Metronomic Chemotherapy: A Systematic Review of the Literature and Clinical Experience

miRNAs, piRNAs, and lncRNAs: A triad of non-coding RNAs regulating the neurovascular unit in diabetic retinopathy and their therapeutic potentials

Diabetic Retinopathy (DR), a leading complication of diabetes mellitus, has long been considered as a microvascular disease of the retina. However, recent evidence suggests that DR is a neurovascular disease, characterized by the degeneration of retinal neural tissue and microvascular abnormalities encompassing ischemia, neovascularization, and blood-retinal barrier breakdown, ultimately leading to blindness. The intricate relationship between the retina and vascular cells constitutes a neurovascular unit, a multi-cellular framework of retinal neurons, glial cells, immune cells, and vascular cells, which facilitates neurovascular coupling, linking neuronal activity to blood flow. These interconnections between the neurovascular components get compromised due to hyperglycemia and are further associated with the progression of DR early on in the disease. As a result, therapeutic approaches are needed to avert the advancement of DR by acting at its initial stage to delay or prevent the pathogenesis. Non-coding RNAs (ncRNAs) such as microRNAs, piwi-interacting RNAs, and long non-coding RNAs regulate various cellular components in the neurovascular unit. These ncRNAs are key regulators of neurodegeneration, apoptosis, inflammation, and oxidative stress in DR. In this review, research related to alterations in the expression of ncRNAs and, correspondingly, their effect on the disintegration of the neurovascular coupling will be discussed briefly to understand the potential of ncRNAs as therapeutic targets for treating this debilitating disease.

Efficacy and Safety of Metronomic Capecitabine in Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Metronomic capecitabine has been found to be useful in several types of cancers such as pancreatic cancer, breast cancer, gastrointestinal cancers, nasopharyngeal carcinoma, and metastatic colorectal cancer. This unique systematic literature review and meta-analysis was undertaken to assess the effectiveness and safety of metronomic capecitabine as a treatment regimen for hepatocellular carcinoma.

METHOD

A systematic search of major databases was performed. Eight studies that dealt with the use of metronomic capecitabine for hepatocellular carcinoma (HCC) were selected, seven were non-randomized control trials (n-RCTs), and one was a randomized control trial (RCT). Meta-analysis of these studies was performed using Review Manager v5.3 and STATA 15.1 software. The pooled prevalence of overall survival (OS), progression-free survival (PFS), overall response rate (ORR), grade 1-2 adverse events (grade 1-2 AEs), grade 3-4 adverse events (grade 3-4 AEs) was determined, including publication bias and sensitivity analysis.

RESULT

Eight studies met the inclusion criteria, combining the pooled data of 476 patients from safety and efficacy studies. The pooled prevalence of disease control rate (DCR) and overall response rate (ORR) achieved with metronomic capecitabine was 36% (95% CI 32-41) and 7% (95% CI 5-9) respectively. The median progression-free survival (PFS) and median overall survival (OS) were 3.57 months (95% CI 3.29-3.85) and 11.75 months (95% CI 10.56-12.95) respectively. The incidence of grade 3-4 adverse events (grade 3-4 AEs) and grade 1-2 adverse events (grade 1-2 AEs) was 38% (95% CI 32-44) and 73% (95% CI 67-79) respectively.

CONCLUSION

This meta-analysis highlights metronomic capecitabine as a potential treatment for hepatocellular carcinoma (HCC) in the advanced stage. However, effective management of capecitabine's side effects is essential.

Exploring potential biomarkers and lead molecules in gastric cancer by network biology, drug repurposing and virtual screening strategies

Gastric cancer poses a significant global health challenge, necessitating innovative approaches for biomarker discovery and therapeutic intervention. This study employs a multifaceted strategy integrating network biology, drug repurposing, and virtual screening to elucidate and expand the molecular landscape of gastric cancer. We identified and prioritized key genes implicated in gastric cancer by utilizing data from diverse databases and text-mining techniques. Network analysis underscored intricate gene interactions, emphasizing potential therapeutic targets such as CTNNB1, BCL2, TP53, etc, and highlighted ACTB among the top hub genes crucial in disease progression. Drug repurposing on 626 FDA-approved drugs for digestive system-related cancers revealed Norgestimate and Nimesulide as likely top candidates for gastric cancer, validated by molecular docking and dynamics simulations. Further, combinatorial synthesis of scaffold libraries derived from known chemotypes generated 56,160 virtual compounds, of which 76 new compounds were prioritized based on promising binding affinities and interactions at critical residues. Hotspot residue analysis identified GLU 214 and others as essential for ligand binding stability, enhancing compound efficacy and specificity. These findings support the therapeutic potential of targeting beta-actin protein in gastric cancer treatment, suggesting a future for further experimental validation and clinical translation. In conclusion, this study highlights the potential of repurposable drugs and virtual screening which can be used in combination with existing anti-gastric cancer drugs for gastric cancer therapy, emphasizing the role of computational methodologies in drug discovery.

Oral Metronomic Chemotherapy in Advanced and Metastatic Oral Squamous Cell Carcinoma: A Need of the Hour

Aim

The present review article aims to compile the best available evidence-based data on oral metronomic chemotherapy (OMCT) including its mechanism of action, its utility, and future directions.

Methods

A systematic search was carried out in PubMed database for available English literature from last 10 years between 2011 and 2021. Keyword combinations used were 'Oral Metronomic chemotherapy for oral cancer, mechanism of action of OMCT, Oral metronomic chemotherapy in India, OMCT in recurrent and palliative treatment of oral cancers.'

Results

Multitudes of studies have been published recently stating the role of OMCT in head and neck squamous cell carcinoma (HNSCC), but the studies with the category of level of evidence required to advocate OMCT as a recognized therapy are still scarce. On careful stratification of these studies, we found that OMCT has a lot to offer in palliative settings, recurrent, and metastatic HNSCC. There is some limited evidence of its role in adjuvant therapy as maintenance and in neoadjuvant setting.

Conclusion

With current evidence, there is a definite role of OMCT in treatment of oral SCC. OMCT can be an alternative in patients who are not tolerable or affordable for standard palliative chemotherapy and also an option for patient who are waiting for surgery. However, results of ongoing and future studies on exact mechanism, indications, and implications of this drug regimen would help in integration OMCT in current standard of therapy.

Graphical abstract

Parthenolide enhances the metronomic chemotherapy effect of cyclophosphamide in lung cancer by inhibiting the NF-kB signaling pathway

BACKGROUND

Parthenolide (PTL), a sesquiterpene lactone derived from the medicinal herb Chrysanthemum parthenium, exhibits various biological effects by targeting NF-kB, STAT3, and other pathways. It has emerged as a promising adjunct therapy for multiple malignancies.

AIM

To evaluate the in vitro and in vivo effect of PTL on cyclophosphamide (CTX) metronomic chemotherapy.

METHODS

The cytotoxicity of PTL and CTX on Lewis lung cancer cells (LLC cells) was assessed by measuring cell activity and apoptosis. The anti-tumor efficiency was evaluated using a tumor xenograft mice model, and the survival of mice and tumor volume were monitored. Additionally, the collected tumor tissues were analyzed for tumor microenvironment indicators and inflammatory factors.

RESULTS

In vitro, PTL demonstrated a synergistic effect with CTX in inhibiting the growth of LLC cells and promoting apoptosis. In vivo, metronomic chemotherapy combined with PTL and CTX improved the survival rate of tumor-bearing mice and reduced tumor growth rate. Furthermore, metronomic chemotherapy combined with PTL and CTX reduced NF-κB activation and improved the tumor immune microenvironment by decreasing tumor angiogenesis, reducing Transforming growth factor β, and α-SMA positive cells.

CONCLUSION

PTL is an efficient compound that enhances the metronomic chemotherapy effects of CTX both in vitro and in vivo, suggesting its potential as a supplementary therapeutic strategy in metronomic chemotherapy to improve the chemotherapy effects.

Metronomic chemotherapy in cancer treatment: new wine in an old bottle

Over the past two decades, metronomic chemotherapy has gained considerable attention and has demonstrated remarkable success in the treatment of cancer. Through chronic administration and low-dose regimens, metronomic chemotherapy is associated with fewer adverse events but still effectively induces disease control. The identification of its antiangiogenic properties, direct impact on cancer cells, immunomodulatory effects on the tumour microenvironment, and metabolic reprogramming ability has established the intrinsic multitargeted nature of this therapeutic approach. Recently, the utilization of metronomic chemotherapy has evolved from salvage treatment for metastatic disease to adjuvant maintenance therapy for high-risk cancer patients, which has been prompted by the success of several substantial phase III trials. In this review, we delve into the mechanisms underlying the antitumour effects of metronomic chemotherapy and provide insights into potential combinations with other therapies for the treatment of various malignancies. Additionally, we discuss health-economic advantages and candidates for the utilization of this treatment option.

