Measures of infection prevention and incidence of SARS-CoV-2 infections in cancer patients undergoing radiotherapy in Germany, Austria and Switzerland

Purpose

COVID-19 infection has manifested as a major threat to both patients and healthcare providers around the world. Radiation oncology institutions (ROI) deliver a major component of cancer treatment, with protocols that might span over several weeks, with the result of increasing susceptibility to COVID-19 infection and presenting with a more severe clinical course when compared with the general population. The aim of this manuscript is to investigate the impact of ROI protocols and performance on daily practice in the high-risk cancer patients during this pandemic.

Methods

We addressed the incidence of positive COVID-19 cases in both patients and health care workers (HCW), in addition to the protective measures adopted in ROIs in Germany, Austria and Switzerland using a specific questionnaire.

Results

The results of the questionnaire showed that a noteworthy number of ROIs were able to complete treatment in SARS-CoV‑2 positive cancer patients, with only a short interruption. The ROIs reported a significant decrease in patient volume that was not impacted by the circumambient disease incidence, the type of ROI or the occurrence of positive cases. Of the ROIs 16.5% also reported infected HCWs. About half of the ROIs (50.5%) adopted a screening program for patients whereas only 23.3% also screened their HCWs. The range of protective measures included the creation of working groups, instituting home office work and protection with face masks.

Regarding the therapeutic options offered, curative procedures were performed with either unchanged or moderately decreased schedules, whereas palliative or benign radiotherapy procedures were more often shortened. Most ROIs postponed or cancelled radiation treatment for benign indications (88.1%). The occurrence of SARS-CoV‑2 infections did not affect the treatment options for curative procedures. Non-university-based ROIs seemed to be more willing to change their treatment options for curative and palliative cases than university-based ROIs.

Conclusion

Most ROIs reported a deep impact of SARS-CoV‑2 infections on their work routine. Modification and prioritization of treatment regimens and the application of protective measures preserved a well-functioning radiation oncology service and patient care.

Electronic supplementary material

The online version of this article (10.1007/s00066-020-01681-1) contains supplementary material, which is available to authorized users.

Face masks: benefits and risks during the COVID-19 crisis

Background

The German government has made it mandatory to wear respiratory masks covering mouth and nose (MNC) as an effective strategy to fight SARS-CoV-2 infections. In many countries, this directive has been extended on shopping malls or public transportation. The aim of this paper is to critically analyze the statutory regulation to wear protective masks during the COVID-19 crisis from a medical standpoint.

Methods

We performed an extensive query of the most recent publications addressing the prevention of viral infections including the use of face masks in the community as a method to prevent the spread of the infection. We addressed the issues of practicability, professional use, and acceptability based on the community and the environment where the user resided.

Results

Upon our critical review of the available literature, we found only weak evidence for wearing a face mask as an efficient hygienic tool to prevent the spread of a viral infection. However, the use of MNC seems to be linked to relevant protection during close contact scenarios by limiting pathogen-containing aerosol and liquid droplet dissemination. Importantly, we found evidence for significant respiratory compromise in patients with severe obstructive pulmonary disease, secondary to the development of hypercapnia. This could also happen in patients with lung infections, with or without SARS-CoV-2.

Conclusion

Epidemiologists currently emphasize that wearing MNC will effectively interrupt airborne infections in the community. The government and the politicians have followed these recommendations and used them to both advise and, in some cases, mandate the general population to wear MNC in public locations. Overall, the results seem to suggest that there are some clinically relevant scenarios where the use of MNC necessitates more defined recommendations. Our critical evaluation of the literature both highlights the protective effects of certain types of face masks in defined risk groups, and emphasizes their potential risks.

The history and value of face masks

In the human population, social contacts are a key for transmission of bacteria and viruses. The use of face masks seems to be critical to prevent the transmission of SARS-CoV-2 for the period, in which therapeutic interventions are lacking. In this review, we describe the history of masks from the middle age to modern times.

