Clinical implication of p53 overexpression in breast cancer patients younger than 50 years with a triple-negative subtype who undergo a modified radical mastectomy

Integrative analysis of multi-omics data highlighted TP53 as a potential diagnostic and prognostic biomarker of survival in breast invasive carcinoma patients

The global incidence of breast invasive carcinoma (BRIC) has risen significantly in recent years, so it is important to identify the novel biomarkers for the early detection and treatment of BRIC. The role of the TP53 gene is well studied in the pathogenesis of BRIC but still, observations are conflicting. Therefore, this study was initiated to have a consolidated overview of TP53 contributions in the BRIC initiation and progression by analyzing its mutatome, expression variations, promoter methylation level, clinical outcome, and drug sensitivity analysis in BRIC using cBioPortal, UALCAN, KM plotter, and CCLE GDSC toolkit database. Mutatome analysis revealed that TP53 was mutated in 30 % BRIC cases and among all the noted mutations, missense and truncation mutation were noticed as the most frequent mutations and thought to be involved in the up-regulation of TP53 expression. TP53 transcription, translation, and promoter methylation levels in BRIC patients of various clinicopathological features were high relative to the normal controls. Kaplan Meier overall survival (OS) analysis revealed a good prognostic value of TP53 overexpression for the survival in BRIC patients. Moreover, TP53 overexpression was found to alter the effectiveness of various drugs used in the chemotherapy of BRIC. Collectively, our findings suggested that TP53 might be a potential diagnostic and prognostic marker for the survival in BRIC patients of various clinicopathological features.

Oncogenic and Tumor Suppressive Components of the Cell Cycle in Breast Cancer Progression and Prognosis

Cancer, a disease of inappropriate cell proliferation, is strongly interconnected with the cell cycle. All cancers consist of an abnormal accumulation of neoplastic cells, which are propagated toward uncontrolled cell division and proliferation in response to mitogenic signals. Mitogenic stimuli include genetic and epigenetic changes in cell cycle regulatory genes and other genes which regulate the cell cycle. This suggests that multiple, distinct pathways of genetic alterations lead to cancer development. Products of both oncogenes (including cyclin-dependent kinase (CDKs) and cyclins) and tumor suppressor genes (including cyclin-dependent kinase inhibitors) regulate cell cycle machinery and promote or suppress cell cycle progression, respectively. The identification of cyclins and CDKs help to explain and understand the molecular mechanisms of cell cycle machinery. During breast cancer tumorigenesis, cyclins A, B, C, D1, and E; cyclin-dependent kinase (CDKs); and CDK-inhibitor proteins p16, p21, p27, and p53 are known to play significant roles in cell cycle control and are tightly regulated in normal breast epithelial cells. Following mitogenic stimuli, these components are deregulated, which promotes neoplastic transformation of breast epithelial cells. Multiple studies implicate the roles of both types of components-oncogenic CDKs and cyclins, along with tumor-suppressing cyclin-dependent inhibitors-in breast cancer initiation and progression. Numerous clinical studies have confirmed that there is a prognostic significance for screening for these described components, regarding patient outcomes and their responses to therapy. The aim of this review article is to summarize the roles of oncogenic and tumor-suppressive components of the cell cycle in breast cancer progression and prognosis.

Breast cancer radioresistance may be overcome by osteopontin gene knocking out with CRISPR/Cas9 technique

PURPOSE

Osteopontin (OPN) is a phosphoglycoprotein, with a wide range of physiological and pathological roles. High expression of OPN promotes aggressive behavior, causes poor prognosis in tumor cells, and reduces the survival of patients. Since overexpression of OPN gives rise to radioresistance, the effects of the gene knock out using the CRISPR/Cas9 system in combination with radiation are emphasized.

MATERIAL AND METHODS

We used the CRISPR/Cas9 technique to knock out the OPN gene in the MDA-MB-231 cell line. After transfection, the cells were irradiated. The changes of the OPN mRNA levels, the apoptosis, and the differences in cell viability were assessed.

RESULTS

A significant reduction in the OPN expression was observed alone or along with irradiation. The knocked out gene alone increased apoptosis rate. The cell viability decreased to after knocking out of the OPN gene. The gene knocking-out combined with irradiation led to more decline of cell viability.

CONCLUSION

Our results demonstrated that after knocking out the OPN gene, the MDA-MB-231 cells showed a significant radiosensitivity. Therefore, the OPN knock out in combination with conventional radiotherapy, may become an efficient therapeutic target in the future.

