High serum level of retinol and α-tocopherol affords protection against oral cancer in a multiethnic population.

ABSTRACT

BACKGROUND: A comparative cross-sectional study involving oral cancer patients and healthy individuals was designed to investigate associations between retinol, α-tocopherol and ß-carotene with the risk of oral cancer. MATERIALS AND METHODS: This study included a total of 240 matched cases and controls where subjects were selected from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). Retinol, α-tocopherol and ß-carotene levels and intake were examined by high-performance liquid chromatography (HPLC) and food frequency questionnaire (FFQ) respectively. RESULTS: It was found that results from the two methods applied did not correlate, so that further analysis was done using the HPLC method utilising blood serum. Serum levels of retinol and α-tocopherol among cases (0.177±0.081, 1.649±1.670µg/ml) were significantly lower than in controls (0.264±0.137, 3.225±2.054µg/ml) (p<0.005). Although serum level of ß-carotene among cases (0.106±0.159 µg/ml) were lower compared to controls (0.134±0.131µg/ml), statistical significance was not observed. Logistic regression analysis showed that high serum level of retinol (OR=0.501, 95% CI=0.254-0.992, p<0.05) and α-tocopherol (OR=0.184, 95% CI=0.091-0.370, p<0.05) was significantly related to lower risk of oral cancer, whereas no relationship was observed between ß-carotene and oral cancer risk. CONCLUSIONS: High serum levels of retinol and α-tocopherol confer protection against oral cancer risk.