Changes in circulating exosome molecular profiles following surgery/(chemo)radiotherapy: early detection of response in head and neck cancer patients

BACKGROUND

Head and neck cancers (HNSCC) are highly immunosuppressive. Plasma-derived exosomes of HNSCC patients carry immunomodulatory molecules, and their cargo correlates with clinical parameters. Here, we evaluated the exosomal molecular profile for early detection of treatment failure in locally advanced HNSCC patients treated with conventional therapy.

METHODS

Plasma from 17 HNSCC patients was collected before, during, and after treatment by surgery with adjuvant (chemo)radiation and at recurrence. Exosomes were isolated by size-exclusion chromatography. Total exosomal protein (TEP) was used to estimate exosome load and on-bead flow cytometry to evaluate relative fluorescence intensity (RFI) of tumour-associated and immunoregulatory proteins on exosomes. Exosomal effects on the activity of and adenosine production by T cells was assessed by flow cytometry and mass spectrometry.

RESULTS

TEP and the ratio of tumour-/immune-cell-derived exosomes varied during and after therapy with an overall decrease in the tumour-free follow-up but an increase at recurrence. RFI values of immunoregulatory proteins on exosomes, their ability for T cell inhibition and adenosine production changed during and after therapy. PD-L1 was the earliest discriminator for treatment failure and disease-free survival.

CONCLUSIONS

Monitoring of plasma exosomes during therapy represents a promising opportunity for early detection of treatment failure and risk stratification to delay/avoid recurrence.

Performance of microvascular anastomosis with a new robotic visualization system: proof of concept

Microvascular procedures require visual magnification of the surgical field, e.g. by a microscope. This can be accompanied by an unergonomic posture with musculoskeletal pain or long-term degenerative changes as the eye is bound to the ocular throughout the whole procedure. The presented study describes the advantages and drawbacks of a 3D exoscope camera system. The RoboticScope^®-system (BHS Technologies^®, Innsbruck, Austria) features a high-resolution 3D-camera that is placed over the surgical field and a head-mounted-display (HMD) that the camera pictures are transferred to. A motion sensor in the HMD allows for hands-free change of the exoscope position via head movements. For general evaluation of the system functions coronary artery anastomoses of ex-vivo pig hearts were performed. Second, the system was evaluated for anastomosis of a radial-forearm-free-flap in a clinical setting/in vivo. The system positioning was possible entirely hands-free using head movements. Camera control was intuitive; visualization of the operation site was adequate and independent from head or body position. Besides technical instructions of the providing company, there was no special surgical training of the surgeons or involved staff upfront performing the procedures necessary. An ergonomic assessment questionnaire showed a favorable ergonomic position in comparison to surgery with a microscope. The outcome of the operated patient was good. There were no intra- or postoperative complications. The exoscope facilitates a change of head and body position without losing focus of the operation site and an ergonomic working position. Repeated applications have to clarify if the system benefits in clinical routine.

[Robotics in otorhinolaryngology, head and neck surgery]

In many surgical specialities, e.g., visceral surgery or urology, the use of robotic assistance is widely regarded as standard for many interventions. By contrast, in European otorhinolaryngology, robotic-assisted surgery (RAS) is rarely conducted. This is because currently available robotic systems are not adequately adapted to the restricted space and partially difficult access to surgical fields in the head and neck area. Furthermore, RAS is associated with high costs at present. In some Anglo-American regions, robot-assisted surgery is already used regularly for different indications, particularly in transoral surgery of oropharyngeal tumors. Several feasibility studies demonstrate multiple fields of application for RAS in head and neck surgery. For standard use, the robotic systems and surgical instruments need to be reduced in size and adapted to application in the head and neck area.

Influence of travel burden on tumor classification and survival of head and neck cancer patients

PURPOSE

Cancer patients have to overcome various barriers to obtain diagnostics and treatment at head and neck cancer centers. Travel distance to a specialized hospital may result in psychosocial and financial distress, thus interfering with diagnostics, treatment, and follow-up care. In this study, we have aimed to analyze the association of travel distance with cTNM status, UICC stage at primary diagnosis, and survival outcomes of head and neck cancer (HNC) patients.