The role of passive immunization in the age of SARS-CoV-2: an update

The rapid spread of the corona virus pandemic is an existential problem for many people in numerous countries. So far, there is no effective vaccine protection or proven therapy available against the SARS-CoV-2 virus. In this review, we describe the role of passive immunization in times of the corona virus. Passive immunization could be a bridging technology to improve the immune defense of critically ill patients until better approaches with effective medications are available.

Breast Cancer Recurrence Risk Assessment: Is Non-Invasive Monitoring an Option?

BACKGROUND

Metastatic breast cancer (MBC) represents a life-threatening disease with a median survival time of 18-24 months that often can only be treated palliatively. The majority of women suffering from MBC are those who had been previously diagnosed with locally advanced disease and subsequently experienced cancer recurrence in the form of metastasis. However, according to guidelines, no systemic follow-up for monitoring purposes is recommended for these women. The purpose of this article is to review current methods of recurrent risk assessment as well as non-invasive monitoring options for women at risk for distant disease relapse and metastasis formation.

METHODS

We used PubMed and national guidelines, such as the National Comprehensive Cancer Network (NCCN), to find recently published studies on breast cancer recurrence risk assessment and systemic monitoring of breast cancer patients through non-invasive means.

RESULTS

The options for recurrence risk assessment of locally invasive breast cancer has improved due to diverse genetic tests, such as Oncotype DX, MammaPrint, the PAM50 (now known as the "Prosigna Test") assay, EndoPredict (EP), and the Breast Cancer Index (BCI), which evaluate a women's risk of relapse according to certain cancer-gene expression patterns. Different promising non-invasive urinary protein-based biomarkers with metastasis surveillance potential that have been identified are MMP-2, MMP-9, NGAL, and ADAM12. In particular, ααCTX, ββCTX, and NTX could help to monitor bone metastasis.

CONCLUSION

In times of improved recurrence risk assessment of women with breast cancer, non-invasive biomarkers are urgently needed as potential monitoring options for women who have an increased risk of recurrence. Urine as a bioliquid of choice provides several advantages - it is non-invasive, can be obtained easily and frequently, and is economical. Promising biomarkers that could help to follow up women with increased recurrence risk have been identified. In order for them to be implemented in clinical usage and national guideline recommendations, further validation in larger independent cohorts will be needed.

The β 2-Adrenergic Agonist Salbutamol Inhibits Migration, Invasion and Metastasis of the Human Breast Cancer MDA-MB- 231 Cell Line

BACKGROUND

Breast cancer is the most diagnosed and the major cause of cancer death in women worldwide. Metastasis is the main cause of these deaths. The metastatic cascade involves multiple steps and it has been described that adrenergic receptors can modulate this process at multiple levels. However, β -adrenergic action in breast cancer is controversial. We have previously shown that β-adrenergic agonists inhibit cell proliferation and tumor growth of numerous breast cancer models.

OBJECTIVE

The purpose of the present investigation was to evaluate adrenergic effect in parameters related to tumor progression (migration, invasion and metastases) in two human breast cancer cell lines.

METHODS

Migration was assessed in IBH-6 and MDA-MB-231 cells by time-lapse videomicroscopy and modified Boyden chambers. Invasion was evaluated by Transwells coated with Matrigel and expression of pro-metastatic genes was determined by RT-qPCR. Experimental metastases studies were performed by injection of the cells in the tail vein of NSG immuno-deficient mice.

RESULTS

In both cell lines, salbutamol (β2-agonist) and propranolol (β-blocker) significantly diminished cell migration while epinephrine exerted opposite effects. Moreover, salbutamol inhibited invasion of both breast cancer cell lines and enhanced adhesion to extracellular matrix. Salbutamol treatment was also able to decrease the expression of pro-metastatic genes in MDA-MB-231 cells. Finally, this compound decreased the number and size of MDA-MB-231 lung experimental metastases in NSG immuno- deficient mice. No effect on the establishment of IBH-6 metastases was observed.

CONCLUSION

Our results suggest that salbutamol could be an effective adjuvant drug for the treatment of metastatic breast cancer.