Trefoil factor 1 (TFF1) is a potential prognostic biomarker with functional significance in breast cancers

Breast cancer (BC) is the most common cancer in women and the second leading cause of their cancer death. Establishing an accurate BC prognosis is very difficult because of its heterogeneity. Elevated TFF1 levels in serum were associated with development of BC, TFF1 expression was upregulated in BC compared to the healthy breast tissue. The aim of this study was to investigate the function of TFF1 in BCs, and to assess whether serum TFF1 could be used in formulating a prognosis for BC patients. In silico analyses were carried out to determine the expression of TFF1 mRNA in different types of BC and the association between TFF1 expression and survival of BC patients. Expression of TFF1 protein was checked in 52 paraffin-embedded tissues of BCs by immunochemistry, and serum concentration of TFF1 in 70 BC patients and 32 healthy controls was measured by ELISA. Functional activities of TFF1 in BC cells were determined by CCK-8 assay, colony formation, BrdU-DNA synthesis, and assays for migration and invasion. Results showed that expression of TFF1 mRNA was correlated with expression of biomarkers of luminal cancers including ESR1, GATA3, FOXA1, MYB and XBP1. In addition, patients with ER⁺BC had higher expression of TFF1 than those with ER^- (p < 0.05). There was also lower expression of TFF1 in triple-negative breast cancer (TNBC) than in non-TNBC (p < 0.05), which corresponds with the level of serum TFF1 in TNBC patients, compared with non-TNBC patients (p < 0.001). Furthermore, expression of TFF1 was associated with tumor size (p = 0.002), nodal status (p < 0.001), histological grade (p < 0.001), ER status (p = 0.012), PR status (p < 0.001) and HER2 (p < 0.001), while serum TFF1 was only statistically different among BC with ER⁺, PR ⁺ and HER2⁺ (p = 0.04139, 0.0018, 0.0004). Elevated TFF1 expression correlated with increased overall survival of BC patients (p = 0.00068). Finally, TFF1 was found to inhibit the cell growth, colony formation, migration and invasion of BC cells in vitro. All these results suggest that expression of TFF1 was related to ER status of BC and that expression of TFF1 was lower in TNBC than in non-TNBC. TFF1 was found to inhibit proliferation, migration and invasion of BC cells in vitro. Expression of TFF1 was associated with clinical characters of patients with BC. Serum TFF1 could be used to predict prognosis of patients with BC, especially non-TNBC.

Triple negative breast cancer: microRNA expression profile and novel discriminators according to BRCA1 status

Triple-negative breast cancer (TNBC) represents 15% of breast carcinomas. More than 80% of women with a breast cancer associated with a breast cancer type 1 (BRCA1) mutation develop a TNBC. microRNAs (miRNAs) play critical roles in diverse biological processes and are aberrantly expressed in several human neoplasms including breast cancer, where they function as actors of tumor onset, behavior, and progression. However, an extensive microRNA profile has not yet been determined for TNBC. Taqman low-density arrays (TLDAs) were used to screen the expression level of 667 miRNAs in TNBC versus normal breast tissues. Our TLDA results revealed 20 differentially expressed miRNAs among which 14 (10 upregulated and four downregulated) were confirmed by an individual quantitative real-time polymerase chain reaction. Interestingly, a novel link between BRCA1 status and miRNA expression level was identified through miR-96 and miR-10b that were very important discriminators between TNBC with mutated BRCA1 and TNBC with wild type BRCA1. This study promises discoveries of new pathological pathways at work in this dreadful disease and clearly warrants validation in large prospective studies with the aim of identifying novel biomarkers for diagnosis and targets for clinical interventions.

Association of ki67 and tumor marker p53 in locally advanced breast cancer patients and evaluation of response to neoadjuvant chemotherapy: a survey in South Iran

Purpose

Heterogeneity of breast cancer, the most common cancer in women, complicates approach to its treatment. Neoadjuvant chemotherapy (NAC) in the treatment of locally advanced breast cancer (LABC) with the endpoint of achieving pathologic complete response (pCR) is not always successful. The purpose of this study was to evaluate the clinicopathologic characteristics, biomarker status and response of LABCs to NAC.

Patients and methods

Core biopsies and post-surgical specimens of LABC patients were evaluated after receiving NAC. Their lymph node involvement, tumor staging, grading, size, tumoral and stromal lymphocytic infiltration (TLI, SLI), hormonal status, ki67, p53 and HER2 expression were evaluated. Response to NAC was assessed using pCR, Miller-Payne grading and residual cancer burden.