METHODS

We have analyzed data of 1921 consecutive HNC patients diagnosed between 2014 and 2019 at the head and neck cancer center of the Comprehensive Cancer Center Ulm (CCCU), Germany. Postal code-based travel distance calculation in kilometers, TNM status, and UICC stage were recorded at initial diagnosis. The assembly of travel distance-related groups (short, intermediate, long-distance) has been investigated. Moreover, group-related survival and recurrence analysis have been performed.

RESULTS

In contrast to observations from overseas, no association of travel distance and higher cTNM status or UICC stage at primary diagnosis has been observed. Furthermore, no significant differences for recurrence-free survival and overall survival by travel distance were detected.

CONCLUSION

In southern Germany, travel distance to head and neck cancer centers seems to be tolerable. Travel burden is not synonymous with travel distance alone but also involves sociodemographic, monetary, and disease-specific aspects as well as accessibility to proper infrastructure of transport and health care system.

[Effects of the SARS-CoV‑2 pandemic on the otolaryngology university hospitals in the field of research, student teaching and specialist training]

Hintergrund

Ab Frühjahr 2020 kam es zur weltweiten Verbreitung von SARS-CoV‑2 mit der heute als erste Welle der Pandemie bezeichneten Phase ab März 2020. Diese resultierte an vielen Kliniken in Umstrukturierungen und Ressourcenverschiebungen. Ziel unserer Arbeit war die Erfassung der Auswirkungen der Pandemie auf die universitäre Hals-Nasen-Ohren(HNO)-Heilkunde für die Forschung, Lehre und Weiterbildung.

Material und Methoden

Die Direktorinnen und Direktoren der 39 Universitäts-HNO-Kliniken in Deutschland wurden mithilfe einer strukturierten Online-Befragung zu den Auswirkungen der Pandemie im Zeitraum von März bis April 2020 auf die Forschung, Lehre und die Weiterbildung befragt.

Ergebnisse

Alle 39 Direktorinnen und Direktoren beteiligten sich an der Umfrage. Hiervon gaben 74,4 % (29/39) an, dass es zu einer Verschlechterung ihrer Forschungstätigkeit infolge der Pandemie gekommen sei. Von 61,5 % (24/39) wurde berichtet, dass pandemiebezogene Forschungsaspekte aufgegriffen wurden. Von allen Kliniken wurde eine Einschränkung der Präsenzlehre berichtet und 97,5 % (38/39) führten neue digitale Lehrformate ein. Im Beobachtungszeitraum sahen 74,4 % der Klinikdirektoren die Weiterbildung der Assistenten nicht gefährdet.

Schlussfolgerung

Die Ergebnisse geben einen Einblick in die heterogenen Auswirkungen der Pandemie. Die kurzfristige Bearbeitung pandemiebezogener Forschungsthemen und die Einführung innovativer digitaler Konzepte für die studentische Lehre belegt eindrücklich das große innovative Potenzial und die schnelle Reaktionsfähigkeit der HNO-Universitätskliniken, um auch während der Pandemie ihre Aufgaben in der Forschung, Lehre und Weiterbildung bestmöglich zu erfüllen.

Preclinical Performance Evaluation of a Robotic Endoscope for Non-Contact Laser Surgery

Despite great efforts, transoral robotic laser surgery has not been established clinically. Patient benefits are yet to be proven to accept shortcomings of robotic systems. In particular, laryngeal reachability and transition from microscope to accurate endoscopic laser ablation have not been achieved. We have addressed those challenges with a highly integrated robotic endoscope for non-contact endolaryngeal laser surgery. The current performance status has been assessed in multi-level user studies. In addition, the system was deployed to an ex vivo porcine larynx. The robotic design comprises an extensible continuum manipulator with multifunctional tip. The latter features laser optics, stereo vision, and illumination. Vision-based performance assessment is derived from depth estimation and scene tracking. Novices and experts (n = 20) conducted teleoperated delineation tasks to mimic laser ablation of delicate anatomy. Delineation with motion-compensated and raw endoscopic visualisation was carried out on planar and non-planar nominal patterns. Root mean square tracing errors of less than 0.75 mm were feasible with task completion times below 45 s. Relevant anatomy in the porcine larynx was exposed successfully. Accuracy and usability of the integrated platform bear potential for dexterous laser manipulation in clinical settings. Cadaver and in vivo animal studies may translate ex vivo findings.