Abstract 4863: Quantification of cell fusion events between breast cancer cells and breast epithelial cells

Recent data suggest that cell-cell fusion contributes to the development of hybrid cell clones showing genetic and behavioural alterations. But less is known about forces triggering cell fusion processes between breast cancer cells and tumor surrounding cells. The influence of chronic inflammation and tumor microenvironment is increasingly being recognized as an etiology for cancer progression and cell fusion. However, information on how and which components particularly affect cell-cell fusion and thereby disease outcome remains elusive.

Available facilities to quantitate these cell-cell fusion processes in vitro could provide a novel method to identify cancer promoting components of the stroma. In the present study cell-cell fusion was measured by using a cre/ loxP reporter system. Therefore, two breast cancer cell lines stable transfected with a double fluorescence reporter vector and a breast epithelial cell line containing cre recombinase were generated and cell fusion was promoted by co-culturing cells under appropriate conditions. Regarding the complex nature of tumor milieu the potential influence of several inflammatory and anti-inflammatory cytokines were tested and revealed alterations in fusogenic behaviour of cell lines. Increased fusion activity was observed while adding the proinflammatory cytokine TNFα or epithelial growth factor (EGF). It could also be assumed that hypoxia is a stimulus for cell-cell fusion. In contrast the chemoattractant SDF-1α which is involved in many cancer metastatic mechanisms hadn't any influence. Interestingly, both breast cancer cell lines showed markedly different fusion activity after activation of the transcription factor NfκB.

The present study establishes an efficient tool for quantification of cell-cell fusion processes in vitro by cre mediated recombination of a loxP reporter system. This highlights a new opportunity to identify a potential link between components priming and triggering cell-cell fusion and therefore carcinogenesis.

Citation Format: Marieke Mohr, Kurt Zänker, Thomas Dittmar, Frank Edenhofer. Quantification of cell fusion events between breast cancer cells and breast epithelial cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4863. doi:10.1158/1538-7445.AM2014-4863

Multiplex and functional detection of antigen-specific human T cells by ITRA--indirect T cell recognition assay

The identification and functional characterization of pathogen-specific T cells plays a critical role in immunological research and diagnostics. In addition to the present standard technologies such as intracellular cytokine staining (ICS), enzyme-linked immunospot (ELISPOT) and peptide-major-histocompatibility-complex (MHC) multimer staining, we aimed to develop a multiplex detection assay, which provides fast in vitro functional data for both human CD4 and CD8 T cells with different antigen specificities in one sample. In this study, we have exploited the expression of CD83 on B cells to develop the cell array-based indirect T cell recognition assay (ITRA). In detail, B cells are pulsed with different pathogen peptide pools and fluorescently barcoded. Thereafter the B cells are pooled and co-cultured with autologous T cells. Subsequently each B cell population is analyzed via flow cytometry for CD83 expression, which indicates antigen-specific interaction with CD4 T cells. Moreover, we revealed donor dependent variations of cytotoxic activity of pathogen-specific CD4 T cells and CD8 T cells, evidenced by specific lysis of peptide-pulsed B cells. Taken together, ITRA is a novel antigen presenting cell (APC) array based method to analyze the presence and function of various antigen-specific T cells in one sample. It has the potential to be used in the future for epitope/antigen screening in research and for analysis of anti-tumor, anti-pathogen or autoimmune T cell responses in patient samples.

The selective role of myosin VI in lymphoid leukemia cell migration

Several myosin isotypes are discussed to be involved in the migration of various cells ranging from tumor cells to leukocytes. We investigated the involvement of myosins II and VI in the lymphoid leukemia cells lines Jurkat, NB4, Dohh-2, and Molt-4 by a three-dimensional, collagen-based migration assay. Down-regulation of myosin VI by siRNA significantly reduced the migratory activity of all cells, whereas the pharmacological inhibition of non-muscle myosin II using blebbistatin had only marginal influence. Therefore, in contrast to differentiated leukocytes and cells from solid tumors, myosin VI plays a crucial role in the migration of leukemic cells.

