Phase I/II trial of metronomic chemotherapy with daily dalteparin and cyclophosphamide, twice-weekly methotrexate, and daily prednisone as therapy for metastatic breast cancer using vascular endothelial growth factor and soluble vascular endothelial growth factor receptor levels as markers of response

Metronomic chemotherapy using capecitabine and cyclophosphamide in metastatic breast cancer - efficacy, tolerability and quality of life results from the phase II METRO trial

BACKGROUND

Chemotherapy is commonly used in metastatic breast cancer (MBC) to prolong life and improve quality of life (QoL). The optimal dosing and sequencing beyond the second line of treatment are unknown and pose a risk of overtreatment. Continuous low oral doses of metronomic chemotherapy using capecitabine 500 mg three times daily and cyclophosphamide 50 mg once daily (MCT-CX) may be an effective and tolerable treatment option for patients with MBC.

METHODS

In this open-label, single-arm single-centre phase II trial patients with MBC received MCT-CX until disease progression or unacceptable toxicity. The primary endpoint was the clinical benefit rate (CBR), defined as the proportion of participants with a best overall response of complete (CR) or partial response (PR) at any time, or stable disease (SD) for ≥24 weeks according to radiological evaluation. Toxicity was assessed according to the Common Toxicity Criteria v 4.0. QoL was assessed with the EORTC-30 questionnaire.

RESULTS

In total, 40 patients were included. Most participants (72 %) presented with visceral disease and received MCT-CX beyond the second line (58 %). The CBR was 45 % (8 PR and 10 SD ≥ 24 weeks). Toxicities were low grade with hand-foot syndrome being the most common. There was no significant change in QoL over the first 24 weeks.

CONCLUSION

MCT-CX is a plausible treatment option in far advanced breast cancer, with almost half of trial participants responding to treatment without QoL impairments.

"Cyclophosphamide and analogues; a matter of dose and schedule for dual anticancer activities"

Cyclophosphamide and ifosfamide are major alkylating agents but their therapeutics uses are limiting by the toxicity due to several toxicities. Indeed conventional chemotherapies are generally used with the maximum tolerated dose. In contrast, metronomic schedule aims to get a minimum dose for efficacy with a good safety. Depending on the dose, their mechanisms of action are different and offer a dual activity: at high dose, cyclophosphamide is mainly used in graft conditioning for its immunosuppressive properties, while at metronomic dose it is used as an immunoactive agent. Currently, at metronomic dose, cyclophosphamide is studied in clinic against various types of cancer, alone or in combination with others anticancer drugs (anti-angiogenic, immune-modulating agents, immune checkpoints blockers, vaccines, radiotherapy, others conventional anticancer agents), as a nth-line or first-line treatment. More than three quarters of clinical studies show promising results, mostly in breast, ovarian and prostate cancers. Taking advantage of the immune system, use dual antitumor action's chemotherapy is clearly a therapeutic strategy that deserves to be confirmed in order to improve the efficacy/toxicity balance of anticancer treatments, and to use CPM or analogues as a standard of care.

Combined oral low-dose cyclophosphamide endocrine therapy may improve clinical response among patients with metastatic breast cancer via Tregs in TLSs

Despite limited research on refractory and/or endocrine therapy failure in elderly metastatic breast cancer (MBC) patients, a prior study showed that low-dose oral cyclophosphamide (CY) can improve the overall survival rate of MBC patients, possibly through the immunoregulation of regulatory T cells (Tregs). We preliminarily investigated the combination of endocrine therapy (ET) with oral low-dose CY as salvage therapy in elderly patients via peripheral blood regulatory T-cell analyses. In addition, we evaluated the associations of tumor tertiary lymphoid structures (TLSs) with therapeutic outcomes. HR+/HER2- advanced breast cancer patients who received low-dose CY combined with ET or ET only from April 2015 to August 2021 were enrolled in this retrospective study. The primary outcome was the clinical control rate (CCR), and the secondary outcome was progression-free survival (PFS). Circulating T lymphocyte subpopulations represented by Tregs were monitored during treatment by flow cytometry methods. TLSs wereconfirmed by hematoxylin-eosin staining of pretreatment specimens, and CD3, CD4, and Foxp3 were detected using Opal multicolor immunofluorescence. A total of 85 patients who received CY + ET and 50 patients who received ET only were enrolled, the percentage of patients who received CCR was 73% (62/85) vs. 70% (45/50), and the objective response rate (ORR) was 28% (24/85) vs. 24% (12/50). No deaths occurred during the study period. The mean PFS time was 13 vs. 11 months (P = 0.03). In the CY + ET group, decreases in CD4+/CD25+/Foxp3+ T cells (P < 0.001) were favorable for both clinical control and prolonged PFS (P < 0.001). Compared with patients without TLSs, those with TLSs were more likely to have better clinical control and PFS (mean time = 6 months), and a greater number of Treg cells during TLS pretreatment correlated with longer PFS (P = 0.043). Oral low-dose CY combined with standard ET exerts immunological effects by decreasing Treg levels to achieve improved clinical responses. Moreover, patients with TLSs might benefit more from such therapy than those without TLSs, and a high Treg cell count in TLSs before treatment predicts better therapeutic efficacy.

A randomized phase II study of metronomic cyclophosphamide and methotrexate (CM) with or without bevacizumab in patients with advanced breast cancer

PURPOSE

Metronomic chemotherapy has the potential to offer tumor control with reduced toxicity when compared to standard dose chemotherapy in patients with metastatic breast cancer. As metronomic chemotherapy may target the tumor microvasculature, it has the potential for synergistic effects with antiangiogenic agents such as the VEGF-A inhibitor bevacizumab.

METHODS

In this randomized phase II study, patients with metastatic breast cancer were randomized to receive metronomic oral cyclophosphamide and methotrexate (CM) combined with bevacizumab (Arm A) or CM alone (Arm B). The primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety and tolerability.

RESULTS

A total of 55 patients were enrolled, with 34 patients treated on Arm A and 21 patients treated on Arm B. The ORR was modestly higher in Arm A (26%) than in Arm B (10%); neither met the 40% cutoff for further clinical evaluation. The median time to progression (TTP) was 5.52 months (3.22-13.6) on Arm A and 1.82 months (1.54-6.70) on Arm B (log-rank p = 0.008). The median OS was 29.6 months (17.2-NA) on Arm A and 16.2 months (15.7-NA) on Arm B (log-rank p = 0.7). Common all-grade adverse events in both arms included nausea, fatigue, and elevated AST.

CONCLUSION

The combination of metronomic CM with bevacizumab significantly improved PFS over CM alone, although there was no significant difference in OS. Oral metronomic chemotherapy alone has limited activity in advanced breast cancer.

CLINICALTRIALS

gov Identifier: NCT00083031. Date of Registration: May 17, 2004.

Targeting tumor microenvironment using tumor-infiltrating lymphocytes as therapeutics against tumorigenesis

The immune system plays a vital role in suppressing tumor cell progression. The tumor microenvironment augmented with significant levels of tumor-infiltrating lymphocytes has been widely investigated and it is suggested that tumor-infiltrating lymphocytes have shown a significant role in the prognosis of cancer patients. Compared to ordinary non-infiltrating lymphocytes, tumor-infiltrating lymphocytes (TILs) are a significant population of lymphocytes that infiltrate tumor tissue and have a higher level of specific immunological reactivity against tumor cells. They serve as an effective immunological defense against various malignancies. TILs are a diverse group of immune cells that are divided into immune subsets based on the pathological and physiological impact they have on the immune system. TILs mainly consist of B-cells, T-cells, or natural killer cells with diverse phenotypic and functional properties. TILs are known to be superior to other immune cells in that they can recognize a wide range of heterogeneous tumor antigens by producing many clones of T cell receptors (TCRs), outperforming treatments like TCR-T cell and CAR-T therapy. With the introduction of genetic engineering technologies, tumor-infiltrating lymphocytes (TILs) have become a ground-breaking therapeutic option for malignancies, but because of the hindrances opposed by the immune microenvironment and the mutation of antigens, the development of TILs as therapeutic has been hindered. By giving some insight into the many variables, such as the various barriers inhibiting its usage as a potential therapeutic agent, we have examined various aspects of TILs in this work.

