Stephan Bodis

Effect of VEGF receptor inhibitor PTK787/ZK222548 combined with ionizing radiation on endothelial cells and tumour growth

The vascular endothelial growth factor (VEGF) receptor is a major target for anti-angiogenesis-based cancer treatment. Here we report the treatment effect of ionizing radiation in combination with the novel orally bioavailable VEGF receptor tyrosine kinase inhibitor PTK787/ZK222584 on endothelial cell proliferation in vitro and with tumour xenografts in vivo. Combined treatment of human umbilical vein endothelial cells with increasing doses of PTK787/ZK222584 and ionizing radiation abrogated VEGF-dependent proliferation in a dose-dependent way, but inhibition of endothelial cell proliferation was not due to apoptosis induction. In vivo, a combined treatment regimen of PTK787/ZK222584 (4 × 100 mg/kg) during 4 consecutive days in combination with ionizing radiation (4 × 3 Gy) exerted a substantial tumour growth delay for radiation-resistant p53-disfunctional tumour xenografts derived from SW480 colon adenocarcinoma cells while each treatment modality alone had only a minimal effect on tumour size and neovascularization. SW480 tumours from animals that received a combined treatment regimen, displayed not only an extended tumour growth delay but also a significant decrease in the number of microvessels in the tumour xenograft. These results support the model of a cooperative antitumoural effect of angiogenesis inhibitor and irradiation and show that the orally bioavailable VEGF receptor tyrosine kinase inhibitor PTK787/ZK222584 is suitable for combination therapy with irradiation.

Clinical presentation and outcome in lymphocyte-predominant Hodgkin's disease

PURPOSE The patterns of presentation, histologic pattern (nodular or diffuse), treatment, and long-term outcome were studied in patients with lymphocyte-predominant (LP) Hodgkins disease (HD) to determine whether these patients should be treated differently than patients with other subtypes of HD. PATIENTS AND METHODS Pathology was reviewed for 97 patients with an initial diagnosis of LPHD made between 1970 and 1993. Seventy-five patients had LPHD on review: 55 had nodular LPHD, 14 had diffuse LPHD, and six had LP histology without subclassification. There were 60 males (80%) and 15 females (20%). Sixty-six patients (88%), presented with clinical stage (CS) I or II disease. Seventy-one patients were treated at the Joint Center for Radiation Therapy (JCRT) and were considered for analysis of treatment outcome. Sixty-one of these 71 were treated with radiation (RT) alone; 17 received mantle RT alone, 27 mantle and paraaortic RT, and seven total-nodal irradiation (TNI). Ten patients with subdiaphragmatic HD received pelvic and paraaortic RT. Of the 10 remaining patients, four were treated with RT and chemotherapy (CT) and six were treated with CT alone. The median follow-up time was 10.8 years. RESULTS The 10-year actuarial freedom-from-first-relapse (FFR) and 10-year overall survival rates for the 71 patients with LPHD treated at the JCRT were 80% and 93%, respectively. The 10-year actuarial FFR by nodular (n = 51), diffuse (n = 14), and unspecified (n = 6) histologic pattern was 74%, 100%, and 60%, respectively. Overall, 14 of 71 patients have relapsed: nine of 61 with stage IA, IB, or IIA disease and five of 10 with stage IIB to IVB disease have relapsed. The median time to relapse was 53 months. Nine of 71 patients have died. Only one death has been from HD: five patients died of second cancers, two of cardiac disease, and one of alcoholic liver cirrhosis. Of seven patients with second malignancies, five died. None of the second malignancies were non-Hodgkins lymphoma (NHL). CONCLUSION Patients with LPHD have different patterns of presentation, sex and age distribution, and likelihood of occult abdominal disease than patients with nodular-sclerosing (NS) or mixed-cellularity (MC) disease. The median time to relapse for LP patients was later than reported for other histologic subtypes; however, there was no pattern of continuous late relapse. With pathologic staging and standard treatment, mortality from LPHD is low; nearly all deaths have been cardiac- or second tumor-related. This suggests that less aggressive treatment for LPHD might continue to yield excellent results, while perhaps lowering the long-term risk of complications.

