Material and methods
Literature search
We performed a systematic literature search in
PubMed, Web of Knowledge, and Embase for articles
published up to November 2013 using relevant keywords
and combinations thereof such as ‘larynx
carcinoma,’ ‘laryngeal cancer,’ ‘pharynx carcinoma,’
‘pharyngeal cancer,’ and ‘reflux’ that addressed gastroesophageal
reflux disease (or laryngopharyngeal
reflux) and laryngeal or pharyngeal cancer. We
followed PRISMA (Preferred Reporting Items for
Systematic reviews and Meta-Analyses) guidelines