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Ablative doses of stereotactic body radiotherapy (SBRT) may improve pancreatic cancer outcomes but may carry greater potential for gastrointestinal toxicity. Rucosopasem, an investigational selective dismutase mimetic that converts superoxide to hydrogen peroxide, can potentially increase tumor control of SBRT without compromising safety. GRECO-2 is a phase II, multicenter, randomized, double-blind, placebo-controlled trial of rucosopasem in combination with SBRT in locally advanced or borderline resectable pancreatic cancer. Patients will be randomized to rucosopasem 100 mg or placebo via intravenous infusion over 15 min, before each SBRT fraction (5 × 10 Gy). The primary end point is overall survival. Secondary end points include progression-free survival, locoregional control, time to metastasis, surgical resection rate, best overall response, in-field local response and acute and long-term toxicity.
The use of high doses of radiation delivered directly to tumors (stereotactic body radiation therapy [SBRT]) may improve survival compared with lower doses of radiation in patients with pancreatic cancer, but it may increase side effects. Rucosopasem, an investigational new drug being developed, can potentially improve the ability of SBRT to treat tumors without decreasing safety. In a previous study, median overall survival was improved when patients were treated with SBRT plus avasopasem, a drug that works the same way as rucosopasem. GRECO-2 is a clinical trial of rucosopasem used in combination with SBRT for treatment of localized pancreatic cancer. Patients will be randomly selected to receive either rucosopasem 100 mg or placebo via intravenous infusion over 15 min, before each SBRT treatment. The main result being studied is overall survival. Additional results include amount of time before tumors start to grow, how often patients get tumors surgically removed, best overall response and long-term safety. Clinical Trial Registration: NCT04698915 (ClinicalTrials.gov).
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Adenocarcinoma , Neoplasias Pancreáticas , Radiocirurgia , Humanos , Ensaios Clínicos Fase II como Assunto , Fracionamento da Dose de Radiação , Estudos Multicêntricos como Assunto , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/radioterapia , Neoplasias Pancreáticas/tratamento farmacológico , Radiocirurgia/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
This work presents a comprehensive commissioning and workflow development process of a real-time, ultrasound (US) image-guided treatment planning system (TPS), a stepper and a US unit. To adequately benchmark the system, commissioning tasks were separated into (1) US imaging, (2) stepper mechanical, and (3) treatment planning aspects. Quality assurance US imaging measurements were performed following the AAPM TG-128 and GEC-ESTRO recommendations and consisted of benchmarking the spatial resolution, accuracy, and low-contrast detectability. Mechanical tests were first used to benchmark the electronic encoders within the stepper and were later expanded to evaluate the needle free length calculation accuracy. Needle reconstruction accuracy was rigorously evaluated at the treatment planning level. The calibration length of each probe was redundantly checked between the calculated and measured needle free length, which was found to be within 1 mm for a variety of scenarios. Needle placement relative to a reference fiducial and coincidence of imaging coordinate origins were verified to within 1 mm in both sagittal and transverse imaging planes. The source strength was also calibrated within the interstitial needle and was found to be 1.14% lower than when measured in a plastic needle. Dose calculations in the TPS and secondary dose calculation software were benchmarked against manual TG-43 calculations. Calculations among the three calculation methods agreed within 1% for all calculated points. Source positioning and dummy coincidence was tested following the recommendations of the TG-40 report. Finally, the development of the clinical workflow, checklists, and planning objectives are discussed and included within this report. The commissioning of real-time, US-guided HDR prostate systems requires careful consideration among several facets including the image quality, dosimetric, and mechanical accuracy. The TPS relies on each of these components to develop and administer a treatment plan, and as such, should be carefully examined.
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Braquiterapia , Humanos , Masculino , Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Ultrassonografia , Ultrassonografia de IntervençãoRESUMO
To assess the impact of internal mammary (IM) vessels radiation dose on autologous free-flap based breast reconstruction outcomes. We retrospectively evaluated the medical records of breast cancer patients who underwent mastectomy and free-flap breast reconstruction after postoperative radiation therapy (RT) to the breast/chest wall with (n = 9) or without (n = 11) electively including the IM lymph nodes. Twenty patients were included. Median age at diagnosis was 50 years (range, 33-63). The median time interval between the start of RT and reconstructive surgery was 16 months (range, 6-45). The maximal IM vessels dose was not associated with the risk of all complications (P = 0.44) or fat necrosis (P = 0.31). The mean IM vessels dose was not significant for the risk of all complications (P = 0.13) but was significant for fat necrosis (P = 0.04). A high mean IM vessels dose was related to the occurrence of fat necrosis.