Radiation Therapy Infrastructure and Human Resources in Low- and Middle-Income Countries: Present Status and Projections for 2020

PURPOSE Radiation therapy, a key component of cancer management, is required in more than half of new cancer patients, particularly in low- and middle-income countries (LMICs). The projected rise in cancer incidence over the next decades in LMICs will result in an increasing demand for radiation therapy services. Considering the present cancer incidence and that projected for 2020 (as listed in GLOBOCAN), we evaluated the current and anticipated needs for radiation therapy infrastructure and staffing by 2020 for each of the LMICs. METHODS AND MATERIALS Based on World Bank classification, 139 countries fall in the category of LMICs. Details of teletherapy, radiation oncologists, medical physicists, and radiation therapy technologists were available for 84 LMICs from the International Atomic Energy Agency-Directory of Radiotherapy Centres (IAEA-DIRAC) database. Present requirements and those for 2020 were estimated according to recommendations from the IAEA and European Society for Radiotherapy & Oncology (ESTRO-QUARTS). RESULTS Only 4 of the 139 LMICs have the requisite number of teletherapy units, and 55 (39.5%) have no radiation therapy facilities at present. Patient access to radiation therapy in the remaining 80 LMICs ranges from 2.3% to 98.8% (median: 36.7%). By 2020, these 84 LMICs would additionally need 9169 teletherapy units, 12,149 radiation oncologists, 9915 medical physicists, and 29,140 radiation therapy technologists. Moreover, de novo radiation therapy facilities would have to be considered for those with no services. CONCLUSIONS Twelve pragmatic steps are proposed for consideration at national and international levels to narrow the gap in radiation therapy access. Multipronged and coordinated action from all national and international stakeholders is required to develop realistic strategies to curb this impending global crisis.

Postoperative Proton Radiotherapy for Localized and Locoregional Breast Cancer: Potential for Clinically Relevant Improvements?

PURPOSE To study the potential reduction of dose to organs at risk (OARs) with intensity-modulated proton radiotherapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) photon radiotherapy for left-sided breast cancer patients. METHODS AND MATERIALS Comparative treatment-planning was performed using planning computed tomography scans of 20 left-sided breast cancer patients. For each patient, three increasingly complex locoregional volumes (planning target volumes [PTVs]) were defined: whole breast (WB) or chest wall (CW) = (PTV1), WB/CW plus medial-supraclavicular (MSC), lateral-supraclavicular (LSC), and level III axillary (AxIII) nodes = (PTV2) and WB/CW+MSC+LSC+AxIII plus internal mammary chain = (PTV3). For each patient, 3D-CRT, IMRT, and IMPT plans were optimized for PTV coverage. Dose to OARs was compared while maintaining target coverage. RESULTS All the techniques met the required PTV coverage except the 3D-CRT plans for PTV3-scenario. All 3D-CRT plans for PTV3 exceeded left-lung V20. IMPT vs. 3D-CRT: significant dose reductions were observed for all OARs using IMPT for all PTVs. IMPT vs. IMRT: For PTV2 and PTV3, low (V5) left lung and cardiac doses were reduced by a factor >2.5, and cardiac doses (V22.5) were by a factor of >20 lower with IMPT compared with IMRT. CONCLUSIONS When complex-target irradiation is needed, 3D-CRT often compromises the target coverage and increases the dose to OARs; IMRT can provide better results but will increase the integral dose. The benefit of IMPT is based on improved target coverage and reduction of low doses to OARs, potentially reducing the risk of late-toxicity. These results indicate a potential role of proton-radiotherapy for extended locoregional irradiation in left breast cancer.

Degradation of PKB/Akt protein by inhibition of the VEGF receptor/mTOR pathway in endothelial cells.

An intact VEGF receptor/PI3K/PKB/Akt signaling cascade protects endothelial cells from apoptotic stress-stimuli and mediates the formation of new blood vessels in pathological conditions such as cancer. Therefore, downregulation of this signaling cascade is of clinical interest for antiangiogenic cancer therapy. In this report, we demonstrate that VEGF controls the protein stability of the serine–threonine kinase PKB/Akt via inhibition of PKB/Akt protein degradation. VEGF deprivation or blockage of the VEGF signal transduction cascade with the VEGF receptor tyrosine kinase inhibitor PTK787/ZK222584 resulted in a specific decrease of the PKB/Akt protein level and subsequent cellular restimulation with VEGF rescued its stability. Real-time quantitative RT–PCR analysis demonstrated that VEGF does not regulate PKB/Akt gene expression. On the other hand, broad range inhibitors of caspases and the proteasome complex prevented VEGF-dependent downregulation of the PKB/Akt protein level indicating that PKB/Akt protein stability is regulated by VEGF-controlled proteolysis. Inhibition of the VEGF receptor and PKB/Akt-downstream PIK-related mTOR-kinase by rapamycin also neutralized the VEGF-protective effect in an PKB/Akt gene expression-independent way but results in proteolysis-dependent reduction of PKB/Akt protein stability. These results demonstrate a novel regulatory mechanism of the activated VEGF receptor/mTOR-signal transduction pathway to control the protein stability of PKB/Akt and survival threshold in endothelial cells.