Lipid-based nanoparticles for cancer immunotherapy

As the fourth most important cancer management strategy except surgery, chemotherapy and radiotherapy, cancer immunotherapy has been confirmed to elicit durable antitumor effects in the clinic by leveraging the patient's own immune system to eradicate the cancer cells. However, the limited population of patients who benefit from the current immunotherapies and the immune related adverse events hinder its development. The immunosuppressive microenvironment is the main cause of the failure, which leads to cancer immune evasion and immunity cycle blockade. Encouragingly, nanotechnology has been engineered to enhance the efficacy and reduce off-target toxicity of their therapeutic cargos by spatiotemporally controlling the biodistribution and release kinetics. Among them, lipid-based nanoparticles are the first nanomedicines to make clinical translation, which are now established platforms for diverse areas. In this perspective, we discuss the available lipid-based nanoparticles in research and market here, then describe their application in cancer immunotherapy, with special emphasis on the T cells-activated and macrophages-targeted delivery system. Through perpetuating each step of cancer immunity cycle, lipid-based nanoparticles can reduce immunosuppression and promote drug delivery to trigger robust antitumor response.

High-throughput metabolomics reveals dysregulation of hydrophobic metabolomes in cancer cell lines by Eleusine indica

Eleusine indica, which is used in traditional medicine, exhibits antiproliferative activity against several cancer cell lines. However, metabolomic studies to evaluate the metabolite changes induced by E. indica in cancer cells are still lacking. The present study investigated the anticancer effects of a root fraction of E. indica (R-S5-C1-H1) on H1299, MCF-7, and SK-HEP-1 cell lines and analyzed metabolic changes in the treated cancer cells using ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). Cell metabolic activity assays demonstrated that the cell viability of the three cancer cell lines was significantly reduced following treatment with R-S5-C1-H1, with half-maximal inhibitory concentrations values of 12.95 µg/mL, 15.99 µg/mL, and 13.69 µg/mL at 72 h, respectively. Microscopy analysis using Hoechst 33342 and Annexin V fluorescent dyes revealed that cells treated with R-S5-C1-H1 underwent apoptotic cell death, while chemometric analysis suggested that apoptosis was triggered 48 h after treatment with R-S5-C1-H1. Deconvoluted cellular metabolomics revealed that hydrophobic metabolites were significantly altered, including triacylglycerols, phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and ceramide, suggesting that apoptosis induction by R-S5-C1-H1 potentially occurred through modulation of phospholipid synthesis and sphingolipid metabolism. These metabolomic profiling results provide new insights into the anticancer mechanisms of E. indica and facilitate the overall understanding of molecular events following therapeutic interventions.

REDD1 is a determinant of low-dose metronomic doxorubicin-elicited endothelial cell dysfunction through downregulation of VEGFR-2/3 expression

Low-dose metronomic chemotherapy (LDMC) inhibits tumor angiogenesis and growth by targeting tumor-associated endothelial cells, but the molecular mechanism has not been fully elucidated. Here, we examined the functional role of regulated in development and DNA damage responses 1 (REDD1), an inhibitor of mammalian target of rapamycin complex 1 (mTORC1), in LDMC-mediated endothelial cell dysfunction. Low-dose doxorubicin (DOX) treatment induced REDD1 expression in cultured vascular and lymphatic endothelial cells and subsequently repressed the mRNA expression of mTORC1-dependent translation of vascular endothelial growth factor receptor (Vegfr)-2/3, resulting in the inhibition of VEGF-mediated angiogenesis and lymphangiogenesis. These regulatory effects of DOX-induced REDD1 expression were additionally confirmed by loss- and gain-of-function studies. Furthermore, LDMC with DOX significantly suppressed tumor angiogenesis, lymphangiogenesis, vascular permeability, growth, and metastasis in B16 melanoma-bearing wild-type but not Redd1-deficient mice. Altogether, our findings indicate that REDD1 is a crucial determinant of LDMC-mediated functional dysregulation of tumor vascular and lymphatic endothelial cells by translational repression of Vegfr-2/3 transcripts, supporting the potential therapeutic properties of REDD1 in highly progressive or metastatic tumors.

Metronomic Chemotherapy

Simple Summary

The present article reviews the state of the art of metronomic chemotherapy use to treat the principal types of cancers, namely breast, non-small cell lung cancer and colorectal ones, and of the most recent progresses in understanding the underlying mechanisms of action. Areas of novelty, in terms of new regimens, new types of cancer suitable for Metronomic chemotherapy (mCHT) and the overview of current ongoing trials, along with a critical review of them, are also provided.

Abstract

Metronomic chemotherapy treatment (mCHT) refers to the chronic administration of low doses chemotherapy that can sustain prolonged, and active plasma levels of drugs, producing favorable tolerability and it is a new promising therapeutic approach in solid and in hematologic tumors. mCHT has not only a direct effect on tumor cells, but also an action on cell microenvironment, by inhibiting tumor angiogenesis, or promoting immune response and for these reasons can be considered a multi-target therapy itself. Here we review the state of the art of mCHT use in some classical tumour types, such as breast and no small cell lung cancer (NSCLC), see what is new regarding most recent data in different cancer types, such as glioblastoma (GBL) and acute myeloid leukemia (AML), and new drugs with potential metronomic administration. Finally, a look at the strategic use of mCHT in the context of health emergencies, or in low –and middle-income countries (LMICs), where access to adequate healthcare is often not easy, is mandatory, as we always need to bear in in mind that equity in care must be a compulsory part of our medical work and research.

Antibody-drug conjugates, cancer immunotherapy, and metronomic chemotherapy as novel approaches in cancer management

Treatment of cancer is a major challenge even though the pathophysiology is becoming clearer with time. A number of new chemical entities are developed to target cancer growth inhibition, but the targeted delivery of these products still needs novel research. This is of utmost importance not only for higher efficacy but also for a reduction in systemic toxicity and cost of treatment. Although multiple novel targets and molecules are being researched, most of them could not pass the regulatory approval process, due to low benefit-risk ratio and lack of target specificity. Failure of a majority of these drugs was in part due to their superiority claimed via surrogate markers. Despite these, currently, more than 100 chemotherapeutic agents are in practice. This review paper discusses in detail the molecular basis, drug discovery, and pros and cons over conventional treatment approaches of three novel approaches in cancer therapy, i.e., (i) antibody-drug conjugates, (ii) cancer immunotherapy, and (iii) metronomic chemotherapy. All the drugs developed using these three novel approaches were compared against the established treatment regimens in clinical trials with clinical end points, such as overall survival, progression-free survival, and quality of life.

