Carmen Timke

Low-Dose Irradiation Programs Macrophage Differentiation to an iNOS+/M1 Phenotype that Orchestrates Effective T Cell Immunotherapy

Inefficient T cell migration is a major limitation of cancer immunotherapy. Targeted activation of the tumor microenvironment may overcome this barrier. We demonstrate that neoadjuvant local low-dose gamma irradiation (LDI) causes normalization of aberrant vasculature and efficient recruitment of tumor-specific T cells in human pancreatic carcinomas and T-cell-mediated tumor rejection and prolonged survival in otherwise immune refractory spontaneous and xenotransplant mouse tumor models. LDI (local or pre-adoptive-transfer) programs the differentiation of iNOS⁺ M1 macrophages that orchestrate CTL recruitment into and killing within solid tumors through iNOS by inducing endothelial activation and the expression of TH1 chemokines and by suppressing the production of angiogenic, immunosuppressive, and tumor growth factors.

Blockade of TGF-β Signaling by the TGFβR-I Kinase Inhibitor LY2109761 Enhances Radiation Response and Prolongs Survival in Glioblastoma

Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor that tends to be resistant to the ionizing radiotherapy used to treat it. Because TGF-β is a modifier of radiation responses, we conducted a preclinical study of the antitumor effects of the TGF-β receptor (TGFβR) I kinase inhibitor LY2109761 in combination with radiotherapy. LY2109761 reduced clonogenicity and increased radiosensitivity in GBM cell lines and cancer stem-like cells, augmenting the tumor growth delay produced by fractionated radiotherapy in a supra-additive manner in vivo. In an orthotopic intracranial model, LY2109761 significantly reduced tumor growth, prolonged survival, and extended the prolongation of survival induced by radiation treatment. Histologic analyses showed that LY2109761 inhibited tumor invasion promoted by radiation, reduced tumor microvessel density, and attenuated mesenchymal transition. Microarray-based gene expression analysis revealed signaling effects of the combinatorial treatments that supported an interpretation of their basis. Together, these results show that a selective inhibitor of the TGFβR-I kinase can potentiate radiation responses in glioblastoma by coordinately increasing apoptosis and cancer stem-like cells targeting while blocking DNA damage repair, invasion, mesenchymal transition, and angiogenesis. Our findings offer a sound rationale for positioning TGFβR kinase inhibitors as radiosensitizers to improve the treatment of glioblastoma.

Combination of Vascular Endothelial Growth Factor Receptor/Platelet-Derived Growth Factor Receptor Inhibition Markedly Improves Radiation Tumor Therapy

Purpose: Investigations on the combination of radiotherapy with vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) antiangiogenic agents, which has the potential to improve the clinical outcome in cancer patients. Experimental Design: Here, we analyze the combined VEGF (SU5416) and PDGF (SU6668) receptor tyrosine kinase inhibition with irradiation in human endothelium (HUVEC), prostate cancer (PC3), and glioblastoma (U87) in vitro and in vivo. Results: Combined inhibition of VEGF and PDGF signaling resulted in enhanced apoptosis, reduced cell proliferation, and clonogenic survival as well as reduced endothelial cell migration and tube formation compared with single pathway inhibition. These effects were further enhanced by additional irradiation. Likewise, in PC3 and U87 tumors growing s.c. on BALB/c nu/nu mice, dual inhibition of VEGF and PDGF signaling significantly increased tumor growth delay versus each monotherapy. Interestingly, radiation at ∼20% of the dose necessary to induce local tumor control exerts similar tumor growth-inhibitory effects as the antiangiogenic drugs given at their maximum effective dose. Addition of radiotherapy to both mono- as well as dual-antiangiogenic treatment markedly increased tumor growth delay. With respect to tumor angiogenesis, radiation further decreased microvessel density (CD31 count) and tumor cell proliferation (Ki-67 index) in all drug-treated groups. Of note, the slowly growing PC3 tumor responded better to the antiangiogenic drug treatments than the faster-growing U87 tumor. In addition to the beneficial effect of abrogating VEGF survival signaling when combined with radiation, we identified here a novel mechanism for the tumor escape from radiation damage. We found that radiation induced up-regulation of all four isoforms of PDGF (A-D) in endothelial cells supporting adjacent smooth muscle cells resulting in a prosurvival effect of radiation. The addition of SU6668 attenuated this undesirable paracrine radiation effect, which may rationalize the combined application of radiation with PDGF signaling inhibition to increase antitumor effects. Conclusion: A relative low radiation dose markedly enhances local antitumor effects of combined VEGF and PDGF signaling inhibition, suggesting a promising combination regimen for local tumor treatment with radiotherapy remaining an essential element.

