The efficacy of molecular subtyping in predicting postoperative recurrence in breast-conserving therapy: a 15-study meta-analysis

The impact of microRNAs on the resistance of breast cancer subtypes to chemotherapy

Breast cancer (BC) formation is primarily influenced by genetics, epigenetics and environmental factors. Aberrant Genetics and epigenetics leads to a condition known as heterogeneity. The heterogeneity of BC can be divided into several subtypes. Among the epigenetic factors, microRNAs (miRNAs) have been shown to play a crucial role in the development and progression of malignancies. These small non-coding RNAs regulate gene expression through a variety of mechanisms, resulting in either mRNA degradation or translation repression. As miRNAs directly control many proteins, genetic anomalies affect tumor metastasis, apoptosis, proliferation, and cell transportation. Consequently, miRNA dysregulations contribute not only in cancer development but also in invasiveness, proliferation rate and more importantly, drug response. Findings mostly indicate subtype-specified identical miRNA profile in BC. Among the BC subtypes, TNBC, HER2 + and luminal are the most resistant to therapy, respectively. Therapy resistance is greatly associated with miRNA expression profile. Hence, concentration of miRNA is the first marker of its role in chemotherapy response. Overexpressed miRNAs may disrupt drug efflux transporters and decrease the drug accumulation in cell. While down-regulated miRNAs which mediate drug resistance processes are mostly correlated with poor treatment response. Moreover, other mechanisms in which miRNAs play crucial roles in chemoresistance such as cell receptor mediations, dysregulation by environmental factors, DNA defects, etc. Recently, several miRNA-based treatments have shown promising results in cancer treatment. Inhibition of up-regulated miRNAs is one of these therapeutic approaches whilst transfecting cell with down-regulated miRNAs also show promising results. Moreover, drug-resistance could also be determined while in the pre-treatment phase via expression levels of miRNAs. Therefore, miRNAs provide intriguing insights and challenges in overcoming chemoresistance. In this article, we have discussed how miRNAs regulate breast cancer subtypes-specific chemoresistance.

The combined effect and mechanism of antiangiogenic drugs and PD-L1 inhibitor on cell apoptosis in triple negative breast cancer

Background

Breast cancer is the most common cancer worldwide, and triple-negative breast cancer (TNBC) has the worst prognosis. Standard systemic treatment includes chemotherapy and immunotherapy. Poly ADP-ribose polymerase (PARP) inhibitors are considered in breast cancer (BRCA) susceptibility genes mutated tumors. The role of antiangiogenic drugs is controversial. Immunotherapy with immune checkpoint inhibitor is now a standard of care for TNBC in the US, but its use in combination with anlotinib, an inhibitor of angiogenesis, on TNBC cells was never investigated.

Methods

We tested the effects of anlotinib and programmed cell death-ligand 1 (PD-L1) inhibitor on the proliferation, apoptosis, migration, and invasion of MDA-MB-468 and BT-549 TNBC cells through 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assays, cell apoptosis assay, wound healing and transwell matrix assays, and verified whether the combination of the two drugs had synergistic effect. Western blotting was used to detect the effect of anlotinib and PD-L1 inhibitor on the protein expression levels of PI3K, p-PI3K, AKT, p-AKT, Bcl-xl in MDA-MB-468 and BT-549 cells. The effects of anlotinib, PD-L1 inhibitor and the combination of the two drugs on the transplanted tumor of TNBC mice were tested by animal experiments.

Results

Anlotinib and PD-L1 inhibitor inhibited the proliferation and promote cell apoptosis of MDA-MB-468 and BT-549 cells, and the combination demonstrated the synergetic effect. Anlotinib and PD-L1 inhibitor inhibited cell migration and invasion, and the effect was strongest in the combination group. Both anlotinib and PD-L1 inhibitor reduced the expression of p-PI3K, p-AKT and Bcl-xl proteins in cells and the effects were the strongest in the combination group. Both anlotinib and PD-L1 inhibitor inhibited the growth of transplanted tumors in mice, and the combined group demonstrated the strongest growth suppression.

