Nutrition and Thyroid Cancer Risk in the CTS Cohort

描述(申请人提供)：在过去的10年里，女性甲状腺癌发病率的增长速度一直快于其他任何癌症，无论是女性还是男性。然而，它的原因在很大程度上仍然是未知的，尽管已经出现了几个与营养有关的有希望的途径。这项拟议的研究将使用以前收集的预期数据来验证和扩展这些发现。此外，我们还将讨论有关胰岛素对甲状腺癌风险影响的一个新的假说。我们的具体目标是：(1)使用新开发的数据库，评估乳头状甲状腺癌风险与(A)十字花科蔬菜和异硫氰酸盐之间的关系，以及(B)总体和腹部肥胖；以及(2)评估乳头状甲状腺癌风险与饮食因素之间的关系，这些饮食因素(A)与胰岛素水平正相关(即精制谷物和血糖负荷)，(B)与胰岛素水平负相关(即全谷物和纤维)。这些分析将在加州教师研究(CTS)的背景下进行，包括117,646名女性。在十年的随访期内(到2005年12月31日)，预计将有154例乳头状甲状腺癌在这一队列中被诊断出来。癌症病例通过与加州癌症登记处(CCR)的年度联系进行识别，并已完成99%以上。通过与参与者的联系和与各种数据库的链接，完成了对生命状态和继续居住加州的队列跟踪。通常的饮食摄入量在基线时使用有效的食物频率问卷进行评估。身高和体重在基线时自我报告，腰围和臀围在第一次随访时自我测量；这些测量也在队列中的一个子样本中与采访者的测量结果进行了验证。以年龄为时间尺度，并对出生队列进行调整的Cox比例风险模型将被用于计算相对风险。这项研究的结果将对改善我们对这种疾病的病因的理解具有重要意义，这种疾病对年轻女性的影响不成比例。

DESCRIPTION (provided by applicant): Over the past 10 years, the incidence of thyroid cancer in women has been increasing faster than any other cancer in either women or men. Yet its causes are still largely unknown, although several promising avenues related to nutrition have emerged. The proposed study will use previously collected, prospective data to verify and expand on these findings. In addition, we will address an emerging hypothesis regarding the impact of insulin on thyroid cancer risk. Our specific aims are: (1) to evaluate the relationship between papillary thyroid cancer risk and (a) cruciferous vegetables and isothiocyanates, using a newly developed database, and (b) overall and abdominal adiposity; and (2) to evaluate the association between papillary thyroid cancer risk and dietary factors that are (a) positively related to insulin levels (i.e., refined grains and glycemic load) and (b) inversely related to insulin levels (i.e., whole grains and fiber). These analyses will take place in the context of the California Teachers Study (CTS) and include 117,646 women. Over a ten- year follow-up period (through December 31, 2005), it is anticipated that 154 cases of papillary thyroid cancer will be diagnosed within this cohort. Cancer cases are identified through annual linkage with the California Cancer Registry (CCR) and are over 99% complete. Cohort follow-up for vital status and continued California residence is accomplished through contact with participants and linkage with various databases. Usual dietary intake was assessed at baseline using a validated food-frequency questionnaire. Height and weight were self-reported at baseline and waist and hip circumferences self-measured at the first follow-up; these measurements have also been validated against interviewer measurements in a subsample of the cohort. Cox proportional hazards models with age as the time scale and adjusting for birth cohort will be used to calculate relative risks. The results of this research will have important implications for improving our understanding of the etiology of this disease which disproportionately affects young women.