Results

In a total of 71 patients, pCR rate was 5.6%. Strong association was observed between ki67 positivity and p53 expression (P-value˂0.001). Also ki67, TLI and SLI showed association with triple negative tumor subtype (P-value 0.011, 0.002 and 0.014). Good response to NAC was associated with p53 expression. Nodal metastatic residue was also associated with primary tumor’s nuclear grade.

Conclusion

Strong correlation of ki67 and p53 can suggest probable interchangeability of both markers in the prognosis of LABC. In this study p53 even showed superiority to ki67 having association with good response. Strong association of ki67, TLI and SLI with triple negative tumor subtype can be parallel to an overall better response rate of this subtype. We can also propose the effectiveness of defining nuclear grade as a prognostic factor towards residual lymph node involvement post NAC.

Ultrasound molecular imaging of breast cancer in MCF-7 orthotopic mice using gold nanoshelled poly(lactic-co-glycolic acid) nanocapsules: a novel dual-targeted ultrasound contrast agent

BACKGROUND

The development of nanoscale molecularly targeted ultrasound contrast agents (UCAs) with high affinity and specificity is critical for ultrasound molecular imaging in the early detection of breast cancer.

PURPOSE

To prospectively evaluate ultrasound molecular imaging with dual-targeted gold nanoshelled poly(lactide-co-glycolic acid) nanocapsules carrying vascular endothelial growth factor receptor type 2 (VEGFR2) and p53 antibodies (DNCs) in MCF-7 orthotopic mice model.

METHODS

DNCs were fabricated with an inner PLGA and outer gold nanoshell spherical structure. Its targeting capabilities were evaluated by confocal laser scanning microscopy (CLSM) and flow cytometry (FCM) in vitro. Contrast-enhanced ultrasound imaging (CEUS) with DNCs was evaluated qualitatively and quantitatively in vitro and in MCF-7 orthotopic mice model by two different systems. The biodistribution of NCs in mice was preliminary investigated. Differences were calculated by using analysis of variance.

RESULTS

DNCs showed a well-defined spherical morphology with an average diameter of 276.90±110.50 nm. In vitro, DNCs exhibited high target specificities (79.01±5.63% vs. 2.11±1.07%, P<0.01; 75.54±6.58% vs. 5.21±3.12%, P<0.01) in VEGFR2- and p53-positive cells compared with control cells. In vivo, CEUS displayed a significantly higher video intensity in two systems using DNCs in comparison with non-targeted PLGA@Au NCs and single-targeted NCs. Biodistribution studies revealed that more DNCs in breast cancer tissue could be detected in mice than in other NCs (P<0.05).

CONCLUSION

DNCs were demonstrated to be novel dual-targeted UCAs and may have potential applications in early non-invasive visualization of breast cancer.

Update on Immunohistochemical Analysis in Breast Lesions

CONTEXT

- The utility of immunohistochemistry (IHC) in breast lesions needs to be updated with exceptions among these lesions. Biomarker studies with IHC in triple-negative breast carcinoma may help develop targeted therapies for this aggressive breast cancer. The distinction of metastatic lung adenocarcinoma to the breast and invasive breast carcinoma has significant prognostic and therapeutic implications. The determination can be challenging because both primary tumors can express estrogen receptor and/or HER2 by IHC, creating a diagnostic dilemma.

OBJECTIVES

- To provide a practical update on the use of IHC markers in differential diagnoses in breast lesions, including benign, atypical, precancerous, and malignant tumors; to highlight recently published research findings on novel IHC markers in triple-negative breast carcinoma cases; and to reinforce the importance of IHC use as an ancillary tool in distinguishing metastatic lung adenocarcinoma to the breast from primary breast carcinoma using real case examples.

DATA SOURCES

- PubMed (US National Library of Medicine, Bethesda, Maryland) literature review and authors' research data and personal experiences were used in this review.

CONCLUSIONS

- Immunohistochemistry has an important role in making differential diagnoses in breast lesions in morphologically equivocal settings; recognizing IHC expression status in the exceptions among these lesions will aid in the correct diagnosis of challenging breast cases. Studies suggest that androgen receptor, p16, p53, GATA3, and PELP1 may have potential diagnostic, prognostic, and predictive value in triple-negative breast carcinoma cases; these findings may provide insight and a greater understanding of the tumor biology in triple-negative breast carcinomas. In distinguishing metastatic estrogen receptor-positive or HER2⁺ lung adenocarcinoma to the breast from primary breast carcinoma, napsin A, TTF-1, and GATA3 comprise a useful IHC panel.