Enhancing tumor T cell infiltration to enable cancer immunotherapy

Cancer immunotherapy has changed the treatment landscape for cancer patients, especially for those with metastatic spread. While the immunotherapeutic armamentarium is constantly growing, as exemplified by approved compounds, clinical outcome remains variable both within and across entities. A sufficient infiltration into the tumor microenvironment and successful activation of effector T lymphocytes against tumor cells have been identified as predictors for responses to T cell-based immunotherapies. However, tumor cells have developed a variety of mechanisms to reduce T cell homing and access to the tumor tissue to prevent activity of anticancer immunity. As a consequence, investigations have interrogated strategies to improve the efficacy of cancer immunotherapies by enhancing T cell infiltration into tumor tissues. In this review, we summarize mechanisms of how tumor tissue shapes immune suppressive microenvironment to prevent T cell access to the tumor site. We focus on current strategies to improve cancer immunotherapies through enhancing T cell infiltration.

Phase 1 study of everolimus and low-dose oral cyclophosphamide in patients with metastatic renal cell carcinoma

mTOR inhibitors are frequently used in the treatment of metastatic renal cell cancer (mRCC). mTOR regulates cell growth, proliferation, angiogenesis, and survival, and additionally plays an important role in immune regulation. Since mTOR inhibitors were shown to benefit immunosuppressive regulatory T-cell (Treg) expansion, this might suppress antitumor immune responses. Metronomic cyclophosphamide (CTX) was shown to selectively deplete Tregs. This study was, therefore, designed to determine the optimal dosage and schedule of CTX when combined with everolimus to prevent this potentially detrimental Treg expansion. In this national multi-center phase I study, patients with mRCC progressive on first line anti-angiogenic therapy received 10 mg everolimus once daily and were enrolled into cohorts with different CTX dosages and schedules. Besides immune monitoring, adverse events and survival data were monitored. 40 patients, 39 evaluable, were treated with different doses and schedules of CTX. Combined with 10 mg everolimus once daily, the optimal Treg depleting dose and schedule of CTX was 50 mg CTX once daily. 23 (59%) patients experienced one or more treatment-related ≥ grade 3 toxicity, mostly fatigue, laboratory abnormalities and pneumonitis. The majority of the patients achieved stable disease, two patients a partial response. Median PFS of all cohorts was 3.5 months. In conclusion, the optimal Treg depleting dose and schedule of CTX, when combined with everolimus, is 50 mg once daily. This combination leads to acceptable adverse events in comparison with everolimus alone. Currently, the here selected combination is being evaluated in a phase II clinical trial. TRIAL REGISTRATION: NCT01462214.

Serum levels of VEGF and MCSF in HER2+ / HER2- breast cancer patients with metronomic neoadjuvant chemotherapy

Metronomic therapy has been gaining importance in the neoadjuvant setting of breast cancer treatment. Its clinical benefits may involve antiangiogenic machinery. Cancer cells induce angiogenesis to support tumor growth by secreting factors, such as vascular endothelial growth factor (VEGF). In breast cancer, Trastuzumab (TZM) based treatment is of key importance and is believed to reduce diameter and volume of blood vessels as well as vascular permeability. Here in we investigated serum levels of angiogenic factors VEGF and MCSF in patients receiving metronomic neoadjuvant therapy with or without TZM. We observed in HER2+ cohort stable levels of MCSF through treatment, whereas VEGF trend was of decreasing levels. In HER2- cohort we observed increasing levels of MCSF and VEGF trend. Overall, HER2+ patients had better pathological response to treatment. These findings suggest that angiogenic pathway may be involved in TZM anti-tumoral effect in the neoadjuvant setting.

Does metronomic chemotherapy induce tumor angiogenic dormancy? A review of available preclinical and clinical data

Tumor dormancy is the ability of cancer cells to survive in a non-proliferating state. This condition can depend on three main mechanisms: cell cycle arrest (quiescence or cell dormancy), immunosurveillance (immunologic dormancy), or lack of functional blood vessels (angiogenic dormancy). In particular, under angiogenic dormancy, cancer cell proliferation is counterbalanced by apoptosis owing to poor vascularization, impeding tumor mass expansion beyond a microscopic size, with an asymptomatic and non-metastatic state. Tumor vasculogenic or non-angiogenic switch is essential to promote escape from tumor dormancy, leading to tumor mass proliferation and metastasis. In avascular lesions angiogenesis process results blocked from the equilibrium between pro- and anti-angiogenic factors, such as vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1), respectively. The angiogenic switch mainly depends on the disruption of this balance, in favor of pro-angiogenic factors, and on the recruitment of circulating endothelial progenitors (CEPs) that promote the formation of new blood vessels. Metronomic chemotherapy, the regular intake of doses able to sustain low but active concentrations of chemotherapeutic drugs during protracted time periods, is an encouraging therapeutic approach that has shown to upregulate anti-angiogenic factors such as TSP-1 and decline pro-angiogenic factors such as VEGF, suppressing the proangiogenic cells such as CEPs. In this perspective, metronomic chemotherapy may be one of the available therapeutic approaches capable to modulate favorably the angiogenic tumor dormancy, but further research is essential to better define this particular characteristic.

Explorative Analysis of Low-Dose Metronomic Chemotherapy with Cyclophosphamide and Methotrexate in a Cohort of Metastatic Breast Cancer Patients

Background

Low-dose metronomic chemotherapy (LDMC) is increasingly used in metastatic breast cancer (MBC). In this retrospective analysis, we examined the therapeutic effects and side effects of LDMC in a cohort of MBC patients.

Methods

Patients with MBC were included when LDMC with oral cyclophosphamide (CTX) and methotrexate (MTX) was administered between 2009 and 2015. The primary endpoint was disease control rate (DCR) ≥ 24 weeks after the start of LDMC. Secondary endpoints were duration of progression-free survival (PFS), rates of discontinuation due to side effects, and DCR with regard to subgroups.

Results

Retrospective data of 35 patients were available for this analysis. 31% patients achieved DCR. The median PFS was 12 weeks. 9% of patients discontinued LDMC due to adverse events. DCR was 37% in the first 2 lines and 25% in further lines of therapy. 22% of patients with multiple metastases and 35% with ≤2 different metastatic sites achieved DCR. DCR was achieved in 33% of hormone receptor(HR)-positive patients and 27% of HR-negative patients.

Conclusion

The DCR of 31% is in line with the results of previous phase II studies. LDMC was well tolerated. Subgroup analysis was not able to identify a group in which LDMC was more efficient.

Use of metronomic chemotherapy in oncology: Results from a national Italian survey

Aims and background

Metronomic chemotherapy refers to the administration of low doses of cytotoxic agents over a prolonged period of time with no or only short drug-free intervals. It is designed to overcome acquired tumor resistance to chemotherapy and reduce neo-angiogenesis despite a lower toxicity than with standard chemotherapy. The role of metronomic chemotherapy remains controversial, and its optimal therapeutic use has not yet been defined.

Methods and study design

The present survey was designed as a short questionnaire and was sent to the medical oncologists registered with Medikey, a national database listing all the Italian oncology specialists linked with the Italian Council of Medical Oncology Hospital Consultants (Collegio Italiano Primari Oncologi Medici Ospedalieri, CIPOMO) and the Italian Association of Medical Oncology (Associazione Italiana di Oncologia Medica, AIOM). The questionnaire was completed on a voluntary basis and it was totally anonymous.

Results

The questionnaire was sent to 3,289 oncologists, and 191 (5.8%) actively participated in the survey. Seventy-two percent of responders declared that they had administered a regimen of metronomic chemotherapy at least once. Metronomic chemotherapy is commonly used in advanced breast cancer patients, and inmost cases it was prescribed after failure of at least two lines of treatment. Oral agents such as cyclophosphamide, capecitabine, methotrexate and vinorelbine were the most commonly prescribed drugs. Nearly 60% of responders was believed to have significantly less toxicity with metronomic chemotherapy than with standard chemotherapy.

