Advances in Radiation Oncology

ORGAVADS: establishment of tumor organoids from head and neck squamous cell carcinoma to assess their response to innovative therapies

BACKGROUND

Radiotherapy is one of the cornerstones of the treatment of Head and Neck Squamous Cell Carcinomas (HNSCC). However, radioresistance is associated with a high risk of recurrence. To propose strategies (such as combinations with drugs) that could over intrinsic radioresistance, it is crucial to predict the response to treatment. Patient-Derived Tumor Organoids (PDTO) are in vitro tridimensional microtumors obtained from patient' own cancer samples. They have been shown to serve as reliable surrogates of the tumor response in patients.

METHODS

The ORGAVADS study is a multicenter observational trial conducted to investigate the feasibility of generating and testing PDTO derived from HNSCC for the evaluation of sensitivity to treatments. PDTO are obtained after dissociation of resected tumors remaining from tissues necessary for the diagnosis. Embedding of tumor cells is then performed in extracellular matrix and culture in medium supplemented with growth factors and inhibitors. Histological and immunohistochemical characterizations are performed to validate the resemblance between PDTO and their original tumor. Response of PDTO to chemotherapy, radiotherapy and innovating combinations are assessed, as well as response to immunotherapy using co-cultures of PDTO with autologous immune cells collected from patient blood samples. Transcriptomic and genetic analyses of PDTO allow validation of the models compared to patients' own tumor and identification of potential predictive biomarkers.

DISCUSSION

This study is designed to develop PDTO models from HNSCC. It will allow comparing the response of PDTO to treatment and the clinical response of the patients from whom they are derived. Our aim is to study the PDTO ability to predict the clinical response to treatment for each patient in view of a personalized medicine as well as to establish a collection of HNSCC models that will be useful for future innovative strategies evaluation.

TRIAL REGISTRATION

NCT04261192, registered February 7, 2020, last amendment v4 accepted on June, 2021.

[Surgery or radiotherapy for oropharyngeal HPV-positive tumours?]

Oropharyngeal carcinomas related to the human papilloma virus (HPV; usually HPV16) exhibit biological differences in terms of carcinogenesis and are of relatively better prognosis (in the absence of tobacco consumption) compared to tobacco-related cancers. The therapeutic strategies between these two forms of cancers of the upper aerodigestive tract related to different risk factors are however identical, except therapeutic trial. In the absence of a sufficient level of evidence to define a specific strategy for induced HPV carcinomas, the analysis of the recent literature nonetheless allows us to suggest ways to guide the clinician in his therapeutic choice. Given the relative good prognosis HPV+ oropharyngeal cancers, an important goal is to avoid if possible a multimodal treatment that increases the sequelae and could degrade the quality of life. For the early stages I/II, it may be desirable to propose minimally invasive surgery if radiotherapy is avoidable or an exclusive conformal radiation therapy by intensity modulation in the opposite case. For the advanced stages III/IV, the recommendations are similar to those of cancers not related to HPV. Current trials should provide answers on the relevance of therapeutic deflation (absence of chemotherapy in the event of capsular rupture, dose reduction or irradiation volumes, etc.).

Therapeutic Implications of the Genetic Landscape of Head and Neck Cancer

Large-scale sequencing studies of head and neck squamous cell carcinoma (HNSCC) have elucidated the genetic changes that characterize HNSCC. These findings have supported the development of therapeutic strategies that target key components of aberrant signaling pathways and immune dysregulation. Cumulative evidence suggests that these agents in combination with radiotherapy may have synergistic effects. This review highlights the predictive biomarkers that have been identified from HNSCC genomic studies and implications on the development of molecular-targeting agents that may effectively treat patients with HNSCC, especially when used in combination with radiation.