[Pickled food, fish, seafood intakes and oral squamous cell carcinoma: a case-control study]

Objective: To investigate the effects between fish, seafood and pickled food intakes on oral squamous cell carcinoma (OSCC). Methods: A case-control study was carried out in Fujian area during September 2010 to December 2016, in which 604 newly diagnosed primary OSCC cases confirmed by pathological diagnosis were collected from hospital and 1 343 control subjects were enrolled from community and healthy hospital population. Demographic data, history of smoking drinking and tea drinking, oral hygiene status and dietary behaviors (fish, seafood and pickled food intakes) were collected by in-person interviews using a standard questionnaire.Using unconditional logistic regression to estimate adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to assess the effects of fish, seafood and pickled food intakes on OSCC. Analysis stratified by smoking, alcohol drinking and bad prosthesis to explore the possible difference in association between subgroups. Multiplicative interactions and additive interactions between fish and bad prosthesis, seafood and alcohol drinking, pickled food and bad prosthesis were assessed by unconditional logistic regression, relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). Results: The average age of case group and control group were separately (58.69±13.92) years old and (59.27±11.37) years old (χ(2)=4.75, P=0.191). The people whose fish and seafood intakes ≥3 times/week had the lower risk of OSCC, the adjusted OR (95%CI) values were 0.63 (0.52-0.77) and 0.51 (0.41-0.64); The stratified analysis indicated that the people having bad prosthesis had the lower risk of OSCC if they eating fish ≥3 times/week, and the adjusted OR (95%CI) values was 0.53 (0.39-0.71); the people having bad prosthesis had the higher risk of OSCC if they eating pickled food ≥3 times/week, the adjusted OR (95%CI) values was 1.37 (1.02-1.88). Regularly eating seafood can decrease the risk of OSCC for non-smokers, smokers, non-drinkers, drinkers, people without bad prosthesis and had bad prosthesis, the adjusted OR (95%CI) values were 0.49 (0.36-0.68), 0.52 (0.37-0.73), 0.41 (0.31-0.55), 0.77 (0.51-0.96), 0.49 (0.36-0.67), 0.59 (0.42-0.83). Crossover analysis showed fish and bad prosthesis exist multiplication interaction relationship (adjusted OR=0.66, 95%CI: 0.44-0.97) and additional interaction relationship (RERI=-0.81, 95%CI:-1.43--0.19; AP=-0.76, 95%CI:-1.35--0.17; S=0.08, 95%CI: 0.01-0.98); pickled food and bad prosthesis exist multiplication interaction relationship (adjusted OR=1.63, 95%CI: 1.06-2.51) and addition interaction relationship (RERI=0.65, 95%CI:0.08-1.22; AP=0.36, 95%CI:0.10-0.62; S=5.19, 95%CI:1.32-54.49). Conclusion: Reducing the consumption of pickled food, quitting smoking and limiting alcohol consumption, and regularly eating fish and seafood can prevent the occurrence of OSCC.