Conclusions

The sample of oncologists who participated in the survey is small but it appears to be representative of the Italian medical oncology community. The answers to the questionnaire indicate a significant interest in metronomic chemotherapy, which is apparently widely prescribed. This is the first large national survey on the use of metronomic chemotherapy. Considering the results, larger research on metronomic chemotherapy is strongly warranted.

Whether low-dose metronomic oral cyclophosphamide improves the response to docetaxel in first-line treatment of non-triple-negative metastatic breast cancer

Oral metronomic chemotherapy may target tumor cells indirectly via antiangiogenic activity, restoration of anticancer immune response, or induction of tumor dormancy. We initiated the single-center, randomized, open-label, phase II study to determine whether the addition of metronomic cyclophosphamide to docetaxel (T) (w/o trastuzumab) improves overall response rate (ORR) as first-line treatment among patients with non-triple-negative metastatic breast cancer (MBC). Eligible patients with previously untreated non-triple-negative MBC were randomly assigned (1:1) to receive 3-weekly cycles of Metro-TC (T 75mg/m², d1 plus oral cyclophosphamide 50 mg daily) or T alone. All patients received treatment until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was ORR. Finally, 35 patients were randomized to Metro-TC group while 31 to T group. Median treatment cycles of T for both groups were 8. ORR was not improved by addition of metronomic cyclophosphamide to T (71.4% vs. 51.6%; P = 0.09). There was no statistically significant difference with regard to progression free survival (median 18.5 vs. 11.7 months; P = 0.07) or overall survival (median 33.7 vs. 33.6 months; P = 0.84) between the two group. Grade 3/4 adverse events (eg. neutropenia [100% vs. 100%], febrile neutropenia [29% vs. 29%], and neurotoxicity [6% vs. 3%]) were also comparable. There were no treatment-related deaths. We conclude that concomitant administration of metronomic cyclophosphamide and T does not appear to be a significantly active schedule for first-line treatment of non-triple-negative MBC.

The efficacy and toxicity profile of metronomic chemotherapy for metastatic breast cancer: A meta-analysis

Purpose

The current meta-analysis aimed to summarize the available evidence for the efficacy and serious adverse events (AEs) associated with use of metronomic chemotherapy (MCT) in patients with metastatic breast cancer (MBC).

Method

Electronic databases (PubMed, EMBASE database, Web of Knowledge, and the Cochrane database) were systematically searched for articles related to the use of MCT in MBC patients. Eligible studies included clinical trials of MBC patients treated with MCT that presented sufficient data related to tumor response, progression-free survival (PFS), overall survival (OS), and grade 3/4 AEs. A meta-analysis was performed using a random effects model.

Results

This meta-analysis consists of 22 clinical trials with 1360 patients. The pooled objective response rate and clinical benefit rate of MCT were 34.1% (95% CI 27.4–41.5) and 55.6% (95% CI 49.2–61.9), respectively. The overall 6-month PFS, 12-month OS, and 24-month OS rates were 56.8% (95% CI 48.3–64.9), 70.3% (95% CI 62.6–76.9), and 40.0% (95% CI 30.6–50.2), respectively. The pooled incidence of grade 3/4 AEs was 29.5% (95% CI 21.1–39.5). There was no statistically significant difference observed in any endpoint between subgroups defined by concomitant anti-cancer therapies or chemotherapy regimens. After excluding one controversial study, we observed a trend showing lower toxicity rates with the use of MCT alone compared to use of MCT with other anti-cancer therapies (P = 0.070).

Conclusions

Metronomic chemotherapy may be effective for use in patients with metastatic breast cancer. MCT used alone is possibly equally effective and less toxic than combination therapies. Well-designed RCTs are needed to obtain more evidence.

Metronomic chemotherapy: A potent macerator of cancer by inducing angiogenesis suppression and antitumor immune activation

Metronomic chemotherapy is a low dosing treatment strategy that attracts growing scientific and clinical interest. It refers to dense and uninterrupted administration of low doses of chemotherapeutic agents (without prolonged drug free intervals) over extended periods of time. Cancer chemotherapy is conventionally given in cycles of maximum tolerated doses (MTD) with the aim of inducing maximum cancer cell apoptosis. In contrast, the primary target of metronomic chemotherapy is the tumor's neovasculature. This is relevant to the emerging concept that tumors exist in a complex microenvironment of cancer cells, stromal cells and supporting vessels. In addition to its anti-angiogenetic properties, metronomic chemotherapy halts tumor growth by activating anti-tumor immunity, thus decreasing the acquired resistance to conventional chemotherapy. Herein, we present a review of the literature that provides a scientific basis for the merits of chemotherapy when administered on a metronomic schedule.

Metronomic Chemotherapy for Metastatic Breast Cancer - a Systematic Review of the Literature

Conventional chemotherapy is generally administered in high doses followed by a treatment-free period to give the body needful time to recover. This "maximum tolerated dose" approach results in high response rates. However, long periods between therapy cycles can lead to development of resistance mechanisms and consequently disease progression. One of the most interesting alternative strategies is metronomic chemotherapy. This concept relies on the continuous administration of chemotherapy at low doses and aims at targeting endothelial cells in the tumor bed as well. Recently, metronomic chemotherapy has been incorporated into the recommendations issued by the German AGO expert panel (www.ago-online.de). A systematic review of PubMed/Medline, ClinicalTrials.gov, the European Clinical Trials Database (EudraCT) and the Cochrane Database was conducted. In the present review, we discuss the current evidence on metronomic chemotherapy in metastatic breast cancer.

Indication of metronomic chemotherapy for metastatic breast cancer: Clinical outcomes and responsive subtypes

The survival of patients with metastatic breast cancer (MBC) has not improved, despite recent advances in therapeutic strategies. This is mainly due to the fact that cytotoxic agents cannot be administered over a long period, even if they exhibit favorable activity, due to treatment-related side effects or acquisition of tumor resistance to the administered agents. Thus, the development of therapeutic strategies that may be used over a long time period is required to improve survival. We assessed the availability and clinical outcomes of metronomic chemotherapy, which is defined as continuous or frequent treatment with low doses of cytotoxic drugs. A total of 80 patients with MBC received chemotherapy in the metastatic setting, and the clinicopathological factors and clinical outcomes were retrospectively compared between 52 patients who received metronomic regimens and 28 patients who received other cytotoxic regimens. As regards clinical outcomes, the median time-to-treatment failure (TTF) and overall survival (OS) were significantly longer in the metronomic group compared with those in the non-metronomic group (TTF, 15 vs. 4 months, P=0.0001; and OS, 53 vs. 28 months P=0.0012, respectively). In the metronomic group, none of the 18 patients who responded to the regimen had triple-negative (TN) cancer (17 had luminal-type tumors and 1 had a human epidermal factor receptor 2-type tumor). Furthermore, TTF and OS were significantly longer in patients with non-TN cancer compared with those in patients with TN cancer in the metronomic group (TTF, 16 vs. 7 months, P=0.0014; and OS, 108 vs. 20 months, P=0.000007, respectively). The proportion of patients who experienced treatment-related adverse events was significantly lower in the metronomic group compared with that in the non-metronomic group (36.5 vs. 61.5%, respectively; P=0.038). In conclusion, metronomic chemotherapy is a viable option for luminal-type MBC in terms of effectiveness and minimal toxicity, regardless of metastatic sites or prior treatment. However, an alternative treatment is required for TN cancer.