LY2109761 Attenuates Radiation-Induced Pulmonary Murine Fibrosis via Reversal of TGF-β and BMP-Associated Proinflammatory and Proangiogenic Signals

Purpose: Radiotherapy is used for the treatment of lung cancer, but at the same time induces acute pneumonitis and subsequent pulmonary fibrosis, where TGF-β signaling is considered to play an important role. Experimental Design: We irradiated thoraces of C57BL/6 mice (single dose, 20 Gy) and administered them a novel small-molecule TGF-β receptor I serine/threonine kinase inhibitor (LY2109761) orally for 4 weeks before, during, or after radiation. Noninvasive lung imaging including volume computed tomography (VCT) and MRI was conducted 6, 16, and 20 weeks after irradiation and was correlated to histologic findings. Expression profiling analysis and protein analysis was conducted in human primary fibroblasts. Results: Radiation alone induced acute pulmonary inflammation and lung fibrosis after 16 weeks associated with reduced life span. VCT, MRI, and histology showed that LY2109761 markedly reduced inflammation and pulmonary fibrosis resulting in prolonged survival. Mechanistically, we found that LY2109761 reduced p-SMAD2 and p-SMAD1 expression, and transcriptomics revealed that LY2109761 suppressed expression of genes involved in canonical and noncanonical TGF-β signaling and downstream signaling of bone morphogenetic proteins (BMP). LY2109761 also suppressed radiation-induced inflammatory [e.g., interleukin (IL)-6, IL-7R, IL-8] and proangiogenic genes (e.g., ID1) indicating that LY2109761 achieves its antifibrotic effect by suppressing radiation-induced proinflammatory, proangiogenic, and profibrotic signals. Conclusion: Small-molecule inhibitors of the TGF-β receptor I kinase may offer a promising approach to treat or attenuate radiation-induced lung toxicity or other diseases associated with fibrosis. Clin Cancer Res; 18(13); 3616–27. ©2012 AACR.

Randomized phase II – study evaluating EGFR targeting therapy with Cetuximab in combination with radiotherapy and chemotherapy for patients with locally advanced pancreatic cancer – PARC: study protocol [ISRCTN56652283]

BackgroundPancreatic cancer is the fourth commonest cause of death from cancer in men and women. Advantages in surgical techniques, radiation therapy techniques, chemotherapeutic regimes, and different combined-modality approaches have yielded only a modest impact on the prognosis of patients with pancreatic cancer. Thus there is clearly a need for additional strategies. One approach involves using the identification of a number of molecular targets that may be responsible for the resistance of cancer cells to radiation or to other cytotoxic agents. As such, these molecular determinants may serve as targets for augmentation of the radiotherapy or chemotherapy response. Of these, the epidermal growth factor receptor (EGFR) has been a molecular target of considerable interest and investigation, and there has been a tremendous surge of interest in pursuing targeted therapy of cancers via inhibition of the EGFR.Methods/designThe PARC study is designed as an open, controlled, prospective, randomized phase II trial. Patients in study arm A will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine infusions weekly over 4 weeks. Patients in study arm B will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine weekly over 4 weeks and cetuximab infusions over 12 weeks. A total of 66 patients with locally advanced adenocarcinoma of the pancreas will be enrolled. An interim analysis for patient safety reasons will be done one year after start of recruitment. Evaluation of the primary endpoint will be performed two years after the last patients enrolment.DiscussionThe primary objective of this study is to evaluate the feasibility and the toxicity profile of trimodal therapy in pancreatic adenocarcinoma with chemoradiation therapy with gemcitabine and intensity modulated radiation therapy (IMRT) and EGFR-targeted therapy using cetuximab and to compare between two different methods of cetuximab treatment schedules (concomitant versus concomitant and sequential cetuximab treatment).Secondary objectives are to determine the role and the mechanism of cetuximab in patients chemoradiation regimen, the response rate, the potential of this combined modality treatment to concert locally advanced lesions to potentially resectable lesions, the time to progression interval and the quality of life.

