Critical normal tissue reactions in head and neck cancer patients treated with radio(chemo)therapy are mucosal
injury (radiomucositis) and associated swallowing problems (dysphagia). Radio(chemo)therapy induces
radiomucositis in all patients and up to 50% may need percutaneous endoscopic gastrostomy (PEG) tube
feeding. Patients in dose-intensification protocols show increased risk of poorly healing mucosal injury, often
complicated by deep ulceration and necrosis of underlying tissues with risk of arterial blow-out.
Probiotics play a key role in maintaining a healthy mucosa at the upper aero-digestive tract.
Radio(chemo)therapy alters the microbiotic population facilitating overgrowth of pathogenic species. We will
investigate the radiation sensitivity of key species colonizing healthy mucosa and oropharyngeal cancers, their
influence on keratinocyte desquamation in vitro, their secretion factors and their modulation effects on
radiation-induced keratinocyte desquamation. If probiotics are able to decrease these radiation-induced effects,
we will further investigate their therapeutic potential in combination with radiotherapy in vitro. In addition,
swabs of tumor and non-tumor mucosa before, during and after radiotherapy will be collected from patients
receiving radiotherapy for oropharyngeal cancer to verify if the in vitro predicted results can be clinically
observed. Probiotic organisms with desirable modulation of radiation effects would allow a novel therapeutic
approach against radiomucositis.