Utility of urinary biomarkers in oral cancer.

OBJECTIVE: Oral cancer is the leading malignancy in India, with tobacco playing a major role in the etiology. The aim of the present study was to quantify nitrate+nitrite (NO2+NO3) in tobacco products as well as to study tobacco exposure related biomarkers in controls, patients with oral precancers (OPC) and oral cancer patients. MATERIALS & METHODS: Healthy individuals (n=90) were grouped into without habit of tobacco (NHT, n=30) and healthy individuals with habit of tobacco (WHT, n=60). Oral cancer patients with a tobacco habit were classified into abstinence (n=62) and non-abstinence (n=64) groups according to status at the study time. Urinary nicotine and cotinine levels were analyzed by modified high-pressure liquid chromatography (HPLC) using a UV detector. Levels of NO2+NO3 in tobacco and urine, and urinary thioether levels were estimated by spectrophotometry. RESULTS: NO2+NO3 levels in different types of tobacco product ranged between 0.13 to 3.39 mg/g. The Odds Ratio (OR) analysis indicated positive associations of both smoking and chewing habits of tobacco with high risk of development of oral cancer. Urinary nicotine, cotinine and NO2+NO3 levels were significantly elevated in WHT, patients with OPC and oral cancer patients as compared with the NHT group. This was also the case for urinary thioether levels. Levels of urinary nicotine and cotinine were also higher in the non-abstinence group with oral cancers. CONCLUSION: The results confirmed that tobacco chewing and smoking habits are prominent risk factors for development of oral cancer in the western part of India (Gujarat). Urinary nicotine, cotinine, NO2+NO3 and thioether levels can be helpful for screening programs for oral cancer.

Urinary levels of nicotine & cotinine in tobacco users.

BACKGROUND & OBJECTIVES: Of the various biochemical markers used to validate the smoking status of a person, nicotine and continine are considered as good markers for both active and passive smoking. In the present study an attempt was made to estimate urinary levels of nicotine and cotinine in healthy individuals from north India using different types of tobacco to identify and validate the smoking status. METHODS: Twenty four hour urine sample of 130 healthy volunteers (smokers=70, passive smokers=20, tobacco chewers=20, non smokers=20) were analyzed by high-pressure liquid chromatography (HPLC) assay. Smokers were divided into different groups, viz., cigarette, bidi and hooka smokers. RESULTS: The mean values of nicotine (ng/ml) and cotinine (ng/ml) in urine were highest in cigarette smokers (nicotine=703.50+/-304.34; cotinine=2736.20+/-983.29), followed by hooka smokers (nicotine 548.0+/-103.47 and cotinine 2379.0+/-424.25), and bidi smokers (nicotine=268.53+/-97.62, cotinine=562.60+/-249.38). There was no correlation of nicotine or cotinine values with smoking index. In passive smokers (nicotine=109.75+/-22.33, cotinine=280.75+/-86.30) and in nonsmokers, the values were much lower (nicotine=55.00+/-13.71, cotinine=7.30+/-2.47) compared to smokers. In tobacco chewers, the values for nicotine and cotinine were 447.75+/-145.09 and 2178.30+/-334.29 respectively. INTERPRETATION & CONCLUSION: All forms of tobacco users had significantly higher values compared to passive smokers and nonusers. Thus, cotinine and nicotine levels in urine may be considered as good indicators to assess the exposure to tobacco in our population.

Urinary cotinine in narguila or chicha tobacco smokers

Urinary levels of nicotine metabolites were measured in nonsmokers and of tobacco either as cigarettes or as the middle eastern water pipes [narguila]. Levels of urinary cotinine were similar for the smokers of cigarettes [median 30 cigarettes per day] and narguila [median 2 pipes per day, or around 40 grams of tobacco]. Use of water pipes may remove a small amount of nicotine, but smokers appear to titrate dose to effect. It is unlikely that narguila smoking confers any less risk