IMRT reirradiation with concurrent cetuximab immunotherapy in recurrent head and neck cancer.

AbstractPurpose:In this retrospective investigation, the outcome and toxicity after reirradiation with concurrent cetuximab immunotherapynof recurrent head and neck cancer (HNC) in patients who had contraindications to platinum-based chemotherapy werenanalyzed.Materials and Methods:Ten patients with locally advanced recurrent HNC were retrospectively evaluated. In 9 cases, histologynwas squamous cell carcinoma, in one case adenoid cystic carcinoma. External beam radiotherapy was part of the initial treatmentnin all cases. Reirradiation was carried out using step-and-shoot intensity-modulated radiotherapy (IMRT) with a median dose ofn50.4 Gy. Cetuximab was applied as loading dose (400 mg/m2) 1 week prior to reirradiation and then weekly concurrently withnradiotherapy (250 mg/m2).Results:The median overall survival time after initiation of reirradiation was 7 months; the 1-year overall survival (OS) rate wasn40%. Local failure was found in 3 patients, resulting in a 1-year local control (LC) rate of 61%. The 1-year locoregional controln(LRC) rate was 44%, while the 1-year distant metastasis-free survival (DMFS) was 75%. Acute hematological toxicity was not observednin the group. Severe acute toxicity included one fatal infield arterial bleeding and one flap necrosis. Severe late toxicitiesnwere noted in 2 patients: fibrosis of the temporomandibular joint in 1 patient and stenosis of the cervical esophagus in another.Conclusions:IMRT reirradiation with concurrent cetuximab immunotherapy in recurrent HNC is feasible with acceptable acutentoxicity. Further investigations are necessary to determine the clinical role of this therapy concept.ZusammenfassungZiel:In dieser Untersuchung analysierten wir Behandlungsergebnis und Toxizität nach kombinierter Re-Bestrahlung mit simultanernCetuximab-Immuntherapie von rezidivierten HNO-Tumoren bei Patienten mit Kontraindikation gegen platinhaltige Chemotherapie.Patientengut und Methode:10 Patienten mit lokal fortgeschrittenen rezidivierten HNO-Tumoren wurden retrospektiv ausgewertet.nIn 9 Fällen lag histologisch ein Plattenepithelkarzinom, in einem Fall ein adenoidzystisches Karzinom vor. In jedem Fallnwar eine Strahlentherapie Teil des initialen Behandlungskonzeptes. Die Re-Bestrahlung wurde mittels Step-and-shoot-IMRT mitneiner medianen Dosis von 50,4 Gy durchgeführt. Cetuximab wurde als „Loading Dose“ (400 mg/m2) eine Woche vor Re-Bestrahlungnund danach wöchentlich simultan zur Bestrahlung (250 mg/m2) verabreicht.Ergebnisse:Das mediane Gesamtüberleben nach Re-Bestrahlung war 7 Monate; das 1-Jahres-Gesamtüberleben betrug 40%. EinnLokalrezidiv trat bei 3 Patienten auf, was zu einer 1-Jahres-Lokalkontrolle von 61% führte. Die 1-Jahres-lokoregionäre Kontrollenbetrug 44%. Das 1-Jahres-Metastasen-freie Überleben war 75% (siehe Abbildungen 1–4). Eine akute hämatologische Toxizitätnwurde in diesem Kollektiv nicht gesehen. Schwere Akuttoxizitäten waren eine fatale arterielle Blutung und eine Flap-Nekrose. Alsnschwere Spättoxizität trat eine Fibrose der Pterygiodmuskulatur bzw. des Kiefergelenks sowie eine zervikale Ösophagusstenosenauf (vgl. Tabellen 2 u. 3).Schlussfolgerungen:Bei rezidivierten HNO-Tumoren ist eine IMRT-Re-Bestrahlung mit 50 Gy und simultaner Cetuximab-nImmuntherapie mit einer akzeptablen Toxizität durchführbar. Es sind weitere Untersuchungen nötig, um den Stellenwert diesernTherapieform zu überprüfen.