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Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Mamoplastia/efeitos adversos , Glândulas Mamárias Humanas/irrigação sanguínea , Dosagem Radioterapêutica , Adulto , Anastomose Cirúrgica , Vasos Sanguíneos/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Retalhos de Tecido Biológico , Humanos , Mamoplastia/métodos , Glândulas Mamárias Humanas/efeitos da radiação , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de TempoRESUMO
The combination chemotherapy regimen of cisplatin (CP) and docetaxel (DTX) is effective against a variety of cancers. However, combination therapies present unique challenges that can complicate clinical application, such as increases in toxicity and imprecise exposure of tumors to specific drug ratios that can produce treatment resistance. Drug co-encapsulation within a single nanoparticle (NP) formulation can overcome these challenges and further improve combinations' therapeutic index. In this report, we employ a CP prodrug (CPP) strategy to formulate poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) NPs carrying both CPP and DTX. The dually loaded NPs display differences in drug release kinetics and in vitro cytotoxicity based on the structure of the chosen CPP. Furthermore, NPs containing both drugs showed a significant improvement in treatment efficacy versus the free drug combination in vivo.
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Antineoplásicos/administração & dosagem , Cisplatino/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Pulmão/efeitos dos fármacos , Nanopartículas/química , Polietilenoglicóis/química , Poliglactina 910/química , Taxoides/administração & dosagem , Animais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Cisplatino/uso terapêutico , Docetaxel , Portadores de Fármacos/química , Combinação de Medicamentos , Feminino , Humanos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Pró-Fármacos/administração & dosagem , Pró-Fármacos/uso terapêutico , Taxoides/uso terapêuticoRESUMO
Nanoparticle (NP) chemotherapeutics can improve the therapeutic index of chemoradiotherapy (CRT). However, the effect of NP physical properties, such particle size, on CRT is unknown. To address this, we examined the effects of NP size on biodistribution, efficacy and toxicity in CRT. PEG-PLGA NPs (50, 100, 150 nm mean diameters) encapsulating wotrmannin (wtmn) or KU50019 were formulated. These NP formulations were potent radiosensitizers in vitro in HT29, SW480, and lovo rectal cancer lines. In vivo, the smallest particles avoided hepatic and splenic accumulation while more homogeneously penetrating tumor xenografts than larger particles. However, smaller particles were no more effective in vivo. Instead, there was a trend toward enhanced efficacy with medium sized NPs. The smallest KU60019 particles caused more small bowel toxicity than larger particles. Our results showed that particle size significantly affects nanotherapeutics' biodistrubtion and toxicity but does not support the conclusion that smaller particles are better for this clinical application.
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Quimiorradioterapia , Nanopartículas , Androstadienos/farmacocinética , Animais , Xenoenxertos , Humanos , Camundongos , Tamanho da Partícula , Polímeros , Neoplasias Retais , Distribuição Tecidual , WortmaninaRESUMO
Collagen IV-targeting peptide-conjugated basement membrane-targeting nanoparticles are successfully engineered to identify early-stage blood vessel injury induced by high-dose radiotherapy.
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Membrana Basal/metabolismo , Nanopartículas/química , Lesões por Radiação/diagnóstico , Radioterapia/efeitos adversos , Lesões do Sistema Vascular/diagnóstico , Animais , Membrana Basal/efeitos dos fármacos , Colágeno Tipo IV/farmacologia , Relação Dose-Resposta à Radiação , Fluorescência , Ácido Láctico/química , Camundongos Nus , Imagem Óptica , Polietilenoglicóis/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
Introduction: This work presents a method to treat stereotactic body radiation therapy (SBRT) for pancreatic cancer on a magnetic resonance-guided linear accelerator (MR-linac) using daily adaptation, real-time motion monitoring, and abdominal compression. Methods: The motion management and treatment planning process involves a magnetic resonance imaging (MRI) simulation with cine and 3D images, a computed tomography (CT) simulation with a breath-hold CT and a 4DCT, pre-treatment verification and planning MRI, and intrafraction MRI cine images. Results: The results from 26 patients were included in this work. Our motion management process results in consistent motion analysis on the CT simulation, MRI simulation, and each treatment fraction. The liver dome was found to be an overestimate of tumor superior/inferior (SI) motion for most patients. Adding compression reduced SI liver dome motion by 6.2 mm on average. Clinical outcomes are similar to those observed in the literature. Conclusions: In this work, we demonstrate how pancreatic SBRT can be successfully treated on an MR-linac using abdominal compression. This allows for an increased duty cycle compared to gating and/or breath-hold techniques.