Conclusions

Anlotinib and PD-L1 inhibitor can inhibit cell proliferation, migration, and invasion of TNBC and promote cell apoptosis, and the two drugs show combined anti-tumor effects in vivo and in vitro. The combination of anlotinib and PD-L1 inhibitor may promote apoptosis of TNBC cells through PI3K/AKT/Bcl-xl signaling pathways, which might offer potential clinical treatment roles for these.

Association between recurrent breast cancer and phthalate exposure modified by hormone receptors and body mass index

The association between phthalate exposure and breast cancer remains controversial. We performed a prospective patient cohort design to explore the interaction between creatinine-corrected urinary phthalate metabolites and hormone receptors as well as body mass index (BMI) on recurrent breast cancer. In this follow-up study, 636 female breast cancer patients and 45 new recurrent cases diagnosed for a total of 1576.68 person-years of follow-up were recruited. Mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) was negatively associated with breast cancer recurrence, with adjusted hazard ratio (aHR) 3rd vs. 1st quartile of 0.15 (95% CI 0.04–0.51). The MEOHP presented as a non-monotonic dose–response (NMDR) curve, being U-shaped. In the stratification of hormone receptors, MEOHP still exhibited a U-shaped dose–response curve. The third quartile of MEOHP showed significant lowest recurrent risk in the status of ER-positive (aHR 0.18, 95% CI 0.05–0.66), PR-negative (aHR 0.14, 95% CI 0.03–0.63), and HER2-negative (aHR 0.24, 95% CI 0.08–0.76). Whether in BMI < 25 or in BMI ≥ 25, the third quartile of MEOHP was negatively associated with recurrent breast cancer, and there was a negative interaction on an additive scale between MEOHP and BMI (p_interaction = 0.042). The association between MEOHP and recurrent breast cancer was modified by hormone receptors and BMI.

The impact of young age (< 40 years) on the outcome of a cohort of patients with primary non-metastatic breast cancer: analysis of 10-year survival of a prospective study

Background

The role of young age (< 40 years) at diagnosis as an independent risk factor for adverse outcomes in female patients with breast cancer has been highlighted in several studies. In this prospective study, we assessed the difference in 10-year survival between two groups of patients diagnosed with non-metastatic breast cancer based on an age cutoff of 40 years. We also assessed the impact of factors including tumor characteristics, molecular markers and immunohistochemical markers on survival outcomes, highlighting the interaction of those variables with age.

Methods

A total of 119 female patients with newly diagnosed non-metastatic breast cancer were recruited at the American University of Beirut Medical Center (AUBMC) between July 2011 and May 2014. Patients were recruited and divided into 2 age groups (< 40 and ≥ 40 years). In addition to clinical characteristics, we assessed immunohistochemistry including estrogen, progesterone and HER2 receptors, p53, cyclin B1, vascular endothelial growth factor receptor (VEGFR), and ki-67. Germline BRCA mutations were also performed on peripheral blood samples. Patient and tumor characteristics were compared between the age groups. 10-year overall survival (OS) and disease-free survival (DFS) were estimated accordingly. Cox regression analysis was performed in order to assess the effect of the different variables on clinical outcomes.

Results

After a median Follow-up of 96 (13–122) months, the estimated 10-year OS was 98.6% for patients ≥40 as compared to 77.6% in patients < 40 (p = 0.001). A similar trend was found for 10-year DFS reaching 90% for patients ≥40 and 70.4% for those < 40 (p = 0.004). On multivariate analysis for DFS and OS, only younger age (< 40 years), higher stage and triple negative phenotype among other parameters assessed significantly affected the outcome in this cohort.

Conclusion

This prospective study confirms the association between younger age and adverse survival outcomes in patients with non-metastatic breast cancer. Future studies of the whole genome sequences may reveal the genomic basis underlying the clinical differences we have observed.

Apatinib enhances the anti-tumor effect of paclitaxel via the PI3K/p65/Bcl-xl pathway in triple-negative breast cancer

Background

Apatinib is a new generation of small molecule tyrosine kinase inhibitor, which can highly selectively inhibit phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR-2). This study aimed to investigate the synergistic effects of apatinib and paclitaxel (PTX) on triple-negative breast cancer (TNBC) in vivo and in vitro, and to explore the molecular mechanism of the PI3K/p65/Bcl-xl pathway.

