151751-Najiba-Chargi

427 Summarizing discussion and future perspectives muscle mass, 0.4% had a large gain of skeletal muscle mass and only 0.4% had a large loss of SMM. Significant predictive factors for loss of skeletal muscle mass after treatment were being overweight or obese (HR 1.75, p<0.05 and HR 1.80, p<0.05, respectively) and a tumor site in the oropharynx (HR 1.85, p< 0.05). Patients with a ECOG performance status of 1 (HR 0.62, p<0.05), who were treated in a postoperative setting (HR 0.55, p<0.02) and who were able to receive an absolute cumulative dose of cisplatin ≥ 300mg (HR 0.57, p<0.05) were significantly less likely to experience loss of skeletal muscle mass after treatment. Low skeletal muscle mass at diagnosis or loss of skeletal muscle mass after treatment were not prognostic for OS nor DFS. As the incidence of oropharyngeal cancer is increasing due to the increase of sexu - ally transmitted infections with the human papillomavirus, we also investigated the role of skeletal muscle mass in patients with oropharyngeal cancer . Chapter 16 presents a study in 216 patients with oropharyngeal squamous cell carcinoma and investigated the prognostic impact of low skeletal muscle mass. A large percentage of low skeletal muscle mass (64.8%) was found in these patients. The prognostic impact of sarcopenic obesity was evaluated, which is the combination of low skeletal muscle mass and obesity. Six percent of patients were identified with sarcopenic obesity. Sarcopenic obesity was associated with a decreased OS (HR 4.42, p<0.05) and disease-free survival (DFS) (HR 3.90, p<0.05), independent from other well-known strong prognostic factors such as an HPV-positive tumor. Chapter 17 presents a prospective observational study in 108 patients with locally advanced oropharyngeal carci- noma in which, among other things, the impact of low skeletal muscle mass on functional outcomes during the first year after radiation-based treatment. Swallowing, mouth opening, and speech function were collected before treatment and at six-and twelve-month follow-up as part of ongoing prospective assessments by speech language pathologists. Objective and patient-perceived function deteriorated until six months and improved until twelve months after treatment. However, functional outcomes did not return to baseline levels, of the includ - ed patients 25%, 20% and 58% had objective dysphagia, trismus and speech problems, re- spectively. Of the included patients, 45% had low skeletal muscle mass at diagnosis. At six months, patients with low skeletal muscle mass had significantly higher modified diets and higher total swallow quality of life (SWAL-QOL) scores, indicating more swallowing related problems, compared to patients without low skeletal muscle mass. Besides low skeletal muscle mass seen in patients with cancer, also referred to as secondary sarcopenia, muscle mass declines gradually with increasing age. Low skeletal muscle mass in older people caused by the ageing process, is also referred to as primary sarcopenia. Due to the ageing population, clinicians are treating more elderly patients with cancer. The elderly pop - ulation with head and neck cancer will grow gradually during the upcoming years. Therefore, Part IV of this thesis, presents the studies performed to investigate the impact of low skeletal musclemass in elderly head and neck cancer patients. Chapter 18 presents a study performed in 85 elderly HNSCC patients (≥70 years). Previous research in elderly people showed that the correlation between skeletal muscle mass and muscle strength is moderate to weak and the relationship between muscle strength and muscle mass to be non-linear. 10,11 Therefore, the European working group on sarcopenia in older people (EWGSOP) recommended diagnosing 21