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

Irradiated Tumor Cell-Derived Microparticles Prevent Lung Metastasis by Remodeling the Pulmonary Immune Microenvironment

PURPOSE

The majority of cancer-related deaths are attributed to metastasis rather than localized primary tumor progression. However, the factors that regulate the pre-metastatic niche (PMN) and metastasis have not yet been clearly elucidated. We investigated the antimetastatic effects of irradiated tumor cell-derived microparticles (RT-MPs) and highlighted the role of innate immune cells in PMN formation.

METHODS AND MATERIALS

Mice were treated three times with isolated RT-MPs, followed by tumor cell injection via the tail vein. H&E staining was performed to assess the number of tumor nodules in the lungs, and in vivo luciferase-based noninvasive bioluminescence imaging was conducted to detected tumor burden. The mechanisms of RT-MPs mediated PMN formation was evaluated using flow cytometry, transwell assay, and RT-PCR.

RESULTS

RT-MPs inhibited tumor cell colonization in the lungs. Neutrophils phagocytosed RT-MPs and secreted CCL3 and CCL4, which induced monocytes chemotaxis and maturation into macrophages. RT-MPs promoted the transition of neutrophils and macrophages into antitumor phenotypes, hence inhibiting cancer cell colonization and proliferation.

CONCLUSIONS

RT-MPs inhibited PMN formation and lung metastasis in a neutrophil- and macrophage-dependent but T cell-independent manner.

Radiotherapy: Brightness and darkness in the era of immunotherapy

The introduction of immunotherapy into cancer treatment has radically changed clinical management of tumors. However, only a minority of patients (approximately 10 to 30%) exhibit long-term response to monotherapy with immunotherapy. Moreover, there are still many cancer types, including pancreatic cancer and glioma, which are resistant to immunotherapy. Due to the immunomodulatory effects of radiotherapy, the combination of radiotherapy and immunotherapy has achieved better therapeutic effects in a number of clinical trials. However, radiotherapy is a double-edged sword in the sense that it also attenuates the immune system under certain doses and fractionation schedules, not all clinical trials show improved survival in the combination of radiotherapy and immunotherapy. Therefore, elucidation of the interactions between radiotherapy and the immune system is warranted to optimize the synergistic effects of radiotherapy and immunotherapy. In this review, we highlight the dark side as well as bright side of radiotherapy on tumor immune microenvironment and immune system. We also elucidate current status of radioimmunotherapy, both in preclinical and clinical studies, and highlight that combination of radiotherapy and immunotherapy attenuates combinatorial effects in some circumstances. Moreover, we provide insights for better combination of radiotherapy and immunotherapy.

Emerging strategies based on nanomaterials for ionizing radiation-optimized drug treatment of cancer

Drug-radiotherapy is a common and effective combinational treatment for cancer. This study aimed to explore the ionizing radiation-optimized drug treatment based on nanomaterials so as to improve the synergistic efficacy of drug-radiotherapy against cancer and limit the adverse effect on healthy organs. In this review, these emerging strategies were divided into four parts. First, the delivery of the drug-loaded nanoparticles was optimized owing to the strengthened passive targeting process, active targeting process, and cell targeting process of nanoparticles after ionizing radiation exposure. Second, nanomaterials were designed to respond to the ionizing radiation, thus leading to the release of the loading drugs controllably. Third, radiation-activated pro-drugs were loaded onto nanoparticles for radiation-triggered drug therapy. In particular, nontoxic nanoparticles with radiosensitization capability and innocuous radio-dynamic contrast agents can be considered as radiation-activated drugs, which were discussed in this review. Fourth, according to the various synergetic mechanisms, radiotherapy could improve the drug response of cancer, obtaining optimized drug-radiotherapy. Finally, relative suggestions were provided to further optimize these aforementioned strategies. Therefore, a novel topic was selected and the emerging strategies in this region were discussed, aiming to stimulate the inspiration for the development of ionizing radiation-optimized drug treatment based on nanomaterials.