Dual Metronomic Chemotherapy with Nab-Paclitaxel and Topotecan Has Potent Antiangiogenic Activity in Ovarian Cancer

There is growing recognition of the important role of metronomic chemotherapy in cancer treatment. On the basis of their unique antiangiogenic effects, we tested the efficacy of nab-paclitaxel, which stimulates thrombospondin-1, and topotecan, which inhibits hypoxia-inducible factor 1-α, at metronomic dosing for the treatment of ovarian carcinoma. In vitro and in vivo SKOV3ip1, HeyA8, and HeyA8-MDR (taxane-resistant) orthotopic models were used to examine the effects of metronomic nab-paclitaxel and metronomic topotecan. We examined cell proliferation (Ki-67), apoptosis (cleaved caspase-3), and angiogenesis (microvessel density, MVD) in tumors obtained at necropsy. In vivo therapy experiments demonstrated treatment with metronomic nab-paclitaxel alone and in combination with metronomic topotecan resulted in significant reductions in tumor weight (62% in the SKOV3ip1 model, P < 0.01 and 96% in the HeyA8 model, P < 0.03) compared with vehicle (P < 0.01). In the HeyA8-MDR model, metronomic monotherapy with either cytotoxic agent had modest effects on tumor growth, but combination therapy decreased tumor burden by 61% compared with vehicle (P < 0.03). The greatest reduction in MVD (P < 0.05) and proliferation was seen in combination metronomic therapy groups. Combination metronomic therapy resulted in prolonged overall survival in vivo compared with other groups (P < 0.001). Tube formation was significantly inhibited in RF-24 endothelial cells exposed to media conditioned with metronomic nab-paclitaxel alone and media conditioned with combination metronomic nab-paclitaxel and metronomic topotecan. The combination of metronomic nab-paclitaxel and metronomic topotecan offers a novel, highly effective therapeutic approach for ovarian carcinoma that merits further clinical development.

A systematic literature analysis of correlative studies in low-dose metronomic chemotherapy trials

Low-dose metronomic (LDM) chemotherapy is a beneficial and very well-tolerated form of chemotherapy utilization characterized by the frequent and uninterrupted administration of low doses of conventional chemotherapeutic agents over prolonged periods of time. While patients resistant to standard maximum tolerated dose (MTD) chemotherapy may still benefit from LDM chemotherapy, there is a lack of predictive markers of response to LDM chemotherapy. We searched the MEDLINE, EMBASE, CENTRAL and PubMed databases for correlative studies conducted as part of LDM chemotherapy trials in order to identify the most promising biomarker candidates. Given the antiangiogenic properties of LDM chemotherapy, angiogenesis-related biomarkers were most commonly studied. However, significant correlations between angiogenesis-related biomarkers and study end points were rare and variable, even so far as biomarkers correlating positively with an end point in some studies and negatively with the same end point in other studies. Pursuing biomarkers outside the angiogenesis field may be more promising.

Metronomic chemotherapy in the neoadjuvant setting: results of two parallel feasibility trials (TraQme and TAME) in patients with HER2+ and HER2- locally advanced breast cancer

Neoadjuvant chemotherapy has practical and theoretical advantages over adjuvant chemotherapy strategy in breast cancer (BC) management. Moreover, metronomic delivery has a more favorable toxicity profile. The present study examined the feasibility of neoadjuvant metronomic chemotherapy in two cohorts [HER2+ (TraQme) and HER2− (TAME)] of locally advanced BC. Twenty patients were prospectively enrolled (TraQme, n=9; TAME, n=11). Both cohorts received weekly paclitaxel at 100 mg/m² during 8 weeks followed by weekly doxorubicin at 24 mg/m² for 9 weeks in combination with oral cyclophosphamide at 100 mg/day (fixed dose). The HER2+ cohort received weekly trastuzumab. The study was interrupted because of safety issues. Thirty-six percent of patients in the TAME cohort and all patients from the TraQme cohort had stage III BC. Of note, 33% from the TraQme cohort and 66% from the TAME cohort displayed hormone receptor positivity in tumor tissue. The pathological complete response rates were 55% and 18% among patients enrolled in the TraQme and TAME cohorts, respectively. Patients in the TraQme cohort had more advanced BC stages at diagnosis, higher-grade pathological classification, and more tumors lacking hormone receptor expression, compared to the TAME cohort. The toxicity profile was also different. Two patients in the TraQme cohort developed pneumonitis, and in the TAME cohort we observed more hematological toxicity and hand-foot syndrome. The neoadjuvant metronomic chemotherapy regimen evaluated in this trial was highly effective in achieving a tumor response, especially in the HER2+ cohort. Pneumonitis was a serious, unexpected adverse event observed in this group. Further larger and randomized trials are warranted to evaluate the association between metronomic chemotherapy and trastuzumab treatment.

Systemic treatment approaches in her2-negative advanced breast cancer-guidance on the guidelines

Despite advancements in the treatment of early-stage breast cancer, many patients still develop disease recurrence; others present with de novo metastatic disease. For most patients with advanced breast cancer, the primary treatment intent is noncurative-that is, palliative-in nature. The goals of treatment should therefore focus on maximizing symptom control and extending survival. Treatments should be evaluated on an individualized basis in terms of evidence, but also with full respect for the wishes of the patient in terms of acceptable toxicity. Given the availability of extensive reviews on the roles of endocrine therapy and her2 (human epidermal growth factor receptor 2)-targeted therapies for advanced disease, we focus here mainly on treatment guidelines for the non-endocrine management of her2-negative advanced breast cancer in a Canadian health care context.

Systematic drug repositioning for a wide range of diseases with integrative analyses of phenotypic and molecular data

Drug repositioning, or the application of known drugs to new indications, is a challenging issue in pharmaceutical science. In this study, we developed a new computational method to predict unknown drug indications for systematic drug repositioning in a framework of supervised network inference. We defined a descriptor for each drug-disease pair based on the phenotypic features of drugs (e.g., medicinal effects and side effects) and various molecular features of diseases (e.g., disease-causing genes, diagnostic markers, disease-related pathways, and environmental factors) and constructed a statistical model to predict new drug-disease associations for a wide range of diseases in the International Classification of Diseases. Our results show that the proposed method outperforms previous methods in terms of accuracy and applicability, and its performance does not depend on drug chemical structure similarity. Finally, we performed a comprehensive prediction of a drug-disease association network consisting of 2349 drugs and 858 diseases and described biologically meaningful examples of newly predicted drug indications for several types of cancers and nonhereditary diseases.

Enhancement of T cell recruitment and infiltration into tumours

Studies have documented that cancer patients with tumours which are highly infiltrated with cytotoxic T lymphocytes show enhanced survival rates. The ultimate goal of cancer immunotherapy is to elicit high-avidity tumour-specific T cells to migrate and kill malignant tumours. Novel antibody therapies such as ipilumimab (a cytotoxic T lymphocyte antigen-4 blocking antibody) show enhanced T cell infiltration into the tumour tissue and increased survival. More conventional therapies such as chemotherapy or anti-angiogenic therapy and recent therapies with oncolytic viruses have been shown to alter the tumour microenvironment and thereby lead to enhanced T cell infiltration. Understanding the mechanisms involved in the migration of high-avidity tumour-specific T cells into tumours will support and provide solutions for the optimization of therapeutic options in cancer immunotherapy.

