Research Group: Marius Bredell BChD MBChB MChD et al.
Clinical co-workers: PD Dr. Dr. Andreas Boss & Dr. Kristian Ikenberg
Head and neck cancer (oral cancer) is the 12th most frequent cancer in Europe with an overall 5 year survival rate of 40% for oxygenated and ~0% survival rate for the most hypoxic (pO2 <2.5mmHg) tumors (Nordsmark, Bentzen, Rudat, Brizel, Lartigau, Stadler, Becker, Adam, Molls, Dunst, Terris, Overgaard, 2005). Thus, oxygenation is a highly important biomarker for these tumors that are dominated by squamous cell carcinomas. Many patients have a locally advanced stage at presentation, with tumor spread to local lymph nodes. Lymphatic dissemination has a clear correlation with poorer prognosis, and curative treatment can then only be achieved with multimodality treatment, including combination of surgery, radiation and chemotherapy. The choice of treatment in Head and Neck squamous cell carcinomas (HNSCC) has to be tailored individually for each patient, according to tumor location and size, individual histological and histochemical parameters, spread into the regional lymph nodes, possibility of function preservation with different treatment approaches with cognisance of co morbidities and expected toxicities. Despite intense treatment, the majority of the patients with locally advanced disease will relapse locally or develop distant metastases.
A major challenge is to select the most effective treatment modality/ies for a specific patient (personalized cancer therapy) and determine at an early stage of treatment whether the patient is responding favourably or not. As most advanced tumors do require multiple modality treatment, there would be obvious advantages in early prognostic indicators to identify high risk tumors that would lead to a more aggressive treatment regime, with a lower rate of local and regional recurrence. Tumor hypoxia has been shown to be associated with significant poorer survival rates, mostly due to local and loco-regional failure. Since tumor response to chemotherapy, photodynamic therapy (PDT) (Evans, Abu-Yousif, Park, Klein, Celli, Rizvi, Zheng, Hasan, 2011) or radiotherapy therapy depends on tumor oxygenation, measuring oxygenation has a great potential in optimizing the choice of treatment, assessing the treatment response and enhancing survival of patients. The level of tumor oxygenation / hypoxia thus represents a biomarker not only at the start of treatment but also during treatment, as the dynamics of tumor oxygenation during treatment may also correlate with treatment response, risk of local and loco-regional relapse or distant metastases. A progression to a more hypoxic state of the tumor may be an early predictive marker for treatment failure that may direct towards an alternative or modified therapy.
Measurement of tumor hypoxia can be done by pathological analysis of certain standardised biomarkers of hypoxic tumor tissue (Carbonic Anhydrase X, HIF -1α, HIF -2β, Glut 1, Secreted markers: VGEF, OPN
Genetic: CPT1c (redox gene) etc.), as well as structural assays like microvascular density measurement and other non-related markers like HPV. These biomarkers will be used as benchmark for new biomarkers to be referenced to. Exploring the risk factors in Head and Neck Cancer shows that human papilloma virus (HPV) infection is a growing risk as well as prognostic factor in oro-pharyngeal and oral cancer. Currently there is no data correlating this risk factor with tumor hypoxia that may further enlighten the prognostic uncertainties in some of the afflicted patients. Until now, no specific biomarker for tumor hypoxia has been employed in routine practice to determine treatment or treatment response.
Oxygenation also plays an important role in non-tumor tissues such as scar tissue after surgery, infection or radiotherapy to assess the potential risk of local complications of wound healing more accurately, however oxygenation of afflicted scar tissue is not routinely measured yet. Monitoring of free microvascular tissue transfer grafts is imperative in the early recognition of imminent vascular compromise that would require early surgical salvage. Furthermore, low bone oxygenation correlates with osteoradionecrosis. Thus, non-invasive oxygenation determination will be highly relevant for treatment response prediction.
To address the multiple clinical challenges and resultant translational research aims of this project, the clinical research project was divided into a dominant surgery, radiation oncology as well as a medical oncology arm. Within the main project there will be separate subprojects with focus on the common clinical application of imaging, pathology and biomarker development as well as saliva biochemistry that will be common to all three studies. The mentioned strategy will enhance the patient cohort and result in improved statistical possibilities to validate results.
Our overall aim is to integrate serial quantification of tumor oxygenation and visualise as well as quantify tumor oxygenation in head and neck cancer and explore its prognostic relevance by O2 PET, BOLD MRI and NIRI with biomarker verification in squamous cell carcinomas of the head and neck.