A novel acid polysaccharide from Boletus edulis: extraction, characteristics and antitumor activities in vitro

A novel cold-water-soluble polysaccharide (BEP), with a molecular weight of 6.0 × 10⁶ Da, was isolated from Boletus edulis. BEP consists of galactose, glucose, xylose, mannose, glucuronic, and galacturonic acid in a ratio of 0.34:0.28:0.28:2.57:1.00:0.44. The IR results showed that BEP was an acid polysaccharide, containing α-type and β-type glucoside bonds. MTT assay showed BEP could inhibit cell proliferation significantly. Morphological observation demonstrated that BEP-treated MDA-MB-231 and Ca761 cells exhibited typical apoptotic morphological features. Flow cytometry analysis revealed that BEP caused mitochondrial membrane potential collapse. Annexin V-FITC/PI staining indicated that BEP induced apoptosis of MDA-MB-231 and Ca761 cells through cell block in S phase and G₀/G₁ phase, respectively. Western blot results showed that BEP could increase the Bax/Bcl-2 ratios, promote the release of cytochrome C, and activate the expression of caspase-3 and caspase-9 in MDA-MB-231 and Ca761 cells. In conclusion, our results demonstrated that BEP could inhibit the proliferation of breast cancer cells and induce apoptosis through mitochondrial pathways.

Breast-conserving surgery vs. total mastectomy in patients with triple negative breast cancer in early stages: A propensity score analysis

BACKGROUND

Breast-conserving surgery (BCS) as an alternative to total mastectomy (TM) in patients with early-stage triple-negative breast cancer (TNBC) is not widely spread.

OBJECTIVE

We aimed to compare the overall survival (OS) and disease-free survival (DFS) between both surgical approaches in early-stage TNBC patients at 10 years.

METHODS

We conducted a retrospective cohort study in TNBC female patients with stage I-IIa, treated at a single-center during the period of 2000-2014. We estimated and compared the survival rates with the Kaplan Meier and Long-rank test. Propensity scores were calculated with the generalized boosted regression model and were used in the multivariate Cox regression analysis with the covariate adjustment method.

RESULTS

We included 288 patients, 111 in the BCS vs. 177 in the TM group. The median follow-up was 102 months. Moreover, the patients in the BCS group had superior OS (85% vs. 81%, p = 0.56) and DFS (83% vs. 80%, p = 0.42) at 10 years. In the multivariate Cox analysis, BCS decreased the mortality risk (HR: 0.79, 95% CI: 0.37-1.67, p = 0.538), and the locoregional or distant recurrence risk (HR: 0.67, 95% CI: 0.32-1.41, p = 0.294), albeit with no statistical significance.

CONCLUSION

BCS is a safe alternative to TM in Latin-American patients with early-stage TNBC.

Radiation treatment in early stage triple-negative breast cancer in New Zealand: A national database study

INTRODUCTION

We aimed to investigate the impact of radiation treatment in early-stage triple negative breast cancer (TNBC).

METHODS

Patients with early stage (T1-3, N0-2, M0) TNBC were identified using the New Zealand breast cancer register. The outcomes of local recurrence (LRFR), local recurrence free survival (LRFS), loco-regional recurrence free rate (LRRFR), loco-regional recurrence free survival (LRRFS), breast cancer specific survival (BCSS), metastasis free (MFS) and overall survival (OS) were determined. Predefined univariate and multivariate cox regression analyses were used to explore associations between known prognostic and treatment factors.

RESULTS

1209 patients were identified with a median follow-up of 3.88 years. The majority were post- menopausal. The mean tumour size was 26mm, the majority had grade III disease and a third were node positive. 625 patients had mastectomy and 584 had breast conservation surgery (BCS). 92% of BCS and 38% of mastectomy patients received radiation. 67% received adjuvant chemotherapy. The 5 year OS was 77.6% (95% CI 74.6-80.2), 5 year BSS was 82.1% (95%CI 79.1-84.7), 5 year LRRFS was 73.9% (95% CI 73.87-73.93), 5 year LRFS was 75.4 (75.37-75.43) and the 5 year LRFR was 92.4% (95% CI 90.6-94.2). The significant prognostic/predictive factors for OS were adjuvant radiation treatment, chemotherapy, T stage, lymph node involvement and lympho-vascular space invasion. Results were similar for BSS, DMFS, LRFS and LRRFS except that LVSI was not significantly associated with BCSS, LRFS or LRRFS. When analysed by surgical type, in the WLE group, radiation was found to be significantly associated with improvement in all outcomes. In mastectomy group, radiation was not found to be significant for BCSS, LRFS, LRRFS or OS.