Factors responsible for long-term survival in metastatic breast cancer

Background

Although survival of patients with metastatic breast cancer (MBC) has been significantly prolonged over the past decade due to improvement of anti-cancer therapeutics, only a few patients survive for more than 10 years. It has not been determined which patients can have long-term survival with treatment.

Methods

To determine prognostic factors responsible for long-term survival, we retrospectively compared clinicopathologic factors of patients with MBC who survived for 50 months or more after diagnosis with patients who did not. Of 70 patients with MBC who received chemotherapy between November 2005 and September 2011, 23 patients who survived for 50 months or more after diagnosis and 28 patients who died within 50 months after diagnosis were assessed for their clinicopathologic factors and outcomes.

Results

The proportion of patients with hormone receptor-positive (HR+) tumors was significantly higher and the proportion of patients with triple negative tumors (TN) was lower in long-term survivors than in non-long-term survivors (HR+: 87% versus 28.6%, P = 0.000037; TN: 13.1% versus 53.6%, P = 0.0028). Metastatic site, number of disease sites, prior chemotherapeutic regimens and human epidermal growth factor receptor-2 (HER2) status did not differ between the two groups. The proportion of patients who received metronomic regimens was significantly higher in long-term survivors than in non-long-term survivors (65.2% versus 35.7%, P = 0.034) when the most effective regimen among regimens that were received in metastatic settings was compared between the two groups. Overall response rate was significantly higher (82.6% versus 17.9%, P <0.00001) and time to treatment failure after receiving the most effective regimen was longer in long-term survivors than in non-long-term survivors (26 versus 5 months, P = 0.0001). The number of chemotherapeutic regimens for breast cancer and that for MBC did not differ between the two groups.

Conclusions

Patients with luminal-type MBC who benefit at least once from chemotherapy including metronomic regimens, or patients who continued to receive the most effective regimen for more than two years can be expected to have long-term survival after diagnosis of MBC, regardless of the number of chemotherapeutic regimens they had received.

Metronomic therapy and breast cancer: a systematic review

Metronomic therapy (MT) refers to repetitive, low doses of chemotherapy drugs. MT exerts an effect not only on tumour cells, but also on their microenvironment. In particular, the low-dose schedule compromises the repairing process of endothelial cells, leading to an anti-angiogenic effect. In addition to the anti-angiogenic effect, MT could have an immunological action through the restoration of the anticancer effect of the immune system and induction of tumour dormancy. Consequently the association of targeted therapy with anti-angiogenic properties or specific immunologic drugs could enhance the efficacy of MT. During the past 15 years, several studies have been published evaluating the metronomic strategy in breast cancer. We conducted a systematic review of the results of phase I, II and III studies testing MT in breast cancer patients. The analyses included the efficacy and toxicity data of MT, and the future development of this strategy in breast cancer are also discussed. The systematic review presented here suggests that MT is a treatment option for breast cancer patients, has a low toxicity profile, efficacy in most patients and has potentially significant cost-effective advantages for public health.

Response assessment in metronomic chemotherapy: RECIST or PERCIST?

INTRODUCTION

Metronomic chemotherapy (MC) is a novel therapeutic variation for resistant cancers, wherein chemotherapeutic drugs are administrated in low doses with no prolonged drug-free break. It lessens the level of toxicity, is better tolerated and enhances the quality of life. This retrospective analysis was undertaken to evaluate whether anatomical (computed tomography [CT]) or functional (positron emission tomography [PET]) imaging be used for response assessment in patients on MC.

MATERIALS AND METHODS

A total of 16 males and 27 females with age range of 12-83 years on MC who underwent PET/CT were assessed by new response evaluation criteria in solid tumors (RECIST 1.1) and PET response criteria in solid tumors (PERCIST 1.0).

RESULTS

Concordance between RECIST 1.1 and PERCIST was seen in 32 (75%) patients. There was discordance in 11 (25%) patients. In patients with discordance, the results were confirmed by follow-up imaging. PET upstaged the disease in 81% of patients (9/11) and down-staged the disease in 19% of patients (2/11).

CONCLUSIONS

Metabolic response accurately identified the disease status as assessed by clinical or imaging follow-up. Alteration in morphology takes time to manifest, which is demonstrated by CT or magnetic resonance; whereas in MC which brings about tumor dormancy, assessing metabolic response by PET would be more appropriate. MC is usually given in palliative setting but in few cases complete metabolic response was demonstrated in our study. In such a scenario this form of treatment has the potential to become an adjunct mode of treatment in some tumors. This needs to be evaluated with larger, homogenous patient population in a prospective mode.

Safety and therapeutic effect of metronomic chemotherapy with cyclophosphamide and celecoxib in advanced breast cancer patients

Metronomic chemotherapy (MCT), the chronic administration, at regular intervals, of low doses of chemotherapeutic drugs without extended rest periods, allows chronic treatment with therapeutic efficacy and low toxicity. Our preclinical results suggested that combined MCT with cyclophosphamide and celecoxib could inhibit breast cancer growth. The aim of this study was to determine the toxicity, safety and efficacy of oral MCT with cyclophosphamide 50 mg per orem daily and celecoxib 400 mg (200 mg per orem two-times a day) in advanced breast cancer patients. During the first stage of the study, the therapeutic response consisted of prolonged stable disease for ≥24 weeks in six out of 15 (40%) patients with a median duration of 37.5 weeks and a partial response in one out of 15 (response rate: 6.7%) patients lasting 6 weeks. The overall clinical benefit rate was 46.7%. The median time to progression was 14 weeks. Progression-free survival at 24 weeks was 40% and the 1-year overall survival rate was 46.7%. The adverse events were mild (gastric, grade 1; and hematologic, grade 1 or 2). No grade 3 or 4 toxicities were associated with the treatment. Evaluation of patients' quality of life showed no changes during the response period. MCT with cyclophosphamide plus celecoxib is safe and shows a therapeutic effect in advanced breast cancer patients.

Metronomic therapy is an effective salvage treatment for heavily pre-treated relapsed/refractory multiple myeloma

Relapsed/refractory multiple myeloma represents a major challenge in multiple myeloma therapy. For patients with relapsed/refractory multiple myeloma, we developed a treatment schema of metronomically scheduled drug therapy. We identified 186 patients who had been treated with metronomic therapy between March 2004 and January 2012 with a median follow up of 24.2 months. Median age was 61 years (range 36-83). Median number of prior therapies was 14 (range 1-51). Median number of completed metronomic therapy cycles was 1 (range 1-5), while 45 of 186 (25%) received 2 or more cycles. Responses included complete remission in 11 of 186 patients (6%), very good partial remission in 12 of 186 (7%), partial remission in 65 of 179 (36%), and minimal response in 29 of 186 (16%), for an overall response rate of 63% (117 of 186). Median overall survival and progression-free survival were 11.2 and 3.6 months, respectively. Hematologic toxicity grading was problematic as 146 of 186 (78%) of patients presented with at least grade 2 thrombocytopenia within 90 days prior to starting metronomic therapy. Grade 4 leukopenia, anemia, and/or thrombocytopenia following metronomic therapy occurred in 108 of 186 (58%), 12 of 186 (6%), and 147 of 186 (79%) patients, respectively. Incidence of grade 3-4 neutropenic fever was 4 of 186 (2%). Most patients (177 of 186, 95%) were treated in an outpatient unit and secondary admissions due to regimen-related toxicity occurred in 37 of 186 (20%). Treatment-related mortality was evident in 2 of 186 (1%). In conclusion, metronomic therapy is an effective late salvage treatment in relapsed/refractory multiple myeloma, with a high overall response rate and a favorable toxicity profile.