Multicenter phase II trial of preoperative induction chemotherapy followed by chemoradiation with docetaxel and cisplatin for locally advanced esophageal carcinoma (SAKK 75/02)

BACKGROUND This multicenter phase II study investigated the efficacy and feasibility of preoperative induction chemotherapy followed by chemoradiation and surgery in patients with esophageal carcinoma. PATIENTS AND METHODS Patients with locally advanced resectable squamous cell carcinoma or adenocarcinoma of the esophagus received induction chemotherapy with cisplatin 75 mg/m(2) and docetaxel (Taxotere) 75 mg/m(2) on days 1 and 22, followed by radiotherapy of 45 Gy (25 x 1.8 Gy) and concurrent chemotherapy comprising cisplatin 25 mg/m(2) and docetaxel 20 mg/m(2) weekly for 5 weeks, followed by surgery. RESULTS Sixty-six patients were enrolled at eleven centers and 57 underwent surgery. R0 resection was achieved in 52 patients. Fifteen patients showed complete, 16 patients nearly complete and 26 patients poor pathological remission. Median overall survival was 36.5 months and median event-free survival was 22.8 months. Squamous cell carcinoma and good pathologically documented response were associated with longer survival. Eighty-two percent of all included patients completed neoadjuvant therapy and survived for 30 days after surgery. Dysphagia and mucositis grade 3/4 were infrequent (<9%) during chemoradiation. Five patients (9%) died due to surgical complications. CONCLUSIONS This neoadjuvant, taxane-containing regimen was efficacious and feasible in patients with locally advanced esophageal cancer in a multicenter, community-based setting and represents a suitable backbone for further investigation.

Hyperthermia-related clinical trials on cancer treatment within the ClinicalTrials.gov registry.

Abstract Purpose: Hyperthermia has been shown to improve the effectiveness of chemotherapy and radiotherapy in the treatment of cancer. This paper summarises all recent clinical trials registered in the ClinicalTrials.gov registry. Materials and methods: The records of 175,538 clinical trials registered at ClinicalTrials.gov were downloaded on 29 September 2014 and a database was established. We searched this database for hyperthermia or equivalent words. Results: A total of 109 trials were identified in which hyperthermia was part of the treatment regimen. Of these, 49 trials (45%) had hyperthermic intraperitoneal chemotherapy after cytoreductive surgery (HIPEC) as the primary intervention, and 14 other trials (13%) were also testing some form of intraperitoneal hyperthermic chemoperfusion. Seven trials (6%) were testing perfusion attempts to other locations (thoracic/pleural n = 4, limb n = 2, hepatic n = 1). Sixteen trials (15%) were testing regional hyperthermia, 13 trials (12%) whole body hyperthermia, seven trials (6%) superficial hyperthermia and two trials (2%) interstitial hyperthermia. One remaining trial tested laser hyperthermia. Conclusions: In contrast to the general opinion, this analysis shows continuous interest and ongoing clinical research in the field of hyperthermia. Interestingly, the majority of trials focused on some form of intraperitoneal hyperthermic chemoperfusion. Despite the high number of active clinical studies, HIPEC is a topic with limited attention at the annual meetings of the European Society for Hyperthermic Oncology and the Society of Thermal Medicine. The registration of on-going clinical trials is of paramount importance for the achievement of a comprehensive overview of available clinical research activities involving hyperthermia.

Effect of high dose per pulse flattening filter-free beams on cancer cell survival.