CONCLUSION

Radiation treatment is significantly associated with improved outcomes in early stage TNBC. This argues against the hypothesis that TNBC has inherent radiation resistance.

Green tea extract for treatment of cancers: A systematic review protocol

BACKGROUND

Previous clinical studies suggested that green tea extract (GTE) may benefit patients with a variety of cancers. However, its efficacy is still inconclusive. Thus, the objective of this study will systematically collate the clinical studies testing its efficacy and safety for cancers.

METHODS

We will perform a systematic review of clinical studies assessing the efficacy of GTE in variety of cancers. We will search Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, MEDILINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine Database (AMED), and Chinese Biomedical Literature Database (CBM) using a comprehensive strategy. We will also screen the reference lists of relevant studies to identify any additional studies for potential inclusion. All databases will be searched up to February 1, 2019. All eligible case-control studies and randomized controlled trials will be included in this study. Two independent authors will review all searched literature. Upon inclusion of trials, we will extract data by using a predefined standardized form. The risk of bias assessment will be evaluated by using Cochrane risk of bias tool. We will use RevMan 5.3 software to pool the data and carry out meta-analysis.

RESULTS

The primary outcome includes overall response rate. The secondary outcomes comprise of overall survival, progression-free survival, the disease control rate, and any adverse events.

CONCLUSIONS

The results of this study will contribute to the understanding of the efficacy of GTE in the setting of cancers and promote future research of GTE in patients with cancers.

DISSEMINATION AND ETHICS

The results of this systematic review are expected to be published through peer-reviewed journals. This study does not need ethic approval, because it does not utilize individual patient data.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019125111.

Radiotherapy with the anti-programmed cell death ligand-1 immune checkpoint blocker avelumab: acute toxicities in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is clinically the most aggressive breast cancer (BC) subtype. There is an urgent need for effective therapies for patients with TNBC. Recent findings confirm the important role of factors related to the immune system in the clinical outcome and response to treatment of TNBC patients. Avelumab selectively binds to PDL1, and competitively blocks its interaction with anti-programmed death 1 (anti-PD-1) antibodies. Unlike anti-PD-1 antibodies, which target T-cells, avelumab targets tumor cells, and is therefore expected to have fewer side effects, including a lower risk of Immune-Related Adverse Events (irAEs). Uncertainties remain regarding a potential synergy resulting in increased toxicities by combining radiotherapy and immune-checkpoint inhibitors (ICIs). Effects of concomitant ICIs with thoracic radiotherapy on pulmonary toxicities is not currently known. There are no published data available on the effects of combining anti-PD-L1 with adjuvant radiotherapy (RT) for BC in a clinical setting. We reported a preliminary experience on the first patient treated at the National Cancer Institute of Milan with the association of avelumab and concomitantly RT for TNBC.

Outcomes for Patients with Non-metastatic Triple-negative Breast Cancer in New Zealand

AIMS

Triple-negative breast cancer (TNBC) has inferior outcomes to other subtypes of breast cancer. We studied the demographics and baseline breast cancer characteristics of patients in New Zealand with TNBC and assessed survival outcomes and prognostic/predictive factors.

MATERIALS AND METHODS

We searched the New Zealand breast cancer registry database and identified patients with TNBC without distant metastatic disease. We retrieved demographic, tumour characteristic and treatment information. Locoregional recurrence-free survival, breast cancer-specific survival (BSS), metastasis-free survival (MRFS) and overall survival were determined. Predefined univariate and multivariate analyses were carried out investigating the association of survival outcomes with treatment and tumour characteristics.

RESULTS

In total, 1390 patients were identified, with a median follow-up of 3.5 years. The median age was 55 years. Thirty-eight per cent were node positive and 79% were grade III. Mastectomy was carried out in 53%, adjuvant radiation delivered in 66% and chemotherapy in 69%. The significant predictive factors for overall survival, BSS and MRFS were radiotherapy, chemotherapy and neoadjuvant chemotherapy. The significant prognostic indicators were lymphovascular invasion, nodal status and tumour size. On Kaplan-Meier analysis, the 5 year overall survival was 72%. The median time to death for those who died was 3.55 years with 92% of deaths within 5 years. Seventy-four per cent of patients had distant metastasis as a first recurrence and isolated local recurrences occurred in only 4.5%. Metastatic disease occurred in lung (55.9%) and was in multiple sites in 51%.