The specific aim of this study will be to measure tumor oxygenation in head and neck cancer with correlation to clinical outcome (O2 PET, BOLD MRI, NIRI, Biomarkers and Microdialysis). At large, the cohort of patients will include patients receiving surgery alone, radio- or chemo-radiotherapy, chemotherapy or multimodal therapy. Resolution limitations currently dictate a tumor size of one centimetre. Oxygenation will be determined prior, during and after treatment as part of exploratory/feasibility studies. Validation of these methods will be done by hypoxia biomarker application to tissue specimens, determination of tumor lactate and glucose measurement by microdialysis as well as inter imaging correlation, with O2 PET as the current gold standard. A preclinical animal study may be indicated in this regard, but will depend on availability of funding. As saliva has been shown to represent an excellent potential medium for tumor biomarkers, collection of saliva prior, during and after treatment will be performed.
Standard therapy for HNSCC will be applied as suggested by the interdisciplinary University Hospital of Zurich Head and Neck tumor board, dependent on the initial tumor stage, and usually includes either surgery, chemoradiation, induction chemotherapy prior to local therapy or as part of multimodality treatment or as palliative therapy. Tumor oxygenation will be determined by O2 PET, BOLD MRI and developing novel technologies (NIRI) that will be assessed as a novel parameter to be phased in the latter stage of the study. Tumor staging, histological staging and risk factors, treatment response, complications and outcome parameters will be prospectively assessed, next to classic tissue biomarkers related to the tumor microenvironment. From the preclinical study group novel, yet unexplored biomarkers will be employed to explore its prognostic significance.
As this is a developmental, translational project, verification of many special investigations regarding newer technologies is imperative. For this purpose the study will be staged in three phases to ensure a robust structure with as few as possible technical and organisational difficulties in the final stages of the study.
Work package 1
A retrospective study regarding the prognostic and predictive value of novel hypoxia biomarkers in HNSCC will be done in routinely archived tissue compared to currently utilised biomarkers. Established as well as to be developed patient cohorts, with specific emphasis on different tumor areas and surrounding tissue will be used.
Work package 2
This second phase will be performed on a series of 10 patients to verify feasibility and optimise patient management strategies. Envisaged is the following protocol, depending on ethical committee approval.
- Informed consent of patients meeting the inclusion criteria
- Biopsy, serum as well as saliva collection for routine as well as biomarker identification
- Routine workup with clinical staging
- Imaging with O2 PET, BOLD MRI and arterial spin labelled MRI and later NIRI
- Surgery with intra operative microdialysis with at least lactate and glucose concentrations to compare the metabolic level of hypoxia in the tumor to the imaging values.
- Tumor extirpation with non-critical tumor tissue to be further examined for standard and novel hypoxia biomarkers
- Tumor bed biopsies for biomarker identification
- Repeat imaging at 6 weeks and 6 months post treatment
- A repeat of the protocol may be performed in patients undergoing further therapy, be it radiation, chemotherapy or a combination thereof.
Work package 3
This third phase will entail the prospective study of all patients undergoing surgery as primary treatment.
The protocol as described in Phase II will be used with modifications as determined by the pilot phase. Of all patients included in phases II and II studies tissue, saliva, and blood samples will be collected at specific time points for biomarker analysis.
Sequential and concurrent chemoradiotherapy (including molecular targeted agents): The level of tumor oxygenation (assessed prior and serially during treatment) will represent a predictive marker for the response to the primary treatment. Early changes of the oxygenation level may represent a predictive marker for treatment sensitivity and response. The level of oxygenation at the end of the treatment may correlate with the risk of local relapse or locoregional or distant metastases. In a clinical prospective study of all patients undergoing head and neck oncological surgery, tissue oxygen levels will be determined as a predictor for wound complications in the head and neck region.
This KFSP on Tumor Oxygenation also includes a specific subproject on tumor oxygenation and radiotherapy, which specifically focuses on the process of re-oxygenation - see project Pruschy and project Riesterer.
This clinical research is aimed to generate a milestone in the evolution of care of head and neck cancer patients by selecting patients for individualised therapies where oxygen and oxygenation or the lack thereof plays a key role. Despite some knowledge regarding the poorer prognosis of these patients no standardized predictive method has been developed that can be used in every day practise to the benefit of our patients. Bridges between the most suitable diagnostics and therapies supplied by various disciplines will optimise treatment and outcome. With the knowledge gained, we will be able to personalize cancer treatment and conduct randomized, controlled trials to investigate tumor oxygenation related to outcome in future KFSP terms.