Sonoda 2004.

Study characteristics
Methods	HCC in Japan
Participants	Participants: 140 cases and 140 controls (all male) Inclusion criteria: aged 59‐73 years, cases with confirmed histological diagnosis of prostatic adenocarcinoma from the Department of Urology of Tsukuba University Hospital in Ibaraki and from the Department of Urology of Sapporo Medical University Hospital in Hokkaido, Japan. Controls were recruited from Department of Oral Surgery, Ophthalmology, or Dermatology of the same hospitals Recruitment: from January 1996‐September 2002
Interventions	N/A
Outcomes	Number of cases Prostate cancer: 140 cases, including 2 cases of stage I, 86 cases of stage II, 36 cases of stage III and 16 cases of stage IV of adenocarcinoma
Green tea in exposure categories	Exposure assessment: green tea intake Lowest exposure: ≤ 1 cup/d Intermediate exposure 1: 2‐4 cups/d Intermediate exposure 2: 5‐9 cups/d Highest exposure: ≥ 10 cups/d
Notes	Funding: not declared Statistical methods: conditional logistic regression Variables controlled in analysis: age, cigarette smoking and energy intake Variables controlled by matching: age (± 5 years)