Methods

In vitro, 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) method, flow cytometry (FCM), wound healing assay, and transwell matrix assay were conducted to measure the effects of apatinib and PTX on cell viability, apoptosis, migration, and invasion in TNBC cell line MDA-MB-468. Western blot (WB) was conducted to detect protein expression levels of PI3K, p65, and Bcl-xl after the application of apatinib and PTX. In vivo, MDA-MB-468 tumor-bearing nude mice were treated with apatinib and PTX, and tumor growth was observed.

Results

In vitro, apatinib and PTX could synergistically suppress the cell viability, the combined group had the most obvious effect. Apatinib and PTX could promote apoptosis and suppress migration and invasion of TNBC cells. Apatinib could reduce the expression of p-PI3K, p65, and Bcl-xl proteins (P<0.05). In vivo, apatinib and PTX could inhibit tumor size and weight of model mice, and the combined agents had a more significant effect.

Conclusions

Apatinib could enhance the anti-tumor effect of PTX on TNBC cells through the PI3K/p65/Bcl-xl molecular pathway, and apatinib combined with PTX might be a promising option for TNBC treatment.

Personalization in Modern Radiation Oncology: Methods, Results and Pitfalls. Personalized Interventions and Breast Cancer

Breast cancer, the most frequent malignancy in women worldwide, is a heterogeneous group of diseases, characterized by distinct molecular aberrations. In precision medicine, radiation oncology for breast cancer aims at tailoring treatment according to tumor biology and each patient’s clinical features and genetics. Although systemic therapies are personalized according to molecular sub-type [i.e. endocrine therapy for receptor-positive disease and anti-human epidermal growth factor receptor 2 (HER2) therapy for HER2-positive disease] and multi-gene assays, personalized radiation therapy has yet to be adopted in the clinical setting. Currently, attempts are being made to identify prognostic and/or predictive factors, biomarkers, signatures that could lead to personalized treatment in order to select appropriate patients who might, or might not, benefit from radiation therapy or whose radiation therapy might be escalated or de-escalated in dosages and volumes. This overview focuses on what has been achieved to date in personalized post-operative radiation therapy and individual patient radiosensitivity assessments by means of tumor sub-types and genetics.

Outcomes After Accelerated Partial Breast Irradiation in Women With Triple Negative Subtype and Other "High Risk" Variables Categorized as Cautionary in The ASTRO Guidelines

PURPOSE

To report a primary objective clinical outcome of ipsilateral breast recurrence following accelerated partial breast irradiation (APBI) in women with triple negative and other high risk breast cancer (as described in 2017 ASTRO guidelines) (i.e., age 40-49, size 2.1-3.0 cm, estrogen receptor negative and invasive lobular breast cancer). Secondary objectives of axillary and regional failure as well as overall survival are also reported.

METHODS AND MATERIAL

Patients from two clinical trials (NCT01185145, NCT01185132) were treated with 38.5 Gy IMRT or 3D-CRT APBI w/3.85 Gy fraction/BID fractionation for 10 fractions. Triple negative and other high risk patients (n=269) were compared to a total of 478 low risk patients which ASTRO defined as "suitable" for APBI. High risk patients, for the purpose of this study, were defined as those who possess one or more high risk criteria: triple negative (n=30), tumor size >2 cm <3 cm (n=50), HER 2+ (n=54), age range 40-50 years (n=120), ER- (n=43), and ILC histology (n=52).

RESULTS

Median follow up was 4.0 years for all patients. No significant difference was found for this high-risk cohort at 5 years for ipsilateral breast, or regional recurrences. Axillary recurrence was significantly adversely impacted by triple negative and ER- statuses (p=0.01, p=0.04). There were significant correlations between triple negative type and axillary recurrence on multivariate analysis (p=0.03). Overall survival for all patients was unaffected by any of the high-risk categories.

