ASSOCIATION BETWEEN SEVERITY OF DYSPHAGIA AND SURVIVAL IN PATIENTS WITH HEAD AND NECK CANCER

Dysphagia is a common and potentially life-threatening occurrence in patients with head and neck cancer, often associated with anatomic and physiologic changes in the oral and pharyngeal cavities due to surgical, radiation, and/or chemoradiation treatments.1–4 The incidence of posttreatment dysphagia in these patients has previously been reported as falling between approximately 50% and 60%.5–9 It has been suggested, though, that dysphagia and rates of aspiration are often underreported because physicians, the common source of referral for swallowing function assessment services, may underestimate or misidentify severity and refer only overtly symptomatic patients.7,9–11 It has also been estimated that 30% to 50% of patients with head and neck cancer demonstrate some degree of malnutrition.12 The combination of dysphagia with poor nutrition, significant weight loss, and impaired immune function often results in cachexia (full-body wasting and muscle atrophy), fatigue, high susceptibility to infection, poor wound healing, or death.12,13 Regardless of the shift toward organ-sparing, non-surgical treatment to preserve function in patients with head and neck cancer, all current modalities can result in swallowing problems, along with aspiration and aspiration pneumonia.14 Surgical resection can damage the muscles most critical to swallowing, including the intrinsic and extrinsic muscles of the tongue and larynx, which can lead to dysphagia.4,15 Radiation and chemotherapy often cause mucositis, neuromuscular fibrosis, and lymphedema changes in the mucosa and muscle tissues and can alter the coordination and flexibility of the swallowing process.1,4,16 These swallowing difficulties can be further exacerbated by the secondary consequences of prolonged NPO ([L.] nil per os or “nothing by mouth”) status, which is a common sequela among patients with head and neck cancer. Prolonged NPO status is directly correlated with worse swallowing outcomes and increased risk for dysphagia.7,17 Atrophy of pharyngeal and tongue-base musculature and increased pharyngeal fibrosis with overall deconditioning can result both from general nonuse of swallowing musculature and from a marked decrease in patient swallows (volitional or spontaneous).3,7 The biopsychosocial ramifications of dysphagia are widespread. Dysphagia can directly result in decreased eating, malnutrition, and weight loss, and the necessity for prolonged enteral feeding, all of which are associated with decreased survival.18–20 Swallowing problems can also result in decreased social participation and increased anxiety, social isolation, and depression, which in turn can lead to decreased quality of life.9 One goal of head and neck cancer research is to identify factors predictive of survival, which can lead to more effective treatment decisions and more accurate prognosis. Although tumor stage and site are well-known predictors of survival in patients with head and neck cancer,18,21 nutritionally related variables also appear to have potent prognostic implications. Weight loss has been shown to be one of the strongest independent predictors of survival, more powerful than stage or site.18 Patients with continued oral intake, in the presence of a gastrostomy tube, were more likely to maintain their weight and have higher survival rates compared with patients who had no continued oral intake.19 Domains specifically related to health-related quality of life, including eating, were also positively associated with survival.20 The extent of the correlation between dysphagia and survival, however, remains unclear. The purpose of this study was to determine the risk factors for developing dysphagia in patients with head and neck cancer and to examine whether the severity of dysphagia was associated with survival. A retrospective design was used to merge existing cancer registry and billing data with ratings provided by speech-language pathologists that quantified the severity of swallowing problems in patients with documented dysphagia.