A mathematical model to study low-dose metronomic scheduling for chemotherapy

Metronomic chemotherapy refers to the frequent administration of chemotherapeutic agents at a lower dose and presents an attractive alternative to conventional chemotherapy with encouraging response rates. However, the schedule of the therapy, including the dosage of the drug, is usually based on empiricism. The confounding effects of tumor-endothelial-immune interactions during metronomic administration of drugs have not yet been explored in detail, resulting in an incomplete assessment of drug dose and frequency evaluations. The present study aimed to gain a mechanistic understanding of different actions of metronomic chemotherapy using a mathematical model. We have established an analytical condition for determining the dosage and frequency of the drug depending on its clearance rate for complete tumor elimination. The model also brings forward the immune-mediated clearance of the tumor during the metronomic administration of the chemotherapeutic agent. The results from the global sensitivity analysis showed an increase in the sensitivity of drug and immune-mediated killing factors toward the tumor population during metronomic scheduling. Our results emphasize metronomic scheduling over the maximum tolerated dose (MTD) and define a model-based approach for approximating the optimal schedule of drug administration to eliminate tumors while minimizing harm to the immune cells and the patient's body.

Metronomic chemotherapy in hematology: Lessons from preclinical and clinical studies to build a solid rationale for future schedules

Metronomic chemotherapy (mCHEMO), based on frequent, regular administration of low, but pharmacologically active drug doses, optimizes antitumor efficacy by targeting multiple targets and reducing toxicity of antineoplastic drugs. This minireview will summarize preclinical and clinical studies on cytotoxic drugs given at weekly, daily, or at continuous metronomic schedules alone or in combination with novel targeted agents for hematological malignancies, including lymphoma, multiple myeloma, and leukemia. Most of the preclinical in vitro and in vivo studies have reported a significant benefit of both mCHEMO monotherapy and combinatorial regimens compared with chemotherapy at the maximum tolerated dose. However, the combination of mCHEMO with targeted drugs is still little explored in the hematologic clinical setting. Data obtained from preclinical studies on low dose metronomic chemotherapy in hematological malignancies clearly suggested the possibility to clinically investigate more tolerable and effective strategies for the treatment of patients with advanced hematological malignancies, or at least for those frail and elderly patients, who are not eligible or resistant to standard treatments.

Optimizing cancer therapy: a review of the multifaceted effects of metronomic chemotherapy

Metronomic chemotherapy (MCT), characterized by the continuous administration of chemotherapeutics at a lower dose without prolonged drug-free periods, has garnered significant attention over the last 2 decades. Extensive evidence from both pre-clinical and clinical settings indicates that MCT induces distinct biological effects than the standard Maximum Tolerated Dose (MTD) chemotherapy. The low toxicity profile, reduced likelihood of inducing acquired therapeutic resistance, and low cost of MCT render it an attractive chemotherapeutic regimen option. One of the most prominent aspects of MCT is its anti-angiogenesis effects. It has been shown to stimulate the expression of anti-angiogenic molecules, thereby inhibiting angiogenesis. In addition, MCT has been shown to decrease the regulatory T-cell population and promote anti-tumor immune response through inducing dendritic cell maturation and increasing the number of cytotoxic T-cells. Combination therapies utilizing MCT along with oncolytic virotherapy, radiotherapy or other chemotherapeutic regimens have been studied extensively. This review provides an overview of the current status of MCT research and the established mechanisms of action of MCT treatment and also offers insights into potential avenues of development for MCT in the future.

The Potential of Integrative Cancer Treatment Using Melatonin and the Challenge of Heterogeneity in Population-Based Studies: A Case Report of Colon Cancer and a Literature Review

Melatonin is a multifunctional hormone regulator that maintains homeostasis through circadian rhythms, and desynchronization of these rhythms can lead to gastrointestinal disorders and increase the risk of cancer. Preliminary clinical studies have shown that exogenous melatonin alleviates the harmful effects of anticancer therapy and improves quality of life, but the results are still inconclusive due to the heterogeneity of the studies. A personalized approach to testing clinical parameters and response to integrative treatment with nontoxic and bioavailable melatonin in patient-centered N-of-1 studies deserves greater attention. This clinical case of colon cancer analyzes and discusses the tumor pathology, the adverse effects of chemotherapy, and the dynamics of markers of inflammation (NLR, LMR, and PLR ratios), tumors (CEA, CA 19-9, and PSA), and hemostasis (D-dimer and activated partial thromboplastin time). The patient took melatonin during and after chemotherapy, nutrients (zinc, selenium, vitamin D, green tea, and taxifolin), and aspirin after chemotherapy. The patient's PSA levels decreased during CT combined with melatonin (19 mg/day), and melatonin normalized inflammatory markers and alleviated symptoms of polyneuropathy but did not help with thrombocytopenia. The results are analyzed and discussed in the context of the literature on oncostatic and systemic effects, alleviating therapy-mediated adverse effects, association with survival, and N-of-1 studies.

Metronomic Chemotherapy in Elderly Patients

PURPOSE OF REVIEW

This review describes the most relevant studies found in the scientific literature regarding metronomic chemotherapy (MCT) in the geriatric oncology population to support its use as a feasible treatment of care in the frail elderly patients.

RECENT FINDINGS

Recent years have seen a reevaluation of cancer chemotherapeutic drugs and MCT is an emerging schedule in phase II and III clinical trials. Ageing is one of the risk factors for the development of cancer, the incidence of whom increases dramatically in people who live longer. To date, standard oncological protocols involve chemotherapeutic drugs in short cycles of therapy at the maximum tolerated dose (MTD). Although these therapeutic regimens may be successful, they can cause important adverse drug reactions, especially in elderly or frail patients. MCT is a different modality of delivery of chemotherapeutic drugs (frequent low dose for prolonged time) and it looks at the overcoming of the limitations and disadvantages of MTD, in particular the toxicity aspect. We reviewed the experience of clinicians who have used MCT in clinical trials enrolling elderly patients with different cancer types.

Personalized treatment options of refractory and relapsed medulloblastoma in children: literature review

Medulloblastoma (MB) is the most common malignant tumor of the central nervous system in pediatric patients. Despite the complex anticancer therapy approach, refractory and relapsing forms of the disease remain fatal in most cases and account for approximately 30%. To date, repeated surgery, radiation, and chemotherapy can be used as life-prolonging treatment options; nevertheless, it should be emphasized that there are no standardized approaches based on existing data of molecular variants of MB. It is obvious that only a deep understanding of the biological mechanisms in association with clinical aspects in refractory and relapsing forms of MB would make it possible to personalize second- and subsequent-line therapy in order to achieve maximum efficiency and minimize early and long-term toxicity. The article presents the current understanding of prognostic factors in relapsed/refractory forms of MB, methods of modern diagnostics, as well as existing and perspective treatment options based on the biological and clinical aspects of the disease.

Metronomic chemotherapy and drug repurposing: A paradigm shift in oncology

Cancer represents a significant global health and economic burden due to its high mortality rates. While effective in some instances, traditional chemotherapy often falls short of entirely eradicating various types of cancer. It can cause severe side effects due to harm to healthy cells. Two therapeutic approaches have risen to the forefront to address these limitations: metronomic chemotherapy (MCT) and drug repurposing. Metronomic chemotherapy is an innovative approach that breaks from traditional models. It involves the administration of chemotherapeutic regimens at lower doses, without long drug-free intervals that have previously been a hallmark of such treatments. This method offers a significant reduction in side effects and improved disease management. Simultaneously, drug repurposing has gained considerable attraction in cancer treatment. This approach involves utilizing existing drugs, initially developed for other therapeutic purposes, as potential cancer treatments. The application of known drugs in a new context accelerates the timeline from laboratory to patient due to pre-existing safety and dosage data. The intersection of these two strategies gives rise to a novel therapeutic approach named 'Metronomics.' This approach encapsulates the benefits of both MCT and drug repurposing, leading to reduced toxicity, potential for oral administration, improved patient quality of life, accelerated clinical implementation, and enhanced affordability. Numerous clinical studies have endorsed the efficacy of metronomic chemotherapy with tolerable side effects, underlining the potential of Metronomics in better cancer management, particularly in low- and middle-income countries. This review underscores the benefits and applications of metronomic chemotherapy and drug repurposing, specifically in the context of breast cancer, showcasing the promising results of pre-clinical and clinical studies. However, we acknowledge the necessity of additional clinical investigations to definitively establish the role of metronomic chemotherapy in conjunction with other treatments in comprehensive cancer management.