Automation and validation of a rapid method to assess neutrophil and monocyte activation by routine fluorescence flow cytometry in vitro

The aim of the present study was to design an automated-gating hematology fluorescence flow cytometry methodology permitting the assessment of neutrophil and monocyte activation in EDTA-anticoagulated whole blood based on cell granularity, lipid membrane components, cell shape and volume, and total cell nucleic acid (NA) compounds. For particularly monitoring the proper functioning of patients' innate immune system as the first line defense against microbial invaders, the suitable test system should be rapid, simple, reliable by yielding reproducible results. It must be validated against established methods, and it must prove to work in selected clinical settings, e.g. in intensive care unit (ICU) environments. The adaptation of a routine hematology cell analyser utilizing fluorescence flow cytometry resulted in a potentially useful system for all requirements. It proved to detect in real-time and in a reliable and reproducible way the main cellular response reactions of neutrophils and monocytes during externally stimulated immune defense. Validation was successful when comparing it to established methods. The quantified activation effects were dose dependent from the applied activating agents. Cellular response kinetics could be measured and described and showed to be in line with the prevailing cell response models. Upon applying the test method to a healthy population of volunteers and a first cohort of ICU patients with and without evident immune depression, the test revealed excellent cellular responses to external activating cytotoxic stimuli (lipopolysaccharide; LPS) for the control group, slightly weaker response from ICU patients without immune depression and no response from patients with evident immune depression.We conclude that routine hematology fluorescence flow cytometry can accurately and reproducibly measure different activation steps of monocytes and polymorphonuclear neutrophilic granulocytes to defined external stimuli. This may potentially be applied as a STAT (Latin statim = immediately) and routine screening and surveillance method for inflammatory diseases.

MCP-1 induces migration of adult neural stem cells

As a model for brain inflammation we previously studied transcriptional profiles of tumor necrosis factor-alpha (TNF)treated U373 astroglioma cells. In previous work we were able to demonstrate that the chemokine monocyte chemoattractant protein-1 (MCP-1, SCYA2, CCL2, MCAF) expression in U373 cells was inducible by TNF-alpha treatment. Demonstrably MCP-1 mRNA and protein expression in U373 cells was sustainable over time and at the highest level of all genes analyzed (Schwamborn et al., BMC Genomics 4, 46, 2003). In the hematopoietic system MCP-1 is a CC chemokine that attracts monocytes, memory T lymphocytes, and natural killer cells. In search of further functions in brain inflammation we tested the hypothesis that MCP-1 acts as a chemokine on neural stem cells. Here we report that MCP-1 activates the migration capacity of rat-derived neural stem cells. The migration of stem cells in a Boyden chamber analysis was elevated after stimulation with MCP-1. Time-lapse video microscopy visualized the migration of single stem cells from neurospheres in MCP-1-treated cultures, whereas untreated cultures depicted no migration at all, but showed signs of sprouting. Expression of the MCP-1 receptor CCR2 in neurosphere cultures was verified by RT-PCR and immunofluorescence microscopy. Supernatants from TNF-treated U373 cells also induced migration of neural stem cells.

Bispecific multivalent antibody studied by real-time interaction analysis for the development of an antigen-inhibition enzyme-linked immunosorbent assay