CONCLUSION

The data from this study suggests that women possessing high risk features are at no more meaningful risk for recurrence than other patients considered to be acceptable for APBI treatment. However, the finding of axillary recurrence in patients with triple negative breast cancer does warrant a degree of caution in proceeding with accelerated partial breast irradiation technique in this patient group.

Local Treatment of Triple-Negative Breast Cancer

ABSTRACT

Triple-negative breast cancer, compared with other molecular subtypes, poses particular challenges for optimizing the timing and the extent of locoregional treatments. In the past, the combination of increased rates of both locoregional and distant recurrences led to a preference of radical surgery and extensive radiation therapy; however, since the introduction of more effective chemotherapy, a sharp de-escalation in the extent of locoregional treatments followed. Current evidence confirms that less aggressive surgery in combination with tailored radiation therapy offers improved oncological outcomes combined with better quality of life. However, further research is required to optimize locoregional treatments, considering the significant heterogeneity in biological behavior and tumor response to systemic treatments.

Impact of molecular subtypes on the prediction of distant recurrence in estrogen receptor (ER) positive, human epidermal growth factor receptor 2 (HER2) negative breast cancer upon five years of endocrine therapy

Background

Current evidence suggests that patients with Luminal A early breast cancer can skip chemotherapy or extended endocrine therapy, but immunohistochemistry-based biomarker analysis for St Gallen subtyping may not be reproducible. We asked whether RT-qPCR can be used instead to address this clinical question.

Methods

RNA was extracted from tumor material derived from ER+/HER2- patients receiving adjuvant endocrine treatment for low-risk cancers and was semi-quantified by RT-qPCR with the MammaTyper®. St Gallen subtypes were based on the mRNA expression of ERBB2/HER2, ESR1/ER, PGR/PR and MKI67/Ki67 after dichotomizing at predefined cut-offs. Differences in distant disease-free survival (DDFS) were assessed by Kaplan Meier analysis and Cox regression.

Results

With a median follow up of 7.8 years, there were ten events in the group of 195 Luminal A-like tumors (5.1%) and 18 events in the remaining 127 tumors (14.1%), consisting mostly of Luminal B-like cases (N = 119). Luminal A-like had significantly better DDFS over the entire follow-up period (HR 0.35, 95% CIs 0.16–0.76, p = 0.0078) with a trend towards reduced probability of recurrences also in the late phase (> 5 years) (HR 0.20, p = 0.052). The survival advantage spanning the entire follow-up period persisted in the pN0 or pN0-N1 subgroups or after correcting for clinicopathological parameters. MKI67 alone significantly predicted for worse DDFS (HR 2.62, 95% CIs 1.24–5.56, p = 0.0088).

Conclusions

St Gallen Luminal A-like tumors identified by RT-qPCR display markedly low rates of distant recurrence at ten years follow-up. Patients with such tumors could be spared chemotherapy due to the obviously unfavourable benefit/toxicity ratio.

Luminal A Breast Cancer and Molecular Assays: A Review

PURPOSE

Chemotherapy has been the historical mainstay of treatment for patients with breast cancer, with immunohistochemical markers and tumor characteristics driving treatment decisions. The discovery of different intrinsic subtypes of breast cancer has advanced the understanding of breast cancer, with gene-based assays shedding further light on tumor behavior and response to treatment.

DESIGN

This review focuses on the landscape of the luminal A subtype, its definition based on immunohistochemistry (IHC) and gene assays, the prognostic and predictive value of these assays, guideline recommendations, and treatment implications.

RESULTS

Clinical studies of the prognostic value of gene-based and IHC-based assays in patients with luminal A-subtype breast cancers suggest a better prognosis for these patients compared with those with breast cancers of other subtypes.

CONCLUSION

In today's era of precision medicine, the best treatment regimen for patients with luminal A-subtype tumors is still undetermined, but available data raise the question whether chemotherapy can be omitted and endocrine therapy alone is sufficient for this patient population.

IMPLICATIONS FOR PRACTICE

Immunohistochemical markers have traditionally guided treatment decisions in breast cancer. However, advances in gene-expression profiling and availability of gene-based assays have launched these newer tests into everyday clinical practice. Luminal A-subtype tumors are a unique subset that may have favorable tumor biology. Properly defining this tumor subtype is important and may identify a subset of patients for whom endocrine therapy alone is sufficient.

