Page 193 - Functional impairment and cues for rehabilitation of head and neck cancer patients -

INTRODUCTION
Sarcopenia is a condition characterized by loss of skeletal muscle mass (1). It is mainly prevalent in the elderly, but also occurs in younger patients with diseases that affect mobility and nutrition (2). Most retrospective studies on sarcopenia in cancer patients consider CT assessed skeletal muscle mass only, as muscle function tests are often not available (3). In several cancer types, pretreatment sarcopenia is associated with inferior treatment outcomes (4) including postoperative complications (5, 6) and treatment-related toxicity (7, 8). Recent studies confirm this association in head and neck cancer (HNC) with regard to treatment outcomes (i.e., chemotherapy dose-limiting toxicity) and survival after concomitant chemoradiotherapy (CRT) and postoperative complications including pharyngocutaneous fistula after total laryngectomy (9-15). There is a paucity of information, however, on the influence of sarcopenia on functional outcomes.
One of the most important functional outcomes for patients with head and neck cancer is swallowing function, which is often compromised after CRT, due to an often multifactorial etiology (16). First, the extent of tumor and treatment disrupt normal swallowing physiology, and with more extensive tumor and treatment the risk for developing swallowing problems is increased (17-24). Second, poor nutritional status can also contribute to swallowing dysfunction, due to loss of muscle mass and function (19-24). As a result of swallowing dysfunction, a substantial proportion (50-70%) of patients becomes feeding tube dependent during CRT (23). Due to the decline in swallowing muscle activity, non-use atrophy of these muscles is inevitable, which is associated with further loss of swallowing muscle mass and function (23, 25-28). Sarcopenia could be a factor worsening this vicious spiral by co-causing long-term swallowing dysfunction, as patients suffering from sarcopenia have limited reserves with regard to muscle mass and function. Consequently, in these patients, non-use atrophy of the swallowing muscles may even sooner lead to prolonged functional impairment (29, 30).
Results from studies among patients with other cancer types suggest that pretreatment optimization of functional status, also known as prehabilitation, may improve functional outcomes (31, 32). In HNC patients, prehabilitation interventions prior to CRT could include exercise programs targeting the swallowing muscles in combination with nutritional interventions. Especially focusing on high-risk patients for prehabilitation interventions to increase benefit has been suggested in the literature (33). A better understanding of the relationship between pretreatment sarcopenia and risk of long-term swallowing impairment and feeding tube dependency will help identify which patients might benefit from targeted interventions, as well as provide clues to the type of interventions to be used.
Therefore, the objective of this study was to assess the direct relationship of pretreatment sarcopenia with prolonged feeding tube dependency in patients treated with primary CRT for HNC.
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Sarcopenia as determinant for tube dependency
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