151751-Najiba-Chargi

287 Systemic therapy: skeletal muscle mass changes and chemoradiotherapy may mask an underlying unfavorable body composition, i.e., a patient may be overweight by a surplus of fatty tissue and still have low SMM. This combination of low SMM and a surplus of fatty tissue is also referred to in the literature as sarcopenic obesity. Sarcopenic obesity has shown to carry the cumulative risk of low SMM and high fat mass. 29 In clinical practice, the start of nutritional support in cancer patients is mainly guided by their body weight at presentation and loss of body weight prior to treatment rather than body composition, i.e., the amount of SMM and fat mass. This approach may result in underdiagnosis of patients in need for nutritional support. Although previous studies have shown that loss of SMM in patients whom received cancer treatment 30,15,16,31 had significant prognostic impact on survival, in this study a loss in SMM showed no prognostic impact for OS nor DFS. This difference may be explained by the het - erogeneity in the definition of muscle mass changes, the timing of the follow-up imaging and the type and stage of cancer and its type of treatment. Another explanation might be that in HNC dietician guidance is incorporated earlier into standard care practice than in non-HNC due to the high risk of malnutrition in patients with HNC. The median time between follow-up imaging and pre-CRT imaging in our study was 6 months (range 5-9]. In previous studies conducted in non-HNC cancer patients in which loss of SMM showed to have prognostic value, this interval ranged between 9-27months 26 and 9-18weeks. 15 Besides the difference in time interval between this study and previous studies, there is also a difference in the investigated study population. In this study we included patients who re - ceived cisplatin-based CRT in a curative setting. In a previous study a prognostic impact of loss of SMM after CRT for decreased survival was also demonstrated in the palliative setting . 14 Timing of baseline and follow-up SMM assessment may influence the prognostic value of loss of SMM. Nevertheless, this study and the previous studies conducted on muscle wast - ing in cancer patients all underline the finding of significant SMM changes, which itself is an interesting finding which needs more standardized and prospective research to evaluate its value for treatment outcomes and prognosis in patients with cancer. For patients with HNC, the frequent use of CT and MRI imaging for staging, evaluation and surveillance provides the opportunity to measure SMM without additional patient burden or costs. SMM assessments can serve as an objective and clinical measure of patient nutritional status and physical vulnerability and can be used to predict treatment outcomes in patients with cancer. SMM can be objectively and reliably measured and is a potentially modifiable risk factor. An increased understanding of the underlying mechanisms of the negative prognostic effects of low SMM in patients with cancer is crucial in order to innovate and to improve current treatment strategies and eventually treatment outcomes. Commonly proposed strategies include combination of high-protein nutritional support, exercise and pharmacological inter- ventions. Use of an intervention program, which includes nutrition support and high-intensity exercise is probably an ideal option for patients with low SMM. 3233 15