A bispecific antibody with specificities for both 7-hydroxycoumarin (7-OHC) and alkaline phosphatase (AP) was produced by chemically cross-linking two parental polyclonal antibodies. Real-time interaction analysis of the bispecific multivalent antibody (bsMAb) was performed using BIAcore, a surface plasmon resonance (SPR)-based biosensor, in order to confirm its bispecific nature. A 7-OHC-BSA conjugate was covalently immobilized to a dextran matrix to serve as the reaction surface and unconjugated bovine serum albumin (BSA) was immobilized on to a separate dextran matrix as a control surface. Immunoaffinity-purified bsMAb, parental anti-7-OHC antibody and AP were injected over both surfaces. The bsMAb was shown to bind both antigens, 7-OHC and AP, simultaneously. Comparison of the ratio of mass bound for bsMAb and AP (5:1) with the ratio of the molecular masses of bsMAb (approximately 300 kDa) and AP (85 kDa) (3.5:1) suggests that most of the bsMAb species possess both specificities. The bsMAb was employed in a one-step antigen-inhibition ELISA for the detection of 7-OHC. The assay was compared with a conventional ELISA approach employing an AP-labelled secondary antibody. The bispecific antibody approach proved to be faster and more sensitive, with a detection limit of 6 ng ml-1 as compared with approximately 50 ng ml-1 for the conventional approach. The assay was used for the quantification of free and total 7-OHC in urine samples from two healthy volunteers who had been administered coumarin. The accuracy and precision of the assay were assessed. The bispecific antibody-based assay gave similar results, accuracy and precision, but proved to be far more sensitive (limit of determination 6 ng ml-1 for total 7-OHC). It is concluded that real-time interaction analysis using BIAcor provides a rapid method for the evaluation of the bsMAb and it was verified that the bispecific product formed by chemical cross-linking of two parental antibodies offers a simple alternative for the development of a highly sensitive ELISA.

[Experiences with therapeutic whole-body hyperthermia]

Therapeutic whole body hyperthermia (WBH) as an additional therapy in the treatment of cancer has been known for a long time and is beginning to attain acceptance. In a clinical study 28 patients were treated 70 times with WBH at a core temperature of 41.8 degrees C. Hyperthermia was induced and maintained with an extracorporal circuit (ECC). Patients were anaesthesized with nitrous oxygen, enflurane and fentanyl. Therefore artificial ventilation was mandatory. Invasive monitoring was used to control vital functions. The effect of WBH includes a rise in cardiac output and heart rate as well as a decrease in total vascular resistance and mean arterial pressure. Pulmonary function almost remains constant. A raised oxygen consumption is compensated by a rise of oxygen availability. In consequence of an augmented perspiratio insensibilis and the ECC, close observation of fluid and electrolyte balance is necessary. According to our experience the small number of complications and problems allows the treatment with WBH even of patients with a high risk of anaesthesia.

Morphology and mitochondrial function of the surviving myocardium following myocardial infarction in the cat

The surviving myocardium of the cat was studied 7 days and 6 weeks following experimental infarction. Seven days after infarction, ultrastructural alterations of the mitochondria indicative of slight hypoxic injury--clearing of the matrix and loss of dense matrix granules--were found. Together with intracellular edema and glycogen depletion this result was considered as a sign of relative hypoxia in the surviving myocardium 7 days after infarction. At the same time beta-glucuronidase activity of tissue homogenates was found to be elevated. Focal ischemic lesions in remote myocardium which have been described by other authors (5, 6, 23) were not detected in our experiments. Six weeks after infarction, the fractional volume occupied by myofibrils had increased whereas the fractional volume of mitochondria had remained unchanged (left ventricle) resp. had decreased (right ventricle). There were no qualitative changes detectable at the ultrastructural level. Based on the morphometric investigation of Anversa (1, 2), our results were regarded indicative of mild compensatory hypertrophy of the surviving myocardium. Glutamate dehydrogenase activity of tissue homogenates was shown to be increased when compared to control values. Furthermore our morphometric results showed that the unit mass of mitochondria has to render an enhanced amount of energy six weeks after infarction which might leave the surviving myocardium with a higher susceptibility to future hypoxic injury.

Morphological, immunocytochemical and biological characteristics of experimental rabbit brain tumors in tissue culture

Brain tumors were induced in 3-month-old rabbits of either sex by repeated intravenous injections of N-methyl-N-nitrosourea. Twelve brain tumors (6 pleomorphic gliomas, 5 grade 2--3 astrocytomas, 1 grade 2--3 oligodendroglioma) were established in culture and, with the exception of 2 neoplasms, were propagated in vitro as permanent cell lines. The glial nature of all cell lines was ascertained at several passage levels by testing the cells for the production of S-100 and GFA. It could be shown that most cells of all lines fluoresced positively for the S-100 protein, albeit differences in intensity of fluorescence were clearly noted between cells of the same culture and between different cultures. In general, astrocytoma cell lines had the strongest fluorescence. Pleomorphic glioma cells but especially astrocytoma cells reacted positively also for the GFA protein. Surprisingly enough, isolated cells of the oligodendroglioma line also showed evidence of GFA production. Exposure of cultures of rabbit glioma cells to db-cAMP for 8--10 hr resulted in inhibition of cell proliferation and stimulation of process formation. Furthermore, positive fluorescence for the S-100 and GFA proteins was more intense in cells treated with db-cAMP than in untreated cells. The latter observation may indicate that production and/or accumulation of glial proteins also was enhanced during the stationary phase of cell cultures.