CONCLUSION

We report a large population-based series of TBNC without distant metastatic disease at diagnosis highlighting the unique behavioural characteristics of TNBC. Traditional therapies are positively associated with survival outcomes, and yet, particularly in the setting of recurrent disease, prognosis remains poor. Increased research into more effective systemic agents and the most effective timing of delivery of these may result in improved outcomes.

Triple Negative Breast Cancer Depends on Sphingosine Kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P)/Sphingosine 1-Phosphate Receptor 3 (S1PR3)/Notch Signaling for Metastasis

Background

Triple negative breast cancer (TNBC) has a more aggressive recurrence. Previous reports have demonstrated that sphingosine kinase 1 (SphK1) is a crucial regulator of breast cancer progression. However, the correlation of SphK1 with clinical prognosis has been poorly investigated. Thus, we aimed to elaborate the role of SphK1 in TNBC metastasis.

Material/Methods

We first determined the level of SphK1 in breast cancer tissue samples and breast cancer cells. Furthermore, the expression of HER2 and phosphor-SphK1 (pSphK1) in human breast cancer tissue samples was determined by immunohistochemical analysis. Associations between SphK1 and clinical parameters of tumors were analyzed. The activity of SphK1 was measured by fluorescence analysis. Extracellular sphingosine-1-phosphate (S1P) was detected using an ELISA kit. Associations between SphK1 and metastasis potential were analyzed by Transwell assay.

Results

Levels of SphK1 in TNBC patients were significantly higher than levels in other patients with other breast tumors. The expression of SphK1 was positively correlated with poor overall survival (OS) and progression-free survival (PFS), as well as poor response to 5-FU and doxorubicin. The depression of SphK1 thus could repress the Notch signaling pathway, reduce migration, and invasion of TNBC cells in vivo and in vitro. Furthermore, silencing of SphK1 by Ad-SPHK1-siRNA or SphK1 inhibitor PF543 sensitized TNBCs to 5-FU and doxorubicin. Our results also indicated that SphK1 inhibition could effectively counteracts tumors metastasis via Notch signaling pathways, indicating a potentially anti-tumor strategy in TNBC.

Conclusions

We found that elevated levels of pSphK1 were positive correlation with high expression of S1P, which in turn promoted metastasis of TNBC through S1P/S1PR3/Notch signaling pathway.

Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer cells by ionizing radiation

Radiation therapy is one of the major tools of cancer treatment, and is widely used for a variety of malignant tumours. Radiotherapy causes DNA damage directly by ionization or indirectly via the generation of reactive oxygen species (ROS), thereby destroying cancer cells. However, ionizing radiation (IR) paradoxically promotes metastasis and invasion of cancer cells by inducing the epithelial-mesenchymal transition (EMT). Metastasis is a major obstacle to successful cancer therapy, and is closely linked to the rates of morbidity and mortality of many cancers. ROS have been shown to play important roles in mediating the biological effects of IR. ROS have been implicated in IR-induced EMT, via activation of several EMT transcription factors—including Snail, HIF-1, ZEB1, and STAT3—that are activated by signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, G-CSF, EGFR/PI3K/Akt, and MAPK. Cancer cells that undergo EMT have been shown to acquire stemness and undergo metabolic changes, although these points are debated. IR is known to induce cancer stem cell (CSC) properties, including dedifferentiation and self-renewal, and to promote oncogenic metabolism by activating these EMT-inducing pathways. Much accumulated evidence has shown that metabolic alterations in cancer cells are closely associated with the EMT and CSC phenotypes; specifically, the IR-induced oncogenic metabolism seems to be required for acquisition of the EMT and CSC phenotypes. IR can also elicit various changes in the tumour microenvironment (TME) that may affect invasion and metastasis. EMT, CSC, and oncogenic metabolism are involved in radioresistance; targeting them may improve the efficacy of radiotherapy, preventing tumour recurrence and metastasis. This study focuses on the molecular mechanisms of IR-induced EMT, CSCs, oncogenic metabolism, and alterations in the TME. We discuss how IR-induced EMT/CSC/oncogenic metabolism may promote resistance to radiotherapy; we also review efforts to develop therapeutic approaches to eliminate these IR-induced adverse effects.

