A residential cohort of 63,257 middle-aged and older (45-74 years) Singapore Chinese men and women was assembled 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.

Between July 1999 and December 2003, all surviving cohort subjects were re-contacted for consent to a telephone interview to update information on selected exposures and medical history (The Followup I Survey). Interviews were completed on 52,326 subjects, representing a consent rate of over 90%. A similar Followup II Survey will be launched in June 2006.

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. As of November 2005, there were 5,281 incident cancer cases within the cohort (907 lung, 599 breast, 581 colon, 363 rectum, 428 stomach, 302 liver).

Biological Samples

Beginning in April 1994, a random 3% sample of cohort participants were asked to provide blood or buccal cell, and spot urine samples. Eligibility for this biospecimen subcohort was extended to all surviving cohort participants starting in January 2000. By April 2005, all surviving cohort subjects had been contacted for biospecimen donation. Samples were obtained from 32,535 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. As of November 2005, the number of incident breast/colorectal cancer cases with pre- or post-diagnostic biospecimens totals 922 (398 female breast, 299 colon, 225 rectum).

Selected References

Koh W-P, Yuan J-M, Sun C-L, van den Berg D, Seow A, Lee H-P, Yu MC. Angiotensin I-converting enzyme (ACE) gene polymorphism and breast cancer risk among Chinese women in Singapore. Cancer Res 63:573-578, 2003.

Yuan J-M, Stram DO, Arakawa K, Lee H-P, Yu MC. Dietary cryptoxanthin and reduced risk of lung cancer: the Singapore Chinese Health Study. Cancer Epidemiol Biomarkers Prev 12:890-898, 2003.

Yuan J-M, Koh W-P, Sun C-L, Lee H-P, Yu MC. Green tea intake, ACE gene polymorphism and breast cancer risk among Chinese women in Singapore. Carcinogenesis 26:1389-1394, 2005.

Seow A, Yuan J-M, Koh W-P, Lee H-P, Yu MC. Diabetes mellitus and risk of colorectal cancer in the Singapore Chinese Health Study. J Natl Cancer Inst 98:135-138, 2006. 5.Koh W-P, Yuan J-M, van den Berg D, Ingles SA, Yu MC. Peroxisome proliferator-activated receptor ? gene polymorphisms and colorectal cancer risk among Chinese in Singapore. Carcinogenesis (in press).