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A highly sensitive, circulating tumor cell (CTC)-based liquid biopsy was used to monitor gastrointestinal cancer patients during treatment to determine if CTC abundance was predictive of disease recurrence. The approach used a combination of biomimetic cell rolling on recombinant E-selectin and dendrimer-mediated multivalent immunocapture at the nanoscale to purify CTCs from peripheral blood mononuclear cells. Due to the exceptionally high numbers of CTCs captured, a machine learning algorithm approach was developed to efficiently and reliably quantify abundance of immunocytochemically-labeled cells. A convolutional neural network and logistic regression model achieved 82.9% true-positive identification of CTCs with a false positive rate below 0.1% on a validation set. The approach was then used to quantify CTC abundance in peripheral blood samples from 27 subjects before, during, and following treatments. Samples drawn from the patients either prior to receiving radiotherapy or early in chemotherapy had a median 50 CTC ml-1 whole blood (range 0.6-541.6). We found that the CTC counts drawn 3 months post treatment were predictive of disease progression (p = .045). This approach to quantifying CTC abundance may be a clinically impactful in the timely determination of gastrointestinal cancer progression or response to treatment.
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Técnicas Biossensoriais , Neoplasias Gastrointestinais , Células Neoplásicas Circulantes , Humanos , Células Neoplásicas Circulantes/patologia , Leucócitos Mononucleares , Biomarcadores , Nanotecnologia , Biomarcadores TumoraisRESUMO
Diffuse intrinsic pontine gliomas (DIPG) are an aggressive type of pediatric brain tumor with a very high mortality rate. Surgery has a limited role given the tumor's location. Palliative radiation therapy alleviates symptoms and prolongs survival, but median survival remains less than 1 year. There is no clear role for chemotherapy in DIPGs as trials adding chemotherapy to palliative radiation therapy have failed to improve survival compared to radiation alone. Thus, there is a critical need to identify tissue-specific radiosensitizers to improve clinical outcomes for patients with DIPGs. Pharmacologic (high dose) ascorbate (P-AscH-) is a promising anticancer therapy that sensitizes human tumors, including adult high-grade gliomas, to radiation by acting selectively as a generator of hydrogen peroxide (H2O2) in cancer cells. In this study we demonstrate that in contrast to adult glioma models, P-AscH- does not radiosensitize DIPG. DIPG cells were sensitive to bolus of H2O2 but have faster H2O2 removal rates than GBM models which are radiosensitized by P-AscH-. These data support the hypothesis that P-AscH- does not enhance DIPG radiosensitivity, likely due to a robust capacity to detoxify and remove hydroperoxides.
