Background: Thyroid cancer incidence rates have been increasing worldwide but the reason behind this is unclear. Both the\r\nincreasing use of diagnostic technologies allowing the detection of thyroid cancer and a true increase in thyroid cancer\r\nincidence have been proposed. This review assesses the role of body mass index (BMI), diet, and reproductive factors on the\r\nthyroid cancer trend.\r\nMethods: Epidemiologic studies of the selected risk factors up to June 2010 were reviewed and critically assessed.\r\nResults: Among the thirty-seven studies reviewed and despite variation in the risk estimates, most papers supported a small\r\nbut positive association for BMI (risk estimate range: 1.1ââ?¬â??2.3 in males and 1.0ââ?¬â??7.4 in females.). Among specific dietary\r\ncomponents, there was no consistent association of thyroid cancer risk with iodine intake through fortification (risk estimate\r\nrange: 0.49ââ?¬â??1.6) or fish consumption (risk estimate range 0.6ââ?¬â??2.2), nor with diets high in cruciferous vegetables (risk\r\nestimate range 0.6ââ?¬â??1.9). A small number of studies showed a consistent protective effect of diets high in non-cruciferous\r\nvegetable (risk estimate range: 0.71ââ?¬â??0.92). Among reproductive factors (pregnancy, parity, number of live births, use of\r\nprescription hormones, menstrual cycle regularity, and menopausal status), none were consistently associated with higher\r\nthyroid cancer risk.\r\nConclusions: BMI had the strongest link to thyroid cancer risk among those examined. Detailed examinations of populationlevel\r\nrisk factors can help identify and support prevention efforts to reduce the burden of thyroid cancer.
Loading....