Targeting Metabolic Remodeling in Triple Negative Breast Cancer in a Murine Model

Background: Chemotherapy is the backbone of systemic treatment for triple negative breast cancer (TNBC), which is one of the most relevant breast cancers molecular types due to the ability of tumor cells to develop drug resistance, highlighting the urgent need to design newer and safer drug combinations for treatment. In this context, to overcome tumor cell drug resistance, we employed a novel combinatorial treatment including Doxorubicin, Metformin, and Sodium Oxamate (DoxMetOx). Such pharmacological combination targets indispensable hallmarks of cancer-related to aerobic glycolysis and DNA synthesis. Materials and Methods: Thirty-five female nude mice were transplanted subcutaneously with MDA-MB-231 triple negative human cancer cell line. Once tumors were visible, mice were treated with doxorubicin, metformin, oxamate or all possible pharmacologic combinations. Treatments were administered daily for 15 days and tumors were measured by calipers every day. MicroPET images were taken in three different occasions, basal state, in the middle of the treatment, and at the end of treatment. Western blot analyses, qRT-PCR, flow cytometry, and cytotoxicity assays were performed to elucidate the mechanism of cell death promoted by the drugs in vitro. Results: In this work we assessed the proof of concept of metabolic correction in solid tumors as an effective drug treatment; hence, mice bearing tumors treated with the DoxMetOx therapy showed a complete inhibition of the tumor mass growing in 15 days of treatment depicted by the micro PET images. In vitro studies displayed that the three drugs together act by inhibiting both, mTOR-phosphorylation and expression of LDH-A gene, promoting apoptosis via dependent on the caspase-3 pathway, accompanied by cleavage of PARP. Moreover, induction of autophagy process was observed by the accumulation of LC3-II, a primordial protein implicated in the conformation and elongation of the autophagolysosome. Conclusions: The lack of effective drugs to inhibit TNBC growth is the main cause of therapy failure and tumor relapse. We have showed that targeting crucial molecular pathways in cancer by the combination of Doxorubicin, Metformin, and Oxamate resulted as an efficient and rapid tumor growth inhibitor in a triple negative xenograft model. Our findings are promising for patients diagnosed with TNBC tumors, for which unfortunately there are no reliable drug therapies.

Omitting radiation therapy in women with triple-negative breast cancer leads to worse breast cancer-specific survival

PURPOSE

To examine locoregional recurrence (LRR) and breast cancer-specific survival (BCSS) after breast-conserving therapy (BCT) or mastectomy (ME) with or without radiation therapy (RT) in triple-negative breast cancer (TNBC).

MATERIAL & METHODS

We identified non-metastatic TNBC cases from a single institution database. BCT, ME with RT (ME + RT) and ME only were compared with respect to LRR and BCSS. Cox regression models were used to analyze the association between prognostic factors and outcome.

RESULTS

439 patients fulfilled the inclusion criteria. Median follow-up was 10.2 years (interquartile range 7.9; 12.4 years). Patients in the BCT (n = 239), ME + RT (n = 116) and ME only (n = 84) group differed with respect to age, pT, pN, lymphovascular invasion, lymph node dissection and chemotherapy administration. Ten-year LRR rates were seven percent, three percent and eight percent for the BCT, ME + RT and ME only group, respectively. pN was associated with LRR. In multivariable analysis LRR were significantly lower in the ME + RT group compared to the BCT and the ME only group (p 0.037 and 0.020, respectively). Ten year BCSS was 87%, 84% and 75% for the BCT, ME + RT and ME only group, respectively. pT, pN, lymph node dissection, lymphovascular invasion and the administration of chemotherapy were associated with BCSS. In multivariable analysis BCSS was significantly lower in the ME only group compared to the BCT group and the ME + RT group (p 0.047 and 0.003, respectively).

CONCLUSION

TNBC patients treated with ME without adjuvant RT showed significant lower BCSS compared to patients treated with BCT or ME + RT and significant more LRR compared to ME + RT when corrected for known clinicopathological prognostic factors.