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Antineoplásicos , Neoplasias do Tronco Encefálico , Glioma Pontino Intrínseco Difuso , Glioma , Criança , Adulto , Humanos , Glioma Pontino Intrínseco Difuso/tratamento farmacológico , Glioma Pontino Intrínseco Difuso/patologia , Neoplasias do Tronco Encefálico/radioterapia , Neoplasias do Tronco Encefálico/patologia , Peróxidos/uso terapêutico , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/uso terapêutico , Glioma/radioterapia , Glioma/patologia , Antineoplásicos/uso terapêuticoRESUMO
PURPOSE: Ataxia telangiectasia mutated kinase (ATM) inhibitors are potent radiosensitizers that regulate DNA damage responses and redox metabolism, but they have not been translated clinically because of the potential for excess normal tissue toxicity. Pharmacologic ascorbate (P-AscH-; intravenous administration achieving mM plasma concentrations) selectively enhances H2O2-induced oxidative stress and radiosensitization in tumors while acting as an antioxidant and mitigating radiation damage in normal tissues including the bowel. We hypothesized that P-AscH- could enhance the therapeutic index of ATM inhibitor-based chemoradiation by simultaneously enhancing the intended effects of ATM inhibitors in tumors and mitigating off-target effects in adjacent normal tissues. METHODS AND MATERIALS: Clonogenic survival was assessed in human (human colon tumor [HCT]116, SW480, HT29) and murine (CT26, MC38) colorectal tumor lines and normal cells (human umbilical vein endothelial cell, FHs74) after radiation ± DNA repair inhibitors ± P-AscH-. Tumor growth delay was assessed in mice with HCT116 or MC38 tumors after fractionated radiation (5 Gy × 3) ± the ATM inhibitor KU60019 ± P-AscH-. Intestinal injury, oxidative damage, and transforming growth factor ß immunoreactivity were quantified using immunohistochemistry after whole abdominal radiation (10 Gy) ± KU60019 ± P-AscH-. Cell cycle distribution and ATM subcellular localization were assessed using flow cytometry and immunohistochemistry. The role of intracellular H2O2 fluxes was assessed using a stably expressed doxycycline-inducible catalase transgene. RESULTS: KU60019 with P-AscH- enhanced radiosensitization in colorectal cancer models in vitro and in vivo by H2O2-dependent oxidative damage to proteins and enhanced DNA damage, abrogation of the postradiation G2 cell cycle checkpoint, and inhibition of ATM nuclear localization. In contrast, concurrent P-AscH- markedly reduced intestinal toxicity and oxidative damage with KU60019. CONCLUSIONS: We provide evidence that redox modulating drugs, such as P-AscH-, may facilitate the clinical translation of ATM inhibitors by enhancing tumor radiosensitization while simultaneously protecting normal tissues.
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Ataxia Telangiectasia , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Ácido Ascórbico/farmacologia , Ácido Ascórbico/uso terapêutico , Peróxido de Hidrogênio , Linhagem Celular Tumoral , Neoplasias Pancreáticas/patologia , Oxirredução , Índice Terapêutico , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Dano ao DNA , Proteínas de Ciclo Celular/metabolismoRESUMO
The intracellular redox-active labile iron pool (LIP) is weakly chelated and available for integration into the iron metalloproteins that are involved in diverse cellular processes, including cancer cell-specific metabolic oxidative stress. Abnormal iron metabolism and elevated LIP levels are linked to the poor survival of lung cancer patients, yet the underlying mechanisms remain unclear. Depletion of the LIP in non-small-cell lung cancer cell lines using the doxycycline-inducible overexpression of the ferritin heavy chain (Ft-H) (H1299 and H292), or treatment with deferoxamine (DFO) (H1299 and A549), inhibited cell growth and decreased clonogenic survival. The Ft-H overexpression-induced inhibition of H1299 and H292 cell growth was also accompanied by a significant delay in transit through the S-phase. In addition, both Ft-H overexpression and DFO in H1299 resulted in increased single- and double-strand DNA breaks, supporting the involvement of replication stress in the response to LIP depletion. The Ft-H and DFO treatment also sensitized H1299 to VE-821, an inhibitor of ataxia telangiectasis and Rad2-related (ATR) kinase, highlighting the potential of LIP depletion, combined with DNA damage response modifiers, to alter lung cancer cell responses. In contrast, only DFO treatment effectively reduced the LIP, clonogenic survival, cell growth, and sensitivity to VE-821 in A549 non-small-cell lung cancer cells. Importantly, the Ft-H and DFO sensitized both H1299 and A549 to chemoradiation in vitro, and Ft-H overexpression increased the efficacy of chemoradiation in vivo in H1299. These results support the hypothesis that the depletion of the LIP can induce genomic instability, cell death, and potentiate therapeutic responses to chemoradiation in NSCLC.
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MR-guided adaptive radiotherapy (MRgART) provides opportunities to benefit patients through enhanced use of advanced imaging during treatment for many patients with various cancer treatment sites. This novel technology presents many new challenges which vary based on anatomic treatment location, technique, and potential changes of both tumor and normal tissue during treatment. When introducing new treatment sites, considerations regarding appropriate patient selection, treatment planning, immobilization, and plan-adaption criteria must be thoroughly explored to ensure adequate treatments are performed. This paper presents an institution's experience in developing a MRgART program for a 1.5T MR-linac for the first 234 patients. The paper suggests practical treatment workflows and considerations for treating with MRgART at different anatomical sites, including imaging guidelines, patient immobilization, adaptive workflows, and utilization of bolus.