Intensity modulated radiotherapy (IMRT) in benign giant cell tumors – a single institution case series and a short review of the literature

BackgroundGiant cell tumors are rare neoplasms, representing less than 5% of all bone tumors. The vast majority of giant cell tumors occurs in extremity sites and is treated by surgery alone. However, a small percentage occurs in pelvis, spine or skull bones, where complete resection is challenging. Radiation therapy seems to be an option in these patients, despite the lack of a generally accepted dose or fractionation concept. Here we present a series of five cases treated with high dose IMRT.Patients and MethodsFrom 2000 and 2006 a total of five patients with histologically proven benign giant cell tumors have been treated with IMRT in our institution. Two patients were male, three female, and median age was 30 years (range 20 -- 60). The tumor was located in the sacral region in four and in the sphenoid sinus in one patient. All patients had measurable gross disease prior to radiotherapy with a median size of 9 cm. All patients were treated with IMRT to a median total dose of 64 Gy (range 57.6 Gy to 66 Gy) in conventional fractionation.ResultsMedian follow up was 46 months ranging from 30 to 107 months. Overall survival was 100%. One patient developed local disease progression three months after radiotherapy and needed extensive surgical salvage. The remaining four patients have been locally controlled, resulting in a local control rate of 80%. We found no substantial tumor shrinkage after radiotherapy but in two patients morphological signs of extensive tumor necrosis were present on MRI scans. Decline of pain and/or neurological symptoms were seen in all four locally controlled patients. The patient who needed surgical salvage showed markedly reduced pain but developed functional deficits of bladder, rectum and lower extremity due to surgery. No severe acute or late toxicities attributable to radiation therapy were observed so far.ConclusionIMRT is a feasible option in giant cells tumors not amendable to complete surgical removal. In our case series local control was achieved in four out of five patients with marked symptom relief in the majority of cases. No severe toxicity was observed.

Correlation of Patient-Related Factors and Dose- Volume Histogram Parameters with the Onset of Radiation Pneumonitis in Patients with Small Cell Lung Cancer

Purpose:To analyze the association of patient- and treatment-related factors with the onset of radiation pneumonitis in a homogeneously treated cohort of patients suffering from small cell lung cancer (SCLC).Patients and Methods:242 patients with SCLC staged as limited disease, who had been treated with chemotherapy and three-dimensional conformal radiotherapy, were retrospectively analyzed. Pneumonitis was defined by typical symptoms and radiographic findings and judged clinically relevant, if drug administration and hospitalization were necessary. Patient- (age, gender, smoking history, performance status, tumor localization, benign lung disease) and treatment-related parameters (V10–V40, mean lung dose [MLD]) were analyzed using χ2-tests for categorical parameters and logistic regression for continuous variables.Results:33 patients (13.6%) developed a clinically relevant pneumonitis, of whom three patients died. All cases of pneumonitis developed within 120 days. None of the patient-related parameters correlated significantly with the onset of pneumonitis. Considering treatment-related parameters, a significant correlation of V30 in regard to total lung and V40 in regard to ipsilateral, contralateral and total lung to the risk of pneumonitis was found. So, the estimated risk of a clinically relevant pneumonitis increased from 10% given a V30 of 13% to 30% given a V30 of 35%. In contrast, no significant correlation was found for V10 and V20 and only a trend for MLD.Conclusion:In this series, high-dose radiation volume parameters, i.e., V30 and especially V40, were identified as the most important factors for the development of radiation pneumonitis. Low-dose radiation volume parameters and clinical parameters played an inferior role in predicting the pneumonitis risk.ZusammenfassungZiel:Überprüfung der Assoziation von patienten- und therapiebezogenen Faktoren mit dem Auftreten einer radiogenen Pneumonitis in einem homogen behandelten Patientenkollektiv mit kleinzelligem Bronchialkarzinom (SCLC).Patienten und Methodik:242 Patienten mit SCLC im Stadium „limited disease“, welche mittels Chemotherapie und dreidimensionaler konformaler Radiotherapie behandelt waren, wurden retrospektiv analysiert. Pneumonitis wurde durch das Auftreten typischer Symptome und radiologischer Befunde definiert und als klinisch relevant eingestuft, wenn medikamentöse Behandlung und Klinikeinweisung nötig waren. Patienten- (Alter, Geschlecht, Rauchanamnese, Allgemeinzustand, Tumorlokalisation, gutartige Lungenerkrankung) und behandlungsbezogene Parameter (V10–V40, mittlere Lungendosis [MLD]) wurden mittels χ2-Tests für kategoriale Parameter und logistischer Regression für kontinuierliche Parameter analysiert.Ergebnisse:33 Patienten (13,6%) entwickelten eine klinisch relevante Pneumonitis, drei Patienten starben. Alle Pneumonitisfälle traten innerhalb von 120 Tagen auf. Für keinen der patientenbezogenen Parameter fand sich eine signifikante Korrelation mit dem Auftreten einer Pneumonitis. Hinsichtlich der behandlungsbezogenen Parameter zeigte sich eine signifikante Korrelation der V30 (gesamte Lunge) sowie der V40 (ipsilaterale, kontralaterale oder gesamte Lunge) mit dem Pneumonitisrisiko. So erhöhte sich das geschätzte Risiko einer klinisch relevanten Pneumonitis von 10% bei einer V30 von 13% auf 30% bei einer V30 von 35%. Im Gegensatz hierzu fanden sich keine signifikanten Korrelationen für V10 und V20 und nur ein Trend für die MLD.Schlussfolgerung:Hochdosis-Volumen-Parameter, d.h. V30 und besonders V40, konnten in dieser Serie als wichtigste Faktoren bezüglich der Entwicklung einer radiogenen Pneumonitis identifiziert werden. Niedrigdosis-Volumen-Parameter und klinische Parameter spielten eine untergeordnete Rolle bei der Vorhersage des Pneumonitisrisikos.

