151751-Najiba-Chargi

199 Systemic therapy: skeletal muscle mass and chemoradiotherapy INTRODUCTION Locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is preferably treated with concomitant chemoradiotherapy (CRT) with cisplatin, with or without prior surgery. 1 The standard-of-care cisplatin regimen consists of three three-weekly courses of high dose cisplatin at a dose of 100mg/m 2 body surface area (BSA), with a cumulative dose of 300mg/m 2 BSA cisplatin. 2 The addition of high dose cisplatin chemotherapy to radiotherapy treatment improves locoregional disease control and results in a 6.5% increase in 5-year overall surviv - al. 3 Large prospective trials and retrospective studies show that a higher cumulative dose is associated with better survival rates. 4–7 The addition of cisplatin also results in a significant increase in the toxicity of treatment, such as acute nephrotoxicity, bonemarrow depression or severe nausea and vomiting, which cause treatment delay, dose reduction and treatment cessation as well as decreased quality of life. 2,8 Approximately 30% of patients experience chemotherapy dose-limiting toxicity (CDLT) and are unable to complete full treatment. 9 There are several contraindications for the use of high dose cisplatin, such as a decreased renal function, severe hearing loss and poor WHO func - tional status. Nevertheless, even in absence of these contra-indications, still 30% of patients experience CDLT in daily clinically practice which currently cannot be identified in advance. Therefore, there is a clinical need for additional predictive characteristics or biomarkers to accurately identify LA-HNSCC patients at high risk for CDLT from cisplatin. In recent years, radiologically identified sarcopenia or low skeletal muscle mass (SMM) has been identified as a novel predictive and prognostic factor in cancer patients. Pre-treatment lowSMM is associatedwith chemotherapy toxicity and CDLT in patients with a variety of cancer types, including lung, renal cell, colorectal and breast cancer. 10,11 Several risk factors for low SMM are known, including malnutrition, immobilization and chronic illness including cancer. 12 In HNSCC, malnutrition at diagnosis is highly common, and several retrospective studies report an incidence of approximately 50% of low SMM in HNSCC patients. 9,13–15 Recent retrospective studies in LA-HNSCC patients also concluded that pre-treatment low SMM was a significant predictor of CDLT in patients treated with CRT with platinum-based chemotherapy. 9,16 The purpose of this study was to investigate and validate the predictive value of low SMM on CDLT in a larger cohort of LA-HNSCC patients, treated with standard-of-care treatment with primary CRT with high dose cisplatin. 11