Selected morphological immunocytochemical and growth characteristics of three experimental rat gliomas and of their cells in vitro

Tumors of the nervous system were induced in Sprague-Dawley and Long-Evans rats by weekly administrations of 6 mg/kg N-methyl-N-nitrosourea in the drinking water. Three of these tumors, a grade 2 mixed glioma, a grade 2 to 3 astrocytoma and a grade 1 to 2 oligodendroglioma, were established in culture and propagated in vitro. The mixed glioma strain (75SD-G-376) and the astrocytoma line (75SD-G-420) were repeatedly subcultured, cloned at passage 90 and 120 and designated as 75SD-G-376C and 75SD-G-420C clone, respectively. The growth rate of the oligodendroglioma cell strain (77LE-G-180) was very low and the cells died off after the 5th in vitro passage. The glial nature of all lines was ascertained by demonstrating the presence of the S-100 protein in the culture cells. 2 1/2 years after the establishment in vitro of the 75SD-G-376 and 75SD-G-420 primary cultures, mass cultures as well as clones derived from them are still producing S-100 and thus are clearly comparable to the primary cultures, at least in this respect. From a morphological standpoint based on light microscopy, cells of clonal lines with relatively few and short processes differ, however, from cells of primary cultures and their uncloned lines. Therefore, the cell morphology of these clones can be viewed upon as a form of adaptation to the in vitro conditions. It can be concluded that permanent cell lines with well-defined properties can be grown from experimental brain gliomas successfully established in culture and maintained in vitro.

[An experimental study on the pathogenesis of the acute pulmonary insufficiency (author's transl)]

Parameters of the lungs as Compliance PaCO2, PaO2, have been measured in connection with experimental, pathophysiological insults like hematoma, bone marrow intravasation and hemorrhage, in rabbits. Concerning the compliance quotient, a statistically proved decrease was found within the groups, which have had a hematoma. Moreover, the histological picture of the lungs from rabbits with a hematom showed perivascular and intersitial edema and considerable atelectases. Serum of animals, which have had a hematom for at least 24 h has been fractionated by gel chromatography; low molecular weight substances of the fractionated serum were injected into healthy recipients. Thereafter, measurement of the centralvenous pressure suggests the appearance of substances, pharmacodynamic similar to 5-Hydroxytryptamin, in blood of rabbits with hematom.

[The influence of methoxyflurane (penthrane) on surface activity of the lung (author's transl)]

Methoxyflurane, at the moment the most potent inhalation anaesthetic, was examined in respect of its surfactant irritating properties in the rabbit. After a five hour anaesthesia with this compound there was, compared with a control group of animals which underwent only mechanical ventilation with room air for the same period, a significant decline of the compliance quotient from 2.99 to 2.55, indicating a relevant impairment of alveolar lining surfactant. A concomitant fall of arterial PaO2 from 84.8 to 71.3 mm Hg showed the resulting deterioration of respiratory function. Postanaesthetic preparations of these lungs examined using the Wilhelmy balance exhibited a significant fall of the stability index from 1.73 to 1.25, though hysteresis remained unaffected. Lung histology showed interstitial edema and patchy atelectasis, features which are found also in the early stages of post-traumatic pulmonary insufficiency. On this basis we recommend that methoxyflurane is not used in patients with impaired surfactant activity as such is found after severe traumatisation, head injury or in special preexisting pulmonary diseases. If this anesthetic is given to healthy individuals, the ventilatory pattern should include periodic sighs and prophylactic PEEP.