151751-Najiba-Chargi

219 Systemic therapy: skeletal muscle mass and bioradiotherapy INTRODUCTION Head and neck cancer is the sixthmost common cancer, with over 600,000 new cases annually worldwide. 1 At diagnosis, locoregionally advanced disease is present in up to 60%of patients. 1 Locoregionally advanced stage head and neck squamous cell carcinoma (HNSCC) is generally treated with surgery plus adjuvant radiotherapy with or without cisplatin chemotherapy or, as primary treatment, concomitant cisplatin chemotherapy and radiotherapy with salvage surgery in reserve for residual disease or recurrence. 1 The addition of chemotherapy to ra- diotherapy improves disease control and survival but also results in increased toxicity and can, therefore, influence adherence to the treatment. 2 Cisplatin dose-limiting toxicity (DLT) includes, among others, bone marrow depression, ototoxicity, and nephrotoxicity. 3 This can cause treatment delay, dose reduction, and possible failure to complete treatment as well as decreased quality of life. 3 To improve treatment adherence and reduce toxicity, predictive factors should be identified that indicate the risk of a patient to experience DLT. Currently, patients are evaluated by their oncologist to determine whether they are medically fit to undergo cisplatin treatment. This takes into consideration age, comorbidities, and the presence of contraindications for cis- platin, such as impaired renal function, poor general health, bone marrow suppression, and impaired hearing. If patients are considered unfit for cisplatin alternative options to increase the anti-tumor effect of radiotherapy include the addition of cetuximab. 4 However, patients treated with cetuximab in combination with radiotherapy may also experience considerable amounts of toxicity, specifically leucopenia, neutropenia, and mucositis. 5 Therefore, to im- prove treatment adherence and reduce toxicity, predictive factors should be identified that indicate the risk of DLT. Low skeletal muscle mass (SMM) is a possible predictive factor to esti - mate whether a patient will experience chemotherapy DLT. Moreover, low SMMmay also be a prognostic factor. Low SMM has a high prevalence in adults with cancer; in HNSCC prevalence as high as 55%has been reported. 3 SMM can bemeasured on a routinely performed computed tomography (CT) or magnetic resonance imaging (MRI) of the head and neck. 6–8 Low SMM has previously been linked to an increased prevalence of chemotherapy DLT for several types of cancer such as breast 9 , colorectal 10 , renal 11 , lung 12 , and oesophago-gastric cancer 13 . Specifical - ly, for HNSCC, Wendrich et al. demonstrated that low SMM is a predictive factor for platin DLT (occurring in 30.4%) in patients treated with platin-based chemotherapy and radiotherapy. 3 Based on previous evidence supporting the predictive value of low SMM for chemotherapy DLT in several types of cancer, it is logical to question whether low SMM is also predictive for DLT in treatment of HNSCC using cetuximab. This study focusses on investigating the possible predictive value of low SMM for DLT during concomitant cetuximab and radiotherapy treat- ment of locally advanced HNSCC. Also, the prognostic value of low SMM for overall survival (OS) and the disease-free survival (DFS) in HNSCC patients treated with concurrent cetuximab and radiotherapy is investigated. 12