Cigarette smoking as a risk factor for cancer of the thyroid in women

Abstract

Aims and background: Thyroid cancer, whose etiology is largely uncertain, has been negatively associated with cigarette smoking in a several studies. We examined the association between cigarette smoking and risk for female thyroid cancer. Methods: A case-control study including 204 histologically verified female thyroid cancer patients and an equal number of hospital controls individually matched with cases by sex, age (± 2 years), place of residence and time of hospitalization was carried out during the period 1996-2000. In the analysis of data, univariate and multivariate conditional logistic regression methods were applied. Results: According to univariate analysis, female thyroid cancer was negatively associated with the initiation of smoking at a younger age, before the age of 20 (OR = 0.66, 95% CI = 0.50-0.90). None of the smoking habits remained independently related to female thyroid cancer after adjustment for other factors which were significantly associated with thyroid cancer in the present study. Conclusions: The results of the study do not suggest a role of cigarette smoking in the development of thyroid cancer in women.