Adenosine production in mesenchymal stromal cells in relation to their developmental status

BACKGROUND

Mesenchymal stromal cells (MSC) are multipotent progenitor cells found in the tumor microenvironment. They have an innate and regulatory immune activity, and they are able to produce immunosuppressive adenosine (ADO) via their ectonucleotidases CD39 and CD73. The present study explores ADO metabolism of MSC in relation to their developmental status.

METHODS

We analyzed MSC (n = 6), chondrogenic progenitor cells (CPC, n = 8), and chondrocytes (n = 8) for surface markers by flow cytometry. The ability to hydrolyze ATP and to produce ADO was tested by luminescence assays and mass spectrometry.

RESULTS

Significant differences in the surface marker expression of MSC, CPC, and chondrocytes were seen. While the expression of CD73 was observed to be the same on all cell types, the expression of the ectonucleotidase CD39 was significantly increased on MSC. Consequently, production of ADO was most abundant in MSC as compared with chondrocytes and CPC.

CONCLUSION

Mesenchymal stromal cells are potent producers of ADO and are, therefore, able to increase immunosuppression. As MSC differentiate into chondrocytes, they lose this ability and may take on other functions.

Age-related changes in T lymphocytes of patients with head and neck squamous cell carcinoma

Introduction

The number of aging cancer patients has increased continuously and will do so further in the future. The immune system of elderly people experiences critical changes over the time. Therefore, tumor-induced changes in the immune system are believed to differ in young and elderly cancer patients as well.

Methods

The effect of aging on the immune system was measured in peripheral blood lymphocytes (PBL) of healthy volunteers (n = 48, 21–84 yrs.) divided into three different age groups. Seventy years was set as a cut-off for defining subjects as elderly. Results were compared to two groups of adult cancer patients, which donated PBL and tumor infiltrating lymphocytes (TIL): young cancer patients (40–69 yrs.; blood: n = 13; TIL: n = 17) and elderly cancer patients (70–90 yrs.; blood: n = 20; TIL: n = 15) with head and neck squamous cell carcinoma (HNSCC). Frequencies and phenotypes of CD4⁺ and CD8⁺ T cells as well as regulatory T cells (T_reg) were assessed by flow cytometry.

Results

We observed lower frequencies of CD8⁺ cytotoxic T cells during aging in both groups. Frequencies of tumor infiltrating regulatory T cells were significantly higher than in the peripheral blood but showed a significant decline in older tumor patients. With increasing age, expression of immunosuppressive CD73 and CCR7 was lower and expression of PD1 elevated on peripheral T cells in healthy volunteers and tumor patients.

Conclusion

Immunosenescence takes place in healthy donors and cancer patients. Our results suggest that in elderly tumor patients, the immune system is impaired and the tumor-induced immune escape is less pronounced. The increased expression of PD1 implies the potential for effective immunotherapies in elderly, as treatment with checkpoint inhibitors could be more beneficial for elderly HNSCC patients.

[Immuno-, radio-, and chemotherapeutic studies in head and neck cancer : Highlights of the ASCO Annual Meeting 2017]

In recent years, immunotherapy has been shown to be a promising approach for the treatment of various tumor entities. Due to further pharmacological developments and new studies, the checkpoint inhibitors have now arrived in the clinic. To date, patients with cancers in the head and neck region have benefited from these agents as part of a palliative therapy. Current clinical trials are testing other indications for the checkpoint inhibitors as monotherapy or in combination with other therapeutic approaches. The following article summarizes the highlights of the American Society of Clinical Oncology (ASCO) Annual Meeting.

Treatment-induced changes of lymphocyte subsets in patients with adenoid cystic carcinoma of the head and neck

PURPOSE

Adenoid cystic carcinoma (ACC) of the head and neck is a rare and highly malignant tumor, characterized by perineural growth and early distant metastases. The composition of immune cells in the peripheral blood and the tumor microenvironment is critical to tumor growth and control. However, little is known about the frequency and function of the relevant immune cell subsets in this entity.

