Urinary Nitrosamines: An Underestimated Biomarker in Laryngeal Cancer

Abstract

Laryngeal cancer is the ninth and the seventh most common cause of cancer in males in Asia and India, respectively, and enlisted as one of the tobacco-related cancers. The carcinogen in tobacco is the tobacco-specific nitrosamines (TSNAs). Both secondary and tertiary amines can react with nitrite yielding nitrosamines which are excreted in urine. This study aims at quantifying urinary nitrosamines. Aims and objectives: • To quantify urinary nitrosamines in smokers and subjects consuming chewable forms of tobacco. • Correlation of urinary nitrosamine levels with the development of laryngeal cancer. Materials and methods: This study was a retrospective cross-sectional study conducted in adult patients presenting at the outpatient department of ENT in a tertiary care hospital over a period of 2 years. One hundred twenty-six cases were studied in detail. The urine of all adult patients presenting with malignant or premalignant lesions of larynx was analyzed and the sample was then subjected to liquid chromatography followed by mass spectrometry and the final amount of urinary nitrosamines was obtained in picograms/nanoliter (pg/nL). Results: Out of 126 laryngeal lesions that presented at the outpatient department, 107 cases were malignant and 19 cases had premalignant lesions. The mean of quantity of urinary nitrosamines was found to be the highest 843pg/nL among the subjects practicing combined modality (smoke + smokeless) of tobacco consumption. The mean of urinary nitrosamines was significantly higher 778.23 pg/nL in smokers as compared with tobacco chewers 613.45 pg/nL. Out of the 107 patients of carcinoma larynx (Ca larynx), 78 cases were smokers suggesting smoking that has a stronger association in the development of carcinoma larynx. Conclusion: The amount of urinary nitrosamines was higher in smokers, high in cases when more than one modality of tobacco was consumed and was more in cases of malignancy of larynx as compared to benign lesions.