Dose selection trial of metronomic oral vinorelbine monotherapy in patients with metastatic cancer: a hellenic cooperative oncology group clinical translational study

Background

Metronomic chemotherapy is considered an anti-angiogenic therapy that involves chronic administration of low-dose chemotherapy at regular short intervals. We investigated the optimal metronomic dose of oral vinorelbine when given as monotherapy in patients with metastatic cancer.

Methods

Patients with recurrent metastatic breast (BC), prostate (PC) or non-small cell lung cancer (NSCLC) and adequate organ functions were randomly assigned to 30, 40 or 50 mg vinorelbine, taken orally three times a week. Treatment continued until disease progression, unacceptable toxicity, withdrawal of consent or maximum 24 months. Primary endpoint was time-to-treatment failure (TTF) and secondary were progression-free survival (PFS), toxicity, changes in blood concentrations of angiogenesis-associated biomarkers and pharmacokinetics.

Results

Seventy-three patients were enrolled. Four-month TTF rate did not differ between the three arms: 25.9% (11.1%-46.2% 95% Confidence Interval), 33.3% (15.6%-55.3%) and 18.2% (5.2%-40.3%) for the 30 mg, 40 mg and 50 mg arms (p-value = 0.56). Objective response was seen in 2 patients with NSCLC (treated at 30 and 50 mg respectively), one with BC (at 40 m g) and one with PC (at 50 mg) and lasted from 4 to 100 weeks, with maximum response duration achieved at 50 mg. Adverse events were mild and negligible and did not differ between the three arms. Blood levels of vinorelbine reached steady state from the second week of treatment and mean values for the 30, 40 and 50 mg were respectively 1.8 ng/ml (SD 1.10), 2.2 ng/ml (SD 1.87) and 2.6 ng/ml (SD 0.69). Low pre-treatment blood concentrations of FGF2 and IL8 predicted favorable response to therapy (p values 0.02 and 0.006, respectively), while high levels of TEK gene transcript predicted treatment resistance.

Conclusions

Considering the antitumor activity and response duration, the negligible toxicity of the highest dose investigated and the lack of drug accumulation over time, we suggest that 50 mg given three times a week is the optimal dose for metronomic oral vinorelbine. Further investigation of metronomic oral vinorelbine (MOVIN) at this dose is warranted in combination with conventional chemotherapy regimens and targeted therapies.

Trial registration

Clinicaltrials.gov NCT00278070

Metronomic chemotherapy for cancer treatment: a decade of clinical studies

PURPOSE

Over the past few years, more and more new selective molecules directed against specific cellular targets have become available for cancer therapy, leading to impressive improvements. In this evolving scenario, a new way of delivering older cytotoxic drugs has also been developing. Many studies demonstrated that several cytotoxic drugs have antiangiogenic properties if administered frequently and at lower doses compared with standard schedules containing maximal tolerated doses (MTD). Such a new strategy, named metronomic chemotherapy, focuses on a different target: the slowly proliferating tumour endothelial cells. About 10 years ago, metronomic chemotherapy was firstly enunciated and hereafter many clinical experiences were published related to almost any cancer disease. This review analyses available studies dealing with metronomic chemotherapy and its combination with several targeted agents in solid tumours.

METHODS

A computerized literature search of MEDLINE was performed using the following search terms: metronomic OR "continuous low dose" AND chemotherapy AND cancer OR solid tumours.

RESULTS

Satisfactory results have been achieved in diverse tumour types, such as breast and prostate cancer or paediatric sarcomas. Moreover, many studies have reported that metronomic chemotherapy determined minimal toxicity compared to MTD chemotherapy. Overall, published series on metronomic schedules are very heterogeneous often reporting on retrospective data, while only very few studies were randomized trials. These limitations still prevent to draw definitive conclusions in diverse tumour types.

CONCLUSIONS

Large well-designed studies are eagerly awaited for confirming the promises of metronomic schedules and their combinations with targeted molecules.

Safety and efficacy of metronomic non-pegylated liposomal encapsulated doxorubicin in heavily pretreated advanced breast cancer patients

PURPOSE

Metronomic administration of the same chemotherapy agents (lower doses with closer intervals) may optimize their antiangiogenic properties. The aim of our study was to determine the efficacy and safety of a metronomic regimen based in non-pegylated liposomal doxorubicin (NPLD) in advanced breast cancer patients.

METHODS

Clinical records of patients with pretreated advanced breast cancer and who were treated with the Metronomic-Cooper-type regimen consisting of weekly fixed doses of NPLD (30 mg IV) plus 5-Fluorouracil (5-FU) (500 mg IV) plus vincristine (0.25 mg IV) and daily oral cyclophosphamide (50 mg) plus prednisone (20 mg) were reviewed.

RESULTS

In 84 pretreated patients, a tumor response was observed in 38 patients (45 %); stable disease was observed in 23 patients (27 %). Median progression-free survival (PFS) time to progression was 8.4 months and median overall survival (OS) was 21 months. The most common grade 2-3 hematologic adverse event was neutropenia, which was observed in 47 patients (56 %). Febrile neutropenia was observed in 10 patients (12 %). The most common non-hematologic adverse events were asthenia and mucositis which were observed in 60 patients (71 %) and 26 patients (31 %), respectively. Three patients (4 %) experienced an asymptomatic decline of the left ventricular ejection fraction.

CONCLUSIONS

NPLD-based metronomic regimen was effective and safe in pretreated advanced breast cancer patients. It could be considered as an appealing option to treat patients previously exposed to anthracyclines.

Metronomic chemotherapy for metastatic breast cancer to prolong time to treatment failure to 12 months or more

The objective of treatment for metastatic breast cancer (MBC) is to control the disease or disease-related symptoms. Prolonged survival has also often been achieved by chemotherapeutic regimens in this setting. Long-term administration of one therapeutic regimen is essential for prolonging survival as well as for maintaining quality of life in these patients. In this study, we focused on time to treatment failure (TTF) as a parameter that predicts patient survival and we retrospectively compared clinical outcomes of patients with MBC who showed TTF of ≥12 months (26 patients) and <12 months (29 patients). The proportion of hormone receptor-positive tumors and the number of prior chemotherapy regimens for MBC were significantly higher and tumor grade was lower in patients with TTF ≥12 months compared to those with TTF <12 months. With regard to clinical outcomes, the objective response rate (ORR) in patients with TTF ≥12 months was significantly higher and median time to progression (TTP) and overall survival (OS) were longer compared to those with TTF <12 months. Of note, the proportion of patients who received metronomic regimens was significantly higher in patients with TTF ≥12 months compared to those with TTF <12 months (80.8 vs. 24.1%, P=0.00003). To assess the clinical benefit of metronomic regimens, the efficacy in patients receiving metronomic and those receiving non-metronomic regimens was compared. Although there was no difference in ORR between the two groups, median TTP and OS were significantly longer in the metronomic compared to the non-metronomic group (TTP: 30 vs. 4 months, P=0.0017; OS: 68 vs. 28 months, P=0.0005). The results suggested that metronomic chemotherapy is useful for palliative care and also improved clinical outcomes as a regimen for which long-term administration may be expected.

Metronomic chemotherapy in progressive pediatric malignancies: old drugs in new package

Despite intensive research in the field of cancer, many pediatric cancers are still incurable with current treatment protocols. Repetitive administration of conventional chemotherapy at maximal tolerated dose imposes many side effects that further limits the dosing and therefore decreases the anticancer effects. Usually limited options remain when a malignancy progresses after one or two lines of standard chemotherapy protocol. The goal of an oncologist at this point of time remains mainly palliative with an effort to halt the progression of cancer and improve quality of life. Metronomic chemotherapy is defined as the chronic administration of chemotherapeutic agents at relatively low, minimally toxic doses, and with no prolonged drug-free breaks. It is thought this type of chemotherapy inhibits tumor growth primarily through anti-angiogenic mechanisms, promoting apoptosis and immune- surveillance.