Proliferative verrucous leukoplakia/multifocal leukoplakia in patients with and without oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) and proliferative verrucous leukoplakia (PVL) are established as oral potentially malignant disorders. Dual pathology of the two conditions is not commonly encountered in clinical practice. This study aims to present a case series of multifocal leukoplakia in patients with and without OSF to outline the clinical behavior and challenges in the management of this high-risk group in clinical practice.

MATERIAL AND METHODS

We retrospectively analyzed cases of six Indian patients (four with OSF) managed over a period of 5.5 to 13 years at the Government Dental College, Nagpur. Patient data consisting of age, gender, medical history, habits, clinical findings, and biopsy reports were recorded at the initial visit. During follow-up visits, the clinicopathological data were reassessed. When surgical intervention failed to arrest the disease or when surgery was contraindicated metronomic therapy with Folitrax 15 mg once a week and Celecoxib 100mg twice daily was initiated.

RESULTS

All patients developed PVL after the initial pathology diagnosis of OSF or oral leukoplakia. Initial lesions were either homogenous or non-homogenous leukoplakia. All patients developed multiple recurrences, regional or systemic metastasis. Despite thorough interventions, the patients died of, or with the disease.

CONCLUSIONS

The occurrence of two or more oral potentially malignant disorders poses challenges in patient management and possibly presents a higher risk of malignant transformation. More clinical trials are necessary to assess the benefits of metronomic therapy for patients diagnosed with aggressive PVL concurrently found with OSF.

A review and metanalysis of metronomic oral single-agent cyclophosphamide for treating advanced ovarian carcinoma in the era of precision medicine

OBJECTIVE

Oral metronomic cyclophosphamide has been used as a single agent or in combination with other drugs for several solid tumors with interesting results in disease palliation and mild to moderate toxicity, notably in patients with recurrent epithelial ovarian cancer (EOC) progressing after systemic chemotherapy. In this paper, we report a review and a metanalysis of heterogeneous data published up to date.

DATA SOURCES

The literature search was restricted to single-agent MOC. The analysis was conducted through March 2023 by consulting PubMed, Embase, Google Scholar, and The Cochrane Library databases. Research string and Medical Subject Headings included "ovarian tumor," "ovarian carcinoma," or "ovarian cancer," "fallopian tube cancer," "primary peritoneal cancer," "oral chemotherapy," and "metronomic cyclophosphamide." All articles were assessed for quality by at least two investigators independently, and a < 18 patients sample size cutoff was chosen as a lower limit with a Cohen's kappa statistical coefficient for accuracy and reliability. Metanalysis of selected papers was carried out according to a fixed model.

DATA SUMMARY

The percentage of agreement between investigators on literature study selection was very high, reaching 96.9% with a Cohen's k of 0.929. MOC pooled objective response rate (ORR) and disease control rate for recurrent or platinum-refractory ovarian cancer were 18.8% (range 4-44%) and 36.2% (range 16-58.8%), respectively. The mean progressive-free survival and overall survival were 3.16 months (range 1.9 to 5.0 months) and 8.7 months (range 8 to 13 months), respectively. The fixed model metanalysis of selected studies showed a 16% median ORR (12-20% CI, p < 0.001).

CONCLUSIONS

Single-agent oral cyclophosphamide in EOC holds promise as a treatment option, even in the era of precision medicine. Genetic factors, such as DNA repair gene polymorphisms, may influence treatment response. Combining cyclophosphamide with biological agents such as PARP inhibitors or immunotherapy agents is an area of active investigation.

A phase 2 study of ibrutinib maintenance following first-line high-dose methotrexate-based chemotherapy for elderly patients with primary central nervous system lymphoma

BACKGROUND

Elderly patients account for nearly 70% of all primary central nervous system lymphoma (PCNSL) cases. They cannot tolerate aggressive treatment and have poor prognosis with a median overall survival (OS) of less than 2 years and progression-free survival (PFS) of 6-16 months. Ibrutinib penetrates the blood-brain barrier and has shown activity in PCNSL.

METHODS

This prospective study investigated whether ibrutinib maintenance is feasible, and whether it can benefit elderly PCNSL patients in terms of expected 2-year PFS. It is an open label, phase 2 study in newly diagnosed PCNSL patients 60-85 years old who responded to first-line high-dose methotrexate (HDMTX)-based treatment with partial or complete response. Ibrutinib maintenance (560 mg/d) was continued until disease progression or intolerable toxicity.

RESULTS

Twenty patients were enrolled, with a median age of 72 years (range, 61-80). Median time on ibrutinib maintenance was 12.5 (range, 2-46) months. Twelve patients stopped treatment: five due to central nervous system relapse and seven due to adverse events that were mainly grade 2. Five patients died (25%) all due to relapse. The 1- and 2-year PFS are 90% and 72.6%, respectively, and the 2-year OS is 89%.

CONCLUSIONS

The study reached its primary end points and also showed that ibrutinib maintenance is tolerated reasonably well by the elderly. Therefore, this study supports the concept that ibrutinib maintenance should be further evaluated as an optional consolidation measure in the elderly.

Metronomic Chemotherapy in Oral Cancer: A Review

Treatment of locally advanced oral cancer requires multidisciplinary care, including surgery, radiotherapy, and chemotherapy, which varies based on the stage of the disease, site of involvement, and surgical access. Oral cancer usually presents with an increased recurrence rate and potential for distant metastatic spread. It confers a poor prognosis with a 50% mortality rate after five years. Oral metronomic chemotherapy aims to achieve higher patient compliance due to its ease of administration, lower dosage, and lesser side effects than conventional IV regimens of platinum-based drugs. In this review, we have summarized the relevant literature to benefit the readers regarding the potential application of metronomic therapy in the management of oral cancer.

Global trajectory and future prospects of metronomic chemotherapy research: A scientometric analysis (2000-2022)

This scientometric study aimed to provide a first comprehensive overview of the global research landscape of Metronomic Chemotherapy (MC) from 2000 to 2022 using a data-driven approach to identify key trends, collaborations, and potential opportunities. This study highlights the increasing prevalence of MC, with annual outputs increasing substantially over the same timeframe. The United States contributed the most to MC research, followed by Italy and China, while there was a lack of collaborative research efforts between countries and organizations. Through keyword co-occurrence analysis, we identified emerging interdisciplinary research areas, such as "nanoparticles," "immunotherapy," and "antitumor immunity." Our citation analysis identified the most influential authors, institutions, and journals, providing a comprehensive overview of the structure of knowledge and dissemination of MC research. Although the number of publications has decreased since 2019, the analysis indicates that this field has received substantial scholarly attention. These discoveries are extremely important for researchers, funding organizations, and policymakers because they highlight the need for more collaboration, interdisciplinary approaches, and resource allocation in underrepresented fields. This study concludes with recommendations for guiding future research and collaboration, resulting in a larger impact and fostering substantial advancements in MC research.

Gemcitabine effects on tumor microenvironment of pancreatic ductal adenocarcinoma: Special focus on resistance mechanisms and metronomic therapies

Pancreatic ductal adenocarcinoma (PDAC) is considered one of the deadliest malignancies, with dismal survival rates and extremely prevalent chemoresistance. Gemcitabine is one of the primary treatments used in treating PDACs, but its benefits are limited due to chemoresistance, which could be attributed to interactions between the tumor microenvironment (TME) and intracellular processes. In preclinical models, certain schedules of administration of gemcitabine modulate the TME in a manner that does not promote resistance. Metronomic therapy constitutes a promising strategy to overcome some barriers associated with current PDAC treatments. This review will focus on gemcitabine's mechanism in treating PDAC, combination therapies, gemcitabine's interactions with the TME, and gemcitabine in metronomic therapies.

Induced Vascular Normalization-Can One Force Tumors to Surrender to a Better Microenvironment?

Immunotherapy has changed the way many cancers are being treated. Researchers in the field of immunotherapy and tumor immunology are investigating similar questions: How can the positive benefits achieved with immunotherapies be enhanced? Can this be achieved through combinations with other agents and if so, which ones? In our view, there is an urgent need to improve immunotherapy to make further gains in the overall survival for those patients that should benefit from immunotherapy. While numerous different approaches are being considered, our team believes that drug delivery methods along with appropriately selected small-molecule drugs and drug candidates could help reach the goal of doubling the overall survival rate that is seen in some patients that are given immunotherapeutics. This review article is prepared to address how immunotherapies should be combined with a second treatment using an approach that could realize therapeutic gains 10 years from now. For context, an overview of immunotherapy and cancer angiogenesis is provided. The major targets in angiogenesis that have modulatory effects on the tumor microenvironment and immune cells are highlighted. A combination approach that, for us, has the greatest potential for success involves treatments that will normalize the tumor's blood vessel structure and alter the immune microenvironment to support the action of immunotherapeutics. So, this is reviewed as well. Our focus is to provide an insight into some strategies that will engender vascular normalization that may be better than previously described approaches. The potential for drug delivery systems to promote tumor blood vessel normalization is considered.