Comparative study of Her-2, p53, Ki-67 expression and clinicopathological characteristics of breast cancer in a cohort of northern China female patients

The objective was to study the relationship among Her-2, Ki-67, p53 expression and the clinicopathologic characteristics of breast cancer in the patients of northern China. Expression of Her-2, Ki-67, p53 and clinical characteristics of 260 breast cancer patients were retrospectively studied. Her-2 overexpression led to higher incidence rates of infiltrating ductal carcinoma and axillary lymph node metastasis, bigger diameters of the primary tumors, later pTNM staging, and a lower incidence rate of ductal carcinoma in situ (p < 0.05). High expression of ER and PR led to fewer patients classified histologically in higher grade (p = 0.001), while high expression of Ki-67 and p53 caused more patients classified histologically in higher grade (p = 0.001). In patients histologically classified in grade 1 and 2, the expression of Ki-67 and p53 was significantly (p = 0.001) higher, and the expression of ER and PR was significantly lower, in Her-2 positive patients than Her-2 negative patients. Breast cancer with Her-2 overexpression was more likely to recur and metastasize than Her-2 negative breast cancer. Higher coincidence of high expression of p53 and Ki-67 with Her-2 overexpression and more progressed tumors suggested that in addition to p53, Ki-67 might also be a prognostic biomarker of breast cancer.

Prognostic Significance of Transverse Relaxation Rate (R2*) in Blood Oxygenation Level-Dependent Magnetic Resonance Imaging in Patients with Invasive Breast Cancer

Objective

To examine the relationship between magnetic resonance transverse relaxation rate (R2*) and prognostic factors.

Materials and Methods

A total of 159 women with invasive ductal carcinomas (IDCs) underwent breast magnetic resonance imaging (MRI) including blood oxygenation level-dependent (BOLD) sequence at 3 T. The distribution of the measured R2* values were analyzed, and the correlation between R2* and various prognostic factors (age, tumor size, histologic grade, lymphovascular invasion, and axillary lymph node status, as well as expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, p53, and Ki-67) were retrospectively assessed using patient medical records.

Results

The baseline R2* values of the IDCs were very heterogeneous with wide range among the patients. The mean R2* value was (32.8 ± 14.0) Hz with a median of 29.3 Hz (range 13.5–109.4 Hz). In multivariate analysis, older age was associated with decreased R2* value (P = 0.011) and IDCs with p53-overexpression showed higher R2* values than those without p53-overexpression group (P = 0.031). Other prognostic factors were not significantly correlated with R2* value.

Conclusion

In this study, R2* values were significantly correlated with age and expression of p53. Further studies are necessary to determine the prognostic value of BOLD-MRI.

Hormone receptor status (estrogen receptor, progesterone receptor), human epidermal growth factor-2 and p53 in South Indian breast cancer patients: A tertiary care center experience

Breast cancer, in India, is the second commonest cancer in females. Receptor status with ER/PR/Her 2 is now routinely done in patients with invasive carcinoma. The tumour suppressor gene, p53, is also present in most breast cancers. Proteins produced by a mutated p53 gene, accumulate in the nucleus of tumour cells and are detected by immunohistochemistry (IHC). We have undertaken this study with the aim to evaluate the ER, PR, HER-2 and p53 expressions in invasive breast carcinomas by IHC and to compare the HER-2 expression with various clinicopathological parameters.

MATERIALS AND METHODS

In this retrospective single institutional study from January 2001 to December 2010, 389 cases of histopathologically diagnosed infiltrating carcinoma of breast were evaluated taking into account various parameters like age, tumour size, grade, lymph node involvement, ER and PR. HER-2 and p53 was done in 352 cases.

RESULTS

The age range was 23-90 years with a mean of 50.7 years. Majority of tumours were T2 (79.6%) and Grade II (60.9%). Our data showed overall 47.6% ER, 48.8% PR, 29.6% HER-2 and 69.2% p53 positivity. There was no significant correlation between HER-2 and age, tumour size, lymph node status, ER, and PR. There was significant correlation between HER-2 and tumour grade (P = 0.031), p53 (P < 0.001). There was no inverse correlation between HER-2 and combined ER, PR status. Triple-negative breast cancers which constituted 22.7% of our cases did not reveal any correlation with various parameters.

CONCLUSION

In our study, ER status was low, and incidence of p53 was high. These findings suggest that many of the tumours in Indian females may be of an aggressive type, and novel treatment approaches may be tried. We conclude that the assessment of all four markers is desirable.

