated flaps and the control flaps was not statistically significant. α-smooth muscle actin and factor VIII staining showed significantly greater numbers of arterioles and capillaries in the irradiated flaps than the control flaps after 4 days of irradiation. CONCLUSIONS: PBMT with 810 nm NIR laser could enhance ischemic flap revascularization and increase flap viability.

Expression and clinical significance of matrix metalloproteinase-9 in lymphatic invasiveness and metastasis of breast cancer.

BACKGROUND: Matrix metalloproteinase 9 (MMP-9) is a type-IV collagenase that is highly expressed in breast cancer, but its exact role in tumor progression and metastasis is unclear. METHODS: MMP-9 mRNA and protein expression was examined by real-time reverse transcriptase PCR and immunohistochemical staining, respectively, in 41 breast cancer specimens with matched peritumoral benign breast epithelial tissue and suspicious metastatic axillary lymph nodes. Lymph vessels were labeled with D2-40 and lymphatic microvessel density (LMVD) was calculated. Correlation of MMP-9 protein expression with clinicopathological parameters and LMVD was also evaluated. RESULTS: MMP-9(+) staining in breast cancer specimens (35/41, 85.4%) was higher than in matched epithelium (21/41, 51.2%; P<0.05) and lymph nodes (13/41, 31.7%; P<0.001). Higher MMP-9 mRNA expression was also detected in tumor specimens compared with matched epithelial tissues and lymph nodes (P<0.05). Elevated MMP-9 expression was correlated with lymph node metastasis and LMVD (P<0.05). CONCLUSION: MMP-9 was overexpressed in breast cancer specimens compared with peritumoral benign breast epithelium and lymph nodes. Moreover, its expression in the matched epithelium and lymph nodes was positively associated with lymph node metastasis, and its expression in lymph nodes was positively associated with lymphangiogenesis in breast cancer. Thus, MMP-9 is a potential marker for breast cancer progression.

Expression and clinical significance of extracellular matrix protein 1 and vascular endothelial growth factor-C in lymphatic metastasis of human breast cancer.

BACKGROUND: Extracellular matrix protein 1 (ECM1) and vascular endothelial growth factor-C (VEGF-C) are secretory glycoproteins that are associated with lymphangiogenesis; these proteins could, therefore, play important roles in the lymphatic dissemination of tumors. However, very little is known about their potential roles in lymphangiogenesis. The aim of this study was to investigate whether correlations exist between ECM1 and VEGF-C in human breast cancer, lymphangiogenesis, and the clinicopathological characteristics of the disease. METHODS: ECM1 and VEGF-C mRNA and protein expression levels in 41 patients were investigated using real-time reverse transcriptase polymerase chain reaction (RT-PCR), or immunohistochemical (IHC) staining of breast cancer tissue, matched noncancerous breast epithelial tissues, and suspicious metastatic axillary lymph nodes. D2-40 labelled lymph vessels and lymphatic microvessel density (LMVD) were counted. Correlations between ECM1 or VEGF-C protein expression levels, LMVD, and clinicopathological parameters were statistically tested. RESULTS: The rate of ECM1 positive staining in breast cancer tissues was higher (31/41, 75.6%) than that in the corresponding epithelial tissues (4/41, 9.8%, P < 0.001) and lymph nodes (13/41, 31.7%, P < 0.001). Similarly, the VEGF-C expression rate in cancer specimens was higher (33/41, 80.5%) than in epithelial tissues (19/41, 46.3%, P < 0.01) or lymph nodes (15/41, 36.6%, P < 0.01). Higher ECM1 and VEGF-C mRNA expression levels were also detected in the tumor tissues, compared to the non-cancerous tissue types or lymph nodes (P < 0.05). ECM1 protein expression was positively correlated with the estrogen receptor status (P < 0.05) and LMVD (P < 0.05). LMVD in the ECM1- and VEGF-C-positive tumor specimens was higher than that in the tissue types with negative staining (P < 0.05). CONCLUSIONS: Both ECM1 and VEGF-C were overexpressed in breast cancer tissue samples. ECM1 expression was positively correlated with estrogen responsiveness and the metastatic properties of breast cancer. We conclude, therefore, that ECM1 and VEGF-C may have a synergistic effect on lymphangiogenesis to facilitate lymphatic metastasis of breast cancer.