Concentration- and schedule-dependent effects of chemotherapy on the angiogenic potential and drug sensitivity of vascular endothelial cells

The anti-angiogenic activity of chemotherapy is both dose- and schedule-dependent. While conventional maximum tolerated dose (MTD) chemotherapy exerts only mild and reversible anti-angiogenic effects, low-dose metronomic (LDM) chemotherapy was developed to specifically target tumour angiogenesis. However, the long-term effects of either MTD or LDM chemotherapy on vascular endothelial cells have never been investigated. Here, we demonstrated that repeated exposure to MTD and LDM chemotherapy differentially impact on the angiogenic potential and chemosensitivity of immortalized endothelial cells. Repeated MTD vinblastine treatment of vascular endothelial cells led to an increased proliferation rate and resistance to paclitaxel. In contrast, repeated LDM treatment with vinblastine or etoposide impaired the angiogenic potential of endothelial cells and increased their chemosensitivity. This effect was associated with a significant decrease in βII- and βIII-tubulin expression. Functional analysis using siRNA showed that silencing the expression of βIII-tubulin in endothelial cells significantly decreased their capacity to form vascular structures and increased their sensitivity to the anti-angiogenic and vascular-disrupting effects of chemotherapy, whereas silencing βII-tubulin expression had no effect. Collectively our results show that LDM chemotherapy impairs the angiogenic potential of endothelial cells while increasing their chemosensitivity-an effect at least in part mediated by the down-regulation of βIII-tubulin expression. Furthermore, our study suggests that βIII-tubulin represents an attractive therapeutic target to increase the anti-angiogenic effects of chemotherapy and overall anti-tumour efficacy.

Low-dose "metronomic chemotherapy" with oral cyclophosphamide and methotrexate in metastatic breast cancer: a case report of extraordinarily prolonged clinical benefit

We report the case of a 34-year-old woman affected by breast cancer that had metastasized to the bone. She had been treated with oral cyclophosphamide and methotrexate (metronomic chemotherapy) and achieved 3.5 years of clinical remission. To our knowledge, this is the first description of such a prolonged response to therapy. This case report adds weight to known data on metronomic treatment and supports further investigation of this therapy.

Combination antiangiogenic therapy in advanced breast cancer: a phase 1 trial of vandetanib, a VEGFR inhibitor, and metronomic chemotherapy, with correlative platelet proteomics

This phase 1 study evaluated the safety and tolerability of antiangiogenic therapy using vandetanib and metronomic cyclophosphamide and methotrexate in metastatic breast cancer. Eligible patients had metastatic breast cancer with 0-4 prior chemotherapy regimens. All received cyclophosphamide 50 mg daily, methotrexate 2.5 mg days 1-2 weekly, and vandetanib daily in 3 dose-escalation cohorts: 100 mg (C1), 200 mg (C2), and 300 mg (C3). The primary endpoint was safety and tolerability; secondary endpoints included response rate and evaluation of platelet-associated proteins. Twenty three patients were treated and evaluable for toxicity. Common mild toxicities included nausea, vomiting, LFTs abnormalities, fatigue, and rash. Three episodes of dose-limiting toxicity occurred in C3. In all cohorts, 1/3 of patients required vandetanib dose reduction, and 22 % ended therapy for toxicity. Of the 20 response-evaluable patients, 10 % demonstrated partial response and 15 % stable disease ≥24 weeks. Proteomic analyses demonstrated changes in platelet content of angiogenesis regulators, including vascular endothelial growth factor and platelet factor 4, with exposure to therapy. This regimen was tolerable at a maximum vandetanib dose of 200 mg; modest clinical activity was observed in this heavily pretreated population. Changes in the platelet proteome may serve as pharmacodynamic markers of angiogenesis inhibition. Metronomic chemotherapy is an attractive partner with biologics and deserves further study in metastatic breast cancer.

Antiangiogenic therapy in the management of breast cancer

An improved understanding of the important role of angiogenesis in tumor biology has led to development of different antiangiogenic therapies. Numerous clinical studies for several antiangiogenic agents have recently been conducted in breast cancer patients and have shown clinically significant improvement in outcomes. This review focuses on current progress in the field of antiangiogenic therapy in the management of breast cancer, also highlighting issues regarding future therapeutic development that result in the greatest clinical benefits and minimizing the adverse effects.

Distinct effects of unfractionated heparin versus bivalirudin on circulating angiogenic peptides

Background

Human studies of therapeutic angiogenesis, stem-cell, and progenitor-cell therapy have failed to demonstrate consistent clinical benefit. Recent studies have shown that heparin increases circulating levels of anti-angiogenic peptides. Given the widely prevalent use of heparin in percutaneous and surgical procedures including those performed as part of studies examining the benefit of therapeutic angiogenesis and cell-based therapy, we compared the effects of unfractionated heparin (UFH) on angiogenic peptides with those of bivalirudin, a relatively newer anticoagulant whose effects on angiogenic peptides have not been studied.

Methodology/Principal Findings

We measured soluble fms-like tyrosine kinase-1 (sFLT1), placental growth factor (PlGF), vascular endothelial growth factor (VEGF), and soluble Endoglin (sEng) serum levels by enzyme linked immunosorbent assays (ELISA) in 16 patients undergoing elective percutaneous coronary intervention. Compared to baseline values, sFLT1 and PlGF levels increased by 2629±313% and 253±54%, respectively, within 30 minutes of UFH therapy (p<0.01 for both; n = 8). VEGF levels decreased by 93.2±5% in patients treated with UFH (p<0.01 versus baseline). No change in sEng levels were observed after UFH therapy. No changes in sFLT1, PlGF, VEGF, or sEng levels were observed in any patients receiving bivalirudin (n = 8). To further explore the direct effect of anticoagulation on circulating angiogenic peptides, adult, male wild-type mice received venous injections of clinically dosed UFH or bivalirudin. Compared to saline controls, sFLT1 and PlGF levels increased by >500% (p<0.01, for both) and VEGF levels increased by 221±101% (p<0.05) 30 minutes after UFH treatment. Bivalirudin had no effect on peptide levels. To study the cellular origin of peptides after anticoagulant therapy, human coronary endothelial cells were treated with UFH and demonstrated increased sFLT1 and PlGF levels (ANOVA p<0.01 for both) with reduced VEGF levels (ANOVA p<0.05). Bivalirudin had no effect on peptide levels in vitro.

Conclusions/Significance

Circulating levels of sFLT1, PlGF, and VEGF are significantly altered by UFH, while bivalirudin therapy has no effect. These findings may have significant implications for clinical studies of therapeutic angiogenesis, stem-cell and progenitor-cell therapy.

Forty-year journey of angiogenesis translational research

Forty years ago, Judah Folkman predicted that tumor growth is dependent on angiogenesis and that inhibiting this process might be a new strategy for cancer therapy. This hypothesis formed the foundation of a new field of research that represents an excellent example of how a groundbreaking scientific discovery can be translated to yield benefits for patients. Today, antiangiogenic drugs are used to treat human cancers and retinal vascular diseases. Here, we guide readers through 40 years of angiogenesis research and discuss challenges of antiangiogenic therapy.