METHODS

In ACC patients (n = 11) and matched healthy donors (n = 11), the frequency of peripheral blood T and B cells was measured by flow cytometry at different treatment stages of disease (24 samples). Cells were further characterized by their expression of CCR7, PD-1, CD39 and CD73. Tumor-infiltrating lymphocytes (TIL) were analyzed by immunohistochemistry for ten patients and for three patients by flow cytometry.

RESULTS

CD4⁺ T cells had significantly lower frequency after radiotherapy (RT). All other cell frequencies, including T_reg, were stable through course of the disease. In B cells, CD73 was reduced after RT. CCR7 expression on T and B cells in patients with relapse/metastases (R/M) differed significantly from patients with active disease. PD-1 remained stable. T_reg were more present in TIL compared to peripheral blood.

CONCLUSION

Composition of lymphocyte subgroups behaves similar to squamous cell carcinoma in the head and neck, except for T_reg, which remained stable. Nevertheless, the CD4⁺/T_reg ratio was lower after RT, which could stand for an immunosuppressive effect in these patients. Therefore, it could be beneficial treating ACC with combined RT and immunomodulatory drugs.

[Immunotherapy highlights of the ASCO annual meeting 2018 for head and neck cancers]

BACKGROUND

Immunotherapeutic strategies are becoming increasingly more important for head and neck cancer and numerous clinical trials were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) 2018.

OBJECTIVE

In this review the most interesting clinical trials and trial results for immunotherapy of head and neck cancer are summarized.

MATERIAL AND METHODS

All abstracts and presentations on immunotherapy of head and neck cancer at the annual meeting of the ASCO 2018 were screened to select the most interesting trials for a more detailed analysis.

RESULTS

For head and neck cancer, practice changing phase III trial results were missing, but several noteworthy new strategies and trial results for immunotherapy were presented. Neoadjuvant immunotherapy trials, results concerning immunotherapy in old age, prognostic implications of immune-mediated adverse events and new immunotherapy combinations are summarized in this article.

CONCLUSION

The role of immunotherapy for the treatment of head and neck cancer is markedly increasing. Many pioneering trials are currently ongoing, in the phase of data analysis or in planning.

[B cells in head and neck oncology]

As immunotherapy is becoming increasingly important in the treatment of head and neck cancer, a fundamental understanding of the immunological relationships in the tumor microenvironment is required. The importance of tumor-infiltrating B cells (TIL-B) has been largely neglected so far. In the current literature, however, a significant influence of B cells on tumor growth is described, so that this cell population is now also perceived as a therapeutic target structure. Regulatory B cells (B_reg) represent a subset of B cells with immunosuppressive properties. In addition to the secretion of IL-10, B_reg can be defined by their ability to produce adenosine. Adenosine is known as an immunosuppressive messenger in the tumor microenvironment whose effect can be prevented by immunotherapeutic approaches. Understanding the tumor immunological relationships, including the different B‑cell functions, can help to effectively combine standard approaches including surgery or radiochemotherapy with immunotherapy. In the present article, recent findings on B cells and adenosine in head and neck cancer are described.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

First use of flat-panel computed tomography during cochlear implant surgery : Perspectives for the use of advanced therapies in cochlear implantation

BACKGROUND

Cochlear implantation in routine cases with normal anatomy is commonly performed without intraoperative image guidance. Revision cochlear implantation as well as surgery in malformations require not only a precise understanding of the underlying complex anatomy, but surgeons need to transform two-dimensional computed tomography (2D CT) scans into the surgical field and use this information for intraoperative surgical navigation. So far, information about the exact position of the electrode during insertion cannot be provided to the surgeon. Here, we present our first operative experience with cochlear implant surgery supported by intraoperative Dyna-CT technology, providing the surgeon with detailed views of the electrode location.

METHODS

To prove the feasibility of the procedure, two cases of cochlear implantation were performed with intraoperative application of cone-beam CT acquired by a C-arm Dyna-CT system (Artis Zeego, Siemens Healthcare, Erlangen, Germany). Image reconstruction was performed intraoperatively in order to assess the correct positioning of the electrodes.

RESULTS

Intraoperative Dyna-CT enabled clear visualization of the surgical anatomy and intracochlear electrode position. Dyna-CT technology can be applied with acceptable additional time requirements without adding too much complexity to the surgical procedure.