PURPOSE To investigate if there is a statistically significant difference in cancer cell survival using a high dose per pulse flattening filter-free (FFF) beam compared to a standard flattened beam. MATERIAL AND METHODS To validate the radiobiological effect of the flattened and FFF beam, two glioblastoma cell lines were treated with either 5 or 10 Gy using different dose rates. Dose verification was performed and colony formation assays were carried out. To compare the predictability of our data, radiobiological models were included. RESULTS The results presented here demonstrate that irradiation of glioblastoma cell lines using the FFF beam is more efficient in reducing clonogenic cell survival than the standard flattened beam, an effect which becomes more significant the higher the single dose. Interestingly, in our experimental setting, the radiobiological effect of the FFF beam is dependent on dose per pulse rather than on delivery time. The used radiobiological models are able to describe the observed dose rate dependency between 6 and 24 Gy/min. CONCLUSION The results presented here show that dose per pulse might become a crucial factor which influences cancer cell survival. Using high dose rates, currently used radiobiological models as well as molecular mechanisms involved urgently need to be re-examined.

Acute Toxicity and Quality of Life After Dose-Intensified Salvage Radiation Therapy for Biochemically Recurrent Prostate Cancer After Prostatectomy: First Results of the Randomized Trial SAKK 09/10

PURPOSE Patients with biochemical failure (BF) after radical prostatectomy may benefit from dose-intensified salvage radiation therapy (SRT) of the prostate bed. We performed a randomized phase III trial assessing dose intensification. PATIENTS AND METHODS Patients with BF but without evidence of macroscopic disease were randomly assigned to either 64 or 70 Gy. Three-dimensional conformal radiation therapy or intensity-modulated radiation therapy/rotational techniques were used. The primary end point was freedom from BF. Secondary end points were acute toxicity according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0) and quality of life (QoL) according to the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and PR25. RESULTS Three hundred fifty patients were enrolled between February 2011 and April 2014. Three patients withdrew informed consent, and three patients were not eligible, resulting in 344 patients age 48 to 75 years in the safety population. Thirty patients (8.7%) had grade 2 and two patients (0.6%) had grade 3 genitourinary (GU) baseline symptoms. Acute grade 2 and 3 GU toxicity was observed in 22 patients (13.0%) and one patient (0.6%), respectively, with 64 Gy and in 29 patients (16.6%) and three patients (1.7%), respectively, with 70 Gy (P = .2). Baseline grade 2 GI toxicity was observed in one patient (0.6%). Acute grade 2 and 3 GI toxicity was observed in 27 patients (16.0%) and one patient (0.6%), respectively, with 64 Gy, and in 27 patients (15.4%) and four patients (2.3%), respectively, with 70 Gy (P = .8). Changes in early QoL were minor. Patients receiving 70 Gy reported a more pronounced and clinically relevant worsening in urinary symptoms (mean difference in change score between arms, 3.6; P = .02). CONCLUSION Dose-intensified SRT was associated with low rates of acute grade 2 and 3 GU and GI toxicity. The impact of dose-intensified SRT on QoL was minor, except for a significantly greater worsening in urinary symptoms.

Differential Activation of the Phosphatidylinositol 3′-Kinase/Akt Survival Pathway by Ionizing Radiation in Tumor and Primary Endothelial Cells

Ionizing radiation induces an intracellular stress response via activation of the phosphatidylinositol 3′-kinase (PI3K)/Akt survival pathway. In tumor cells, the PI3K/Akt pathway is induced through activation of members of ErbB receptor tyrosine kinases. Here, we investigated the receptor dependence of radiation-induced PI3K/Akt activation in tumor cells and in endothelial cells. The integrity of both the ErbB and the vascular endothelial growth factor (VEGF) ligand-activated PI3K/Akt pathway in endothelial cells was demonstrated using specific ErbB and VEGF receptor tyrosine kinase inhibitors. Irradiation of endothelial cells resulted in protein kinase B (PKB)/Akt activation in a similar time course as observed in response to VEGF. More importantly, radiation-induced PKB/Akt phosphorylation in endothelial cells was strongly down-regulated by the VEGF receptor tyrosine kinase inhibitor, whereas the ErbB receptor tyrosine kinase inhibitor did not affect PKB/Akt stimulation in response to irradiation. An opposite receptor dependence for radiation-induced PKB/Akt phosphorylation was observed in ErbB receptor-overexpressing A431 tumor cells. Furthermore, direct VEGF receptor phosphorylation was detected after irradiation in endothelial cells in absence of VEGF, which was almost completely inhibited after irradiation in presence of the VEGF receptor tyrosine kinase inhibitor. These data demonstrate that ionizing radiation induces VEGF ligand-independent but VEGF receptor-dependent PKB/Akt activation in endothelial cells and that PI3K/Akt pathway activation by radiation occurs in a differential cell type and receptor-dependent pattern.