Metronomic Administration of Topotecan Alone and in Combination with Docetaxel Inhibits Epithelial-mesenchymal Transition in Aggressive Variant Prostate Cancers

Prostate cancer is the second leading cause of noncutaneous cancer-related deaths in American men. Androgen deprivation therapy (ADT), radical prostatectomy, and radiotherapy remain the primary treatment for patients with early-stage prostate cancer (castration-sensitive prostate cancer). Following ADT, many patients ultimately develop metastatic castration-resistant prostate cancer (mCRPC). Standard chemotherapy options for CRPC are docetaxel (DTX) and cabazitaxel, which increase median survival, although the development of resistance is common. Cancer stem-like cells possess mesenchymal phenotypes [epithelial-to-mesenchymal transition (EMT)] and play crucial roles in tumor initiation and progression of mCRPC. We have shown that low-dose continuous administration of topotecan (METRO-TOPO) inhibits prostate cancer growth by interfering with key cancer pathway genes. This study utilized bulk and single-cell or whole-transcriptome analysis [(RNA sequencing (RNA-seq) and single-cell RNA sequencing (scRNA-seq)], and we observed greater expression of several EMT markers, including Vimentin, hyaluronan synthase-3, S100 calcium binding protein A6, TGFB1, CD44, CD55, and CD109 in European American and African American aggressive variant prostate cancer (AVPC) subtypes-mCRPC, neuroendocrine variant (NEPC), and taxane-resistant. The taxane-resistant gene FSCN1 was also expressed highly in single-cell subclonal populations in mCRPC. Furthermore, metronomic-topotecan single agent and combinations with DTX downregulated these EMT markers as well as CD44+ and CD44+/CD133+ "stem-like" cell populations. A microfluidic chip-based cell invasion assay revealed that METRO-TOPO treatment as a single agent or in combination with DTX was potentially effective against invasive prostate cancer spread. Our RNA-seq and scRNA-seq analysis were supported by in silico and in vitro studies, suggesting METRO-TOPO combined with DTX may inhibit oncogenic progression by reducing cancer stemness in AVPC through the inhibition of EMT markers and multiple oncogenic factors/pathways.

Significance

The utilization of metronomic-like dosing regimens of topotecan alone and in combination with DTX resulted in the suppression of makers associated with EMT and stem-like cell populations in AVPC models. The identification of molecular signatures and their potential to serve as novel biomarkers for monitoring treatment efficacy and disease progression response to treatment efficacy and disease progression were achieved using bulk RNA-seq and single-cell-omics methodologies.

Metronomic Photodynamic Therapy with Conjugated Polymer Nanoparticles in Glioblastoma Tumor Microenvironment

Alternative therapies such as photodynamic therapy (PDT) that combine light, oxygen and photosensitizers (PSs) have been proposed for glioblastoma (GBM) management to overcome conventional treatment issues. An important disadvantage of PDT using a high light irradiance (fluence rate) (cPDT) is the abrupt oxygen consumption that leads to resistance to the treatment. PDT metronomic regimens (mPDT) involving administering light at a low irradiation intensity over a relatively long period of time could be an alternative to circumvent the limitations of conventional PDT protocols. The main objective of the present work was to compare the effectiveness of PDT with an advanced PS based on conjugated polymer nanoparticles (CPN) developed by our group in two irradiation modalities: cPDT and mPDT. The in vitro evaluation was carried out based on cell viability, the impact on the macrophage population of the tumor microenvironment in co-culture conditions and the modulation of HIF-1α as an indirect indicator of oxygen consumption. mPDT regimens with CPNs resulted in more effective cell death, a lower activation of molecular pathways of therapeutic resistance and macrophage polarization towards an antitumoral phenotype. Additionally, mPDT was tested in a GBM heterotopic mouse model, confirming its good performance with promising tumor growth inhibition and apoptotic cell death induction.

Continuous low-dose cyclophosphamide plus prednisone in the treatment of relapsed and refractory multiple myeloma with severe complications

Background/objective

We retrospectively analyzed the effective and safety of continuous low-dose cyclophosphamide combined with prednisone (CP) in relapsed and refractory multiple myeloma (RRMM) patients with severe complications.

Methods

A total of 130 RRMM patients with severe complications were enrolled in this study, among which 41 patients were further given bortezomib, lenalidomide, thalidomide or ixazomib on the basis of CP regimen (CP+X group). The response to therapy, adverse events (AEs), overall survival (OS) and progression-free survival (PFS) were recorded.

Results

Among the 130 patients, 128 patients received therapeutic response assessment, with a complete remission rate (CRR) and objective response rate (ORR) of 4.7% and 58.6%, respectively. The median OS and PFS time were (38.0 ± 3.6) and (22.9±5.2) months, respectively. The most common AEs were hyperglycemia (7.7%), pneumonia (6.2%) and Cushing's syndrome (5.4%). In addition, we found the pro-BNP/BNP level was obviously decreased while the LVEF (left ventricular ejection fraction) was increased in RRMM patients following CP treatment as compared with those before treatment. Furthermore, CP+X regimen further improved the CRR compared with that before receiving the CP+X regimen (24.4% vs. 2.4%, P=0.007). Also, both the OS and PFS rates were significantly elevated in patients received CP+X regimen following CP regimen as compared with the patients received CP regimen only.

Conclusion

This study demonstrates the metronomic chemotherapy regimen of CP is effective to RRMM patients with severe complications.

Extended Exposure Topotecan Significantly Improves Long-Term Drug Sensitivity by Decreasing Malignant Cell Heterogeneity and by Preventing Epithelial-Mesenchymal Transition

Maximum tolerable dosing (MTD) of chemotherapeutics has long been the gold standard for aggressive malignancies. Recently, alternative dosing strategies have gained traction for their improved toxicity profiles and unique mechanisms of action, such as inhibition of angiogenesis and stimulation of immunity. In this article, we investigated whether extended exposure (EE) topotecan could improve long-term drug sensitivity by preventing drug resistance. To achieve significantly longer exposure times, we used a spheroidal model system of castration-resistant prostate cancer. We also used state-of-the-art transcriptomic analysis to further elucidate any underlying phenotypic changes that occurred in the malignant population following each treatment. We determined that EE topotecan had a much higher barrier to resistance relative to MTD topotecan and was able to maintain consistent efficacy throughout the study period (EE IC50 of 54.4 nM (Week 6) vs. MTD IC50 of 2200 nM (Week 6) vs. 83.8 nM IC50 for control (Week 6) vs. 37.8 nM IC50 for control (Week 0)). As a possible explanation for these results, we determined that MTD topotecan stimulated epithelial-mesenchymal transition (EMT), upregulated efflux pumps, and produced altered topoisomerases relative to EE topotecan. Overall, EE topotecan resulted in a more sustained treatment response and maintained a less aggressive malignant phenotype relative to MTD topotecan.

Effectiveness of metronomic chemotherapy in a child with medulloblastoma: A case report

Medulloblastoma (MB) is one of the most common pediatric malignant tumors arising from the central nervous system with an unknown etiology and variable prognosis. Relapsed or refractory MB in pediatric patients after intensive anticancer therapy (chemo-, radiotherapy) is associated with treatment resistance and poor survival prognosis. Metronomic chemotherapy in combination with mTOR inhibitors may have advantages due to an alternate mechanism of cytotoxicity and a favourable adverse effects profile. Furthermore, it is considered to be a prospective anticancer regimen regardless of the presence/absence of molecular targets. The present study reported a successful result of this treatment option with optimal tolerability in relapsed MB in a pediatric male patient and highlighted the advantages for a selected group of patients.

Nanoformulations-Based Metronomic Chemotherapy: Mechanism, Challenges, Recent Advances, and Future Perspectives

Cancer-related death is a significant health and economic burden worldwide, and some conventional chemotherapy is associated with limited effectiveness in completely curing various cancers, severe adverse effects, and destruction of healthy cells. To overcome the complications associated with conventional treatment, metronomic chemotherapy (MCT) is extensively suggested. In this review, we aim to highlight the importance of MCT over conventional chemotherapeutic approach with emphasis on nanoformulations-based MCT, their mechanism, challenges, recent advances, and future perspectives. Nanoformulations-based MCT revealed remarkable antitumor activity in both preclinical and clinical settings. For example, the metronomic scheduling of oxaliplatin-loaded nanoemulsion and polyethylene glycol-coated stealth nanoparticles incorporating paclitaxel were proven very effective in tumor-bearing mice and rats, respectively. Additionally, several clinical studies have demonstrated the benefit of MCT with acceptable tolerance. Moreover, metronomic might be a promising treatment strategy for improving cancer care in low- and middle-income nations. However, an appropriate alternative to a metronomic regimen for an individual ailment, suitable combinational delivery and scheduling, and predictive biomarkers are certain parts that remain unanswered. Further clinical-based comparative research studies are mandatory to be performed before entailing this treatment modality in clinical practice as alternative maintenance therapy or in place of transferring to therapeutic management.