CONCLUSION

Intraoperative data acquisition by Dyna-CT represents a suitable option for online surgical navigation during cochlear implant surgery. This imaging technology will push further advances in cochlear implant surgery and lateral skull base surgery, particularly if linked to intraoperative navigation.

Response Evaluation in Head and Neck Oncology: Definition and Prediction

Curative treatment of head and neck squamous cell carcinoma includes surgery and/or (chemo)radiation, whereas in the palliative setting, chemotherapy and/or immunotherapy represent(s) the standard approach. With regard to quality control, methods for determining treatment response are sorely needed. For surgical therapy, histopathology is the standard quality control. Established criteria for high-risk patients include resection margins of the primary tumor and extracapsular extension of lymph node metastases. After definitive chemoradiation, treatment response is generally evaluated by tomographic imaging combined with endoscopy including re-biopsy of the tumor region. Single-cycle induction chemotherapy may be used to determine the radiosensitivity of tumors, helping to define surgical and nonsurgical treatment options. Innovative approaches with implications for prognosis include the analysis of immune infiltrates, liquid biopsy, molecular characterization (proteomics, genomics), molecular and functional imaging (PET-CT, PET-MRI), as well as advanced imaging data analysis (radio[geno]mics/texture analysis). Human papilloma virus, as a prognostically relevant parameter, is currently being investigated for de-escalation strategies. With regard to the extended personalization of oncologic therapy, markers predicting treatment response are desirable and seem to be important, also from a socioeconomic perspective.

[Immunotherapy for HNSCC : Quo vadis?]

BACKGROUND

Immunotherapy remains a hot topic with an endless stream of new upcoming clinical trials. The results of studies to date are promising for second-line palliative treatment of head and neck squamous cell carcinoma (HNSCC). The next step is testing these strategies in randomized trials for first-line and curative treatment in an adjuvant, neoadjuvant, and primarily nonsurgical setting. So far, established biomarkers have not proven reliable enough to predict response rates precisely.

OBJECTIVES

On occasion of the annual meeting of the American Society of Clinical Oncology (ASCO), we aimed to invesitage the future of immunotherapies.

METHODS

We collected the most promising upcoming studies alongside current research in the field of biomarkers with a  view to interesting new immunotherapeutic strategies.

RESULTS

The search for appropriate biomarkers in particular seems to be a central research objective in the short term. There is a broad range of new agents that will be tested in clinical trials as well as the combination of immunotherapy with chemo- and chemoradiotherapy or other immune-modulating drugs.

CONCLUSION

The real challenge will be to find the most fitting therapy for each patient out of a large panel of available regimens. Therefore, it is most important to find a set of reliable biomarkers that together could predict treatment response.

[Molecular approaches to systemic therapy of adenoid cystic carcinoma of the head and neck area]

The adenoid cystic carcinoma (ACC) is a neurotropic salivary gland tumor with a high blood-borne metastasis tendency. The treatment of choice for localized disease consists of radical surgical resection and, depending on resection status, adjuvant radiotherapy. Due to the high recurrence rate with limited local therapeutic options and frequent occurrence of distant metastases, one is confronted inevitably with the search for an adequate systemic therapy. ACC shows little response to a variety of chemotherapeutic agents, partial or complete remissions are extremely rare. Beside classical chemotherapies, immunotherapeutics and targeted therapies with more favorable side effect profiles were tested in trials, but due to the small number of patients, a definitive statement on the effectiveness can be hardly made. This results in the need for prospective multicenter studies that allow clear recommendations for systemic therapy of the tumor. The present paper gives an overview of the sub-cellular and genetic characteristics of ACC, which represent possible targets for systemic therapies and have partly already been included in running clinical trials.

