THE SINGAPORE COHORT STUDY OF DIET AND CANCER

这是一项为1993年至1998年期间累积的63,257名中老年（45-74岁）新加坡华裔男性和女性的居住队列继续提供资金的请求。这项长期、以人群为基础的队列研究的主要目的是阐明饮食及其与遗传因素在人类癌症发病中的作用。在招募时，每个研究对象都由训练有素的采访者亲自采访，使用结构化问卷，通过有效的165项食物频率问卷评估当前饮食。从1994年4月开始，随机抽取3%的队列参与者提供血液或口腔细胞和尿样。从2000年1月开始，我们将这种生物标本收集扩展到所有幸存的队列参与者。到2004年5月，已经联系了所有幸存的队列受试者，并从31,318名受试者中收集了生物标本，同意率约为60%。我们还要求从1994年4月开始的所有女性乳腺癌和结直肠癌病例的血液/口腔/尿液标本。迄今为止，诊断前或诊断后生物标本的癌症病例总数为686例（女性乳腺癌304例，结肠癌223例，直肠癌159例）。在1999年7月至2003年12月期间，对所有幸存的队列受试者进行了重新联系，征求他们同意进行电话访谈，以更新有关选定暴露和病史的信息。52,326名受试者完成了访谈，同意率超过90%。通过与以人口为基础的新加坡癌症登记处和新加坡出生和死亡登记处的定期记录联系，被动跟踪该队列的死亡和癌症发生情况。该队列中观察到的癌症发病率和死亡人数与基于新加坡所有华人年龄性别特定发病率的相应预期数字相当。我们将继续利用这一队列来检查在充分研究的西方人群中很少食用的潜在的癌症保护饮食因素。我们未来5年的具体目标是：(1)评估茶摄入量在癌症保护中的作用，考虑茶的饮用类型（绿茶与红茶）和个体易感因素，包括控制茶多酚3种主要排泄途径（o -甲基化、葡萄糖醛酸化、硫酸化）的关键多态性基因；(2)评估参与DMA损伤修复和细胞周期调节的基因在改变茶以及其他已确定的饮食保护因素与癌症之间的特定关联中的潜在作用。

This is a request for continued funding of a residential cohort of 63,257 middle-aged and older (45-74 years) Singapore Chinese men and women accrued between 1993 and 1998. The primary goal of this long-term, population-based cohort study is to elucidate the role of diet and its interaction with genetic factors in the causation of human cancer. At recruitment, each study subject was interviewed in person by a trained interviewer using a structured questionnaire that emphasized current diet assessed via a validated, 165-item food frequency questionnaire. Beginning in April 1994, a random 3% sample of cohort participants were asked to provide blood or buccal cell, and spot urine samples. We extended this biospecimen collection to all surviving cohort participants starting in January 2000. By May 2004, all surviving cohort subjects had been contacted, and biospecimens were collected from 31,318 subjects, representing a consent rate of about 60%. We also asked for blood/buccal/urine specimens from all incident cases of female breast and colorectal cancers beginning in April 1994. To date, the number of cancer cases with pre- or post-diagnostic biospecimens totals 686 (304 female breast, 223 colon, 159 rectum). Between July 1999 and December 2003, all surviving cohort subjects were recontacted for consent to a telephone interview to update information on selected exposures and medical history. Interviews were completed on 52,326 subjects, representing a consent rate of over 90%. The cohort has been passively followed for death and cancer occurrence through regular record linkage with the population-based Singapore Cancer Registry and the Singapore Registry of Births and Deaths. The observed numbers of incident cancers and deaths within the cohort are comparable to corresponding expected numbers based on age-sex-specific incidence rates for all Chinese in Singapore. We will continue to take advantage of this cohort to examine potential cancer protective dietary factors that are rarely consumed among the well-studied occidental populations. Our specific aims for the next 5 years are: (1) to assess the role of tea intake in cancer protection, with consideration for the type of tea drunk (green vs. black tea) and for individual susceptibility factors including key polymorphic genes controlling the 3 major excretion pathways (O-methylation, glucuronidation, sulfation) for tea polyphenols; and (2) to assess the potential roles of genes involved in repair of DMA damage and in cell cycle regulation in modifying a given association between tea as well as other identified dietary protective factors and cancer.