Role of laryngopharyngeal reflux on the pathogenesis of vocal cord leukoplakia and early glottic cancer

Objective To explore the significance of laryngopharyngeal reflux （ LPR ） and gastroesophageal reflux （ GER） in patients with vocal cord leukoplakia and early glottic cancer . Methods Patients with vocal cord leukoplakia and early glottic cancer encountered in Nanfang Hospital between December 2012 to January 2014 were included in this study .Ambulatory 24 hour multichannel intraluminal impedance-pH monitoring （MII-pH） was applied to obtain LPR and GER events, as well as the reflux properties of substances.Tobacco and alcohol history was also evaluated .Sixteen healthy volunteers were recruited as normal controls . Results There were 26.3% （5/19 ） LPR patients in glottic cancer group , 35.3%（6/17） LPR patients in vocal cord leukoplakia group and 12.5%（2/16） LPR volunteers in normal controls.There was no statistically significant difference in the positive rate of LPR between early glottic cancer patients and normal controls as well as between vocal cord leukoplakia patients and normal controls （P＆gt;0.05）.There was statistically significance in numbers of acid reflux events , time of acid exposure, and time of acid clearance between vocal cord leukoplakia patients and normal controls as well as between glottic cancer patients and normal controls （P ＆lt;0.05）.GER was found in 26.3% （5/19） patients in glottic cancer group and 23.5%（4/17） patients in vocal cord leukoplakia group and 6.3% （1/16） volunteer in normal controls.There was no statistically significant difference in the positive rate of GER between early glottic cancer patients and normal controls as well as between vocal cord leukoplakia patients and normal controls （P＆gt;0.05）.However, there was statistically significance in DeMeester scores between＆amp;nbsp;glottic cancer patients and normal controls （P＆lt;0.05）, while no statistically significance between vocal cord leukoplakia patients and normal controls （P＆gt;0.05）.Reflux events were dominated by acid and weakly acidic reflux in upright position.Weakly alkaline reflux events in upright position , acid reflux events in supine position , and weakly alkaline reflux events in supine position in vocal cord leukoplakia patients were significantly more than those in normal controls （P＆lt;0.05）.No statistically significant difference existed in positions and contents between early glottic cancer patients and normal controls （P＆gt;0.05）.There was also no statistically significant correlation between happening LPR and GER , smoking and drinking in patients with vocal cord leukoplakia and early glottic cancer （P＆gt;0.05）. Conclusions Reflux events are more in vocal cord leukoplakia patients and early glottic cancer patients , however , the relationship between laryngopharyngeal reflux and canceration of the vocal cord is still needed to be invesgated .The significance of mucosal injury induced by nonacids refluxes is needed to be further studies . Key words: Laryngeal neoplasms; Carcinoma,squamous cell; Leukoplakia; Vocal cords; Laryngopharyngeal reflux; Hydrogen-ion concentration