Surgery and radiation therapy of triple-negative breast cancers: From biology to clinics

Triple negative breast cancer refers to tumours lacking the expression of the three most used tumour markers, namely oestrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2). These cancers are known to carry a more dismal prognosis than the other molecular subtypes. Whether a more aggressive local-regional treatment is warranted or not in patients with triple-negative breast cancer is still a matter of debate. Indeed there remain a number of grey zones with respect to the optimization of the extent and the timing of surgery and radiation therapy (RT) in this patient population, also in consideration of the significant heterogeneity in biological behaviour and response to treatment identified for these tumours. The objective of this review is to provide an insight into the biological and clinical behaviour of triple-negative breast cancers and revisit the most recent advances in their management, focussing on local-regional treatments.

Relationship between P53 status and prognosis and clinicopathologic characteristics in esophagus squamous cell carcinoma: A systematic review

AIM: To evaluate the prognostic role of p53 status and its relationship with clinicopathologic characteristics in esophagus squamous cell carcinoma (ESCC).

METHODS: A systematic search of PubMed, SCI-Ex-panded, EMBASE, the Cochrane library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Database (CBM), and science and technology periodical database (VIP) was performed. Related references were also searched for additional clinical studies. Two reviewers independently performed screening of identified studies and data extracting according to inclusion and exclusion criteria. The quality assessment was conducted on the basis of the Newcastle-Ottawa Quality Assessment Scale (NOS). The evaluation of the publication bias of the included studies and data synthesis were performed with RevMan 5.3. A fixed-effect or random effects model was adopted according to heterogeneity.

RESULTS: A total of 85 studies involing 8825 cases met the inclusion criteria. The experimental group (4608 cases) was positive for either p53 gene mutation or protein expression, and the control group (4217 cases) was negative for either p53 gene mutation or protein expression. The pooled hazard ratio (HR) for OS was 1.35 (95%CI: 1.23-1.47, P < 0.00001; heterogeneity: P = 0.39, I² = 5%). The pooled risk ratio (RR) for the 5-year and 3-year survival rates was 0.73 (95%CI: 0.62-0.87, P = 0.0003; heterogeneity: P = 0.001, I² = 50%) and 0.87 (95%CI: 0.74-1.02, P = 0.09; heterogeneity: P = 0.28, I² = 18%). p53 gene mutation or protein expression was significantly associated with poorer T stage (RR = 1.09, P = 0.004), N stage (RR = 1.24, P < 0.00001), M stage (RR = 1.65, P < 0.00001), TNM stage (RR = 1.25, P < 0.00001) and differentiation degree (RR = 1.06, P = 0.03). However, there were no association between P53 status and vascular invasion, tumor location, size, age or gender in ESCC (P>0.05).

CONCLUSION: p53 gene mutation or protein expression abnormality is a marker of poor prognosis in patients with ESCC. Meantime, patients with P53 abnormalities are associated with higher depth of invasion, higher rate of lymph node metastasis and distant metastasis, later TNM stage, and poorer grade of differentiation.

Radiation therapy in the locoregional treatment of triple-negative breast cancer

This Review assesses the relevant data and controversies regarding the use of radiotherapy for, and locoregional management of, women with triple-negative breast cancer (TNBC). In view of the strong association between BRCA1 and TNBC, knowledge of baseline mutation status can be useful to guide locoregional treatment decisions. TNBC is not a contraindication for breast conservation therapy because data suggest increased locoregional recurrence risks (relative to luminal subtypes) with breast conservation therapy or mastectomy. Although a boost to the tumour bed should routinely be considered after whole breast radiation therapy, TNBC should not be the sole indication for post-mastectomy radiation, and accelerated delivery methods for TNBC should be offered on clinical trials. Preliminary data implying a relative radioresistance for TNBC do not imply radiation omission because radiation provides an absolute locoregional risk reduction. At present, the integration of subtypes in locoregional management decisions is still in its infancy. Until level 1 data supporting treatment decisions based on subtypes are available, standard locoregional management principles should be adhered to.