correlation between cigarette smoking and urine cotinine level in gastric cancer patients

various substances in cigarette smoke including nicotine have been shown to promote/induce cancer cell proliferation. since cotinine has a longer half life and stability in the blood, it has become the preferred biomarker for cigarette smoking exposure. seventy-three gastric cancer patients were included in this study. the tumor tissues were stained with h and e for pathological evaluation. the cotinine levels were measured in urine using a competitive elisa. tumors were 90% adenocarcinoma with 63% intestinal and 37% diffuse subtypes. tumors were poorly (45.2%) or moderately differentiated (41.1%) and localized mainly (77%) in the upper part of stomach. the levels of cotinine were significantly different between smoker (283.83 ± 178.10 ng/ml) and non-smoker (39.28 ± 113.34 ng/ml) groups (p < 0.001). however, there is no-significant correlation between tumor characteristics and cotinine level in smoker patients. cotinine level correlates with smoking in gastric patients, however, correlation with the tumor features has not been observed.