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BACKGROUND: Approximately 40% of patients with esophageal cancer present with metastatic disease. Survival with palliative treatment is poor, and the benefit of aggressive focal therapies is unclear. This study aimed to identify a subset of patients with metastatic esophageal cancer with favorable outcomes after curative doses of radiation therapy, esophagectomy, or both. METHODS: Between 2004 and 2015, the study investigators found 28,101 patients with metastatic esophageal cancer in the National Cancer Database and identified those who underwent chemotherapy and definitive radiation therapy with or without surgery over the study period. The study compared the estimated median overall survival (OS) of all patients with metastatic esophageal cancer with the estimated median OS of patients with metastatic esophageal cancer who underwent radiation therapy with or without surgery. Multivariable analysis was used to examine clinical and pathologic factors associated with OS. RESULTS: At a median follow-up of 11.1 months, 3219 patients with a median age of 64 years and a radiation dose of 50.4 Gy were identified. Only 202 (6.2%) patients undergoing definitive-dose radiation therapy underwent esophagectomy, with a median age of 60 years. The median OS durations for all patients, for patients treated with radiation, and for patients treated with radiation therapy in combination with esophagectomy were 6.6, 11.5, and 30.2 months, respectively. Among patients undergoing surgery, median OS after surgery was 23.7 months. Patients with lung, liver, or bone metastases were less likely to undergo esophagectomy. On multivariable analysis, esophagectomy and low tumor grade were associated with higher OS, whereas liver and bone metastases at diagnosis were associated with worse OS. CONCLUSIONS: This analysis suggests that select subsets of patients with primarily nonvisceral, nonosseous metastatic esophageal cancer have favorable survival and may potentially benefit from aggressive local therapies.
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Neoplasias Esofágicas/terapia , Esofagectomia/métodos , Estadiamento de Neoplasias , Quimiorradioterapia/métodos , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/secundário , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos RetrospectivosRESUMO
PURPOSE: The cohort of patients with locally advanced prostate cancer (PC) and positive surgical margin(s) at radical prostatectomy (RP) who would benefit from salvage or adjuvant treatment is unclear. This study examines the risk of prostate-specific antigen (PSA) relapse in a large population of men with PC after margin-positive RP. METHODS AND MATERIALS: Using a multi-institutional database, patients with clinically localized PC who underwent RP between 2002 and 2010 with recorded follow-up PSA were retrospectively selected. Patients were excluded for pathologic seminal vesicle or lymph node involvement, metastatic disease, pre-RP PSA ≥ 30, or adjuvant (nonsalvage) radiation therapy or hormone therapy. The primary endpoint was biochemical relapse free survival (bRFS), where PSA failure was defined as PSA > 0.10 ng/mL and rising, or at salvage intervention. The Kaplan-Meier method was employed for bRFS estimates; recursive partitioning analysis using cumulative or single maximal margin extent (ME) and Gleason grade (GG) at RP was applied to identify variables associated with bRFS. RESULTS: At median follow-up of 105 months, 210 patients with positive margins at RP were eligible for analysis, and 89 had experienced PSA relapse. Median age was 61 years (range, 43-76), and median pre-RP PSA 5.8 ng/mL (1.6-26.0). Recursive partitioning analysis yielded 5 discrete risk groups, with the lowest risk group (GG1, ≤ 2 mm ME) demonstrating a bRFS of 92% at 8 years compared with the highest risk group (GG3-5, ≥ 3 mm ME) of 11%. CONCLUSIONS: This retrospective study suggests that it may be possible to risk-stratify patients undergoing margin-positive RP using commonly acquired clinical and pathologic variables. Patients with low-grade tumors and minimally involved margins have a very low recurrence risk and may be able to forego postprostatectomy radiation. Meanwhile, those with higher grade and greater involvement could benefit from adjuvant or early salvage radiation therapy.
