Association between Urinary Cotinine Levels and Buccal Mucosal Micronuclei Cells of Smokeless Tobacco Chewers Attending a Tertiary Care District Hospital

Introduction: Oral squamous cell carcinoma encompasses at least 90% of all oral malignancies. It is sixth most common malignancy and the major cause of cancer morbidity and mortality worldwide. Early detection of a premalignant oral lesion would improve the survival to a greater extent. Tobacco lays an enormous effect of disease for health, economic, social and environment issues. Cross sectional study was done at tertiary care hospital to find association between urinary cotinine levels and buccal mucosal micronuclei cells of smokeless tobacco chewers.

Method: Study comprised of 300 Smokeless Tobacco chewers (STC) and 300 Non tobacco chewers (NTC). Physical examination and Anthropometric parameters were recorded. Fasting urine samples collected for extraction of cotinine. Buccal smears were prepared for exfoliated cells. Slides were stained by Papanicolaou stain and micronuclei (MN) cells was examined by using 100X, 400X magnification as per the Tolbert et al criteria.

Results: Mean Urinary Cotinine in STC was enhanced as compared to NTC. The MN cells were also increased in STC as compared to NTC & statistically highly significant (Mean SD of STC 21.30±10.55, 95% CI; 20.11 to 22.49, NTC Mean SD 3.74±3.43, 95% CI; 3.35 to 4.12). The MN cells of STC showed strong positive association & statistically highly significant correlation with urinary cotinine levels (r= 0.692, p=<0.0001).

Conclusions: The present study establishes link between rise in exfoliated buccal MN and determination of urinary cotinine levels which is a biomarker of genotoxicity and epithelial carcinogenic progression.