A prognostic model for triple-negative breast cancer patients based on node status, cathepsin-D and Ki-67 index

Objective

The aim of this study was to evaluate clinicopathologic factors that could possibly affect the outcome of patients with triple negative breast cancer and subsequently build a prognostic model to predict patients’ outcome.

Methods

We retrospectively analyzed clinicopathologic characteristics and outcome of 504 patients diagnosed with triple-negative invasive ductal breast cancer. 185 patients enrolled between 2000 and 2002 were designated to the training set. The variables that had statistically significant correlation with prognosis were combined to build a model. The prognostic value of the model was further validated in the separate validation set containing 319 patients enrolled between 2003 and 2006.

Results

The median follow-up duration was 66 months. 174 patients experienced recurrence, and 111 patients died. Positivity for ≥4 lymph nodes, Cathepsin-D positivity, and Ki-67 index ≥20% were independent factors for DFS, while the lymph nodes status and Ki-67 index were the prognostic factors for OS. The prognostic model was established based on the sum of all three factors, where positivity for ≥4 lymph nodes, Cathepsin-D and Ki-67 index ≥20% would individually contribute 1 point to the risk score. The patients in the validation set were assigned to a low-risk group (0 and 1 point) and a high-risk group (2 and 3 points). The external validation analysis also demonstrated that our prognostic model provided the independent high predictive accuracy of recurrence.

Conclusion

This model has a considerable clinical value in predicting recurrence, and will help clinicians to design an appropriate level of adjuvant treatment and schedule adequate appointments of surveillance visits.

Roles of p53 and p16 in triple-negative breast cancer

SUMMARY p53 and p16 are both tumor suppressors. This article summarizes the current investigation status on their roles and interaction in triple-negative breast cancer (TNBC) to explore their potential as prognostic, predictive and therapeutic targets. There is significant evidence implicating that p53 mutation as a driver plays an important role in tumorigenesis and progression of TNBC. p53 mutations are more frequently observed in TNBCs compared with ER-positive breast cancers. The presence of a p53 mutation is associated with poorer prognosis in TNBC patients. The status of p53 protein expression divides TNBCs into two biologically distinct subgroups (p53-positive vs p53-negative); p53-positive tumors have more aggressive behavior. p53 has clinical prognostic utility and is a promising target candidate for directed therapy for TNBC patients. p16 appears to play a significant role in tumorigenesis of TNBC through the Rb/p16 dysfunction pathway. A high level of p16 protein expression is associated with aggressive behavior and tumor proliferation of TNBC. The status of p16 expression may have potential predictive value for TNBC response to chemotherapy; further investigation is needed to support the proposal. p16 expression has been strongly correlated with p53 expression in TNBC, suggesting interactions between the two mutations in tumorigenesis. It has been proposed that the two tumor suppressors appear to be involved in early events of TNBC formation with subsequent interplay resulting in their mutual inactivation and, ultimately, leading to a proliferative environment.

Expression of breast cancer anti-estrogen resistance 1 in relation to vascular endothelial growth factor, p53, and prognosis in esophageal squamous cell cancer

The purpose of this study was to clarify the role of breast cancer anti-estrogen resistance 1 (BCAR1) expression in relation to vascular endothelial growth factor (VEGF), p53, and proliferation in esophageal squamous cell cancer (ESCC). Expression of BCAR1, VEGF, p53, and the ki-67 proliferative index were examined by tissue microarray and immunohistochemistry in 106 specimens with ESCC and matched adjacent normal tissues. Among them, 40 cases were simultaneously examined by Western blot. Both Western blot and immunohistochemistry showed that BCAR1 expression was substantially higher in ESCC than in adjacent normal tissues (P < 0.001). BCAR1 expression was significantly connected with degree of tumor differentiation, with poorly differentiated tumors showing higher BCAR1 expression (P < 0.001). BCAR1 expression was significantly and positively correlated with VEGF and p53 expression levels (r= 0.541, P < 0.001; r= 0.374; P < 0.001) but not proliferative index (r= 0.44; P= 0.066). Additionally, a significant relationship was also observed between VEGF and p53 (r= 0.321; P= 0.001). Kaplan-Meier survival analysis revealed that patients with high BCAR1 expression had significantly shorter survival times than those with low BCAR1 expression levels (median survival 40 months vs. 27 months, P= 0.09). Multivariate analysis also revealed that levels of BCAR1 expression (hazard ratio 2.250, P= 0.015) was a significant and independent prognostic indicator. High expression of BCAR1 is associated with elevated VEGF and p53 expression levels, as well as poor prognosis in ESCC. Therefore, BCAR1 may be a potential candidate for predicting prognosis and a new therapy target for ESCC.

