Body size and risk of differentiated thyroid carcinomas: Findings from the EPIC study

Abstract

Results from case-control and prospective studies suggest a moderate positive association between obesity and height and differentiated thyroid carcinoma (TC). Little is known on the relationship between other measures of adiposity and differentiated TC risk. Here, we present the results of a study on body size and risk of differentiated TC based on a large European prospective study (EPIC). During follow-up, 508 incident cases of differentiated TC were identified in women, and 58 in men. 78% of cases were papillary TC. Cox proportional hazard models were used to estimate hazard ratios (HRs). In women, differentiated TC risk was significantly associated with body mass index (BMI, kg/m 2 ) (HR highest vs lowest quintile 5 1.41, 95% CI: 1.03-1.94); height (HR 5 1.61; 95% CI: 1.18-2.20); HR highest vs lowest tertile waist (HR 5 1.34, 95% CI: 1.00-1.79) and waist-to-hip ratio (HR 5 1.42, 95% CI: 1.05-1.91). The association with BMI was somewhat stronger in women below age 50. Corresponding associations for papillary TC were similar to those for all differentiated TC. In men the only body size factors significantly associated with differentiated TC were height (non linear), and leg length (HR highest vs. lowest tertile 5 3.03, 95% CI: 1.30-7.07). Our study lends further support to the presence of a moderate positive association between differentiated TC risk and overweight and obesity in women. The risk increase among taller individuals of both sexes suggests that some genetic characteristics or early environmental exposures may also be implicated in the etiology of differentiated TC.

Anthropometric Factors and Thyroid Cancer Risk by Histological Subtype: Pooled Analysis of 22 Prospective Studies

“…The association for adulthood BMI gain was restricted to men (HR for men = 1. did not materially change (data not shown). As observed previously (14), the HRs for height and BMI in EPIC did not materially change after excluding self-reported values (data not shown). Adjusting for history of benign thyroid conditions from the subset of studies with this information yielded similar results (data not shown).…”

“…Greater body mass index (BMI), a measure of total adiposity, has been associated with an increased risk of thyroid cancer in several observational studies (6,(8)(9)(10)(11)(12)(13)(14), with some exceptions (15)(16)(17)(18). Most of these studies also showed positive associations with greater height.…”

“…Compared with BMI, waist circumference more directly measures the amount of central adipose tissue, the metabolic consequences of which include insulin resistance and inflammation (19). However, associations of waist circumference with thyroid cancer risk have been examined in only three studies, with conflicting results (14,15,20). BMI specifically in young adulthood has been associated with an increased risk of thyroid cancer in some studies (6,10,11,15) but not others (8,21).…”

The Epidemic of Thyroid Cancer in the United States: The Role of Endocrinologists and Ultrasounds

“…Epidemiological studies have consistently reported that individuals who are either overweight or obese are at an increased risk of thyroid cancer (23)(24)(25)(26)(27). The increasing trend of obesity might be another factor that accounts for some of the observed increasing incidence of thyroid cancer, although the degree of its contribution is unclear.…”

Thyroid cancer: An epidemic of disease or an epidemic of diagnosis?

“…4 Today, more patients receive a TC diagnosis after an evaluation of an incidentally found thyroid nodule than after evaluation of a symptomatic or palpable nodule. 4 A contribution of known TC risk factors (environmental or medical radiation, 5 deficit or excess of iodine intake, 2 body mass, including being overweight or tall 6 ) or suspected risk factors (dietary aspects, 7 nitrates and nitrites, certain microelements in the diet or drinking water, 8 etc.) to TC incidence increases has been neither proven nor ruled out.…”