Risk for Occurrence of Laryngeal Cancer Among Current Cigarette Smokers

Abstract

Background: Cancer is a leading cause of death worldwide. It is on the second place as a death cause in developed countries and among the three leading death causes in adults in developing countries. Every year, worldwide, approximately 10 million persons have been diagnosed with malignant tumors (in every locations), and more than 6 million of these people die. According to many studies, several risk factors are brought in connection with laryngeal cancer (LarC). The most significant and generally accepted is alcohol consumption and the habit of cigarette smoking. Cigarette smoking habit caused about 30% of all cancers, due to which it represents the most significant risk factor for occurrence of these disorders in humans. Aim: Aim of the study was to determine the existence of the eventual causal associations among the cigarette smoking and development and distribution of the laryngeal cancer. Methods: This study is an analytical type of case-control study. It elaborated 185 patients, suffering from laryngeal cancer and the same number of persons without malignant disease (control group-CG). Risk analyses were done using unconditional logistic regression, which provides results in the form of adjusted odds ratio. The odds ratios and their 95% confidence intervals (CI) were computed. Results: Among patients were 79% of current smokers (CS), 18.3% of former smokers (FS) and only 2.7% of never smokers (NS), compared with 40.5% of CS, 28.7% of FS and 30.8% of NS among controls. More than a half of the CS has been smoking 21-40 cigarettes per day (c/day) (54.8%), while in CG members this percent was 29.3%. Group of so called “heavy” smokers (> 40c/day), includes 13.7% of patients, and only 4% from CG. Majority of CS with LarC had smoking length, ranging from 31-45 years (56.2%). CS had 16.03 (95% CI, 6.25-41.12), times significantly higher risk to become ill from LarC, compared with NS. CS who were smoking < 20 c/day had 10.49 (95% CI, 3.87-28.45), while those who were smoking > 20 c/day, had 45.6 (95% CI, 16.55-125.67), times significantly higher risk to become ill, compared with NS. Univariate analysis in CS showed significantly higher risk for the persons to become ill, who were smoking > 40 years, compared with those who were smoking < 40 years (OR=3.73; 95% CI 2.03-6.84). The risk of occurring LarC has been four times (95% CI, 2.35-7.88), significantly higher in the CS who are smoking > 20 years, > 20 c/day, compared with those, who in the same time period, smoke < 20 c/day. Conclusion: Cigarette smoking is by far the most important risk factor for laryngeal cancer. Concerted control of smoking appears to be an urgent priority in LarC prevention, including efforts to prevent adolescents from starting to smoke.