Trends in Reporting of Swallowing Outcomes in Oropharyngeal Cancer Studies: A Systematic Review

Over the last two decades, dysphagia is increasingly recognized as a significant short-term and long-term issue in oropharyngeal cancer patients. However, there remains a lack of standardization and agreement about reporting swallowing outcomes in studies that assess treatment outcomes in this population. A systematic review was performed following PRISMA Guidelines by searching Pubmed (MEDLINE) and Scopus. The inclusion criteria used included (1) prospective and retrospective clinical studies involving adult patients with oropharyngeal cancer, (2) reports swallowing outcomes, (3) English studies or studies with English translation, (4) full text retrievable and (5) publication between 1990 and 2016. 410 unique studies were identified, and 106 were analyzed. A majority (> 80%) of studies that reported swallowing outcomes were published after 2010. While 75.4% of studies reported subjective outcomes (e.g., patient-reported or clinician-reported outcome measures), only 30.2% of studies presented results of objective instrumental assessment of swallowing. The majority (61%) of studies reported short-term swallowing outcomes at 1 year or less, and only 10% of studies examined 5-year swallowing comes. One study examined late-dysphagia (> 10 years) in the oropharyngeal cancer population. Considerable heterogeneity remains in the reporting of swallowing outcomes after treatment of oropharyngeal cancer despite its importance for quality of life. Studies reporting long-term swallowing outcomes are lacking in the literature, and objective measures of swallowing function remain underutilized and nonstandardized.