title: Hypopharyngeal acid exposure: an independent risk factor for laryngeal cancer?
abstract: OBJECTIVE
  Gastroesophageal reflux disease has in recent years been linked to a variety of extraesophageal conditions including laryngeal cancer. However, whether a causal relationship exists is still under debate. The present study aimed to compare the occurrence and severity of gastroesophago-hypopharyngeal reflux in patients with laryngeal cancer with those of healthy volunteers.
  
  
  METHODS
  Prospective, controlled study. METHODS Forty-one consecutive patients with newly diagnosed laryngeal cancer were examined by esophageal manometry and an ambulatory, 24-hour, double-probe pH monitoring. Their results were compared with those of 40 healthy volunteers.
  
  
  RESULTS
  Hypopharyngeal acid exposure was registered mainly in the upright body position. A pathological acid exposure, as compared with the upper levels of normality among the healthy volunteers, was found in the hypopharynx in six (16%) patients with laryngeal cancer and in the distal esophagus in 10 (25%) patients. Pathological acid exposure in either location was found in 15 (37%) patients and in both locations in 1 (3%) patient. However, the mean acid exposure time and the mean value of the number of reflux events did not differ significantly between cancer patients and control subjects at either location. The exclusion of meal periods from the analysis did not alter these observations. Nonsmoking cancer patients (n = 5) and nonsmoking control subjects (n = 36) had similar acid exposure both in the hypopharynx and in the distal esophagus.
  
  
  CONCLUSIONS
  The present results do not support gastroesophago-hypopharyngeal reflux as being an independent risk factor for laryngeal cancer.
authors.affiliation: Department of Otolaryngology, Sahlgrenska University Hospital, SE-413 45 Göteborg, Sweden.
authors.forename: Ake
authors.initials: A
authors.lastname: Geterud
authors.forename: Mogens
authors.initials: M
authors.lastname: Bove
authors.forename: Magnus
authors.initials: M
authors.lastname: Ruth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004784:Environmental Monitoring; D005260:Female; D005744:Gastric Acid / Q000502:physiology*; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000150:complications / Q000503:physiopathology; D006801:Humans; D007013:Hypopharynx; D007822:Laryngeal Neoplasms / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010608:Pharyngeal Diseases / Q000150:complications*