Influencing factors of oral cancer in nonsmokers:a case-control study in Fujian province

ObjectiveTo investigate influencing factors of oral cancer in nonsmokers in Fujian province and to provide evidences for prevention of oral cancer.MethodsA case-control study was carried out in 161 nonsmoking oral cancer cases and 547 age- and gender-matched nonsmoking controls.The pathologically confirmed oral cancer cases were recruited from the First Affiliated Hospital of Fujian Medical University.Controls were selected from physical examinees and patients other than oral cancer at the same hospital.Eligible participants were personally interviewed using a questionnaire.ResultsSignificantly higher ratios of secondhand smoking before the age 18 years (37.27% vs.10.97%), secondhand smoking after the age of 18 years(49.07% vs.29.62%), bad prosthesis(53.42% vs.36.56%), with the frequency of brushing teeth>2 times/day(5.59% vs,5.30%), having dental ulcer(8.70% vs.2.01%), and eating fruits<1 time/day(49.69% vs.43.69%)were observed in the cases compared to those in the controls(P<0.01 for all);whereas the proportion of brushing teeth 1-2 times/day(84.47%), eating fish≥1 time/day(13.66%),eating seafood<1 time/day(53.42%),eating seafood≥1 time/day(3.11%),eating green vegetables≥1 time/day(83.23%),eating other vegetables≥1 time/day(77.64%),and frequency of eating fruits≥1 time/day(25.47%)in case group were lower than those in the controls(92.87%,40.04%,55.94%,22.85%,97.26%,96.53%,and 47.90%,respectively).Multivariate unconditional logistic regression analysis indicated that secondhand smoking before age of 18 years,secondhand smoking after age of 18 years,bad prosthesis,and dental ulcer were risk factors of oral cancer in nonsmokers;eating fish,other vegetables,fresh fruits no less than once a day and eating seafood were the protective factors of oral cancer in nonsmokers.ConclusionSecondhand smoking,bad prosthesis,dental ulcer,and eating fish,seafood,other vegetables,and fruits are influencing factors of oral cancer in nonsmokers.