Activity and safety of KEES - an oral multi-drug chemo-hormonal metronomic combination regimen in metastatic castration-resistant prostate cancer

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) remains a therapeutic challenge and evidence for late-line treatments in real-life is limited. The present study investigates the efficacy and safety of an oral metronomic chemo-hormonal regimen including cyclophosphamide, etoposide, estramustine, ketoconazole and prednisolone (KEES) administered in a consecutive biweekly schedule.

METHODS

A retrospective cohort study in two Swedish regions was conducted. Overall (OS) and progression-free survival (PFS), biochemical response rate (bRR) and toxicities were analyzed.

RESULTS

One hundred and twenty-three patients treated with KEES after initial treatment with at least a taxane or an androgen-receptor targeting agents (ARTA) were identified. Of those, 95 (77%) had received both agents and were the primary analysis population. Median (95% CI) OS and PFS in the pre-treated population were 12.3 (10.1-15.0) and 4.4 (3.8-5.5) months, respectively. Biochemical response, defined as ≥ 50% prostate-specific antigen (PSA) reduction, occurred in 26 patients (29%), and any PSA reduction in 59 (65%). PFS was independent of prior treatments used, and KEES seemed to be effective in late treatment lines. The bRR was higher compared to historical data of metronomic treatments in docetaxel and ARTA pre-treated populations. In multivariable analyses, performance status (PS) ≥ 2 and increasing alkaline phosphatase (ALP) predicted for worse OS. Nausea, fatigue, thromboembolic events and bone marrow suppression were the predominant toxicities.

CONCLUSIONS

KEES demonstrated meaningful efficacy in heavily pre-treated CRPC patients, especially those with PS 0-1 and lower baseline ALP, and had an acceptable toxicity profile.

A Mechanistic Review of Methotrexate and Celecoxib as a Potential Metronomic Chemotherapy for Oral Squamous Cell Carcinoma

The combination of low-dose methotrexate and celecoxib as metronomic chemotherapy (MCT) is a novel therapy, believed to act by modulating the immune response, inhibiting angiogenesis and its cytotoxic action, though the exact mechanism of action is unclear. Clinically, MCT was found to be very effective in delaying tumor progression in patients with head and neck squamous cell carcinoma in both curative and palliative settings. This review was aimed to give a brief insight into the mechanism of action and potential molecular alterations of MCT in the treatment of oral cancers taking into consideration the various in vivo and in vitro studies.

Optimal control design for drug delivery of immunotherapy in chemoimmunotherapy treatment

BACKGROUND AND OBJECTIVE

There are various approaches to control a mathematical dynamic of cancer, each of which is suitable for a special goal. Optimal control is considered as an applicable method to calculate the minimum necessary drug delivery in such systems.

METHODS

In this paper, a mathematical dynamic of cancer is proposed considering tumor cells, natural killer cells, CD8+T cells, circulating lymphocytes, IL-2 cytokine and Regulatory T cells as the system states, and chemotherapy, IL-2 and activated CD8+T cells injection rate as the control signals. After verifying the proposed mathematical model, the importance of the drug delivery timing and the effect of cancer cells initial condition are discussed. Afterwards, an optimal control is designed by defining a proper cost function with the goal of minimizing the number of tumor cells, and two immunotherapy drug amounts during treatment CONCLUSIONS: Results show that inappropriate injection of immunotherapy time schedule and the number of initial conditions of cancer cells might result in chemoimmunotherapy failure and auxiliary treatment must be prescribed to decrease tumor size before any treatment takes place. The obtained optimal control signals show that with lower amount of drug delivery and a suitable drug injection time schedule, tumor cells can be eliminated while a fixed immunotherapy time schedule protocol fails with larger amount of drug injection. This conclusion can be utilized with the aim of personalizing drug delivery and designing more accurate clinical trials based on the improved model simulations in order to save cost and time.

High-Frequency Nanosecond Bleomycin Electrochemotherapy and its Effects on Changes in the Immune System and Survival

In this work, a time-dependent and time-independent study on bleomycin-based high-frequency nsECT (3.5 kV/cm × 200 pulses) for the elimination of LLC1 tumours in C57BL/6J mice is performed. We show the efficiency of nsECT (200 ns and 700 ns delivered at 1 kHz and 1 MHz) for the elimination of tumours in mice and increase of their survival. The dynamics of the immunomodulatory effects were observed after electrochemotherapy by investigating immune cell populations and antitumour antibodies at different timepoints after the treatment. ECT treatment resulted in an increased percentage of CD4⁺ T, splenic memory B and tumour-associated dendritic cell subsets. Moreover, increased levels of antitumour IgG antibodies after ECT treatment were detected. Based on the time-dependent study results, nsECT treatment upregulated PD 1 expression on splenic CD4⁺ Tr1 cells, increased the expansion of splenic CD8⁺ T, CD4⁺CD8⁺ T, plasma cells and the proportion of tumour-associated pro inflammatory macrophages. The Lin^- population of immune cells that was increased in the spleens and tumour after nsECT was identified. It was shown that nsECT prolonged survival of the treated mice and induced significant changes in the immune system, which shows a promising alliance of nanosecond electrochemotherapy and immunotherapy.

Co-targeting triple-negative breast cancer cells and endothelial cells by metronomic chemotherapy inhibits cell regrowth and migration via downregulation of the FAK/VEGFR2/VEGF axis and autophagy/apoptosis activation

High-dose standard-of-care chemotherapy is the only option for triple-negative breast cancer (TNBC) patients, which eventually die due to metastatic tumors. Recently, metronomic chemotherapy (mCHT) showed advantages in treating TNBCs leading us to investigate the anti-metastatic and anti-angiogenic potential of metronomic 5-Fluorouracil plus Vinorelbine (5-FU+VNR) on endothelial cells (ECs) and TNBCs in comparison to standard treatment (STD). We found that 10-fold lower doses of 5-FU+VNR given mCHT vs. STD inhibits cell proliferation and survival of ECs and TNBC cells. Both schedules strongly affect ECs migration and invasion, but in TNBC cells mCHT is significantly more effective than STD in impairing cell migration and invasion. The two treatments disrupt FAK/VEGFR/VEGF signaling in both ECs and TNBC cells. mCHT, and to a much lesser extent STD treatment, induces apoptosis in ECs, whereas it switches the route of cell death from apoptosis (as induced by STD) to autophagy in TNBC cells. mCHT-treated TNBCs-derived conditioned medium also strongly affects ECs' migration, modulates different angiogenesis-associated proteins, and hampers angiogenesis in matrix sponge in vivo. In conclusion, mCHT administration of 5-FU+VNR is more effective than STD schedule in controlling cell proliferation/survival and migration/invasion of both ECs and TNBC cells and has a strong anti-angiogenic effect. Our data suggest that the stabilization of tumor growth observed in TNBC patients treated with mCHT therapy schedule is likely due not only to direct cytotoxic effects but also to anti-metastatic and anti-angiogenic effects.

Analysis of the Biological Properties of Blood Plasma Protein with GcMAF Functional Activity

The main problem related to the studies focusing on group-specific component protein-derived macrophage-activating factor (GcMAF) is the lack of clarity about changes occurring in different types of macrophages and related changes in their properties under the effect of GcMAF in various clinical conditions. We analyzed the antitumor therapeutic properties of GcMAF in a Lewis carcinoma model in two clinical conditions: untreated tumor lesion and tumor resorption after exposure to Karanahan therapy. GcMAF is formed during site-specific deglycosylation of vitamin D3 binding protein (DBP). DBP was obtained from the blood of healthy donors using affinity chromatography on a column with covalently bound actin. GcMAF-related factor (GcMAF-RF) was converted in a mixture with induced lymphocytes through the cellular enzymatic pathway. The obtained GcMAF-RF activates murine peritoneal macrophages (p < 0.05), induces functional properties of dendritic cells (p < 0.05) and promotes in vitro polarization of human M0 macrophages to M1 macrophages (p < 0.01). Treatment of whole blood cells with GcMAF-RF results in active production of both pro- and anti-inflammatory cytokines. It is shown that macrophage activation by GcMAF-RF is inhibited by tumor-secreted factors. In order to identify the specific antitumor effect of GcMAF-RF-activated macrophages, an approach to primary reduction of humoral suppressor activity of the tumor using the Karanahan therapy followed by macrophage activation in the tumor-associated stroma (TAS) was proposed. A prominent additive effect of GcMAF-RF, which enhances the primary immune response activation by the Karanahan therapy, was shown in the model of murine Lewis carcinoma. Inhibition of the suppressive effect of TAS is the main condition required for the manifestation of the antitumor effect of GcMAF-RF. When properly applied in combination with any chemotherapy, significantly reducing the humoral immune response at the advanced tumor site, GcMAF-RF is a promising antitumor therapeutic agent that additively destroys the pro-tumor properties of macrophages of the tumor stroma.

