Comparing dose-response measurements of oral habits on oral leukoplakia and oral submucous fibrosis from a community screening program

Background: Many studies have reported that the interaction and dose-response effects of betel quid chewing, tobacco smoking and alcohol drinking habits are important risk factors for oral cancer and precancerous lesions or conditions. These results are useful for comparing statistics, but may not be informative for personal disease-related information. Methods: This study used data from a community screening program to evaluate the dose-response effects of daily frequency and duration from oral habits in Taiwan. The receiver operating characteristic (ROC) curves were further used to compare exposure measurements on indicating the occurrence of lesions/conditions. Results: Our results showed that the highest prevalence was found in leukoplakia (11.1%) and followed by oral submucous fibrosis (OSF, 4.4%). Betel quid chewing habit was found to have dose-response effects on leukoplakia and OSF, cigarette smoking habit only has the dose-response effect on leukoplakia, and alcohol drinking was not associated with both oral precancers. The daily frequency of chewing habit is a better indicator than other dose-response measurements for the occurrence of precancers. In addition, the cut-off points of two to five counts per day have about 60-82% of sensitivities and 79-88% of specificities. Conclusions: The cut-off points from ROC curves can provide an informative message to people with oral habits and their chances of developing diseases. High daily frequency of chewing can lead to excessive irritation to oral mucosa. Although the tobacco is never added to chewing quid in Taiwan, intensive irritation may play an important role in developing oral precancers in Taiwan.