Wu 2003.

Study characteristics
Methods	PCC in USA
Participants	Participants: 501 cases and 594 controls (all women) Inclusion criteria: aged 25‐74 years, in Asian Americans (Chinese, Japanese or Filipino), newly diagnosed cases identified through the Los Angeles County Cancer Surveillance Program, Los Angeles, USA Recruitment: from 1 January 1995‐31 December 1998
Interventions	N/A
Outcomes	Number of cases Breast cancer: 501 cases (all women)
Green tea in exposure categories	Exposure assessment: green tea drinking habit Lowest exposure: nondrinkers Intermediate exposure: > 0‐85.7 mL/d Highest exposure: ≥ 85.7 mL/d
Notes	Funding: grants of California Breast Cancer Research Program (1RB‐0287, 3PB‐0102) and of USC/Norris Comprehensive Cancer Center (2 P30 CA14089‐26) Statistical methods: conditional logistic regression Variables controlled in analysis: age, Asian ethnicity, birthplace, education, age at menarche, pregnancy, current BMI, total caloric intake, menopausal status, use of menopausal hormones, intake of soy, dark green vegetables, smoking history, alcohol intake, physical activity and family history of breast cancer, coffee intake and black tea intake Variables controlled by matching: Asian ethnicity, age (5‐year groups) and birthplace