Oral dryness and moisture degree at the lingual but not buccal mucosa predict prognosis in end-of-life cancer patients.

purposeThe aim of this study is to investigate the association of oral dryness with overall survival and determine the threshold points of moisture degree for predicting 7-day survival in palliative care patients.

methodsA total of 147 consecutive palliative care patients were included between January 2017 and November 2018. Oral dryness at the lingual and buccal mucosa was measured using an oral moisture-checking device. Overall survival was compared between patients with and without oral dryness using Kaplan-Meier curves with a log-rank test. Prediction accuracy was evaluated by the receiver operating characteristic (ROC) curve and the area under the curve (AUC).

resultsMedian survival (95% confidence interval) in patients with oral dryness at the lingual mucosa was shorter than that in patients without oral dryness (17 [11-24] days vs. 28 [22-37] days, log-rank test, p <0.001), but not at the buccal mucosa. Time-dependent ROC revealed that the AUCs for 7-, 14-, 21-, and 28-day survival predictions were 0.72, 0.68, 0.61, and 0.59 with a cutoff value of 19.2%, respectively. The prevalence of performance status (PS) 4 and oxygen administration in the 7-day death group were higher than those in the non-7-day death group. A stratified analysis indicated that moisture degree <19.2% showed fair predictive performance with an AUC of 0.74 and 0.74, in the case of PS ≤3 or without oxygen administration.

conclusionOral dryness was associated with increased risk of mortality in palliative care patients. Moisture degree <19.2% at the lingual mucosa predicted less than 7-day survival.