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Most life-long drug addiction begins during adolescence. Important structural and functional changes in brain occur during adolescence and developmental differences in forebrain dopamine systems could mediate a biologic vulnerability to drug addiction during adolescence. Studies investigating age differences in psychostimulant responses have yielded mixed results, possibly because of different mechanisms for increasing extracellular dopamine. Recent research from our laboratory suggests that adolescent dopamine systems may be most affected by selective dopamine uptake inhibitors. We investigated age-related behavioral responses to acute administration of several dopamine uptake inhibitors [methylphenidate, 1-{2-[bis-(4-fluorophenyl)methoxy]ethyl}-4-(3-phenylpropyl)piperazine (GBR12909), and nomifensine] and releasing agents [amphetamine and methylenedioxymethamphetamine (MDMA)] in adolescent and adult male rats. Methylphenidate and amphetamine effects on stimulated dopamine efflux were determined using fast-scan cyclic voltammetry in vivo. Dopamine uptake inhibitors but not dopamine releasing agents induced more locomotion and/or stereotypy in adolescent relative to adult rats. MDMA effects were greater in adults at early time points after dosing. Methylphenidate but not amphetamine induced much greater dopamine efflux in periadolescent relative to adult rats. Periadolescent male rats are particularly sensitive to psychostimulants that are DAT inhibitors but are not internalized and do not release dopamine. Immaturity of DAT and/or DAT associated signaling systems in adolescence specifically enhances behavioral and dopaminergic responses in adolescence.
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Envelhecimento/fisiologia , Inibidores da Captação de Dopamina/farmacologia , Dopamina/metabolismo , Atividade Motora/efeitos dos fármacos , Anfetaminas/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Eletrofisiologia , Masculino , Metilfenidato/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Nomifensina/farmacologia , Piperazinas/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
Purpose: This study aimed to investigate the feasibility of stereotactic body radiation therapy (SBRT) as salvage therapy for locally recurrent esophageal cancer. We hypothesized that SBRT would provide durable treated tumor control with minimal associated toxicity in patients with progressive disease after definitive radiation, chemotherapy, and surgical resection. Methods: This single-institution retrospective study assessed outcomes in patients who received SBRT for locoregional failure of esophageal cancer after initial curative-intent treatment. Only patients who had received neoadjuvant chemoradiation (≥41.4 Gy) for esophageal cancer were selected. Subsequent surgical resection was optional but institutional follow-up by an oncologist was required. The primary endpoints of this study were gastrointestinal and constitutional toxicity, scored with the Common Terminology Criteria for Adverse Events v5.0. A secondary outcome, treated-tumor control, was assessed with RECIST v1.1. Results: Nine patients (11 locoregional recurrences) treated with SBRT were reviewed, with a median follow-up time of 10.5 months. Most patients initially presented with T3 (88.9%), N1 (55.6%), moderately differentiated (66.7%) adenocarcinoma (88.9%), and had received a median 50.4 Gy delivered over 28 fractions with concurrent carboplatin/paclitaxel chemotherapy followed by surgical resection. Median time to recurrence was 16.3 months. Median total dose delivered by SBRT was 27.5 Gy (delivered in five fractions). Two patients experienced acute grade 1 fatigue and vomiting. No patient experienced grade 3 or higher toxicity. One patient experienced failure in the SBRT treatment field at 5.8 months after treatment and six patients developed distant failure. The median progression-free survival time for SBRT-treated tumors was 5.0 months, and median overall survival time was 12.9 months. Conclusions: This single-institution study demonstrated the feasibility of SBRT for locoregional recurrence of esophageal cancer with minimal treatment-related toxicity and high rates of treated tumor control. Prospective studies identifying ideal salvage SBRT candidates for locoregional failure as well as validating its safety are needed.
