title: Direct measurement of gastroesophageal reflux episodes in patients with squamous cell carcinoma by 24-h pH-impedance monitoring.
abstract: OBJECTIVE
  Recent studies have consistently reported a significant association between gastric atrophy and esophageal squamous cell carcinomas (ESCCs). However, causative factors responsible for the linkage remain to be clarified. Multichannel intraluminal impedance monitoring in conjunction with a pH sensor (MII-pH) is a reliable technique to evaluate gastroesophageal reflux (GER) episodes, independent of the acidity. We investigated the potential roles of GER in the pathogenesis of ESCC with MII-pH.
  
  
  METHODS
  From August 2008 to May 2010, 14 consecutive inpatients with superficial ESCCs (ESCC group) and 14 age- and sex-matched inpatients without any esophageal dysplastic lesions (non-ESCC group) were enrolled. Twenty-four hour portable MII-pH monitoring was performed under standard hospitalized conditions. The data of MII-pH were used to identify acid reflux (AR: pH drop below 4.0 during a reflux episode) and non-AR (NAR: pH drop above 4.0 during a reflux episode).
  
  
  RESULTS
  The median intragastric pH of the ESCC group was 4.7 (2.3-6.4), implying hypochlorhydria in this patient group. The numbers of total reflux and NAR episodes in the ESCC group were significantly higher than those in the non-ESCC group (56 (43-87) vs. 35.5 (18-47), P=0.016 for total reflux and 46.5 (32-84) vs. 24.5 (8-37), P=0.012 for NAR), whereas the numbers of AR were similar in both groups. In addition, there was significance in the category of percentage time of bolus reflux episodes.
  
  
  CONCLUSIONS
  Using MII-pH monitoring, we revealed the clinical significance of GER, especially NAR, in ESCCs. NAR may be a key factor in the link between gastric atrophy and ESCCs.
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kaname
authors.initials: K
authors.lastname: Uno
authors.forename: Katsunori
authors.initials: K
authors.lastname: Iijima
authors.forename: Waku
authors.initials: W
authors.lastname: Hatta
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Koike
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Abe
authors.forename: Naoki
authors.initials: N
authors.lastname: Asano
authors.forename: Gen
authors.initials: G
authors.lastname: Kusaka
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000209:etiology* / Q000503:physiopathology; D017097:Electric Impedance; D004938:Esophageal Neoplasms / Q000209:etiology* / Q000503:physiopathology; D005744:Gastric Acid / Q000737:chemistry; D005745:Gastric Acidity Determination; D005757:Gastritis, Atrophic / Q000150:complications / Q000503:physiopathology*; D005764:Gastroesophageal Reflux / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D018709:Statistics, Nonparametric