Study on antioxidant micronutrient intervention of oral pre-cancerous lesion in selected population of Bangladesh

Abstract

Oral precancerous lesion mainly oral leukoplakia is one of the common potentially premalignant disorders which may turn in to malignancy. It is commonly associated with bad oral hygiene, deficiency of antioxidant rich foods and sharp teeth. The use of tobacco either in the form of smoking or smokeless. Clinical studies suggest that antioxidant vitamins such as vitamin C, vitamin E and β-carotene prevent cancer development from oral leukoplakia. This study investigated the effectiveness of antioxidants supplementations - vitamin C, vitamin E and β-carotene for the remission of oral leukoplakia. A total of 140 biopsy proven oral leukoplakia patient’s were selected purposively with inclusion and exclusion criteria. These total 140 cases were divided into two groups: study group and placebo group. The study group was again divided 3 (three) groups and both the groups consisted of 35 subjects. A single blind clinical trial was carried out with antioxidant vitamin C, vitamin E and β-carotene for the study groups, while placebo for the placebo group. The dose of antioxidant vitamins were: vitamin C 500mg/day, vitamin E 400mg/day and β-carotene 30mg/day. The intervention was carried out for a period of 06 (six) months. Anthropometric measurement and biochemical tests were performed at the base line and at the end of 6 (six) months intervention. The histopathological examination of the lesion was also conducted at the base line and at the end of 06 (six) months intervention. Dietary intake was assessed using 24 hours recall method for consecutive 3 (three) days at the base line and after 3 (three) months of intervention. Clinical examination was done at the base line, 01 (one) month, 03 (three) months and 06 (six) months interval of the intervention. Nutritional status was assessed using Body Mass Index (BMI). Biochemical analysis such as complete blood count (CBC), serum vitamin C, vitamin E and β carotene were measured by standard method of analysis. Clinical evaluation was performed by naked eye observation and photograph of the lesion. Histopathological examination was conducted in the standard laboratory by hematoxilin and eosin stain method. It was found that most of the patient’s were between 50-60 years who were suffering from oral leukoplakia. Males were more affected than females. At the base line the mean serum level of vitamin C was 0.5125mg/dl, vitamin E 499.71µg/dl, β carotene 42.85µg/dl; while after supplementation, mean vitamin C was 1.29mg/dl, vitamin E 854.914µg/dl and β carotene 115.91µg/dl among the 3 (three) study groups. The mean serum level of vitamin C, vitamin E and β-carotene increased after supplementation in each study group. Increased serum level of antioxidants may have helped to the precancerous cell to normal cellular architecture and this was supported in histological examination. Abnormal oral cellular morphology and characters were changed to normal cellular architecture in smokers (38%), non-smokers (62%), tobacco receiving patients (40%) and non-tobacco receiving patients (60%) after supplementation. At the base line, 43% of the total population (intervention + placebo) had good nutritional status, 34% were malnourished, while 23% were overweight. After the intervention, it was found that subjects who had good nutritional status showed positive oral cellular change of the lesion compared to those who were malnourished. It is to be noted that nutritional status was measured anthropometrically. The mean BMI of the patients were not changed during the study period. The remission rate of oral leukoplakia in case of vitamin C was 56%, vitamin E 60% and β carotene 64% based on both clinical and histological investigation. These results were statistically significant (p < 0.05). However, low rate of remission was observed for placebo patients (15%) which was not statistically significant. Supplementation of antioxidant vitamin C, vitamin E, and β carotene offers overall benefits in the prevention oral cancer from oral leukoplakia. Antioxidants could play a positive role in the treatment of oral leukoplakia, especially β carotene which was found more effective than vitamin C and vitamin E.