The Nitrogen Mustards

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve.

Chronometric Administration of Cyclophosphamide and a Double-Stranded DNA-Mix at Interstrand Crosslinks Repair Timing, Called "Karanahan" Therapy, Is Highly Efficient in a Weakly Immunogenic Lewis Carcinoma Model

Background and Aims: A new technology based on the chronometric administration of cyclophosphamide and complex composite double-stranded DNA-based compound, which is scheduled in strict dependence on interstrand crosslinks repair timing, and named “Karanahan”, has been developed. Being applied, this technology results in the eradication of tumor-initiating stem cells and full-scale apoptosis of committed tumor cells. In the present study, the efficacy of this novel approach has been estimated in the model of Lewis carcinoma.

Methods: To determine the basic indicative parameters for the approach, the duration of DNA repair in tumor cells, as well as their distribution along the cell cycle, have been assessed. Injections were done into one or both tumors in femoral region of the engrafted mice in accordance with the developed regimen. Four series of experiments were carried out at different periods of time. The content of poorly differentiated CD34⁺/TAMRA+ cells in the bone marrow and peripheral blood has been determined. Immunostaining followed by the flow cytometry was used to analyze the subpopulations of immune cells.

Results: The high antitumor efficacy of the new technology against the developed experimental Lewis carcinoma was shown. It was found that the therapy efficacy depended on the number of tumor growth sites, seasonal and annual peculiarities. In some experiments, a long-term remission has been reached in 70% of animals with a single tumor and in 60% with two tumors. In mice with two developed grafts, mobilization capabilities of both poorly differentiated hematopoietic cells of the host and tumor stem-like cells decrease significantly. Being applied, this new technology was shown to activate a specific immune response. There is an increase in the number of NK cell populations in the blood, tumor, and spleen, killer T cells and T helper cells in the tumor and spleen, CD11b+Ly-6C+ and CD11b+Ly-6G+ cells in the tumor. A population of mature dendritic cells is found in the tumor.

Conclusion: The performed experiments indicate the efficacy of the Karanahan approach against incurable Lewis carcinoma. Thus, the discussed therapy is a new approach for treating experimental neoplasms, which has a potential as a personalized anti-tumor therapeutic approach in humans.

Metronomic Chemotherapy for Advanced Prostate Cancer: A Literature Review

Metastatic castration-resistant prostate cancer (mCRPC) is the ultimately lethal form of prostate cancer. Docetaxel chemotherapy was the first life-prolonging treatment for mCRPC; however, the standard maximally tolerated dose (MTD) docetaxel regimen is often not considered for patients with mCRPC who are older and/or frail due to its toxicity. Low-dose metronomic chemotherapy (LDMC) is the frequent administration of typically oral and off-patent chemotherapeutics at low doses, which is associated with a superior safety profile and higher tolerability than MTD chemotherapy. We conducted a systematic literature review using the PUBMED, EMBASE, and MEDLINE electronic databases to identify clinical studies that examined the impact of LDMC on patients with advanced prostate cancer. The search identified 30 reports that retrospectively or prospectively investigated LDMC, 29 of which focused on mCRPC. Cyclophosphamide was the most commonly used agent integrated into 27/30 (90%) of LDMC regimens. LDMC resulted in a clinical benefit rate of 56.8 ± 24.5% across all studies. Overall, there were only a few non-hematological grade 3 or 4 adverse events reported. As such, LDMC is a well-tolerated treatment option for patients with mCRPC, including those who are older and frail. Furthermore, LDMC is considered more affordable than conventional mCRPC therapies. However, prospective phase III trials are needed to further characterize the efficacy and safety of LDMC in mCRPC before its use in practice.

Metronomic chemotherapy using oral cyclophosphamide and bevacizumab for recurrent cervical cancer: a multi-institutional retrospective study

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No standard chemotherapy exists for recurrent cervical cancer patients who respond poorly to platinum administration.

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Metronomic chemotherapy is a low-toxicity treatment and can maintain quality of life.

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Low-dose oral cyclophosphamide and bevacizumab (CPA-BEV) chemotherapy shows promising results in recurrent cervical cancer.

No standard chemotherapy is available after disease progression or anaphylaxis during platinum chemotherapy among patients with recurrent cervical cancer. Here we report the efficacy and toxicities of metronomic chemotherapy consisting of 50 mg of oral cyclophosphamide (CPA) daily and intravenous 15 mg/kg of bevacizumab (BEV) repeated every 3 weeks (CPA-BEV). Treated patients were retrospectively reviewed. Adverse events and response rates were recorded according to the Common Toxicity Criteria for Adverse Events (CTCAE) ver 5.0 and Response Evaluation Criteria In Solid Tumors ver 1.1, respectively. Eleven patients had been treated with CPA-BEV between 2016 and 2021.The pathologic types were squamous cell carcinoma in seven patients, adenocarcinoma in three, and large cell neuroendocrine carcinoma in one. Nine patients had primary concurrent chemoradiotherapy (CCRT). Five patients received more than one prior chemotherapy (excluding CCRT). Six patients had progressive disease during prior platinum-based chemotherapy, four patients recurred within 6 months of the last platinum administration, and one patient had platinum anaphylaxis. Grade 3 or more hematologic toxicities and grade 2 or more non-hematological toxicities were observed in one with grade 3 neutropenia and in one with grade 2 proteinuria, respectively. The median duration of chemotherapy was 2.8 months (range 0.2–30.6 months). One patient had CR but none had PR. Median progression-free survival was 2.8 months (95 %CI: 2.1–10.7 months), and median overall survival was 13.6 months (95 %CI: 8.4–33.7 months). In conclusion, the CPA-BEV regimen showed favorable antitumor activity with minimal toxicity and is promising candidate for second-line chemotherapy.

Chemotherapy-induced cachexia and model-informed dosing to preserve lean mass in cancer treatment

Although chemotherapy is a standard treatment for cancer, it comes with significant side effects. In particular, certain agents can induce severe muscle loss, known as cachexia, worsening patient quality of life and treatment outcomes. 5-fluorouracil, an anti-cancer agent used to treat several cancers, has been shown to cause muscle loss. Experimental data indicates a non-linear dose-dependence for muscle loss in mice treated with daily or week-day schedules. We present a mathematical model of chemotherapy-induced muscle wasting that captures this non-linear dose-dependence. Area-under-the-curve metrics are proposed to quantify the treatment’s effects on lean mass and tumour control. Model simulations are used to explore alternate dosing schedules, aging effects, and morphine use in chemotherapy treatment with the aim of better protecting lean mass while actively targeting the tumour, ultimately leading to improved personalization of treatment planning and improved patient quality of life.

In this paper we present a novel mathematical model for muscle loss due to cancer chemotherapy treatment. Loss of muscle mass relates to increased drug toxicity and side-effects, and to decreased patient quality of life and survival rates. With our model, we examine the therapeutic efficacy of various dosing schedules with the aim of controlling a growing tumour while also preserving lean mass. Preservation of body composition, in addition to consideration of inflammation and immune interactions, the gut microbiome, and other systemic health measures, may lead to improved patient-specific treatment plans that improve patient quality of life.

Normalizing tumor microenvironment with nanomedicine and metronomic therapy to improve immunotherapy

Nanomedicine offered hope for improving the treatment of cancer but the survival benefits of the clinically approved nanomedicines are modest in many cases when compared to conventional chemotherapy. Metronomic therapy, defined as the frequent, low dose administration of chemotherapeutics – is being tested in clinical trials as an alternative to the conventional maximum tolerated dose (MTD) chemotherapy schedule. Although metronomic chemotherapy has not been clinically approved yet, it has shown better survival than MTD in many preclinical studies. When beneficial, metronomic therapy seems to be associated with normalization of the tumor microenvironment including improvements in tumor perfusion, tissue oxygenation and drug delivery as well as activation of the immune system. Recent preclinical studies suggest that nanomedicines can cause similar changes in the tumor microenvironment. Here, by employing a mathematical framework, we show that both approaches can serve as normalization strategies to enhance treatment. Furthermore, employing murine breast and fibrosarcoma tumor models as well as ultrasound shear wave elastography and contrast-enhanced ultrasound, we provide evidence that the approved nanomedicine Doxil can induce normalization in a dose-dependent manner by improving tumor perfusion as a result of tissue softening. Finally, we show that pretreatment with a normalizing dose of Doxil can improve the efficacy of immune checkpoint inhibition.

