Page 201 - Functional impairment and cues for rehabilitation of head and neck cancer patients -

DISCUSSION
To the best of our knowledge, this is the first study reporting on the direct relation between sarcopenia and prolonged feeding tube dependency during primary CRT for HNC. Our results show that SMI measured at C3 level, as measure of sarcopenia, was significantly associated with an increased risk of prolonged feeding tube dependency. Adjusting for BMI, FOIS and SES did not lead to substantial changes of the estimate of the RR, suggesting the relationship was not confounded.
The results support our hypothesis that the relationship between sarcopenia and prolonged tube dependency is a causal one (43). First, the effect of SMI on the risk of tube dependency was substantial: the effect size (RR 1.08) translates into a relative risk increase of 26% for patients per interquartile range decrease in SMI. Second, adjustment for confounders resulted in a minimal change of the estimated RR. Last, the relation between low muscle mass and functional impairment later on (i.e., tube dependency) is biologically plausible, and analogous effects of low skeletal muscle mass have been observed for other clinical and functional outcomes of head and neck cancer treatment (12, 44).
Our findings implicate that muscle mass and function may also modify patients risk of feeding tube dependency. Thus, the presence of sarcopenia may be a relevant indication for optimization of patients’ physical condition (through nutritional interventions and exercise programs targeting the (swallowing) muscles) prior to treatment, and routine assessment of neck SMI could be used to identify patients who will benefit most from prehabilitation. Future experimental studies are needed to assess the effect of such a policy.
Recently, we developed and published a clinical prediction model to estimate the risk of prolonged feeding tube dependency (23). This prediction model could be used to select high risk patients for proactive placement of a feeding tube to prevent unnecessary weight loss. In this cohort, 16 of the 17 patients (94%) with a high estimated risk (> 60%) on prolonged feeding tube dependency – for whom clinicians might recommend proactive feeding tube placement – had a neck SMI below 12.7 (median SMI 11 (range 8–13)). Therefore, for these patients, the effort of assessing neck SMI can be saved since it is likely that all patients in this risk category will benefit from pretreatment supportive care focusing on optimizing muscle mass. We would recommend considering routine assessment of neck SMI for patients with an estimated risk below 60%, however, especially the intermediate risk category (30-60%), since 49 of the 80 patients (61%) with an intermediate estimated risk (30-60%) had a neck SMI below 12.7. Assessment of neck SMI in this risk category has added clinical value, as it enables identification of a modifiable factor. This can aid targeted optimization of patients’ pretreatment condition to decrease the risk on swallowing impairment and tube feeding dependency; if low neck SMI is present and considered modifiable, proactive tube placement, with its associated risk for non use atrophy of swallowing musculature, may be postponed. Postponing placement
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Sarcopenia as determinant for tube dependency
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