Treatment of non-small cell lung cancer with intensity-modulated radiation therapy in combination with cetuximab: the NEAR protocol (NCT00115518)

BackgroundEven today, treatment of Stage III NSCLC still poses a serious challenge. So far, surgical resection is the treatment of choice. Patients whose tumour is not resectable or who are unfit to undergo surgery are usually referred to a combined radio-chemotherapy. However, combined radio-chemotherapeutic treatment is also associated with sometimes marked side effects but has been shown to be more efficient than radiation therapy alone.Nevertheless, there is a significant subset of patients whose overall condition does not permit administration of chemotherapy in a combined-modality treatment.It could be demonstrated though, that NSCLCs often exhibit over-expression of EGF-receptors hence providing an excellent target for the monoclonal EGFR-antagonist cetuximab (Erbitux®) which has already been shown to be effective in colorectal as well as head-and-neck tumours with comparatively mild side-effects.Methods/designThe NEAR trial is a prospective phase II feasibility study combining a monoclonal EGF-receptor antibody with loco-regional irradiation in patients with stage III NSCLC. This trial aims at testing the combinations efficacy and rate of development of distant metastases with an accrual of 30 patients.Patients receive weekly infusions of cetuximab (Erbitux®) plus loco-regional radiation therapy as intensity-modulated radiation therapy. After conclusion of radiation treatment patients continue to receive weekly cetuximab for 13 more cycles.DiscussionThe primary objective of the NEAR trial is to evaluate toxicities and feasibility of the combined treatment with cetuximab (Erbitux®) and IMRT loco-regional irradiation.Secondary objectives are remission rates, 3-year-survival and local/systemic progression-free survival.

Palliative total skin electron beam therapy (TSEBT) for advanced cutaneous T-cell lymphoma

Our aim was to analyze the effectiveness of palliative total skin electron beam therapy (TSEBT) in the management of advanced cutaneous T-cell non-Hodgkins lymphoma (CTCL). Eighteen patients (median age 59 years) with advanced and therapy-refractory CTCL in stages IIB-IV were treated with TSEBT for the first time. The most common histological subtype was Mycosis fungoides (72%). All patients suffered from lymphoma-associated symptoms. Median daily fractions of 1 Gy were administered up to a median total dose of 25 Gy. The median follow-up period was 11 months. Nine patients (50%) achieved a complete response and seven patients (39%) had a limited response. The actuarial one-year progression-free survival was 24%. Four patients (22%) had continuing remission over a median period of six months. Lymphoma associated symptoms were improved in 16 patients (89%). The median overall survival after receiving TSEBT was 12 months, resulting in an actuarial one-year overall survival of 48%. Treatment related acute effects (grade 1 or 2) were observed in all patients during radiation therapy. Transient grade 3 epitheliolyses developed in five patients (28%), late skin effects (grade 1 and 2) in 16 patients (89%), and hypohidrosis was seen in six patients (33%). We conclude that TSEBT is a very efficient and tolerable palliative treatment for patients with advanced CTCL.