Human CD4+ CD39+ regulatory T cells produce adenosine upon co-expression of surface CD73 or contact with CD73+ exosomes or CD73+ cells

While murine CD4(+) CD39(+) regulatory T cells (T(reg)) co-express CD73 and hydrolyze exogenous (e) adenosine triphosphate (ATP) to immunosuppressive adenosine (ADO), surface co-expression of CD73 on human circulating CD4(+) CD39(+) T(reg) is rare. Therefore, the ability of human T(reg) to produce and utilize ADO for suppression remains unclear. Using mass spectrometry, we measured nucleoside production by subsets of human CD4(+) CD39(+) and CD4(+) CD39(-)CD73(+) T cells or CD19(+) B cells isolated from blood of 30 volunteers and 14 cancer patients. CD39 and CD73 expression was evaluated by flow cytometry, Western blots, confocal microscopy or reverse transcription-polymerase chain reaction (RT-PCR). Circulating CD4(+) CD39(+) T(reg) which hydrolyzed eATP to 5'-AMP contained few intracytoplasmic granules and had low CD73 mRNA levels. Only ∼1% of these T(reg) were CD39(+) CD73(+) . In contrast, CD4(+) CD39(neg) CD73(+) T cells contained numerous CD73(+) granules in the cytoplasm and strongly expressed surface CD73. In vitro-generated T(reg) (Tr1) and most B cells were CD39(+) CD73(+) . All these CD73(+) T cell subsets and B cells hydrolyzed 5'-AMP to ADO. Exosomes isolated from plasma of normal control (NC) or cancer patients carried enzymatically active CD39 and CD73(+) and, when supplied with eATP, hydrolyzed it to ADO. Only CD4(+) CD39(+) T(reg) co-incubated with CD4(+) CD73(+) T cells, B cells or CD39(+) CD73(+) exosomes produced ADO. Thus, contact with membrane-tethered CD73 was sufficient for ADO production by CD4(+) CD39(+) T(reg). In microenvironments containing CD4(+) CD73(+) T cells, B cells or CD39(+) CD73(+) exosomes, CD73 is readily available to CD4(+) CD39(+) CD73(neg) T(reg) for the production of immunosuppressive ADO.

[Penetrating injuries of the head and neck region - a potentially life threatening situation]

Penetrating Injuries of the Head and Neck Region - A Potentially Life Threatening Situation Background: Cuts, stabs and gunshot wounds in the head and neck region are potentially life-threatening because of the high risk of vascular lesions. A consistent emergency management is usually based on an operative exploration of the wound with effective reconstruction of viable structures.

PATIENTS AND METHODS

Various penetrating injuries of the head and neck region are described in 11 cases with respect of age, gender, course of events of injury, type of injury, involved structures, diagnostic and operative procedures and outcome and compared with current literature and guidelines.

RESULTS

In 10 of 11 patients, in the context of an interdisciplinary emergency room management, CT angiography was performed following clinical examination. A surgical exploration and wound treatment was performed in 9 of these patients. The common carotid artery, the external carotid artery and large venous blood vessels of the neck were injured in 2 cases respectively. None of the patients deceased or suffered permanent damage.

CONCLUSION

The outcome of deep head and neck lesions with relevant vascular trauma is determined by a rapid and interdisciplinary approach. A rapid, systematic and interdisciplinary approach in specialized trauma centers has a significant role in ensuring that patients with penetrating wounds in the head and neck -region rarely die due to their serious injury or their consequences.

[The use of a flexible CO2-laser fiber in transoral robotic surgery (TORS)]

BACKGROUND

Recently transoral robotic surgery has gained importance in the resection of head and neck tumors, especially in North America. The available resection tools are a fiber guided Tm:YAG-laser and a monopolar cautery, both causing wide coagulation and vaporization zones in healthy tissue. In order to improve the cutting properties we combined the system with a flexible CO2-laser fiber.

MATERIAL AND METHODS

6 patients suffering from T1 and T2 oropharyngeal carcinomas were treated between July 2012 and September 2012. In a prospective study we analyzed the feasibility, cutting properties, speed of resection as well as hemostasis and compared those with the monopolar cautery and the Tm:YAG laser which were recently examined in a series of 17 patients.

RESULTS

The application of a CO2-laser fiber with the da Vinci system was feasible and showed good cutting properties. Using a 15 watts energy level resulted in a favourable cutting depth and adequate hemostasis. In comparison to the monopolar cautery or the Tm:YAG laser, smaller coagulation and vaporization zones could be achieved.