Toxicity profile, adverse drug reactions and drug-drug interactions among geriatric cancer patients under metronomic chemotherapy in a South Indian tertiary care hospital

OBJECTIVE

The study aims to examine the toxicity profile, pattern of adverse drug reactions (ADRs) and drug-drug interactions (DDIs) in geriatric cancer patients receiving metronomic chemotherapy.

PATIENTS AND METHODS

Patients were followed after each cycle till 12 weeks. Haematological parameters such as complete blood count, liver function test and renal function test were recorded from the baseline to the final visit. The Common Terminology Criteria for Adverse Events (CTCAE) scale was used to characterise the toxicity profile. ADRs that the patients had were documented and assessed for its causality, severity and preventability. The Lexicomp drug interaction checker was used to grade DDIs.

RESULTS

Of 129 patients, according to CTCAE grading, haemoglobin indicated grade 1 toxicity, while other haematological parameters revealed no toxicity. Although there was a statistically significant difference in ALT, alkaline phosphate, serum creatinine and potassium (p < 0.05), it was not clinically significant. A total of 226 ADRs were documented. Anaemia was the most frequently occurred ADR (14%) and Capecitabine caused the highest number of ADRs. Assessments of causality showed that the majority of cases are "possible" (63%). In evaluating the severity of ADRs, 99% ADRs were "mild" and 61% of ADRs were "probably" preventable. Upon assessing the DDIs, 82% of the prescriptions had "no known interaction".

CONCLUSION

Metronomic chemotherapy in geriatric cancer patients exhibited grade 1 toxicity for haemoglobin. Anemia was the most common ADRs. The majority of cases were "possible" in causality, "mild" in severity, and "probably" preventable. The majority of the prescriptions have no known DDIs.

A multiscale cell-based model of tumor growth for chemotherapy assessment and tumor-targeted therapy through a 3D computational approach

OBJECTIVES

Computational modeling of biological systems is a powerful tool to clarify diverse processes contributing to cancer. The aim is to clarify the complex biochemical and mechanical interactions between cells, the relevance of intracellular signaling pathways in tumor progression and related events to the cancer treatments, which are largely ignored in previous studies.

MATERIALS AND METHODS

A three-dimensional multiscale cell-based model is developed, covering multiple time and spatial scales, including intracellular, cellular, and extracellular processes. The model generates a realistic representation of the processes involved from an implementation of the signaling transduction network.

RESULTS

Considering a benign tumor development, results are in good agreement with the experimental ones, which identify three different phases in tumor growth. Simulating tumor vascular growth, results predict a highly vascularized tumor morphology in a lobulated form, a consequence of cells' motile behavior. A novel systematic study of chemotherapy intervention, in combination with targeted therapy, is presented to address the capability of the model to evaluate typical clinical protocols. The model also performs a dose comparison study in order to optimize treatment efficacy and surveys the effect of chemotherapy initiation delays and different regimens.

CONCLUSIONS

Results not only provide detailed insights into tumor progression, but also support suggestions for clinical implementation. This is a major step toward the goal of predicting the effects of not only traditional chemotherapy but also tumor-targeted therapies.

Theoretical premises of a "three in one" therapeutic approach to treat immunogenic and nonimmunogenic cancers: a narrative review

Objective

We describe experimental and theoretical premises of a powerful cancer therapy based on the combination of three approaches. These include (I) in situ vaccination (intratumoral injections of CpG oligonucleotides and anti-OX40 antibody); (II) chronometric or metronomic low-dose cyclophosphamide (CMLD CP)-based chemotherapy; (III) cancer stem cell-eradicating therapy referred to as Karanahan (from the Sanskrit kāraṇa [“source”] + han [“to kill”]).

Background

In murine models, the first two approaches are particularly potent in targeting immunogenic tumors for destruction. In situ vaccination activates a fully fledged anticancer immune response via an intricate network of ligand–receptor–cytokine interactions. CMLD CP-based chemotherapy primarily targets the suppressive tumor microenvironment and activates tumor-infiltrating effectors. In contrast, Karanahan technology, being aimed at replicative machinery of tumor cells (both stem-like and committed), does not depend on tumor immunogenicity. With this technology, mice engrafted with ascites and/or solid tumors can be successfully cured. There is a significant degree of mechanistic and therapeutic overlap between these three approaches. For instance, the similarities shared between in situ vaccination and Karanahan technology include the therapeutic procedure, the cell target [antigen-presenting cells (APC) and dendritic cells (DC)], and the use of DNA-based preparations (CpG and DNAmix). Features shared between CMLD CP-based chemotherapy and Karanahan technology are the timing and the dose of the cytostatic drug administration, which lead to tumor regression.

Methods

The following keywords were used to search PubMed for the latest research reporting successful eradication of transplantable cancers in animal models that relied on approaches distinct from those used in the Karanahan technology: eradication of malignancy, cure cancer, complete tumor regression, permanently eradicating advanced mouse tumor, metronomic chemotherapy, in situ vaccination, immunotherapy, and others.

Conclusion

We hypothesize, therefore, that very potent anticancer activity can be achieved once these three therapeutic modalities are combined into a single approach. This multimodal approach is theoretically curative for any type of cancer that depends on the presence of tumor-inducing cancer stem cells, provided that the active therapeutic components are efficiently delivered into the tumor and the specific biological features of a given patient’s tumor are properly addressed. We expect this multimodal approach to be primarily applicable to late-stage or terminal cancer patients who have exhausted all treatment options as well as patients with inoperable tumors.

The Spectrum of Histomorphological Changes and Pathological Tumor Response following Preoperative Oral Metronomic Chemotherapy in Oral Squamous Cell Carcinoma

Background Oral metronomic chemotherapy (OMCT) represents an emerging concept in cancer treatment involving frequent administration of chemotherapeutic drugs at doses below maximum tolerated doses and with no prolonged drug-free break. OMCT is being tried preoperatively in developing nations with constrained resources to prevent disease progression during the waiting period from diagnosis to surgery (bridge OMCT). The aim of the present study was to assess the spectrum of histomorphological changes and pathological tumor response following bridge OMCT in oral squamous cell carcinoma (OSCC) and to propose a new pathological response scoring system.

Materials and Methods A retrospective single-center study comprised of tissue sections of tumor proper and metastatic lymph nodes of 50, locally advanced OSCC patients treated with bridge OMCT, and had completed definitive surgery were analyzed. The present study evaluated the histomorphological features and proposed a new scoring system for pathologic tumor response. The pathologic tumor response was categorized as complete response (pCR), no response (pNR), and partial response (pPR).

Results Of the total 50 patients, 2 patients had pCR, 3 had pNR, and 45 patients had pPR as per the new proposed scoring system. Note that 96% of the cases showed no disease progression.

Conclusion Bridge OMCT is a novel treatment method that can be used to tide over the waiting period between the diagnosis and surgery in resource-constrained institutions with heavy patient load. This mode of treatment in locally advanced OSCC seems to provide promising results in this setting. Large multicentric trials are warranted to confirm these results.

DNA-double strand breaks enhance the expression of major histocompatibility complex class II through the ATM-NF-κΒ-IRF1-CIITA pathway

Major histocompatibility complex class II (MHC II) is important for the adaptive immune response because MHC II presents processed antigens to a cluster of differentiation 4 (CD4)-positive T-cells. Conventional doses of chemotherapeutic agents induce tumor cell death by causing DNA double-strand breaks (DSBs). However, cellular responses caused by sub-lethal doses of chemotherapeutic agents are poorly understood. In this study, using low doses of chemotherapeutic agents, we showed that DSBs enhanced the expression of MHC II on cells that originate from antigen-presenting cells (APCs). These agents induced the MHC class II transactivator (CIITA), the master regulator of MHC II, and interferon regulatory factor 1 (IRF1), a transcription factor for CIITA. Short hairpin RNA against IRF1 suppressed chemotherapeutic agent-induced CIITA expression, whereas exogenous expression of IRF1 induced CIITA. Inhibition of ataxia-telangiectasia mutated (ATM), a DSB-activated kinase, suppressed induction of IRF1, CIITA, and MHC II. Similar results were observed by inhibiting NF-κB, a downstream target of ATM. These results suggest that DSBs induce MHC II activity via the ATM-NF-κB-IRF1-CIITA pathway in cells that intrinsically present antigens. Additionally, chemotherapeutic agents induced T-cell regulatory molecules. Our findings suggest that chemotherapeutic agents enhance the antigen presentation activity of APCs for T-cell activation.

