Serum Cotinine Level as a Biomarker for Tobacco-Related Oral Cavity Malignancy.

Abstract

Background & Objective: Relationship between cotinine and oral cancer is still an unexplored area.
Limited availability of studies embarks to investigate its importance in cancer. This study aims to quantify
serum cotinine level as a biomarker for tobacco exposure related oral cavity malignancy.
Methodology: Patients (n=150) of either sex, aged between 31-80 years, were distributed into group A (Oral
cancer), group B (Chronic tobacco chewers) and group C (Control) with 50 in each group. Details of gender,
age and tobacco habit were recorded. For Group A, clinical data for anatomical site of tumour, type of lesion
and pathology oral hygiene were collected. Serum cotinine levels were estimated by ELISA. Chi-square test,
unpaired t-test, two-sample proportion test were performed using SPSS software.
Results: Significant difference was observed in the duration, frequency of tobacco consumption and serum
cotinine levels among group A and B (P<0.01). Group B showed higher levels of serum cotinine (32.458
±0.31ng/ml). The mean serum cotinine levels in group A, B and C were 6.218±0.34ng/ml, 5.753±0.62ng/
ml and 0.245 ±0.81ng/ml.
Conclusion: Chronic tobacco chewers had high serum cotinine levels and could be at high-risk group for
oral cavity cancer indicating the effectiveness of serum cotinine as a tobacco exposure related biomarker in
oral cancer.