Elevated serum haptoglobin is associated with clinical outcome in triple-negative breast cancer patients

BACKGROUND

Breast cancer is the most common malignancy with the highest incidence rates among women worldwide. Triple-negative breast cancer (TNBC) disease is diagnosed more frequently in younger women, and is associated with a poor prognosis. Elevated levels of serum haptoglobin protein (Hp) are observed in many malignant diseases including breast cancer. We evaluated the expression and prognostic value of Hp among patients with TNBC.

MATERIALS AND METHODS

Serum Hp levels were determined by Elisa in 41 patients with TNBC and 10 normal individuals. Hp status was correlated with other clinico-pathological parameters including patient survival.

RESULTS

Of the 41 patients with TNBC, Hp over expression was detected in 24 (59%) by Elisa. Hp up-regulation was confirmed by Elisa based quantification in the serum of 41 TNBC patients against lower grades and 10 normal individuals. Survival analysis revealed that Hp (p=2.016x10-5), stage (p=2.166x10-5), distant metastasis (p=2.217x10-5), tumor size (p=1.053x10-5), and tumor grade (p=0.001), correlated with patient survival on univariate analysis. Multivariate analysis revealed that Hp (p=0.001), and grade of the disease (p=0.008) were independent predictors of survival.

CONCLUSION

Our results indicate that serum levels of Hp may play a role as a potential serum biomarker and prognostic indicator among TNBC patients. Thus, Hp may present a new promising prognostic biomarker in TNBC patients, but independent validations are now necessary for confirmation.

Outcome of triple-negative breast cancer in patients with or without markers regulating cell cycle and cell death

Purpose

The genes p53 and B-cell lymphoma (bcl)-2 play an important role in regulating the mechanisms of apoptosis. In this paper, we retrospectively applied these factors to our series of triple negative breast cancer (TNBC) patients, in conjunction with an evaluation of the prognostic significance of these factors' influence on TNBC survival rate. Particular focus was placed on the role of bcl-2, p53, Ki-67.

Methods

The study subjects, 94 women with TNBC, were a subset of patients operated at Kosin University Gospel Hospital from January 2000 to December 2005. Chi-squared tests were used for statistical analysis.

Results

Positive staining for cytokeratin (CK)5/6 in 23 cases (24.5%), epidermal growth factor receptor in 15 cases (16.0%), bcl-2 in 26 cases (27.7%), p53 in 55 cases (58.5%) and Ki-67 in 74 cases (78.7%) was determined. Lymph node status, tumor size and expression of CK5/6 or Ki-67 were independent prognostic factors for patients with TNBC.

Conclusion

Markers regulating cell cycle and cell death such as p53 and bcl-2 cannot be used to classify TNBCs into two subtypes with differing disease-free survival. But because our study is small in size, more abundant patient data will be needed to evaluate the factors' predictive role in regulating cell cycle and cell death.

MiR-34b is associated with clinical outcome in triple-negative breast cancer patients

Background

Breast cancer is the most common malignancy with the highest incidence rates among women worldwide. Triple-negative breast cancer (TNBC) represents the major phenotype of basal-like molecular subtype of breast cancer, characterized by higher incidence in young women and a very poor prognosis. MicroRNAs (miRNAs) are small non-coding RNAs playing significant role in the pathogenesis of many cancers including breast cancer. Therefore, miRNAs are also potential prognostic and/or predictive biomarkers in triple-negative breast cancer patients.

Methods

Thirty-nine TNBC patients with available formalin-fixed paraffin-embedded (FFPE) tissues were enrolled in the study. MiR-34a, miR-34b, and miR-34c were analyzed using qRT-PCR and correlated to clinico-pathological features of TNBC patients.

Results

Expression levels of miR-34b significantly correlate with disease free survival (DFS) (p = 0.0020, log-rank test) and overall survival (OS) (p = 0.0008, log-rank test) of TNBC patients. No other significant associations between miR-34a, miR-34b, and miR-34c with available clinical pathological data were observed.

Conclusions

MiR-34b expression negatively correlates with disease free survival and overall survival in TNBC patients. Thus, miR-34b may present a new promising prognostic biomarker in TNBC patients, but independent validations are necessary.