Metronomic chemotherapy regimens and targeted therapies in non-Hodgkin lymphoma: The best of two worlds

Novel drugs are rapidly moving forward the treatment-paradigm of non-Hodgkin-lymphomas (NHLs). Notwithstanding, especially in aggressive subtypes, chemotherapy remains the pillar of treatment. Indeed, the combination of highly effective Maximum-Tolerated-Dose Chemotherapy (MTD-CHEMO) + "novel drugs", has so far, fallen short from expectations, often because it caused excessive toxicity. Metronomic chemotherapy (mCHEMO), which is the frequent, long-term administration of low dose cytotoxic drugs, may allow more effective and tolerable combinations. mCHEMO pharmacodynamics, has been described as pleiotropic. In fact, it may have different cellular and molecular targets, when drugs or their schedules are modified. Although mCHEMO has been little explored in NHLs, pre-clinical studies - in lymphoma models - which addressed the activity of mCHEMO in combination with novel drugs, have shown very promising results. These included inhibitors of histone deacetylase, mTOR and PI3K/mTOR, as well as the immune checkpoint inhibitor anti-PD-L1. Moreover, a few impressive reports have recently shown all-oral mCHEMO schedules, with or without rituximab, can effectively shrink both B and T-cell aggressive NHLs. Indeed, these regimens allowed elderly-frail patients to achieve sustained remission, while toxicity proved manageable. In our opinion, all-oral mCHEMO, is an active, easy-to start, well-tolerated, and inexpensive therapeutic approach, which deserves further investigation. Most importantly, mCHEMO, holds promise to empower the activity of novel targeted therapies, without causing excessive toxicity.

Boosting the oral bioavailability of anticancer drugs through intentional drug-drug interactions

Oral anticancer drugs suffer from significant variability in pharmacokinetics and pharmacodynamics partially due to limited bioavailability. The limited bioavailability of anticancer drugs is due to both pharmaceutical limitations and physiological barriers. Pharmacokinetic boosting is a strategy to enhance the oral bioavailability of a therapeutic drug by inhibiting physiological barriers through an intentional drug-drug interaction (DDI). This type of strategy has proven effective across several therapeutic indications including anticancer treatment. Pharmacokinetic boosting could improve anticancer drugs lacking or with otherwise unacceptable oral formulations through logistic, economic, pharmacodynamic and pharmacokinetic benefits. Despite these benefits, pharmacokinetic boosting strategies could result in unintended DDIs and are only likely to benefit a limited number of targets. Highlighting this concern, pharmacokinetic boosting has mixed results depending on the boosted drug. While pharmacokinetic boosting did not significantly improve certain drugs, it has resulted in the commercial approval of boosted oral formulations for other drugs. Pharmacokinetic boosting to improve oral anticancer therapy is an expanding area of research that is likely to improve treatment options for cancer patients.

Metronomic chemotherapy with cyclophosphamide for the treatment of advanced hepatocellular cancer: A case report

Introduction and importance

Metronomic chemotherapy entails chronic, equally spaced administration of low doses of various chemotherapeutic drugs without extended rest periods. Its use as a second-line treatment in advanced or metastatic hepatocellular cancer remains under investigation.

Case presentation

We report a case of a 49-year-old Caucasian female patient with an enlarged (∼14 cm) hepatocellular cancer. In July 2016, she underwent right hepatectomy (after preceding TACE). During the follow-up period, she presented early disease recurrence with lung and peritoneal metastasis. Initially, she received an inhibitor of protein kinase (sorafenib) for six months without response. Afterwards, cyclophosphamide administration at low doses as metronomic chemotherapy provided complete regression of the metastatic lesions. The patient remains in good performance status almost 4 years after initial treatment, without signs of recurrence in her recent follow-up.

Clinical discussion

Using cyclophosphamide as metronomic chemotherapy in advanced hepatocellular cancer may have a promising antiangiogenic antitumor effect. Future clinical trials need to demonstrate this effect in terms of tumor suppression and increased disease-free survival.

Conclusion

Large multi-centered clinical trials have to be planned to investigate the precise role of cyclophosphamide in the therapy of hepatocellular cancer while defining the patients’ profile that will benefit most from cyclophosphamide.

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MET is well tolerated and demonstrated modest activity in advanced/metastatic HCC.

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Studies in mice have shown promising results for both advanced and early-stage HCC.

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Cyclophosphamide has demonstrated antiangiogenic and immunomodulatory effects.

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It may prevent tumor resistance.

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Its beneficial efficacy in HCC is not fully determined in clinical practice yet.

Identification and Characterization of Key Differentially Expressed Genes Associated With Metronomic Dosing of Topotecan in Human Prostate Cancer

Repetitive, low-dose (metronomic; METRO) drug administration of some anticancer agents can overcome drug resistance and increase drug efficacy in many cancers, but the mechanisms are not understood fully. Previously, we showed that METRO dosing of topotecan (TOPO) is more effective than conventional (CONV) dosing in aggressive human prostate cancer (PCa) cell lines and in mouse tumor xenograft models. To gain mechanistic insights into METRO-TOPO activity, in this study we determined the effect of METRO- and CONV-TOPO treatment in a panel of human PCa cell lines representing castration-sensitive/resistant, androgen receptor (+/−), and those of different ethnicity on cell growth and gene expression. Differentially expressed genes (DEGs) were identified for METRO-TOPO therapy and compared to a PCa patient cohort and The Cancer Genome Atlas (TCGA) database. The top five DEGs were SERPINB5, CDKN1A, TNF, FOS, and ANGPT1. Ingenuity Pathway Analysis predicted several upstream regulators and identified top molecular networks associated with METRO dosing, including tumor suppression, anti-proliferation, angiogenesis, invasion, metastasis, and inflammation. Further, the top DEGs were associated with increase survival of PCa patients (TCGA database), as well as ethnic differences in gene expression patterns in patients and cell lines representing African Americans (AA) and European Americans (EA). Thus, we have identified candidate pharmacogenomic biomarkers and novel pathways associated with METRO-TOPO therapy that will serve as a foundation for further investigation and validation of METRO-TOPO as a novel treatment option for prostate cancers.

Stewart-Treves syndrome in an older woman successfully treated by metronomic chemotherapy: case report and literature survey

The authors present the case of a 94-year-old woman suffering from a right arm angiosarcoma developed after primary breast cancer and treated with success by oral metronomic chemotherapy based on daily low doses of cyclophosphamide and prednisone. The case description is followed by a short review of actual knowledge on the subject.

Exceptional response to oral metronomic chemotherapy in a rare case of sinonasal mucosal melanoma

Sinonasal mucosal melanoma is a rare malignancy with limited treatment options and a poor prognosis. They are usually diagnosed at an advanced stage owing to their late and nonspecific clinical presentation. Here we present a case of relapsed refractory unresectable malignant melanoma involving the right nasal cavity managed with Oral Metronomic Chemotherapy (OMCT). A 75-year-old male patient was diagnosed with unresectable malignant melanoma involving the right nasal cavity and showed radiological progression after initial management with four cycles of Dacarbazine. He was then shifted to OMCT (Cyclophosphamide, Celecoxib and Tamoxifen), as immunotherapy could not be given due to financial constraints, on which he showed approximately 40% reduction in tumour size after 6 months. This result can have important clinical implications in resource constrained settings, where the use of immunotherapy is limited by great financial burden.

Metronomic delivery of orally available pemetrexed-incorporated colloidal dispersions for boosting tumor-specific immunity

In this study, we developed oral pemetrexed (PMX) for metronomic dosing to enhance antitumor immunity. PMX was electrostatically complexed with positively charged lysine-linked deoxycholic acid (DL) as an intestinal permeation enhancer, forming PMX/DL, to enhance its intestinal permeability. PMX/DL was also incorporated into a colloidal dispersion (CD) comprised of the block copolymer of poly(ethylene oxide) and poly(propylene oxide), and caprylocaproyl macrogol-8 glycerides (PMX/DL-CD). CD-containing PMX/DL complex in a 1:1 molar ratio [PMX/DL(1:1)-CD] showed 4.66- and 7.19-fold greater permeability than free PMX through the Caco-2 cell monolayer and rat intestine, respectively. This resulted in a 282% improvement in oral bioavailability in rats. In addition, low-dose metronomic PMX led to more immunogenic cell death in CT26.CL25 cells compared to high PMX concentrations at the maximum tolerated dose. In CT26.CL25 tumor-bearing mice, oral metronomic PMX/DL-CD elicited greater antitumor immunity not only by enhancing the number of tumor-infiltrating lymphocytes but also by suppressing T cell functions. Oral PMX/DL-CD substantially increased programmed cell death protein ligand-1 (PD-L1) expression on tumor cells compared to the control and PMX-IV groups. This increased antitumor efficacy in combination with anti-programmed cell death protein-1 (aPD-1) antibody in terms of tumor rejection and immunological memory compared to the combination of PMX-IV and aPD-1. These results suggest that oral metronomic scheduling of PMX/DL-CD in combination with immunotherapy has synergistic antitumor effects.