CONCLUSION

Cutting properties of the da Vinci system can be improved by using a flexible CO2-laser fiber. Further prospective evaluations will follow.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

[Secondary wound healing. Effective treatment concept after basal cell carcinoma resection in the central midface]

Plastic reconstruction of facial skin defects after tumor surgery is a commonly accepted principle. However, healing by secondary intention is discussed controversially. Here we describe a series of 22 patients after full thickness resection of basal cell carcinoma who underwent wound healing by secondary intention. A semipermeable membrane was used for wound dressing, which was changed on a weekly basis. No antibiotics or pain killers were necessary. Defects up to 2 cm, particularly those of concave subunits of the midface, entirely closed within 4-6 weeks, and secondary wound healing led to excellent functional and aesthetic results. Thus, secondary wound healing is a safe, effective and economic alternative to surgical reconstruction in selected facial areas.

In vitro chemosensitivity of head and neck cancer cell lines

Background

Systemic treatment of head and neck squamous cell carcinoma (HNSCC) includes a variety of antineoplastic drugs. However, drug-resistance interferes with the effectiveness of chemotherapy. Preclinical testing models are needed in order to develop approaches to overcome chemoresistance.

Methods

Ten human cell lines were obtained from HNSCC, including one with experimentally-induced cisplatin resistance. Inhibition of cell growth by seven chemotherapeutic agents (cisplatin, carboplatin, 5- fluorouracil, methotrexate, bleomycin, vincristin, and paclitaxel) was measured using metabolic MTT-uptake assay and correlated to clinically-achievable plasma concentrations.

Results

All drugs inhibited cell growth in a concentration-dependent manner with an IC50 comparable to that achievable in vivo. However, response curves for methotrexate were unsatisfactory and for paclitaxel, the solubilizer cremophor EL was toxic. Cross-resistance was observed between cisplatin and carboplatin.

Conclusion

Chemosensitivity of HNSCC cell lines can be determined using the MTT-uptake assay. For DNA-interfering cytostatics and vinca alkaloids this is a simple and reproducible procedure. Determined in vitro chemosensitivity serves as a baseline for further experimental approaches aiming to modulate chemoresistance in HNSCC with potential clinical significance.

[Coagulation factors as potential tumour markers in patients with head and neck carcinomas?]

OBJECTIVE

Carcinomas can have influence on the coagulation system by different factors. Locally pathological changes of metabolism, neo-vascularisation, oxygenation and tissue pressure as well as locally and systemically activities of the tumor cells, are part of it. The coagulation situation in patients with head and neck carcinomata is characterized only insufficiently till now.

MATERIAL AND METHODS

In a prospective pilot study 20 male patients with squamous-cell carcinomas of the head and neck area were subjected to a detailed coagulation diagnostics pre and post therapeutically and, age and sex corrected, compared with a control group (n=37).

RESULTS

For the routine parameters PTT, Quick, TZ and INR no differences between the groups could be recognized. For the tumour patients a statistically significant increase arose for the acute phase proteins like factor I (fibrinogen), factor VIII, factor IX, von- Willebrand antigen and activity before therapy. Increased values were found also for plasmin, factor II, factor V and the thrombin-antithrombin-III-complex (TAT) whereas the values for antithrombin-III were degraded significantly. In the tumour patients the pre-therapeutical increased values for the activation marker TAT brought themselves back to normal after the tumour ablative therapy.

CONCLUSIONS

TAT could be suitable as a potential tumour marker but also for relapse tumours. To evidence this, a study of longer duration and with a larger number of patients is necessary.

[Breast cancer metastases in the head and neck region]

Breast cancer metastases to the head and neck region are very rare and therefore represent a challenge for the clinician in terms of diagnosis and therapy. Recent advances in breast cancer treatment have achieved longer median survival times in affected patients. However, at the same time, the risk of a clinical manifestation of metastasis increases. Here we present the cases of two breast cancer patients who developed filiae into the petrous portion of the temporal bone and one very rare case of metastasis to the larynx. Diagnosis, therapy and distinctive features of metastasis to the head and neck region are discussed.Secondary to long-term endocrine hormone therapy, a reduction in estrogen receptor expression occurred in all three cases. We believe that the loss of steroid receptor expression contributed to tumor resistance to endocrine therapy. Moreover, this receptor loss hindered the pathologist from confirming the diagnosis of metastases at very unusual sites.