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PURPOSE: The majority of colorectal cancers are resistant to cancer immune checkpoint inhibitors. Ionizing radiation (IR) and several radiosensitizers, including PARP inhibitors, can enhance responsiveness to immune checkpoint inhibitors by potentially complementary mechanisms of action. We assessed the ability of radiation and PARP inhibition to induce proimmunogenic changes in tumor cells and enhance their in vivo responsiveness to anti-PD-1 antibodies. METHODS AND MATERIALS: We performed a candidate drug screen and used flow cytometry to assess effects of the PARP inhibitor veliparib on IR-mediated changes in MHC-1 antigen presentation and surface localization of immune-modulating proteins including PD-L1 and calreticulin in colorectal cancer tumor models. Reverse transcription polymerase chain reaction was used to assess the effects of veliparib and radiation on the expression of proinflammatory and immunosuppressive cytokines. The ability of concurrent PARP inhibition and subablative doses of radiation therapy to enhance in vivo responsiveness to anti-PD-1 antibodies was assessed using unilateral flank-tumor models with or without T-cell depletion. RESULTS: Veliparib was a potent radiosensitizer in both cell lines. Radiation increased surface localization of MHC-1 and PD-L1 in a dose-dependent manner, and veliparib pretreatment significantly enhanced these effects with high (8 Gy) but not with lower radiation doses. Enhancement of MHC-1 and PD-L1 surface localization by IR and IR+ veliparib remained significant 1, 3, and 7 days after treatment. IR significantly increased delayed tumoral expression of proinflammatory cytokines interferon-Ƴ and CXCL10 but had no significant effect on the expression of IL-6 or TGF-ß. Concurrent administration of veliparib and subablative radiation therapy (8 Gy × 2) significantly prolonged anti-PD-1-mediated in vivo tumor growth delay and survival in both tumor models. Moreover, these effects were more pronounced in the microsatellite instability-mutated MC38 tumor model. Enhancement of anti-PD-1 mediated tumor growth delay with veliparib and IR was attenuated by CD8+ T-cell depletion. CONCLUSIONS: We provide preclinical evidence for a novel therapeutic strategy to enhance responsiveness of colorectal tumors to immune checkpoint inhibitors.
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Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/radioterapia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Apresentação de Antígeno/efeitos dos fármacos , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Transformação Celular Neoplásica , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Terapia Combinada , Feminino , Humanos , Masculino , Camundongos , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Radiossensibilizantes/farmacologia , Radiossensibilizantes/uso terapêutico , Resultado do TratamentoRESUMO
The present studies assessed the roles of sex, age, novelty-seeking and plus-maze behavior on cocaine drinking in rats. Cocaine/saccharin solution was available in three daily, 5-hour sessions then a saccharin-only solution was also available in following sessions. In the one-bottle drinking phase, early and late adolescent males, post-natal day 28 (PN28) and PN42, consumed more cocaine/saccharin solution than young adults (PN65), but females did not exhibit significant age differences. Adolescents of both sexes consumed more cocaine/saccharin than adults during choice drinking. Saccharin availability in the two-bottle trials decreased cocaine/saccharin consumption in PN28 and PN65 rats. After a drug-free period, cocaine-stimulated locomotion was lower in cocaine/saccharin drinking than saccharin-only males, indicating tolerance. We tested the hypothesis that individual differences in pre-screened behavioral traits would correlate with cocaine/saccharin consumption in PN28 and PN65 male rats. High locomotor responses to novelty were associated with greater cocaine/saccharin drinking in adults in one-bottle sessions. In the subsequent choice drinking phase, correlations were age-specific. Adolescents with high novelty-induced locomotion and adults that spent less time on open arms of the elevated plus-maze drank more cocaine/saccharin. Thus, behavioral phenotypes correlated with individual differences in cocaine/saccharin consumption in an age-related manner.
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Envelhecimento/psicologia , Ansiedade/psicologia , Transtornos Relacionados ao Uso de Cocaína/psicologia , Atividade Motora/efeitos dos fármacos , Animais , Cocaína/química , Cocaína/farmacologia , Interpretação Estatística de Dados , Meio Ambiente , Feminino , Masculino , Soluções Farmacêuticas , Ratos , Recompensa , Caracteres SexuaisRESUMO
Cancer immunotherapy is one of the fastest growing and most promising fields in clinical oncology. T-cell checkpoint inhibitors are revolutionizing the management of advanced cancers including non-small cell lung cancer and melanoma. Unfortunately, many common cancers are not responsive to these drugs and resistance remains problematic. A growing number of novel cancer immunotherapies have been discovered but their clinical translation has been limited by shortcomings of conventional drug delivery. Immune signaling is tightly-regulated and often requires simultaneous or near-simultaneous activation of multiple signals in specific subpopulations of immune cells. Nucleic acid therapies, which require intact intracellular delivery, are among the most promising approaches to modulate the tumor microenvironment to a pro-immunogenic phenotype. Advanced nanomedicines can be precisely engineered to overcome many of these limitations and appear well-poised to enable the clinical translation of promising cancer immunotherapies.